It is accepted that resurfacing hip replacement preserves the bone mineral density (BMD) of the femur better than total hip replacement (THR). However, no studies have investigated any possible difference on the acetabular side. Between April 2007 and March 2009, 39 patients were randomised into two groups to receive either a resurfacing or a THR and were followed for two years. One patient’s resurfacing subsequently failed, leaving 19 patients in each group. Resurfaced replacements maintained proximal femoral BMD and, compared with THR, had an increased bone mineral density in Gruen zones 2, 3, 6, and particularly zone 7, with a gain of 7.5% (95% confidence interval (CI) 2.6 to 12.5) compared with a loss of 14.6% (95% CI 7.6 to 21.6). Resurfacing replacements maintained the BMD of the medial femoral neck and increased that in the lateral zones between 12.8% (95% CI 4.3 to 21.4) and 25.9% (95% CI 7.1 to 44.6). On the acetabular side, BMD was similar in every zone at each point in time. The mean BMD of all acetabular regions in the resurfaced group was reduced to 96.2% (95% CI 93.7 to 98.6) and for the total hip replacement group to 97.6% (95% CI 93.7 to 101.5) (p = 0.4863). A mean total loss of 3.7% (95% CI 1.0 to 6.5) and 4.9% (95% CI 0.8 to 9.0) of BMD was found above the acetabular component in W1 and 10.2% (95% CI 0.9 to 19.4) and 9.1% (95% CI 3.8 to 14.4) medial to the implant in W2 for resurfaced replacements and THRs respectively. Resurfacing resulted in a mean loss of BMD of 6.7% (95% CI 0.7 to 12.7) in W3 but the BMD inferior to the acetabular component was maintained in both groups. These results suggest that the ability of a resurfacing hip replacement to preserve BMD only applies to the femoral side

Stress shielding resulting in diminished bone density following total knee replacement (TKR) may increase the risk of migration and loosening of the prosthesis. This retrospective study was designed to quantify the effects of the method of fixation on peri-prosthetic tibial bone density beneath cemented and uncemented tibial components of similar design and with similar long-term survival rates. Standard radiographs taken between two months and 15 years post-operatively were digitised from a matched group of TKRs using cemented (n = 67) and uncemented (n = 67) AGC tibial prostheses. Digital radiograph densitometry was used to quantify changes in bone density over time. Age, length of follow-up, gender, body mass index and alignment each significantly influenced the long-term pattern of peri-prosthetic bone density. Similar long-term changes in density irrespective of the method of fixation correlated well with the high rate of survival of this TKR at 20 years, and suggest that cemented and uncemented fixation are both equally viable.

Cite this article: Bone Joint J 2013;95-B:911–16.

Aims. The aim of this study was to compare the pattern of initial fixation and changes in periprosthetic bone mineral density (BMD) between patients who underwent total hip arthroplasty (THA) using a traditional fully hydroxyapatite (HA)-coated stem (T-HA group) and those with a newly introduced fully HA-coated stem (N-HA group). Methods. The study included 36 patients with T-HA stems and 30 with N-HA stems. Dual-energy X-ray absorptiometry was used to measure the change in periprosthetic BMD, one and two years postoperatively. The 3D contact between the stem and femoral cortical bone was evaluated using a density-mapping system, and clinical assessment, including patient-reported outcome measurements, was recorded. Results. There were significantly larger contact areas in Gruen zones 3, 5, and 6 in the N-HA group than in the T-HA group. At two years postoperatively, there was a significant decrease in BMD around the proximal-medial femur (zone 6) in the N-HA group and a significant increase in the T-HA group. BMD changes in both groups correlated with BMI or preoperative lumbar BMD rather than with the extent of contact with the femoral cortical bone. Conclusion. The N-HA-coated stem showed a significantly larger contact area, indicating a distal fixation pattern, compared with the traditional fully HA-coated stem. The T-HA-coated stem showed better preservation of periprosthetic BMD, two years postoperatively. Surgeons should consider these patterns of fixation and differences in BMD when selecting fully HA-coated stems for THA, to improve the long-term outcomes. Cite this article: Bone Joint J 2024;106-B(6):548–554

Aims. Osteoporosis can determine surgical strategy for total hip arthroplasty (THA), and perioperative fracture risk. The aims of this study were to use hip CT to measure femoral bone mineral density (BMD) using CT X-ray absorptiometry (CTXA), determine if systematic evaluation of preoperative femoral BMD with CTXA would improve identification of osteopenia and osteoporosis compared with available preoperative dual-energy X-ray absorptiometry (DXA) analysis, and determine if improved recognition of low BMD would affect the use of cemented stem fixation. Methods. Retrospective chart review of a single-surgeon database identified 78 patients with CTXA performed prior to robotic-assisted THA (raTHA) (Group 1). Group 1 was age- and sex-matched to 78 raTHAs that had a preoperative hip CT but did not have CTXA analysis (Group 2). Clinical demographics, femoral fixation method, CTXA, and DXA data were recorded. Demographic data were similar for both groups. Results. Preoperative femoral BMD was available for 100% of Group 1 patients (CTXA) and 43.6% of Group 2 patients (DXA). CTXA analysis for all Group 1 patients preoperatively identified 13 osteopenic and eight osteoporotic patients for whom there were no available preoperative DXA data. Cemented stem fixation was used with higher frequency in Group 1 versus Group 2 (28.2% vs 14.3%, respectively; p = 0.030), and in all cases where osteoporosis was diagnosed, irrespective of technique (DXA or CTXA). Conclusion. Preoperative hip CT scans which are routinely obtained prior to raTHA can determine bone health, and thus guide femoral fixation strategy. Systematic preoperative evaluation with CTXA resulted in increased recognition of osteopenia and osteoporosis, and contributed to increased use of cemented femoral fixation compared with routine clinical care; in this small study, however, it did not impact short-term periprosthetic fracture risk. Cite this article: Bone Joint J 2023;105-B(3):254–260

Aims. Uncemented metal acetabular components show good osseointegration, but material stiffness causes stress shielding and retroacetabular bone loss. Cemented monoblock polyethylene components load more physiologically; however, the cement bone interface can suffer fibrous encapsulation and loosening. It was hypothesized that an uncemented titanium-sintered monoblock polyethylene component may offer the optimum combination of osseointegration and anatomical loading. Methods. A total of 38 patients were prospectively enrolled and received an uncemented monoblock polyethylene acetabular (pressfit) component. This single cohort was then retrospectively compared with previously reported randomized cohorts of cemented monoblock (cemented) and trabecular metal (trabecular) acetabular implants. The primary outcome measure was periprosthetic bone density using dual-energy x-ray absorptiometry over two years. Secondary outcomes included radiological and clinical analysis. Results. Although there were differences in the number of males and females in each group, no significant sex bias was noted (p = 0.080). Furthermore, there was no significant difference in age (p = 0.910) or baseline lumbar bone mineral density (BMD) (p = 0.998) found between any of the groups (pressfit, cemented, or trabecular). The pressfit implant initially behaved like the trabecular component with an immediate fall in BMD in the inferior and medial regions, with preserved BMD laterally, suggesting lateral rim loading. However, the pressfit component subsequently showed a reversal in BMD medially with recovery back towards baseline, and a continued rise in lateral BMD. This would suggest that the pressfit component begins to reload the medial bone over time, more akin to the cemented component. Analysis of postoperative radiographs revealed no pressfit component subsidence or movement up to two years postoperatively (100% interobserver reliability). Medial defects seen immediately postoperatively in five cases had completely resolved by two years in four patients. Conclusion. Initially, the uncemented monoblock component behaved similarly to the rigid trabecular metal component with lateral rim loading; however, over two years this changed to more closely resemble the loading pattern of a cemented polyethylene component with increasing medial pelvic loading. This indicates that the uncemented monoblock acetabular component may result in optimized fixation and preservation of retroacetabular bone stock. Cite this article: Bone Joint J 2021;103-B(5):872–880

Aims. The aim of this study was to compare the mid-term patient-reported outcome, bone remodelling, and migration of a short stem (Collum Femoris Preserving; CFP) with a conventional uncemented stem (Corail). Methods. Of 81 patients who were initially enrolled, 71 were available at five years’ follow-up. The outcomes at two years have previously been reported. The primary outcome measure was the clinical result assessed using the Oxford Hip Score (OHS). Secondary outcomes were the migration of the stem, measured using radiostereometric analysis (RSA), change of bone mineral density (BMD) around the stem, the development of radiolucent lines, and additional patient-reported outcome measures (PROMs). Results. There were no statistically significant differences between the groups regarding PROMs (median OHS (CFP 45 (interquartile range (IQR) 35 to 48); Corail 45 (IQR 40 to 48); p = 0.568). RSA showed stable stems in both groups, with little or no further subsidence between two and five years. Resorption of the femoral neck was evident in nine patients in the CFP group and in none of the 15 Corail stems with a collar that could be studied. Dual X-ray absorbiometry showed a significantly higher loss of BMD in the proximal Gruen zones in the CFP group (mean changes in BMD: Gruen zone 1, CFP -9.5 (95% confidence interval (CI) -14.8 to -4.2), Corail 1.0 (95% CI 3.4 to 5.4); Gruen zone 7, CFP -23.0 (95% CI -29.4 to -16.6), Corail -7.2 (95% CI -15.9 to 1.4). Two CFP stems were revised before two years’ follow-up due to loosening, and one Corail stem was revised after two years due to chronic infection. Conclusion. The CFP stem has a similar clinical outcome and subsidence pattern when compared with the Corail stem. More pronounced proximal stress-shielding was seen with the CFP stem, suggesting diaphyseal fixation, and questioning its femoral neck-sparing properties in the long term. Cite this article: Bone Joint J 2022;104-B(5):581–588

Aims. Dual mobility (DM) implants have been shown to reduce the dislocation rate after total hip arthroplasty (THA), but there remain concerns about the use of cobalt chrome liners inserted into titanium shells. The aim of this study was to assess the clinical outcomes, metal ion levels, and periprosthetic femoral bone mineral density (BMD) at mid-term follow-up in young, active patients receiving a modular DM THA. Methods. This was a prospective study involving patients aged < 65 years, with a BMI of < 35 kg/m. 2. , and University of California, Los Angeles activity score of > 6 who underwent primary THA with a modular cobalt chrome acetabular liner, highly cross-linked polyethylene mobile bearing, and a cementless titanium femoral stem. Patient-reported outcome measures, whole blood metal ion levels (μg/l), and periprosthetic femoral BMD were measured at baseline and at one, two, and five years postoperatively. The results two years postoperatively for this cohort have been previously reported. Results. A total of 43 patients were enrolled. At minimum follow-up of five years, 23 (53.4%) returned for clinical and radiological review, 25 (58.1%) had metal ion analysis performed, 19 (44.2%) underwent dual energy x-ray absorptiometry scans, and 25 (58%) completed a pain-drawing questionnaire. The mean modified Harris Hip Scores improved significantly from 54.8 (SD 19) preoperatively to 93.08 (SD 10.5) five years postoperatively (p < 0.001). One patient was revised for aseptic acetabular loosening. The mean cobalt levels increased from 0.065 μg/l (SD 0.03) to 0.08 (SD 0.05) and the mean titanium levels increased from 0.35 (SD 0.13) to 0.78 (SD 0.29). The femoral BMD ratio decreased in Gruen Zone 1 (91.9%) at five years postoperatively compared with the baseline scores at six weeks potoperatively. The femoral BMD ratio was maintained in Gruen zones 2 to 7. Conclusion. The use of a modular DM component and a cementless, tapered femoral stem shows excellent mid-term survivorship with minimal concerns for corrosion and metal ion release in a cohort of young, active patients undergoing primary THA. Cite this article: Bone Joint J 2021;103-B(7 Supple B):73–77

Aims. To analyze the short-term outcome of two types of total wrist arthroplasty (TWA) in terms of wrist function, migration, and periprosthetic bone behaviour. Methods. A total of 40 patients suffering from non-rheumatoid wrist arthritis were enrolled in a randomized controlled trial comparing the ReMotion and Motec TWAs. Patient-rated and functional outcomes, radiological changes, blood metal ion levels, migration measured by model-based radiostereometric analysis (RSA), bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA), complications, loosening, and revision rates at two years were compared. Results. Patient-Rated Wrist and Hand Evaluation (PRWHE) scores, abbreviated version of the Disabilities of the Arm, Shoulder and Hand questionnaire (QuickDASH) scores, and pain improved similarly and significantly in both groups. Wrist motion improved significantly in the Motec group only, and forearm rotation in the ReMotion group only. Cobalt (Co) and chromium (Cr) blood ion levels were significantly higher in the metal-on-metal (MoM) Motec group than in the metal-on-polyethylene (MoP) ReMotion group. Mean total translation was 0.65 mm (95% confidence interval (CI) 0.26 to 1.12) and 0.27 mm (95% CI 0.14 to 0.47) for the ReMotion carpal and radial components, and 0.32 mm (95% CI 0.22 to 0.45) and 0.26 mm (95% CI 0.20 to 0.34) for the Motec metacarpal and radial components, respectively. Apart from dorsal and volar tilts, which were significantly higher for the radial ReMotion than for the Motec component, no significant differences in absolute migration occurred. BMD around the radial components never returned to baseline. Almost one-third of patients required reoperation due to complications. Two ReMotion implants were revised to Motec TWAs due to carpal component loosening, and three Motec MoM articulations were revised to metal-on-polyether ether ketone due to painful synovitis. Conclusion. Both implants provided matched function and were stable at short-term follow-up, but with a high complication rate. This procedure should be restricted to specialist centres undertaking prospective analysis until its role is clarified. Cite this article: Bone Joint J 2022;104-B(10):1132–1141

We sought to determine whether specific characteristics of vertebral fractures in elderly men are associated with low bone mineral density (BMD) and osteoporosis. . Mister osteoporosis Sweden is a population based cohort study involving 3014 men aged 69 to 81 years. Of these, 1427 had readable lateral radiographs of the thoracic and lumbar spine. Total body (TB) BMD (g/cm²) and total right hip (TH) BMD were measured by dual energy x-ray absorptiometry. The proportion of men with osteoporosis was calculated from TH BMD. There were 215 men (15.1%) with a vertebral fracture. Those with a fracture had lower TB BMD than those without (p < 0.001). Among men with a fracture, TB BMD was lower in those with more than three fractures (p = 0.02), those with biconcave fractures (p = 0.02) and those with vertebral body compression of > 42% (worst quartile) (p = 0.03). The mean odds ratio (OR) for having osteoporosis when having any type of vertebral fracture was 6.1 (95% confidence interval (CI) 3.9 to 9.5) compared with those without a fracture. A combination of more than three fractures and compression in the worst quartile had a mean OR of 114.2 (95% CI 6.7 to 1938.3) of having osteoporosis compared with those without a fracture. . We recommend BMD studies to be undertaken in these subcohorts of elderly men with a vertebral fracture. Cite this article: 2015;97-B:1106–10

Aims. Modular dual mobility (DM) prostheses in which a cobalt-chromium liner is inserted into a titanium acetabular shell (vs a monoblock acetabular component) have the advantage of allowing supplementary screw fixation, but the potential for corrosion between the liner and acetabulum has raised concerns. While DM prostheses have shown improved stability in patients deemed ‘high-risk’ for dislocation undergoing total hip arthroplasty (THA), their performance in young, active patients has not been reported. This study’s purpose was to assess clinical outcomes, metal ion levels, and periprosthetic femoral bone mineral density (BMD) in young, active patients receiving a modular DM acetabulum and recently introduced titanium, proximally coated, tapered femoral stem design. Patients and Methods. This was a prospective study of patients between 18 and 65 years of age, with a body mass index (BMI) < 35 kg/m. 2. and University of California at Los Angeles (UCLA) activity score > 6, who received a modular cobalt-chromium acetabular liner, highly crosslinked polyethylene mobile bearing, and cementless titanium femoral stem for their primary THA. Patients with a history of renal disease and metal hardware elsewhere in the body were excluded. A total of 43 patients (30 male, 13 female; mean age 52.6 years (. sd. 6.5)) were enrolled. All patients had a minimum of two years’ clinical follow-up. Patient-reported outcome measures, whole blood metal ion levels (ug/l), and periprosthetic femoral BMD were measured at baseline, as well as at one and two years postoperatively. Power analysis indicated 40 patients necessary to demonstrate a five-fold increase in cobalt levels from baseline (alpha = 0.05, beta = 0.80). A mixed model with repeated measures was used for statistical analysis. Results. Mean Harris Hip Scores improved from 54.1 (. sd. 20.5) to 91.2 (. sd. 10.8) at two years postoperatively (p < 0.001). All patients had radiologically well-fixed components, no patients experienced any instability, and no patients required any further intervention. Mean cobalt levels increased from 0.065 ug/l (. sd. 0.03) preoperatively to 0.30 ug/l (. sd. 0.51) at one year postoperatively (p = 0.01) but decreased at two years postoperatively to 0.16 ug/l (. sd. 0.23; p = 0.2). Four patients (9.3%) had a cobalt level outside the reference range (0.03 ug/l to 0.29 ug/l) at two years postoperatively, with values from 0.32 ug/l to 0.94 ug/l. The mean femoral BMD ratio was maintained in Gruen zones 2 to 7 at both one and two years postoperatively using this stem design. At two years postoperatively, mean BMD in the medial calcar was 101.5% of the baseline value. Conclusion. Use of a modular DM prosthesis and cementless, tapered femoral stem has shown encouraging results in young, active patients undergoing primary THA. Elevation in mean cobalt levels and the presence of four patients outside the reference range at two years postoperatively demonstrates the necessity of continued surveillance in this cohort. Cite this article: Bone Joint J 2019;101-B:365–371

Bone mineral density (BMD) around the femoral component has been reported to decrease after total knee replacement (TKR) because of stress shielding. Our aim was to determine whether a cemented mobile-bearing component reduced the post-operative loss of BMD. In our study 28 knees receiving a cemented fixed-bearing TKR were matched with 28 receiving a cemented mobile-bearing TKR. They underwent dual-energy x-ray absorptiometry, pre-operatively and at three weeks and at three, six, 12, 18 and 24 months post-operatively. The patients were not taking medication to improve the BMD. The pre-operative differences in the BMD of the femoral neck, wrist, lumbar spine and knee in the two groups were not significant. The BMD of the femur decreased postoperatively in the fixed-bearing group, but not the mobile-bearing group. The difference in the post-operative change in the BMD in the two groups was statistically significant (p < 0.05) at 18 and 24 months. Our findings show that a cemented mobile-bearing TKR has a favourable effect on the BMD of the distal femur after TKR in the short term. Further study is required to determine the long-term effects

Total knee arthroplasty (TKA) is known to lead to a reduction in periprosthetic bone mineral density (BMD). In theory, this may lead to migration, instability and aseptic loosening of the prosthetic components. Bisphosphonates inhibit bone resorption and may reduce this loss in BMD. We hypothesised that treatment with bisphosphonates and calcium would lead to improved BMD and clinical outcomes compared with treatment with calcium supplementation alone following TKA. A total of 26 patients, (nine male and 17 female, mean age 67 years) were prospectively randomised into two study groups: alendronate and calcium (bisphosphonate group, n = 14) or calcium only (control group, n = 12). Dual energy X-ray absorptiometry (DEXA) measurements were performed post-operatively, and at three months, six months, one, two, four, and seven years post-operatively. . Mean femoral metaphyseal BMD was significantly higher in the bisphosphonate group compared with controls, up to four years following surgery in some areas of the femur (p = 0.045). BMD was observed to increase in the lateral tibial metaphysis in the bisphosphonate group until seven years (p = 0.002), and was significantly higher than that observed in the control group throughout (p = 0.024). There were no significant differences between the groups in the central femoral metaphyseal, tibial medial metaphyseal or diaphyseal regions of interest (ROI) of either the femur or tibia. Bisphosphonate treatment after TKA may be of benefit for patients with poor bone quality. However, further studies with a larger number of patients are necessary to assess whether this is clinically beneficial. Cite this article: Bone Joint J 2015;97-B:337–45

We studied the bone mineral density (BMD) and the bone mineral content (BMC) of the proximal tibia in patients with a well-functioning uncemented Oxford medial compartment arthroplasty using the Lunar iDXA bone densitometer. Our hypothesis was that there would be decreased BMD and BMC adjacent to the tibial base plate and increased BMD and BMC at the tip of the keel. There were 79 consecutive patients (33 men, 46 women) with a mean age of 65 years (44 to 84) with a minimum two-year follow-up (mean 2.6 years (2.0 to 5.0)) after unilateral arthroplasty, who were scanned using a validated standard protocol where seven regions of interest (ROI) were examined and compared with the contralateral normal knee. All had well-functioning knees with a mean Oxford knee score of 43 (14 to 48) and mean Knee Society function score of 90 (20 to 100), showing a correlation with the increasing scores and higher BMC and BMD values in ROI 2 in the non-implanted knee relative to the implanted knee (p = 0.013 and p = 0.015, respectively). The absolute and percentage changes in BMD and BMC were decreased in all ROIs in the implanted knee compared with the non-implanted knee, but this did not reach statistical significance. Bone loss was markedly less than reported losses with total knee replacement. There was no significant association with side, although there was a tendency for the BMC to decrease with age in men. The BMC was less in the implanted side relative to the non-implanted side in men compared with women in ROI 2 (p = 0.027), ROI 3 (p = 0.049) and ROI 4 (p = 0.029). The uncemented Oxford medial compartment arthroplasty appears to allow relative preservation of the BMC and BMD of the proximal tibia, suggesting that the implant acts more physiologically than total knee replacement. Peri-prosthetic bone loss is an important factor in assessing long-term implant stability and survival, and the results of this study are encouraging for the long-term outcome of this arthroplasty. Cite this article: Bone Joint J 2013;95-B:1480–3

We undertook a randomised prospective follow-up study of changes in peri-prosthetic bone mineral density (BMD) after hip resurfacing and compared them with the results after total hip replacement. A total of 59 patients were allocated to receive a hip resurfacing (n = 29) or an uncemented distally fixed total hip replacement (n = 30). The BMD was prospectively determined in four separate regions of interest of the femoral neck and in the calcar region corresponding to Gruen zone 7 for the hip resurfacing group and compared only to the calcar region in the total hip replacement group. Standardised measurements were performed pre-operatively and after three, six and 12 months. The groups were well matched in terms of gender distribution and mean age. The mean BMD in the calcar region increased after one year to 105.2% of baseline levels in the resurfaced group compared with a significant decrease to 82.1% in the total hip replacement group (p < 0.001) by 12 months. For the resurfaced group, there was a decrease in bone density in all four regions of the femoral neck at three months which did not reach statistical significance and was followed by recovery to baseline levels after 12 months. Hip resurfacing did indeed preserve BMD in the inferior femoral neck. In contrast, a decrease in the mean BMD in Gruen zone 7 followed uncemented distally fixed total hip replacement. Long term follow-up studies are necessary to see whether this benefit in preservation of BMD will be clinically relevant at future revision surgery

The primary purpose of this study of metal-on-metal (MoM) hip resurfacing was to compare the effect of using a cementless or cemented femoral component on the subsequent bone mineral density (BMD) of the femoral neck. . This was a single-centre, prospective, double-blinded control trial which randomised 120 patients (105 men and 15 women) with a mean age of 49.4 years (21 to 68) to receive either a cemented or cementless femoral component. Follow-up was to two years. Outcome measures included total and six-point region-of-interest BMD of the femoral neck, radiological measurements of acetabular inclination, neck-shaft and stem-shaft angles, and functional outcome scores including the Harris hip score, the Western Ontario and McMaster Universities Osteoarthritis Index and the University of California at Los Angeles activity scale. In total, 17 patients were lost to follow-up leaving 103 patients at two years. There were no revisions in the cementless group and three revisions (5%) in the cemented group (two because of hip pain and one for pseudotumour). The total BMD was significantly higher in the cementless group at six months (p < 0.001) and one year (p = 0.01) than in the cemented group, although there was a loss of statistical significance in the difference at two years (p = 0.155). . All patient outcomes improved significantly: there were no significant differences between the two groups. . The results show better preservation of femoral neck BMD with a cementless femoral component after two years of follow-up. Further investigation is needed to establish whether this translates into improved survivorship. Cite this article: Bone Joint J 2015;97-B:1608–14

The aims of this study were to examine the repeatability of measurements of bone mineral density (BMD) around a cemented polyethylene Charnley acetabular component using dual-energy x-ray absorptiometry and to determine the longitudinal pattern of change in BMD during the first 24 months after surgery. The precision of measurements of BMD in 19 subjects ranged from 7.7% to 10.8% between regions, using a four-region-of-interest model. A longitudinal study of 27 patients demonstrated a transient decrease in net pelvic BMD during the first 12 months, which recovered to baseline at 24 months. The BMD in the region medial to the dome of the component reduced by between 7% and 10% during the first three months, but recovered to approximately baseline values by two years. Changes in BMD in the pelvis around cemented acetabular components may be measured using dual-energy x-ray absorptiometry. Bone loss after insertion of a cemented Charnley acetabular component is small, transient and occurs mainly at the medial wall of the acetabulum. After two years, bone mass returns to baseline values, with a pattern suggesting a uniform transmission of load to the acetabulum

In patients with osteoporosis there is always a strong possibility that pedicle screws will loosen. This makes it difficult to select the appropriate osteoporotic patient for a spinal fusion. The purpose of this study was to determine the correlation between bone mineral density (BMD) and the magnitude of torque required to insert a pedicle screw. To accomplish this, 181 patients with degenerative disease of the lumbar spine were studied prospectively. Each underwent dual-energy x-ray absorptiometry (DEXA) and intra-operative measurement of the torque required to insert each pedicle screw. The levels of torque generated in patients with osteoporosis and osteopenia were significantly lower than those achieved in normal patients. Positive correlations were observed between BMD and T-value at the instrumented lumbar vertebrae, mean BMD and mean T-value of the lumbar vertebrae, and mean BMD and mean T-value of the proximal femur. The predictive torque (Nm) generated during pedicle screw insertion was [-0.127 + 1.62 × (BMD at the corresponding lumbar vertebrae)], as measured by linear regression analysis. The positive correlation between BMD and the maximum torque required to insert a pedicle screw suggests that pre-operative assessment of BMD may be useful in determining the ultimate strength of fixation of a device, as well as the number of levels that need to be fixed with pedicle screws in patients who are suspected of having osteoporosis

Our aim in this prospective study was to compare the bone mineral density (BMD) around cementless acetabular and femoral components which were identical in geometry and had the same alumina modular femoral head, but differed in regard to the material of the acetabular liners (alumina ceramic or polyethylene) in 50 patients (100 hips) who had undergone bilateral simultaneous primary total hip replacement. Dual energy X-ray absorptiometry scans of the pelvis and proximal femur were obtained at one week, at one year, and annually thereafter during the five-year period of the study. At the final follow-up, the mean BMD had increased significantly in each group in acetabular zone I of DeLee and Charnley (20% (15% to 26%), p = 0.003), but had decreased in acetabular zone II (24% (18% to 36%) in the alumina group and 25% (17% to 31%) in the polyethylene group, p = 0.001). There was an increase in the mean BMD in zone III of 2% (0.8% to 3.2%) in the alumina group and 1% (0.6% to 2.2%) in the polyethylene group (p = 0.315). There was a decrease in the mean BMD in the calcar region (femoral zone 7) of 15% (8% to 24%) in the alumina group and 14% (6% to 23%) in the polyethylene group (p < 0.001). The mean bone loss in femoral zone 1 of Gruen et al was 2% (1.1% to 3.1%) in the alumina group and 3% (1.3% to 4.3%) in the polyethylene group (p = 0.03), and in femoral zone 6, the mean bone loss was 15% (9% to 27%) in the alumina group and 14% (11% to 29%) in the polyethylene group compared with baseline values. There was an increase in the mean BMD on the final scans in femoral zones 2 (p = 0.04), 3 (p = 0.04), 4 (p = 0.12) and 5 (p = 0.049) in both groups. There was thus no significant difference in the bone remodelling of the acetabulum and femur five years after total hip replacement in those two groups where the only difference was in the acetabular liner

Aims. Idiopathic scoliosis is the most common spinal deformity in adolescents and children. The aetiology of the disease remains unknown. Previous studies have shown a lower bone mineral density in individuals with idiopathic scoliosis, which may contribute to the causation. The aim of the present study was to compare bone health in adolescents with idiopathic scoliosis with controls. Methods. We included 78 adolescents with idiopathic scoliosis (57 female patients) at a mean age of 13.7 years (8.5 to 19.6) and 52 age- and sex-matched healthy controls (39 female patients) at a mean age of 13.8 years (9.1 to 17.6). Mean skeletal age, estimated according to the Tanner-Whitehouse 3 system (TW3), was 13.4 years (7.4 to 17.8) for those with idiopathic scoliosis, and 13.1 years (7.4 to 16.5) for the controls. Mean Cobb angle for those with idiopathic scoliosis was 29° (SD 11°). All individuals were scanned with dual energy x-ray absorptiometry (DXA) and peripheral quantitative CT (pQCT) of the left radius and tibia to assess bone density. Statistical analyses were performed with independent-samples t-test, the Mann-Whitney U test, and the chi-squared test. Results. Compared with controls, adolescents with idiopathic scoliosis had mean lower DXA values in the left femoral neck (0.94 g/cm. 2. (SD 0.14) vs 1.00 g/cm. 2. (SD 0.15)), left total hip (0.94 g/cm. 2. (SD 0.14) vs 1.01 g/cm. 2. (SD 0.17)), L1 to L4 (0.99 g/cm. 2. (SD 0.15) vs 1.06 g/cm. 2. (SD 0.17)) and distal radius (0.35 g/cm. 2. (SD 0.07) vs 0.39 g/cm. 2. (SD 0.08; all p ≤ 0.024), but not in the mid-radius (0.72 g/cm. 2. vs 0.74 g/cm. 2. ; p = 0.198, independent t-test) and total body less head (1,559 g (SD 380) vs 1,649 g (SD 492; p = 0.0.247, independent t-test). Compared with controls, adolescents with idiopathic scoliosis had lower trabecular volume bone mineral density (BMD) on pQCT in the distal radius (184.7 mg/cm. 3. (SD 40.0) vs 201.7 mg/cm. 3. (SD 46.8); p = 0.029), but not in other parts of the radius or the tibia (p ≥ 0.062, Mann-Whitney U test). Conclusion. In the present study, idiopathic scoliosis patients seemed to have lower BMD at central skeletal sites and less evident differences at peripheral skeletal sites when compared with controls. Cite this article: Bone Joint J 2020;102-B(2):268–272

Aims. The aim of this study was to compare the peak pull-out force (PPF) of pedicle-lengthening screws (PLS) and traditional pedicle screws (TPS) using instant and cyclic fatigue testing. Materials and Methods. A total of 60 lumbar vertebrae were divided into six groups: PLS submitted to instant pull-out and fatigue-resistance testing (groups A1 and A2, respectively), TPS submitted to instant pull-out and fatigue-resistance testing (groups B1 and B2, respectively) and PLS augmented with 2 ml polymethylmethacrylate, submitted to instant pull-out and fatigue-resistance testing (groups C1 and C2, respectively). The PPF and normalized PPF (PPFn) for bone mineral density (BMD) were compared within and between all groups. Results. In all groups, BMD was significantly correlated with PPF (r = 0.83, p < 0.001). The PPFn in A1 was significantly less than in B1 (p = 0.006) and C1 (p = 0.002). The PPFn of A2 was significantly less than in B2 (p < 0.001) and C2 (p < 0.001). The PPFn in A1, B1, and C1 was significantly greater than in A2 (p = 0.002), B2 (p = 0.027), and C2 (p = 0.003). There were no significant differences in PPFn between B1 and C1, or between B2 and C2. Conclusion. Pedicle lengthening screws with cement augmentation can provide the same fixation stability as traditional pedicle screws and may be a viable clinical option. Cite this article: Bone Joint J 2018;100-B:516–21

Our aim was to determine the precision of the measurements of bone mineral density (BMD) by dual-energy x-ray absorptiometry in the proximal femur before and after implantation of an uncemented implant, with particular regard to the significance of retro- and prospective studies. We examined 60 patients to determine the difference in preoperative BMD between osteoarthritic and healthy hips. The results showed a preoperative BMD of the affected hip which was lower by a mean of 4% and by a maximum of 9% compared with the opposite side. In addition, measurements were made in the operated hip before and at ten days after operation to determine the effect of the implantation of an uncemented custom-made femoral stem. The mean increase in the BMD was 8% and the maximum was 24%. Previous retrospective studies have reported a marked loss of BMD on the operated side. The precision of double measurements using a special foot jig showed a modified coefficient of variation of 0.6% for the non-operated side in 15 patients and of 0.6% for the operated femur in 20 patients. The effect of rotation on the precision of the measurements after implantation of an uncemented femoral stem was determined in ten explanted femora and for the operated side in ten patients at 10° rotation and in 20 patients at 30° rotation. Rotation within 30° influenced the precision in studies in vivo and in vitro by a mean of 3% and in single cases in up to 60%. Precise prediction of the degree of loss of BMD is thus only possible in prospective cross-sectional measurements, since the effect of the difference in preoperative BMD, as well as the apparent increase in BMD after implantation of an uncemented stem, is not known from retrospective studies. The DEXA method is a reliable procedure for determining periprosthetic BMD when positioning and rotation are strictly controlled

We aimed to evaluate the precision and longitudinal sensitivity of measurement of bone mineral density (BMD) in the pelvis and to determine the effect of bone cement on the measurement of BMD in femoral regions of interest (ROI) after total hip arthroplasty (THA). A series of 29 patients had duplicate dual-energy x-ray absorptiometry (DXA) scans of the hip within 13 months of THA. Pelvic analyses using 3- and 4-ROI models gave a coefficient of variation (CV) of 2.5% to 3.6% and of 2.5% to 4.8%, respectively. Repeat scans in 17 subjects one year later showed a significant change in BMD in three regions using the 4-ROI model, compared with change in only one region with the 3-ROI model (p < 0.05). Manual exclusion of cement from femoral ROIs increased the net CV from 1.6% to 3.6% (p = 0.001), and decreased the measured BMD by 20% (t = 12.1, p < 0.001). Studies of two cement phantoms in vitro showed a small downward drift in bone cement BMD giving a measurement error of less than 0.03 g/cm. 2. /year associated with inclusion of cement in femoral ROIs. Changes in pelvic periprosthetic BMD are best detected using a 4-ROI model. Analysis of femoral ROI is more precise without exclusion of cement although an awareness of its effect on the measurement of the BMD is needed

Aims

The aim of this study was to report the patterns of symptoms and insufficiency fractures in patients with tumour-induced osteomalacia (TIO) to allow the early diagnosis of this rare condition.

Aims

The aim of the study was to investigate whether the primary stability of press-fit acetabular components can be improved by altering the impaction procedure.

There is a disparity in sport-related injuries between sexes, with females sustaining non-contact musculoskeletal injuries at a higher rate. Anterior cruciate ligament ruptures are between two and eight times more common than in males, and females also have a higher incidence of ankle sprains, patellofemoral pain, and bone stress injuries. The sequelae of such injuries can be devastating to an athlete, resulting in time out of sport, surgery, and the early onset of osteoarthritis. It is important to identify the causes of this disparity and introduce prevention programmes to reduce the incidence of these injuries. A natural difference reflects the effect of reproductive hormones in females, which have receptors in certain musculoskeletal tissues. Relaxin increases ligamentous laxity. Oestrogen decreases the synthesis of collagen and progesterone does the opposite. Insufficient diet and intensive training can lead to menstrual irregularities, which are common in female athletes and result in injury, whereas oral contraception may have a protective effect against certain injuries. It is important for coaches, physiotherapists, nutritionists, doctors, and athletes to be aware of these issues and to implement preventive measures. This annotation explores the relationship between the menstrual cycle and orthopaedic sports injuries in pre-menopausal females, and proposes recommendations to mitigate the risk of sustaining these injuries.

Cite this article: Bone Joint J 2023;105-B(7):723–728.

We used dual-energy x-ray absorptiometry (DEXA) to evaluate the extent of periprosthetic bone remodelling around a prosthesis for distal femoral reconstruction, the Kotz modular femoral tibial replacement (KMFTR; Howmedica, Rutherford, New Jersey). A total of 23 patients was entered into the study which had four parts: 1) 17 patients were scanned three times on both the implant and contralateral legs to determine whether the precision of DEXA measurements was adequate to estimate bone loss surrounding the anchorage piece of the KMFTR; 2) in 23 patients the bone mineral density (BMD) in different regions of interest surrounding the diaphyseal anchorage was compared with that of the contralateral femur at the same location to test whether there was consistent evidence of loss of BMD adjacent to the prosthetic stem; 3) in 12 patients sequential studies were performed about one year apart to compare bone loss; and 4) bone loss was compared in ten patients with implants fixed by three screws and in 13 without screws. The mean coefficients of variation (SD/mean) for the 17 sets of repeated scans ranged from 2.9% to 7.8% at different regions of interest in the KMFTR leg and from 1.4% to 2.5% in the contralateral leg. BMD was decreased in the KMFTR leg relative to the contralateral limb and the percentage of BMD loss in general increased as the region of interest moved distally in the femur. Studies done after one year showed no consistent pattern of progressive bone loss between the two measurements. The ten patients with implants fixed by screws were found to have a mean loss of BMD of 42% in the most distal part of the femur, while the 13 without screw fixation had a mean loss of 11%. DEXA was shown to have adequate precision to evaluate loss of BMD around the KMFTR. This was evident relative to the contralateral leg in all patients and generally increased in the most distal part of the femur. In general, it stabilised between two measurements taken one year apart and was greater surrounding implants fixed by cross-locking screws

We investigated prospectively the bone mineral density (BMD) of the proximal femur after implantation of a tapered rectangular cementless stem in 100 patients with a mean age of 60 years (16 to 87). It was determined using dual energy x-ray absorptiometry, performed one week after surgery and then every six months until the end-point of five years. The BMD increased significantly in Gruen zones 2, 4 and 5 by 11%, 3% and 11% respectively, and decreased significantly in Gruen zones 1, 6 and 7 by 3%, 6% and 14% respectively, over the five-year period. The net mean BMD did not change over this time period. The changes in the BMD were not confined to the first 12 months after surgery. This investigation revealed no change in the overall periprosthetic BMD, but demonstrated a regional redistribution of bone mass from the proximal to distal zones

We studied 37 patients with varus osteoarthritis of the knee to determine the influence of the bone mineral density (BMD) on the varus deformity. There were 15 men (21 knees) and 22 women (38 knees). The mean age of the men was 69 years and of the women 68 years. BMD was measured in the L1–L4 spinal region using dual X-ray absorptiometry. In the women a low level of BMD was associated with varus deformity originating at the proximal tibia, but a high level was predominantly linked with deformity originating in the joint space. Similar findings were obtained in the men. Our results suggest that a low BMD predisposes to trabecular microfractures and consequently increased stress on the articular cartilage. A low BMD does not preclude osteoarthritic change in the knee

We evaluated changes in bone mineral density (BMD) after tibial fractures, both at the site of fracture and at adjacent sites, using dual-energy X-ray absorptiometry. Five patients were studied prospectively for six months after fractures of the midshaft treated by intramedullary nailing or the application of an external fixator. We also reviewed 21 adult and 10 children who had sustained fractures of the tibia at least five years previously, comparing BMD in the injured limb with that in the non-injured limb and in a control group of 10 normal subjects. We found a significant fall in BMD distal to a tibial fracture; this was evident at one month, fell to approximately 50% of normal at three months and persisted at six months. We found no significant improvement with weight-bearing. Review at 5 to 11 years after adult midshaft fractures showed persistent bone loss in the distal tibia (46.5 +/- 9.8% of control values), but persisting sclerosis at old fracture sites (172 +/- 38% of control values). In contrast, we found no significant differences in BMD between the injured and control limb after fractures sustained in childhood either at the fracture site or in the distal segment. We conclude that, in adults, tibial fractures are associated with definite and persistent post-traumatic loss of distal BMD

Rotator cuff tears are common in middle-aged and elderly patients. Despite advances in the surgical repair of rotator cuff tears, the rates of recurrent tear remain high. This may be due to the complexity of the tendons of the rotator cuff, which contributes to an inherently hostile healing environment. During the past 20 years, there has been an increased interest in the use of biologics to complement the healing environment in the shoulder, in order to improve rotator cuff healing and reduce the rate of recurrent tears. The aim of this review is to provide a summary of the current evidence for the use of forms of biological augmentation when repairing rotator cuff tears.

Cite this article: Bone Joint J 2024;106-B(9):978–985.

We measured bone mineral density (BMD) in the proximal femur by dual-energy X-ray absorptiometry (DEXA) in 20 patients after cemented total hip arthroplasty over a period of one year. We found a statistically significant reduction in periprosthetic BMD after six months on the medial side and on the lateral side adjacent to the mid and distal thirds of the prosthesis. At one year after operation there was a mean 6.7% reduction in BMD in the region of the calcar and a mean 5.3% increase in BMD in the femoral shaft distal to the tip of the implant. These changes reflect a pattern of reduced stress in the proximal femur and increased stress around the tip of the prosthesis. They support current concepts of bone remodelling in the proximal femur in response to prosthetic implantation

We investigated the effect of the Birmingham hip resurfacing (BHR) arthroplasty on the bone mineral density (BMD) of the femur. A comparative study was carried out on 26 hips in 25 patients. Group A consisted of 13 patients (13 hips) who had undergone resurfacing hip arthroplasty with the BHR system and group B of 12 patients (13 hips) who had had cementless total hip arthroplasty with a proximal circumferential plasma-spray titanium-coated anatomic Ti6A14V stem. Patients were matched for gender, state of disease and age at the time of surgery. The periprosthetic BMD of the femur was measured using dual-energy x-ray absorptiomentry of the Gruen zones at two years in patients in groups A and B. The median values of the BMD in zones 1 and 7 were 99% and 111%, respectively. The post-operative loss of the BMD in the proximal femur was significantly greater in group B than in group A. These findings show that the BHR system preserves the bone stock of the proximal femur after surgery

We used dual-energy X-ray absorptiometry (DEXA) to compare the bone mineral density (BMD) of nine children aged from 2 years 7 months to 13 years 5 months who had mild osteogenesis imperfecta with an age- and sex-matched control group. The patients had only mild clinical symptoms but DEXA detected highly significant differences in BMD between them and the controls. The mean BMD in the children with osteogenesis imperfecta was 76.7% of normal in the lumbar spine (p < 0.001) and 71.2% of normal in the femoral neck (p < 0.001). DEXA is an objective, reproducible and sensitive method of measurement of BMD in children. It may help to establish the diagnosis, to assess prognosis and possibly to monitor the response to different types of treatment

In a prospective study of 14 patients undergoing total hip replacement we have used dual-energy X-ray absorptiometry (DEXA) to investigate remodelling of the bone around two different designs of cementless femoral prosthesis. The bone mineral density (BMD) was measured at 12-weekly intervals for a year. Eight patients (group A) had a stiff, collarless implant and six (group B) a flexible isoelastic implant. Patients in group A showed a decrease in BMD from 14 weeks after operation. By 12 months, the mean loss in BMD was 27%, both medially and laterally to the proximal part of the implant. Those in group B showed an overall increase in BMD which reached a mean of 12.6% on the lateral side of the distal portion of the implant. Our results support the current concepts of the effects of stem stiffness and flexibility on periprosthetic remodelling

Aims

BoneMaster is a thin electrochemically applied hydroxyapatite (HA) coating for orthopaedic implants that is quickly resorbed during osseointegration. Early stabilization is a surrogacy marker of good survival of femoral stems. The hypothesis of this study was that a BoneMaster coating yields a fast early and lasting fixation of stems.

We examined the effect on bone mineral density (BMD) of a single dose of 3 mg/kg of the bisphosphonate, pamidronate (Novartis) in distraction osteogenesis in immature rabbits. Seventeen rabbits (9 control, 8 given pamidronate) were examined by dual-energy x-ray absorptiometry. There was a significant increase in the BMD in the pamidronate group compared with the control animals. The mean areal BMD (g/cm. 2. ) in the bone proximal and distal to the regenerate was increased by 40% and 39%, respectively, compared with the control group (p < 0.05). The BMD of the regenerate bone was increased by a mean of 43% (p < 0.05). There was an increase of 22% in the mean area of regenerate formed in the pamidronate group (p< 0.05). Histological examination of bone in nine rabbits (5 control, 4 pamidronate) showed an increase in osteoblastic rimming and mineralisation of the regenerate, increased formation of bone around the pin sites and an increase in the cortical width of the bone adjacent to the regenerate in the rabbits given pamidronate. Pamidronate had a markedly positive effect. It reduced the disuse osteoporosis normally associated with lengthening using an external fixator and increased the amount and density of the regenerate bone. Further study is required to examine the mechanical properties of the regenerate after the administration of pamidronate

Aims

There is no level I evidence dealing with the optimal period of immobilization for patients with a displaced distal radial fracture following closed reduction. A shorter period might lead to a better functional outcome due to less stiffness and pain. The aim of this study was to investigate whether this period could be safely reduced from six to four weeks.

Aims

To determine if patient ethnicity among patients with a hip fracture influences the type of fracture, surgical care, and outcome.

Literature surrounding artificial intelligence (AI)-related applications for hip and knee arthroplasty has proliferated. However, meaningful advances that fundamentally transform the practice and delivery of joint arthroplasty are yet to be realized, despite the broad range of applications as we continue to search for meaningful and appropriate use of AI. AI literature in hip and knee arthroplasty between 2018 and 2021 regarding image-based analyses, value-based care, remote patient monitoring, and augmented reality was reviewed. Concerns surrounding meaningful use and appropriate methodological approaches of AI in joint arthroplasty research are summarized. Of the 233 AI-related orthopaedics articles published, 178 (76%) constituted original research, while the rest consisted of editorials or reviews. A total of 52% of original AI-related research concerns hip and knee arthroplasty (n = 92), and a narrative review is described. Three studies were externally validated. Pitfalls surrounding present-day research include conflating vernacular (“AI/machine learning”), repackaging limited registry data, prematurely releasing internally validated prediction models, appraising model architecture instead of inputted data, withholding code, and evaluating studies using antiquated regression-based guidelines. While AI has been applied to a variety of hip and knee arthroplasty applications with limited clinical impact, the future remains promising if the question is meaningful, the methodology is rigorous and transparent, the data are rich, and the model is externally validated. Simple checkpoints for meaningful AI adoption include ensuring applications focus on: administrative support over clinical evaluation and management; necessity of the advanced model; and the novelty of the question being answered.

Cite this article: Bone Joint J 2022;104-B(12):1292–1303.

We studied the bone mineral density (BMD) of 48 long-term survivors of highly malignant osteosarcoma who had been treated according to the chemotherapy protocols of the German- Swiss-Austrian Co-operative Osteosarcoma Study Group which include high-dose methotrexate. The mean age of the patients was 31 ± 4.2 years and the mean follow-up 16 ± 2.2 years. The BMD of the lumbar spine and of the proximal femur of the non-operated side was measured by dual- energy x-ray absorptiometry. A questionnaire was given to determine life-style factors, medical history and medication. Ten patients were osteoporotic, 21 osteopenic and 17 normal according to the WHO definition. Eighteen patients suffered fractures after receiving chemotherapy and all had significantly lower levels of BMD for all the sites measured

Aims

Type 2 diabetes mellitus (T2DM) impairs bone strength and is a significant risk factor for hip fracture, yet currently there is no reliable tool to assess this risk. Most risk stratification methods rely on bone mineral density, which is not impaired by diabetes, rendering current tests ineffective. CT-based finite element analysis (CTFEA) calculates the mechanical response of bone to load and uses the yield strain, which is reduced in T2DM patients, to measure bone strength. The purpose of this feasibility study was to examine whether CTFEA could be used to assess the hip fracture risk for T2DM patients.

Aims

The incidence of atypical femoral fractures (AFFs) continues to increase. However, there are currently few long-term studies on the complications of AFFs and factors affecting them. Therefore, we attempted to investigate the outcomes, complications, and risk factors for complication through mid-term follow-up of more than three years.

The relationship between the bone mineral density (BMD) and Charcot arthropathy is unclear. Prospectively, 55 consecutive diabetic patients presenting with a Charcot arthropathy of the foot or ankle were classified as having a fracture, dislocation, or a combination fracture-dislocation pattern of initial destruction. In these groups we used dual-energy x-ray absorptiometry to compare the peripheral bone of the affected and unaffected limbs. The clinical data relating to diabetes and related major comorbidities and the site of the arthropathy (ankle, hindfoot, midfoot, forefoot) were also compared. There were 23 patients with a fracture pattern, 23 with a dislocation pattern, and nine with a combination. The age-adjusted odds ratio for developing a Charcot joint with a fracture pattern as opposed to a dislocation pattern in patients with osteopenia was 9.5 (95% confidence interval 2.4 to 37.4; p = 0.0014). Groups also differed as to the site of the arthropathy. Fracture patterns predominated at the ankle and forefoot whereas dislocations did so in the midfoot. Diabetic Charcot arthropathy of the foot and ankle differs according to the pattern of the initial destruction. The fracture pattern is associated with peripheral deficiency of BMD. The dislocation pattern is associated with a normal BMD

We have used dual-energy X-ray absorptiometry to measure bone mineral density (BMD) in patients with ankylosing spondylitis comparing 41 healthy control subjects and 33 patients with either mild or advanced ankylosing spondylitis. A Norland XR-28 bone densitometer was used to measure the BMD of the lumbar spine and that of the head, trunk, arms, femoral neck, Ward's triangle, legs, pelvis, and total body. Mild ankylosing spondylitis was defined as that showing no or incipient syndesmophytes between L1 and L5 vertebrae: we studied 16 men of mean age 37 years and six women of mean age 37 years. Advanced ankylosing spondylitis, in 11 men of mean age 42 years, showed a bamboo spine with bridging syndesmophytes across all disc spaces between L1 and L5. The mean BMD of the lumbar spine was significantly different in the patients and control subjects of the same sex (0.01 < p < 0.05, analysis of variance), being significantly reduced compared with control subjects in mild disease (0.001 < p < 0.01, t-test) and significantly increased in advanced disease over control subjects (0.01 < p < 0.05; t-test) and over patients with mild disease (0.001 < p < 0.01; t-test). The relevance of these findings to the aetiology and pathogenesis of spinal deformities and other complications in ankylosing spondylitis is discussed

Aims

As the population ages and the surgical complexity of lumbar spinal surgery increases, the preoperative stratification of risk becomes increasingly important. Understanding the risks is an important factor in decision-making and optimizing the preoperative condition of the patient. Our aim was to determine whether the modified five-item frailty index (mFI-5) and nutritional parameters could be used to predict postoperative complications in patients undergoing simple or complex lumbar spinal fusion.

Aims

Higher osteoblastic bone activity is expected in aseptic loosening and painful unicompartmental knee arthroplasty (UKA). However, insights into normal bone activity patterns after medial UKAs are lacking. The aim of this study was to identify the evolution in bone activity pattern in well-functioning medial mobile-bearing UKAs.

Aims

The aim of this prospective cohort study was to evaluate the early migration of the TriFit cementless proximally coated tapered femoral stem using radiostereometric analysis (RSA).

Aims

For many designs of total knee arthroplasty (TKA) it remains unclear whether cemented or uncemented fixation provides optimal long-term survival. The main limitation in most studies is a retrospective or non-comparative study design. The same is true for comparative trials looking only at the survival rate as extensive sample sizes are needed to detect true differences in fixation and durability. Studies using radiostereometric analysis (RSA) techniques have shown to be highly predictive in detecting late occurring aseptic loosening at an early stage. To investigate the difference in predicted long-term survival between cemented, uncemented, and hybrid fixation of TKA, we performed a randomized controlled trial using RSA.

Aims

The aim of this study was to explore why some calcar screws are malpositioned when a proximal humeral fracture is treated by internal fixation with a locking plate, and to identify risk factors for this phenomenon. Some suggestions can be made of ways to avoid this error.

Aims

Options for the treatment of intra-articular ligament injuries are limited, and insufficient ligament reconstruction can cause painful joint instability, loss of function, and progressive development of degenerative arthritis. This study aimed to assess the capability of a biologically enhanced matrix material for ligament reconstruction to withstand tensile forces within the joint and enhance ligament regeneration needed to regain joint function.

Fractures of the distal forearm are widely regarded as the result of “fragility”. We have examined the extent to which patients with Colles’ fractures have osteopenia. We measured the bone mineral density (BMD) in the contralateral radius of 235 women presenting with Colles’ fractures over a period of two years. While women of all ages had low values for ultra-distal BMD, the values, in age-matched terms, were particularly low among premenopausal women aged less than 45 years. This result was not due to the presence of women with an early menopause. This large survey confirms and extends the findings from earlier small studies. We consider that it is particularly important to investigate young patients with fractures of the distal forearm to identify those with osteoporosis, to seek an underlying cause and to consider treatment

Dual-energy X-ray absorptiometry (DEXA) is increasingly used to measure changes in bone mineral density (BMD) around femoral prostheses after total hip arthroplasty. We have studied the factors which affect the accuracy of these measurements. The coefficient of variation was < 2% using a hydroxyapatite phantom, 2.7% in an anthropomorphic phantom specimen, and < 1% in repeated measurements on implanted cadaver femora. The precision did not vary with different implant materials or designs. In patients we found a mean precision error of 2.7% to 3.4%. The most significant factor affecting reproducibility was rotation of the femur. We conclude that DEXA is a precise method of measurement for small changes in BMD around femoral implants, but that correct and careful positioning of patients is essential to obtain reliable results

The operative treatment of fractures of the proximal humerus can be complicated by poor bone quality. Our aim was to evaluate a new method which allows prediction of the bone quality of the proximal humerus from radiographs. Anteroposterior radiographs were taken of 19 human cadaver humeri. The cortical thickness was measured at two levels of the proximal humeral diaphysis. The bone mineral density (BMD) was determined for the humeral head (HH), the surgical neck (SN), the greater tuberosity (GT) and lesser tuberosity (LT) using dual-energy x-ray absorptiometry. The mean cortical thickness was 4.4 ± 1.0 mm. Specimens aged 70 years or less had a significantly higher cortical thickness than those aged over 70 years. A significant positive correlation was found between cortical thickness and the BMD for each region of interest. The cortical thickness of the proximal diaphysis is a reliable predictor of the bone quality of the proximal humerus

Aims

In order to determine whether and for whom serial radiological evaluation is necessary in one-part proximal humerus fractures, we set out to describe the clinical history and predictors of secondary displacement in patients sustaining these injuries.

We have studied the effect of hydroxyapatite (HA) coating in 15 ovariectomised and 15 normal rats which had had a sham procedure. Twenty-four weeks after operation, HA-coated implants were inserted into the intramedullary canal of the right femur and uncoated implants into the left femur. The prostheses were removed four weeks after implantation. Twelve specimens in each group had mechanical push-out tests. Sagittal sections of the other three were evaluated by SEM. The bone mineral density (BMD) of the dissected left tibia was measured by dual-energy x-ray absorptiometry. The difference in BMD between the control and ovariectomised tibiae was 35.01 mg/cm. 2. (95% CI, 26.60 to 43.42). The push-out strength of the HA-coated implants was higher than that of the uncoated implants in both groups (p < 0.0001), but the HA-coated implants of the ovariectomised group had a reduction in push-out strength of 40.3% compared with the control group (p < 0.0001). Our findings suggest that HA-coated implants may improve the fixation of a cementless total hip prosthesis but that the presence of osteoporosis may limit the magnitude of this benefit

We carried out limb lengthening in rabbits and then transplanted osteoblast-like cells derived from the tibial periosteum to the centres of distracted callus immediately after distraction had been terminated. Two weeks later the transaxial area ratio at the centre of the distracted callus and the bone mineral density (BMD) were significantly higher in the transplanted group, by 21% and 42%, respectively, than in the non-injected group or the group injected with physiological saline (p < 0.05). Callus BMD as a percentage of density in uninvolved bone was also significantly higher in the transplanted group (p < 0.05) than in the other two groups, by 27% and 20% in the second and fourth weeks, respectively (p < 0.05). Mechanically, the callus in the transplanted group tended to be stronger as shown by the three-point bending test although the difference in fracture strength was not statistically significant. Our results show that transplantation of osteoblast-like cells promotes maturity of the distracted callus as observed at the second and fourth weeks after lengthening. The method appears promising as a means of shortening the consolidation period of callus distraction and decreasing complications during limb lengthening with an external fixator

We investigated the effects of low-intensity pulsed ultrasound on distraction osteogenesis in a rabbit model. Callotasis of the right tibia was performed in 70 male Japanese white rabbits using mini-external fixators. In the first part of the study in 64 animals using normal distraction (waiting period seven days; distraction rate 0.5 mm/12 hours; distraction period ten days), we evaluated the distraction site by radiography, measurement of the bone mineral density (BMD), mechanical testing, and histology. In the second part in six rabbits using fast distraction (waiting period 0 days; distraction rate 1.5 mm/12 hours; distraction period seven days) the site was evaluated radiologically. Half of the animals (35) had received ultrasound to their right leg (30mW/cm. 2. ) for 20 minutes daily after ceasing distraction (ultrasound group), while rigid fixation only was maintained in the other half (control group). With normal distraction, the hard callus area, as shown by radiography, the BMD, and the findings on mechanical testing, were significantly greater in those receiving ultrasound than in the control group. Histological analysis showed no tissue damage attributable to exposure to ultrasound. With fast distraction, immature bone regeneration was observed radiologically in the control group, while bone maturation was achieved in the ultrasound group. We conclude that ultrasound can accelerate bone maturation in distraction osteogenesis in rabbits, even in states of poor callotasis

The properties of impacted morsellised bone graft (MBG) in revision total knee arthroplasty (TKA) were studied in 12 horses. The left hind metatarsophalangeal joint was replaced by a human TKA. The horses were then randomly divided into graft and control groups. In the graft group, a unicondylar, lateral uncontained defect was created in the third metatarsal bone and reconstructed using autologous MBG before cementing the TKA. In the control group, a cemented TKA was implanted without the bone resection and grafting procedure. After four to eight months, the animals were killed and a biomechanical loading test was performed with a cyclic load equivalent to the horse’s body-weight to study mechanical stability. After removal of the prosthesis, the distal third metatarsal bone was studied radiologically, histologically and by quantitative and micro CT. Biomechanical testing showed that the differences in deformation between the graft and the control condyles were not significant for either elastic or time-dependent deformations. The differences in bone mineral density (BMD) between the graft and the control condyles were not significant. The BMD of the MBG was significantly lower than that in the other regions in the same limb. Micro CT showed a significant difference in the degree of anisotropy between the graft and host bone, even although the structure of the area of the MBG had trabecular orientation in the direction of the axial load. Histological analysis revealed that all the grafts were revascularised and completely incorporated into a new trabecular structure with few or no remnants of graft. Our study provides a basis for the clinical application of this technique with MBG in revision TKA

Aims

The early mortality in patients with hip fractures from bony metastases is unknown. The objectives of this study were to quantify 30- and 90-day mortality in patients with proximal femoral metastases, and to create a mortality prediction tool based on biomarkers associated with early death.

Aims

The aim of this study was to determine the stability of a new short femoral stem compared with a conventional femoral stem in patients undergoing cementless total hip arthroplasty (THA), in a prospective randomized controlled trial using radiostereometric analysis (RSA).

Aims

The traditional transosseus flexor hallucis longus (FHL) tendon transfer for patients with Achilles tendinopathy requires two incisions to harvest a long tendon graft. The use of a bio-tenodesis screw enables a short graft to be used and is less invasive, but lacks supporting evidence about its biomechanical behaviour. We aimed, in this study, to compare the strength of the traditional transosseus tendon-to-tendon fixation with tendon-to-bone fixation using a tenodesis screw, in cyclical loading and ultimate load testing.

Aims

Osteolysis, secondary to local and systemic physiological effects, is a major challenge in total hip arthroplasty (THA). While osteolytic defects are commonly observed in long-term follow-up, how such lesions alter the distribution of stress is unclear. The aim of this study was to quantitatively describe the biomechanical implication of such lesions by performing subject-specific finite-element (FE) analysis on patients with osteolysis after THA.

Aims

The aim of this study was to estimate the 90-day risk of revision for periprosthetic femoral fracture associated with design features of cementless femoral stems, and to investigate the effect of a collar on this risk using a biomechanical in vitro model.

Aims

Surface replacement arthroplasty (SRA), compared with traditional total hip arthroplasty (THA), is more expensive and carries unique concern related to metal ions production and hypersensitivity. Additionally, SRA is a more demanding procedure with a decreased margin for error compared with THA. To justify its use, SRA must demonstrate comparable component survival and some clinical advantages. We therefore performed a systematic literature review to investigate the differences in complication rates, patient-reported outcomes, stress shielding, and hip biomechanics between SRA and THA.

Aims

The aim of this study was to evaluate the clinical and radiological outcomes of locking plate fixation, with and without an associated fibular strut allograft, for the treatment of displaced proximal humeral fractures in elderly osteoporotic patients.

Aims

In previous studies, we identified multiple factors influencing the survivorship of hip resurfacing arthroplasties (HRAs), such as initial anatomical conditions and surgical technique. In addition, the University of California, Los Angeles (UCLA) activity score presents a ceiling effect, so a better quantification of activity is important to determine which activities may be advisable or detrimental to the recovered patient. We aimed to determine the effect of specific groups of sporting activities on the survivorship free of aseptic failure of a large series of HRA.

Aims

The aim of this study was to evaluate the outcome of spinal instrumentation in haemodialyzed patients with native pyogenic spondylodiscitis. Spinal instrumentation in these patients can be dangerous due to rates of complications and mortality, and biofilm formation on the instrumentation.

Aims

The aim of this study was to investigate the effect of a posterior malleolar fragment (PMF), with < 25% ankle joint surface, on pressure distribution and joint-stability. There is still little scientific evidence available to advise on the size of PMF, which is essential to provide treatment. To date, studies show inconsistent results and recommendations for surgical treatment date from 1940.

Aims

The aims of this study were to evaluate the clinical and radiological outcomes of instrumented posterolateral fusion (PLF) performed in patients with rheumatoid arthritis (RA).

As the number of younger and more active patients treated with total knee arthroplasty (TKA) continues to increase, consideration of better fixation as a means of improving implant longevity is required. Cemented TKA remains the reference standard with the largest body of evidence and the longest follow-up to support its use. However, cementless TKA, may offer the opportunity of a more bone-sparing procedure with long lasting biological fixation to the bone. We undertook a review of the literature examining advances of cementless TKA and the reported results.

Cite this article: Bone Joint J 2016;98-B:867–73.

It is becoming increasingly common for a patient to have ipsilateral hip and knee replacements. The inter-prosthetic (IP) distance, the distance between the tips of hip and knee prostheses, has been thought to be associated with an increased risk of IP fracture. Small gap distances are generally assumed to act as stress risers, although there is no real biomechanical evidence to support this.

The purpose of this study was to evaluate the influence of IP distance, cortical thickness and bone mineral density on the likelihood of an IP femoral fracture.

A total of 18 human femur specimens were randomised into three groups by bone density and cortical thickness. For each group, a defined IP distance of 35 mm, 80 mm or 160 mm was created by choosing the appropriate lengths of component. The maximum fracture strength was determined using a four-point bending test.

The fracture force of all three groups was similar (p = 0.498). There was a highly significant correlation between the cortical area and the fracture strength (r = 0.804, p <  0.001), whereas bone density showed no influence.

This study suggests that the IP distance has little influence on fracture strength in IP femoral fractures: the thickness of the cortex seems to be the decisive factor.

Cite this article: Bone Joint J 2014;96-B:1378–84.

We performed a retrospective study to determine the effect of osteoporosis on the functional outcome of osteoporotic distal radial fractures treated with a volar locking plate. Between 2009 and 2012 a total of 90 postmenopausal women with an unstable fracture of the distal radius treated with a volar locking plate were studied. Changes in the radiological parameters of 51 patients with osteoporosis (group 1, mean age 66.9, mean T-score –3.16 (sd 0.56)) were not significantly different from those in 39 patients without osteoporosis (group 2, mean age 61.1, mean T-score –1.72 (sd 0.57)). The mean Disabilities of the Arm, Shoulder and Hand (DASH) score at final follow-up was 11.5 (sd 12.2) in group 1 and 10.5 (sd 13.25) in group 2. The mean modified Mayo wrist score at final follow-up was 79.0 (sd 14.04) in group 1 and 82.6 (sd 13.1) in group 2. However, this difference was not statistically significant (p = 0.35 for DASH score, p = 0.2 for modified Mayo wrist score). Univariable and multivariable logistic regression analysis showed that only the step-off of the radiocarpal joint was related to both a poor DASH and modified Mayo wrist score. Pearson’s correlation coefficient showed a weak negative relationship only between the T-score and the change in volar tilt (intraclass coefficient –0.26, p = 0.02).

We found that osteoporosis does not have a negative effect on the functional outcome and additional analysis did not show a correlation between T-score and outcome.

Cite this article: Bone Joint J 2015;97-B:229–34.

The relationship between post-operative bone density and subsequent failure of total knee replacement (TKR) is not known. This retrospective study aimed to determine the relationship between bone density and failure, both overall and according to failure mechanism. All 54 aseptic failures occurring in 50 patients from 7760 consecutive primary cemented TKRs between 1983 and 2004 were matched with non-failing TKRs, and 47 failures in 44 patients involved tibial failures with the matching characteristics of age (65.1 for failed and 69.8 for non-failed), gender (70.2% female), diagnosis (93.6% OA), date of operation, bilaterality, pre-operative alignment (0.4 and 0.3 respectively), and body mass index (30.2 and 30.0 respectively). In each case, the density of bone beneath the tibial component was assessed at each follow-up interval using standardised, calibrated radiographs. Failing knees were compared with controls both overall and, as a subgroup analysis, by failure mechanism. Knees were compared with controls using univariable linear regression.

Significant and continuous elevation in tibial density was found in knees that eventually failed by medial collapse (p < 0.001) and progressive radiolucency (p < 0.001) compared with controls, particularly in the medial region of the tibia. Knees failing due to ligamentous instability demonstrated an initial decline in density (p = 0.0152) followed by a non-decreasing density over time (p = 0.034 for equivalence). Non-failing knees reported a decline in density similar to that reported previously using dual-energy x-ray absorptiometry (DEXA). Differences between failing and non-failing knees were observable as early as two months following surgery. This tool may be used to identify patients at risk of failure following TKR, but more validation work is needed.

Cite this article: Bone Joint J 2014;96-B:1503–9.

This multicentre prospective clinical trial aimed to determine whether early administration of alendronate (ALN) delays fracture healing after surgical treatment of fractures of the distal radius. The study population comprised 80 patients (four men and 76 women) with a mean age of 70 years (52 to 86) with acute fragility fractures of the distal radius requiring open reduction and internal fixation with a volar locking plate and screws. Two groups of 40 patients each were randomly allocated either to receive once weekly oral ALN administration (35 mg) within a few days after surgery and continued for six months, or oral ALN administration delayed until four months after surgery. Postero-anterior and lateral radiographs of the affected wrist were taken monthly for six months after surgery. No differences between groups was observed with regard to gender (p = 1.0), age (p = 0.916), fracture classification (p = 0.274) or bone mineral density measured at the spine (p = 0.714). The radiographs were assessed by three independent assessors. There were no significant differences in the mean time to complete cortical bridging observed between the ALN group (3.5 months (se 0.16)) and the no-ALN group (3.1 months (se 0.15)) (p = 0.068). All the fractures healed in the both groups by the last follow-up. Improvement of the Quick-Disabilities of the Arm, Shoulder and Hand (QuickDASH) score, grip strength, wrist range of movement, and tenderness over the fracture site did not differ between the groups over the six-month period. Based on our results, early administration of ALN after surgery for distal radius fracture did not appear to delay fracture healing times either radiologically or clinically.

Cite this article: Bone Joint J 2013;95-B:1544–50.

Osteoporosis is common and the health and financial cost of fragility fractures is considerable. The burden of cardiovascular disease has been reduced dramatically by identifying and targeting those most at risk. A similar approach is potentially possible in the context of fragility fractures. The World Health Organization created and endorsed the use of FRAX, a fracture risk assessment tool, which uses selected risk factors to calculate a quantitative, patient-specific, ten-year risk of sustaining a fragility fracture. Treatment can thus be based on this as well as on measured bone mineral density. It may also be used to determine at-risk individuals, who should undergo bone densitometry. FRAX has been incorporated into the national osteoporosis guidelines of countries in the Americas, Europe, the Far East and Australasia. The United Kingdom National Institute for Health and Clinical Excellence also advocates its use in their guidance on the assessment of the risk of fragility fracture, and it may become an important tool to combat the health challenges posed by fragility fractures.

Cemented femoral stems with force closed fixation designs have shown good clinical results despite high early subsidence. A new triple-tapered stem in this category (C-stem AMT) was introduced in 2005. This study compares this new stem with an established stem of similar design (Exeter) in terms of migration (as measured using radiostereometric analysis), peri-prosthetic bone remodelling (measured using dual energy x-ray densitometry, DXA), Oxford Hip Score, and plain radiographs.

A total of 70 patients (70 hips) with a mean age of 66 years (53 to 78) were followed for two years. Owing to missing data of miscellaneous reasons, the final analysis represents data from 51 (RSA) and 65 (DXA) patients. Both stems showed a typical pattern of migration: Subsidence and retroversion that primarily occurred during the first three months. C-stem AMT subsided less during the first three months (p = 0.01), before stabilising at a subsidence rate similar to the Exeter stem from years one to two. The rate of migration into retroversion was slightly higher for C-stem AMT during the second year (p = 0.03). Whilst there were slight differences in movement patterns between the stems, the C-stem AMT exhibits good early clinical outcomes and displays a pattern of migration and bone remodelling that predicts good clinical performance.

Cite this article: Bone Joint J 2015;97-B:755–61.

The ideal acetabular component is characterised by reliable, long-term fixation with physiological loading of bone and a low rate of wear. Trabecular metal is a porous construct of tantalum which promotes bony ingrowth, has a modulus of elasticity similar to that of cancellous bone, and should be an excellent material for fixation.

Between 2004 and 2006, 55 patients were randomised to receive either a cemented polyethylene or a monobloc trabecular metal acetabular component with a polyethylene articular surface. We measured the peri-prosthetic bone density around the acetabular components for up to two years using dual-energy x-ray absorptiometry.

We found evidence that the cemented acetabular component loaded the acetabular bone centromedially whereas the trabecular metal monobloc loaded the lateral rim and behaved like a hemispherical rigid metal component with regard to loading of the acetabular bone. We suspect that this was due to the peripheral titanium rim used for the mechanism of insertion.

The major advantage of hip resurfacing is the decreased amount of bone resection compared with a standard total hip replacement. Fracture of the femoral neck is the most common early complication and poor bone quality is a major risk factor. We undertook a prospective consecutive case control study examining the effect of bone mineral density changes in patients undergoing hip resurfacing surgery. A total of 423 patients were recruited with a mean age of 54 years (24 to 87). Recruitment for this study was dependent on pre-operative bilateral femoral bone mineral density results not being osteoporotic. The operated and non-operated hips were assessed. Bone mineral density studies were repeated over a two-year period. The results showed no significant deterioration in the bone mineral density in the superolateral region in the femoral neck, during that period.

These findings were in the presence of a markedly increased level of physical activity, as measured by the short-form 36 health survey physical function score.

Our aim in this pilot study was to evaluate the fixation of, the bone remodelling around, and the clinical outcome after surgery of a new, uncemented, fully hydroxyapatite-coated, collared and tapered femoral component, designed specifically for elderly patients with a fracture of the femoral neck.

We enrolled 50 patients, of at least 70 years of age, with an acute displaced fracture of the femoral neck in this prospective single-series study. They received a total hip replacement using the new component and were followed up regularly for two years.

Fixation was evaluated by radiostereometric analysis and bone remodelling by dual-energy x-ray absorptiometry. Hip function and the health-related quality of life were assessed using the Harris hip score and the EuroQol-5D.

Up to six weeks post-operatively there was a mean subsidence of 0.2 mm (−2.1 to +0.5) and a retroversion of a mean of 1.2° (−8.2° to +1.5°). No component migrated after three months. The patients had a continuous loss of peri-prosthetic bone which amounted to a mean of 16% (−49% to +10%) at two years. The mean Harris hip score was 82 (51 to 100) after two years.

The two-year results from this pilot study indicate that this new, uncemented femoral component can be used for elderly patients with osteoporotic fractures of the femoral neck.

Aseptic loosening of the femoral component is an important indication for revision surgery in unicompartmental knee replacement (UKR). A new design of femoral component with an additional peg was introduced for the cemented Oxford UKR to increase its stability. The purpose of this study was to compare the primary stability of the two designs of component.

Medial Oxford UKR was performed in 12 pairs of human cadaver knees. In each pair, one knee received the single peg and one received the twin peg design. Three dimensional micromotion and subsidence of the component in relation to the bone was measured under cyclical loading at flexion of 40° and 70° using an optical measuring system. Wilcoxon matched pairs signed-rank test was performed to detect differences between the two groups.

There was no significant difference in the relative micromotion (p = 0.791 and 0.380, respectively) and subsidence (p = 0.301 and 0.176, respectively) of the component between the two groups at both angles of flexion. Both designs of component offered good strength of fixation in this cadaver study.

Cite this article: Bone Joint J 2014;96-B:896–901.

Low bone mass and osteopenia have been described in the axial and peripheral skeleton of patients with adolescent idiopathic scoliosis (AIS). Recently, many studies have shown that gene polymorphism is related to osteoporosis. However, no studies have linked the association between IL6 gene polymorphism and bone mass in AIS. This study examined the association between bone mass and IL6 gene polymorphism in 198 girls with AIS. The polymorphisms of IL6-597 G→A, IL6-572 G→C and IL6-174 G→A and the bone mineral density in the lumbar spine and femoral neck were analysed and compared with their levels in healthy controls. The mean bone mineral density at both sites in patients with AIS was decreased compared with controls (p = 0.0022 and p = 0.0013, respectively). Comparison of genotype frequencies between AIS and healthy controls revealed a statistically significant difference in IL6-572 G→C polymorphism (p = 0.0305). There was a significant association between the IL6-572 G→C polymorphism and bone mineral density in the lumbar spine, with the CC genotype significantly higher with the GC (p = 0.0124) or GG (p = 0.0066) genotypes.

These results suggest that the IL6-572 G→C polymorphism is associated with bone mineral density in the lumbar spine in Korean girls with AIS.

For over a decade, bisphosphonate administration has evolved and become the cornerstone of the prevention and treatment of fragility fractures. Millions of post-menopausal women have relied on, and continue to depend on, the long-acting, bone density-maintaining pharmaceutical drug to prevent low-energy fractures. In return, we have seen the number of fragility fractures decrease, along with associated costs and emotional benefits. However, with any drug, there are often concerns with side effects and complications, and this unique drug class is seeing one such complication in atypical subtrochanteric femoral fracture, counterproductive to that which it was designed to prevent. This has created concern over long-term bisphosphonate administration and its potential link to these atypical fractures. There is controversial evidence surrounding such a definitive link, and no protocol for managing these fractures.

This review offers the latest information regarding this rare but increasingly controversial adverse effect and its potential connection to one of the most successful forms of treatment that is available for the management of fragility fractures.

Low-energy fractures of the proximal humerus indicate osteoporosis and it is important to direct treatment to this group of patients who are at high risk of further fracture. Data were prospectively collected from 79 patients (11 men, 68 women) with a mean age of 69 years (55 to 86) with fractures of the proximal humerus in order to determine if current guidelines on the measurement of the bone mineral density at the hip and lumbar spine were adequate to stratify the risk and to guide the treatment of osteoporosis. Bone mineral density measurements were made by dual-energy x-ray absorptiometry at the proximal femur, lumbar spine (L2-4) and contralateral distal radius, and the T-scores were generated for comparison. Data were also collected on the use of steroids, smoking, the use of alcohol, hand dominance and comorbidity.

The mean T-score for the distal radius was −2.97 (sd 1.56) compared with −1.61 (sd 1.62) for the lumbar spine and −1.78 (sd 1.33) for the femur. There was a significant difference between the mean lumbar and radial T scores (1.36 (1.03 to 1.68); p < 0.001) and between the mean femoral and radial T-scores (1.18 (0.92 to 1.44); p < 0.001). The inclusion of all three sites in the determination of the T-score increased the sensitivity to 66% compared with that of 46% when only the proximal femur and lumbar spine were used. This difference between measurements in the upper limb compared with the axial skeleton and lower limb suggests that basing risk assessment and treatment on only the bone mineral density taken at the hip or lumbar spine may misrepresent the extent of osteoporosis in the upper limb and the subsequent risk of fracture at this site.

The assessment of osteoporosis must include measurement of the bone mineral density at the distal radius to avoid underestimation of osteoporosis in the upper limb.

Antegrade nailing of proximal humeral fractures using a straight nail can damage the bony insertion of the supraspinatus tendon and may lead to varus failure of the construct. In order to establish the ideal anatomical landmarks for insertion of the nail and their clinical relevance we analysed CT scans of bilateral proximal humeri in 200 patients (mean age 45.1 years (sd 19.6; 18 to 97) without humeral fractures. The entry point of the nail was defined by the point of intersection of the anteroposterior and lateral vertical axes with the cortex of the humeral head. The critical point was defined as the intersection of the sagittal axis with the medial limit of the insertion of the supraspinatus tendon on the greater tuberosity. The region of interest, i.e. the biggest entry hole that would not encroach on the insertion of the supraspinatus tendon, was calculated setting a 3 mm minimal distance from the critical point. This identified that 38.5% of the humeral heads were categorised as ‘critical types’, due to morphology in which the predicted offset of the entry point would encroach on the insertion of the supraspinatus tendon that may damage the tendon and reduce the stability of fixation.

We therefore emphasise the need for ‘fastidious’ pre-operative planning to minimise this risk.

Cite this article: Bone Joint J 2014;96-B:249–53.

The management of children’s fractures has evolved as a result of better health education, changes in lifestyle, improved implant technology and the changing expectations of society. This review focuses on the changes seen in paediatric fractures, including epidemiology, the increasing problems of obesity, the mechanisms of injury, non-accidental injuries and litigation. We also examine the changes in the management of fractures at three specific sites: the supracondylar humerus, femoral shaft and forearm. There has been an increasing trend towards surgical stabilisation of these fractures. The reasons for this are multifactorial, including societal expectations of a perfect result and reduced hospital stay. Reduced hospital stay is beneficial to the social, educational and psychological needs of the child and beneficial to society as a whole, due to reduced costs.

Cite this article: Bone Joint J 2015; 97-B:442–8.

This study was designed to test the hypothesis that the sensory innervation of bone might play an important role in sensing and responding to low-intensity pulsed ultrasound and explain its effect in promoting fracture healing. In 112 rats a standardised mid-shaft tibial fracture was created, supported with an intramedullary needle and divided into four groups of 28. These either had a sciatic neurectomy or a patellar tendon resection as control, and received the ultrasound or not as a sham treatment. Fracture union, callus mineralisation and remodelling were assessed using plain radiography, peripheral quantitative computed tomography and histomorphology.

Daily ultrasound treatment significantly increased the rate of union and the volumetric bone mineral density in the fracture callus in the neurally intact rats (p = 0.025), but this stimulating effect was absent in the rats with sciatic neurectomy. Histomorphology demonstrated faster maturation of the callus in the group treated with ultrasound when compared with the control group. The results supported the hypothesis that intact innervation plays an important role in allowing low-intensity pulsed ultrasound to promote fracture healing.

Highly active anti-retroviral therapy has transformed HIV into a chronic disease with a long-term asymptomatic phase. As a result, emphasis is shifting to other effects of the virus, aside from immunosuppression and mortality. We have reviewed the current evidence for an association between HIV infection and poor fracture healing.

The increased prevalence of osteoporosis and fragility fractures in HIV patients is well recognised. The suggestion that this may be purely as a result of highly active anti-retroviral therapy has been largely rejected. Apart from directly impeding cellular function in bone remodelling, HIV infection is known to cause derangement in the levels of those cytokines involved in fracture healing (particularly tumour necrosis factor-α) and appears to impair the blood supply of bone.

Many other factors complicate this issue, including a reduced body mass index, suboptimal nutrition, the effects of anti-retroviral drugs and the avoidance of operative intervention because of high rates of wound infection. However, there are sound molecular and biochemical hypotheses for a direct relationship between HIV infection and impaired fracture healing, and the rewards for further knowledge in this area are extensive in terms of optimised fracture management, reduced patient morbidity and educated resource allocation. Further investigation in this area is overdue.

Medial open-wedge high tibial osteotomy has been gaining popularity in recent years, but adequate supporting material is required in the osteotomy gap for early weight-bearing and rapid union. The purpose of this study was to investigate whether the implantation of a polycaprolactone-tricalcium phosphate composite scaffold wedge would enhance healing of the osteotomy in a micro pig model. We carried out open-wedge high tibial osteotomies in 12 micro pigs aged from 12 to 16 months. A scaffold wedge was inserted into six of the osteotomies while the other six were left open. Bone healing was evaluated after three and six months using plain radiographs, CT scans, measurement of the bone mineral density and histological examination.

Complete bone union was obtained at six months in both groups. There was no collapse at the osteotomy site, loss of correction or failure of fixation in either group. Staining with haematoxylin and eosin demonstrated that there was infiltration of new bone tissue into the macropores and along the periphery of the implanted scaffold in the scaffold group. The CT scans and measurement of the bone mineral density showed that at six months specimens in the scaffold group had a higher bone mineral density than in the control group, although the implantation of the polycaprolactone-tricalcium phosphate composite scaffold wedge did not enhance healing of the osteotomy.

This prospective multicentre study was undertaken to determine whether the timing of the post-operative administration of bisphosphonate affects fracture healing and the rate of complication following an intertrochanteric fracture. Between August 2008 and December 2009, 90 patients with an intertrochanteric fracture who underwent internal fixation were randomised to three groups according to the timing of the commencement of risedronate treatment after surgery: Group A (from one week after surgery), Group B (from one month after surgery), and Group C (from three months after surgery). The radiological time to fracture healing was assessed as the primary endpoint, and the incidence of complications, including excessive displacement or any complication requiring revision surgery, as the secondary endpoint. The mean time to fracture healing post-operatively in groups A, B and C was 10.7 weeks (sd 4.4), 12.9 weeks (sd 6.2) and 12.3 weeks (sd 7.1), respectively (p = 0.420). At 24 weeks after surgery, all fractures had united, except six that had a loss of fixation. Functional outcomes at one year after surgery according to the Koval classification (p = 0.948) and the incidence of complications (p = 0.386) were similar in the three groups.

This study demonstrates that the timing of the post-operative administration of bisphosphonates does not appear to affect the rate of healing of an intertrochanteric fracture or the incidence of complications.

We investigated several factors which affect the stability of cortical screws in osteoporotic bone using 18 femora from cadavers of women aged between 45 and 96 years (mean 76). We performed bone densitometry to measure the bone mineral density of the cortical and cancellous bone of the shaft and head of the femur, respectively. The thickness and overall bone mass of the cortical layer of the shaft of the femur were measured using a microCT scanner. The force required to pull-out a 3.5 mm titanium cortical bone screw was determined after standardised insertion into specimens of the cortex of the femoral shaft.

A significant correlation was found between the pull-out strength and the overall bone mass of the cortical layer (r² = 0.867, p < 0.01) and also between its thickness (r² = 0.826, p < 0.01) and bone mineral density (r² = 0.861, p < 0.01). There was no statistically significant correlation between the age of the donor and the pull-out force (p = 0.246), the cortical thickness (p = 0.199), the bone mineral density (p = 0.697) or the level of osteoporosis (p = 0.378).

We conclude that the overall bone mass, the thickness and the bone mineral density of the cortical layer, are the main factors which affect the stability of a screw in human female osteoporotic cortical bone.

Operative fixation is the treatment of choice for a rupture of the distal tendon of biceps. A variety of techniques have been described including transosseous sutures and suture anchors. The poor quality of the bone of the radial tuberosity might affect the load to failure of the tendon repair in early rehabilitation.

The aim of this study was to determine the loads to failure of different techniques of fixation and to investigate their association with the bone mineral density of the radial tuberosity.

Peripheral quantitative computed tomography was carried out to measure the trabecular and cortical bone mineral density of the radial tuberosity in 40 cadaver specimens. The loads to failure in four different techniques of fixation were determined.

The Endobutton-based method showed the highest failure load at 270 N (sd 22) (p < 0.05). The mean failure load of the transosseous suture technique was 210 N (sd 66) and that of the TwinFix-QuickT 5.0 mm was 57 N (sd 22), significantly lower than those of all other repairs (p < 0.05). No significant correlation was seen between bone mineral density and loads to failure.

The transosseous technique is an easy and cost-saving procedure for fixation of the distal biceps tendon. TwinFix-QuickT 5.0 mm had significantly lower failure loads, which might affect early rehabilitation, particularly in older patients.

Transient osteoporosis of the hip is a disorder characterised by pain, and associated with temporary osteopaenia. Although osteopaenia is the essence of the condition, data do not exist about the local bone density of the femoral neck if no medication is administered. We describe three patients who were treated with limitation of weight-bearing only. Repeated bone mineral density measurements were obtained, and that at the femoral neck was lowest two months after the onset of the condition. The mean reduction in bone mineral density when compared with an age-matched control group was 13% (3% to 24%). Spontaneous recovery was observed in all patients.

We compared peri-prosthetic bone mineral density between identical cemented and cementless LCS rotating platform total knee arthroplasties. Two matched cohorts had dual energy x-ray absorptiometry scans two years post-operatively using a modified validated densitometric analysis protocol, to assess peri-prosthetic bone mineral density. The knee that was not operated on was also scanned to enable the calculation of a relative bone mineral density difference. Oxford Knee and American Knee Society scores were comparable in the two cohorts.

Statistical analysis revealed no significant difference in absolute, or relative peri-prosthetic bone mineral density with respect to the method of fixation. However, the femoral peri-prosthetic bone mineral density and relative bone mineral density difference were significantly decreased, irrespective of the method of fixation, particularly in the anterior distal portion of the femur, with a mean reduction in relative bone mineral density difference of 27%.

There was no difference in clinical outcome between the cemented and cementless LCS total knee arthroplasty. However, both produce stress-shielding around the femoral implants. This leads us to question the use of more expensive cementless total knee components.

Aims

Although atlantoaxial rotatory fixation (AARF) is a common cause of torticollis in children, the diagnosis may be delayed. The condition is characterised by a lack of rotation at the atlantoaxial joint which becomes fixed in a rotated and subluxed position. The management of children with a delayed presentation of this condition is controversial. This is a retrospective study of a group of such children.

The medial periosteal hinge plays a key role in fractures of the head of the humerus, offering mechanical support during and after reduction and maintaining perfusion of the head by the vessels in the posteromedial periosteum. We have investigated the biomechanical properties of the medial periosteum in fractures of the proximal humerus using a standard model in 20 fresh-frozen cadaver specimens comparable in age, gender and bone mineral density. After creating the fracture, we displaced the humeral head medial or lateral to the shaft with controlled force until complete disruption of the posteromedial periosteum was recorded. As the quality of periosteum might be affected by age and bone quality, the results were correlated with the age and the local bone mineral density of the specimens measured with quantitative CT.

Periosteal rupture started at a mean displacement of 2.96 mm (sd 2.92) with a mean load of 100.9 N (sd 47.1). The mean maximum load of 111.4 N (sd 42.5) was reached at a mean displacement of 4.9 mm (sd 4.2). The periosteum was completely ruptured at a mean displacement of 34.4 mm (sd 11.1). There was no significant difference in the mean distance to complete rupture for medial (mean 35.8 mm (sd 13.8)) or lateral (mean 33.0 mm (sd 8.2)) displacement (p = 0.589).

The mean bone mineral density was 0.111 g/cm³ (sd 0.035). A statistically significant but low correlation between bone mineral density and the maximum load uptake (r = 0.475, p = 0.034) was observed.

This study showed that the posteromedial hinge is a mechanical structure capable of providing support for percutaneous reduction and stabilisation of a fracture by ligamentotaxis. Periosteal rupture started at a mean of about 3 mm and was completed by a mean displacement of just under 35 mm. The microvascular situation of the rupturing periosteum cannot be investigated with the current model.

There have been recent reports linking alendronate and a specific pattern of subtrochanteric insufficiency fracture. We performed a retrospective review of all subtrochanteric fractures admitted to our institution between 2001 and 2007. There were 20 patients who met the inclusion criteria, 12 of whom were on long-term alendronate. Alendronate-associated fractures tend to be bilateral (Fisher’s exact test, p = 0.018), have unique radiological features (p < 0.0005), be associated radiologically with a pre-existing ellipsoid thickening of the lateral femoral cortex and are likely to be preceded by prodromal pain. Biomechanical investigations did not suggest overt metabolic bone disease. Only one patient on alendronate had osteoporosis prior to the start of therapy. We used these findings to develop a management protocol to optimise fracture healing. We also advocate careful surveillance in individuals at-risk, and present our experience with screening and prophylactic fixation in selected patients.

Corticosteroids are prescribed for the treatment of many medical conditions and their adverse effects on bone, including steroid-associated osteoporosis and osteonecrosis, are well documented. Core decompression is performed to treat osteonecrosis, but the results are variable. As steroids may affect bone turnover, this study was designed to investigate bone healing within a bone tunnel after core decompression in an experimental model of steroid-associated osteonecrosis. A total of five 28-week-old New Zealand rabbits were used to establish a model of steroid-induced osteonecrosis and another five rabbits served as controls. Two weeks after the induction of osteonecrosis, core decompression was performed by creating a bone tunnel 3 mm in diameter in both distal femora of each rabbit in both the experimental osteonecrosis and control groups. An in vivo micro-CT scanner was used to monitor healing within the bone tunnel at four, eight and 12 weeks postoperatively. At week 12, the animals were killed for histological and biomechanical analysis.

In the osteonecrosis group all measurements of bone healing and maturation were lower compared with the control group. Impaired osteogenesis and remodelling within the bone tunnel was demonstrated in the steroid-induced osteonecrosis, accompanied by inferior mechanical properties of the bone.

We have confirmed impaired bone healing in a model of bone defects in rabbits with pulsed administration of corticosteroids. This finding may be important in the development of strategies for treatment to improve the prognosis of fracture healing or the repair of bone defects in patients receiving steroid treatment.

We matched 78 patients with a loose cemented Charnley Elite Plus total hip replacement (THR) by age, gender, race, prosthesis and time from surgery with 49 patients with a well-fixed stable hip replacement, to determine if poor bone quality predisposes to loosening. Clinical, radiological, biomechanical and bone mineral density indicators of bone quality were assessed.

Patients with loose replacements had more pain, were more likely to have presented with atrophic arthritis and to have a history of fragility fracture, narrower femoral cortices and lower peri-prosthetic or lumbar spine bone mineral density (all t-test, p < 0.01). They also tended to be smokers (chi-squared test, p = 0.08). Vitamin-D deficiency was common, but not significantly different between the two groups (t-test, p = 0.31)

In this series of cemented hip replacements performed between 1994 and 1998, aseptic loosening was associated with poor bone quality. Patients with a THR should be screened for osteoporosis and have regular radiological surveillance.

The osteoinductive properties of demineralised bone matrix have been demonstrated in animal studies. However, its therapeutic efficacy has yet to be proven in humans. The clinical properties of AlloMatrix, an injectable calcium-based demineralised bone matrix allograft, were studied in a prospective randomised study of 50 patients with an isolated unstable distal radial fracture treated by reduction and Kirschner (K-) wire fixation. A total of 24 patients were randomised to the graft group (13 men and 11 women, mean age 42.3 years (20 to 62)) and 26 to the no graft group (8 men and 18 women, mean age 45.0 years (17 to 69)).

At one, three, six and nine weeks, and six and 12 months post-operatively, patients underwent radiological evaluation, assessments for range of movement, grip and pinch strength, and also completed the Disabilities of Arm, Shoulder and Hand questionnaire. At one and six weeks and one year post-operatively, bone mineral density evaluations of both wrists were performed.

No significant difference in wrist function and speed of recovery, rate of union, complications or bone mineral density was found between the two groups. The operating time was significantly higher in the graft group (p = 0.004). Radiologically, the reduction parameters remained similar in the two groups and all AlloMatrix extraosseous leakages disappeared after nine weeks.

This prospective randomised controlled trial did not demonstrate a beneficial effect of AlloMatrix demineralised bone matrix in the treatment of this category of distal radial fractures treated by K-wire fixation.

Cite this article: Bone Joint J 2013;95-B:1514–20.