Aims

To compare rates of serious adverse events in patients undergoing revision knee arthroplasty with consideration of the indication for revision (urgent versus elective indications), and compare these with primary arthroplasty and re-revision arthroplasty.

Aims

Many patients undergoing total knee arthroplasty (TKA) have severe osteoarthritis (OA) in both knees and may consider either simultaneous or staged bilateral TKA. The implications of simultaneous versus staged bilateral TKA for return to work are not well understood. We hypothesized that employed patients who underwent simultaneous bilateral TKA would have significantly fewer days missed from work compared with the sum of days missed from each operation for patients who underwent staged bilateral TKA.

We tested four types of surgical repair for load to failure and distraction in a bovine model of Achilles tendon repair. A total of 20 fresh bovine Achilles tendons were divided transversely 4 cm proximal to the calcaneal insertion and randomly repaired using the Dresden technique, a Krackow suture, a triple-strand Dresden technique or a modified oblique Dresden technique, all using a Fiberwire suture. Each tendon was loaded to failure. The force applied when a 5 mm gap was formed, peak load to failure, and mechanism of failure were recorded. The resistance to distraction was significantly greater for the triple technique (mean 246.1 N (205 to 309) to initial gapping) than for the Dresden (mean 180 N (152 to 208); p = 0.012) and the Krackow repairs (mean 101 N (78 to 112; p < 0.001). Peak load to failure was significantly greater for the triple-strand repair (mean 675 N (453 to 749)) than for the Dresden (mean 327.8 N (238 to 406); p < 0.001), Krackow (mean 223.6 N (210 to 252); p <  0.001) and oblique repairs (mean 437.2 N (372 to 526); p < 0.001). Failure of the tendon was the mechanism of failure for all specimens except for the tendons sutured using the Krackow technique, where the failure occurred at the knot.

The triple-strand technique significantly increased the tensile strength (p = 0.0001) and gap resistance (p = 0.01) of bovine tendon repairs, and might have advantages in human application for accelerated post-operative rehabilitation.

In order to assess current opinions on the long-term outcome after primary total hip replacement, we performed a multicentre, cross-sectional survey in 22 centres from 12 European countries. Different patient characteristics were categorised into ‘decreases chances’, ‘does not affect chances’, and ‘increases chances’ of a favourable long-term outcome, by 304 orthopaedic surgeons and 314 referring practitioners. The latter were less likely to associate age older than 80 years and obesity with a favourable outcome than orthopaedic surgeons (p < 0.001 and p = 0.006, respectively) and more likely to associate age younger than 50 years with a favourable outcome (p = 0.006). Comorbidity, rheumatoid arthritis, and poor bone quality were thought to be associated with a decreased chance of a favourable outcome. We found important differences in the opinions regarding long-term outcome after total hip replacement within and between referring practitioners and orthopaedic surgeons. These are likely to affect access to and the provision of total hip replacement.

Modern metal-on-metal bearings produce less wear debris and osteolysis, but have the potential adverse effect of release of ions. Improved ceramic-on-ceramic bearings have the lowest wear of all, but the corrosion process has not been analysed.

Our aim was to measure the serum ion release (ng/ml) in 23 patients having stable hip prostheses with a ceramic-on-ceramic coupling (group A) and to compare it with the release in 42 patients with a metal-on-metal bearing (group B) in the medium term. Reference values were obtained from a population of 47 healthy subjects (group C). The concentrations of chromium, cobalt, aluminium and titanium were measured.

There was a significant increase of cobalt, chromium and aluminium levels (p < 0.05) in group B compared with groups A and C. Group A did not differ significantly from the control group. Despite the apparent advantage of a metal-on-metal coupling, especially in younger patients with a long life expectancy, a major concern arises regarding the extent and duration of ion exposure. For this reason, the low corrosion level in a ceramic-on-ceramic coupling could be advantageous.

The purpose of this anatomical study was to explore the morphological variations of the semitendinosus and gracilis tendons in length and cross-section and the statistical relationship between length, cross-section, and body height.

We studied the legs of 93 humans in 136 cadavers. In 43 specimens (46.2%) it was possible to harvest the tendons from both legs.

We found considerable differences in the length and cross-section of the semitendinosus and the gracilis tendons with a significant correlation between the two. A correlation between the length of the femur, reflecting height, and the length of the tendons was only observed in specimens harvested from women. The reason for this gender difference was unclear. Additionally, there was a correlation between the cross-sectional area of the tendons and the length of the femur. Surgeons should be aware of the possibility of encountering insufficient length of tendon when undertaking reconstructive surgery as a result of anatomical variations between patients.

We investigated differences in the location and mode of labral tears between dysplastic hips and hips with femoroacetabular impingement (FAI). We also investigated the relationship between labral tear and adjacent cartilage damage. We retrospectively studied 72 symptomatic hips (in 68 patients: 19 men and 49 women) with radiological evidence of dysplasia or FAI on high-resolution CT arthrography. The incidence and location of labral tears and modes of tear associated with the base of the labrum (Mode 1) or body of the labrum (Mode 2) were compared among FAI, mildly dysplastic and severely dysplastic hips. The locations predominantly involved with labral tears were different in FAI and mild dysplastic hips (anterior and anterosuperior zones) and in severely dysplastic hips (anterosuperior and superior zones) around the acetabulum. Significant differences were observed in the prevalence of Mode 1 versus Mode 2 tears in FAI hips (72% (n = 13) vs 28% (n = 5)) and severe dysplastic hips (25% (n = 2) vs 75% (n = 6)). The frequency of cartilage damage adjacent to Mode 1 tears was significantly higher (42% (n = 14)) than that adjacent to Mode 2 tears (14% (n = 3)).

Hip pathology is significantly related to the locations and modes of labral tears. Mode 1 tears may be a risk factor for the development of adjacent acetabular cartilage damage.

Cite this article: Bone Joint J 2013;95-B:1320–5.

This single-blinded randomised controlled trial investigated whether one design of mobile-bearing (MB) total knee replacement (TKR) has any advantage over a fixed-bearing (FB) design on long-term fixation as measured by radiostereometry. The amount of wear underneath the mobile bearing was also evaluated. A series of 42 knees was randomised to MB or FB tibial components with appropriate polyethylene inserts and followed for between ten and 12 years, or until the death of the patient. The polyethylene in the MB group was superior in that it was gamma-irradiated in inert gas and was calcium-stearate free; the polyethylene in the FB group was gamma-irradiated in air and contained calcium stearate. In theory this should be advantageous to the wear rate of the MB group. At final follow-up the overall mean migration was 0.75 mm (sd 0.76) in the MB group and 0.66 mm (sd 0.4) in the FB group, with the FB group demonstrating more posterior tilt and the MB group more internal rotation. In the FB group there was one revision for aseptic loosening, but none in the MB group. There were no significant differences in clinical or radiological scores.

For the MB group, the mean linear wear rate on the under-surface was 0.026 mm/year (sd 0.014). This was significantly smaller than the wear rate of 0.11 mm/year (sd 0.06) in the MB between femur and polyethylene (p < 0.001). Nevertheless, even in a best-case setting the mobile bearings of this TKR design had no apparent advantage in terms of fixation over the FB knee prosthesis at ten to 12 years. The wear underneath the mobile bearing was small and is unlikely to be clinically relevant.

We examined the differences in post-operative functional disability and patient satisfaction between 56 patients who underwent a lumbar fusion at three or more levels for degenerative disease (group I) and 69 patients, matched by age and gender, who had undergone a one or two level fusion (group II). Their mean age was 66 years (49 to 84) and the mean follow-up was 43 months (24 to 65).

The mean pre-operative Oswestry Disability Index (ODI) and visual analogue scale (VAS) for back and leg pain, and the mean post-operative VAS were similar in both groups (p >  0.05), but post-operatively the improvement in ODI was significantly less in group I (40.6%) than in group II (49.5%) (p < 0.001). Of the ten ODI items, patients in group I showed significant problems with lifting, sitting, standing, and travelling (p < 0.05). The most significant differences in the post-operative ODI were observed between patients who had undergone fusion at four or more levels and those who had undergone fusion at less than four levels (p = 0.005). The proportion of patients who were satisfied with their operations was similar in groups I and II (72.7% and 77.0%, respectively) (p = 0.668). The mean number of fused levels was associated with the post-operative ODI (r = 0.266, p = 0.003), but not with the post-operative VAS or satisfaction grade (p > 0.05). Post-operative functional disability was more severe in those with a long-level lumbar fusion, particularly at four or more levels, but patient satisfaction remained similar for those with both long- and short-level fusions.

Aims. This multicentre retrospective observational study’s aims were to investigate whether there are differences in the occurrence of radiolucent lines (RLLs) following total knee arthroplasty (TKA) between the conventional Attune baseplate and its successor, the novel Attune S+, independent from other potentially influencing factors; and whether tibial baseplate design and presence of RLLs are associated with differing risk of revision. Methods. A total of 780 patients (39% male; median age 70.7 years (IQR 62.0 to 77.2)) underwent cemented TKA using the Attune Knee System) at five centres, and with the latest radiograph available for the evaluation of RLL at between six and 36 months from surgery. Univariate and multivariate logistic regression models were performed to assess associations between patient and implant-associated factors on the presence of tibial and femoral RLLs. Differences in revision risk depending on RLLs and tibial baseplate design were investigated with the log-rank test. Results. The conventional and novel Attune baseplates were used in 349 (45%) and 431 (55%) patients, respectively. At a median follow-up of 14 months (IQR 11 to 25), RLLs were present in 29% (n = 228/777) and 15% (n = 116/776) of the tibial and femoral components, respectively, and were more common in the conventional compared to the novel baseplate. The novel baseplate was independently associated with a lower incidence of tibial and femoral RLLs (both regardless of age, sex, BMI, and time to radiograph). One- and three-year revision risk was 1% (95% CI 0.4% to 1.9%)and 6% (95% CI 2.6% to 13.2%), respectively. There was no difference between baseplate design and the presence of RLLs on the the risk of revision at short-term follow-up. Conclusion. The overall incidence of RLLs, as well as the incidence of tibial and femoral RLLs, was lower with the novel compared to the conventional tibial Attune baseplate design, but higher than in the predecessor design and other commonly used TKA systems. Cite this article: Bone Joint J 2024;106-B(11):1240–1248

Aims. The aims of this study were to assess quality of life after hip fractures, to characterize respondents to patient-reported outcome measures (PROMs), and to describe the recovery trajectory of hip fracture patients. Methods. Data on 35,206 hip fractures (2014 to 2018; 67.2% female) in the Norwegian Hip Fracture Register were linked to data from the Norwegian Patient Registry and Statistics Norway. PROMs data were collected using the EuroQol five-dimension three-level questionnaire (EQ-5D-3L) scoring instrument and living patients were invited to respond at four, 12, and 36 months post fracture. Multiple imputation procedures were performed as a model to substitute missing PROM data. Differences in response rates between categories of covariates were analyzed using chi-squared test statistics. The association between patient and socioeconomic characteristics and the reported EQ-5D-3L scores was analyzed using linear regression. Results. The median age was 83 years (interquartile range 76 to 90), and 3,561 (10%) lived in a healthcare facility. Observed mean pre-fracture EQ-5D-3L index score was 0.81 (95% confidence interval 0.803 to 0.810), which decreased to 0.66 at four months, to 0.70 at 12 months, and to 0.73 at 36 months. In the imputed datasets, the reduction from pre-fracture was similar (0.15 points) but an improvement up to 36 months was modest (0.01 to 0.03 points). Patients with higher age, male sex, severe comorbidity, cognitive impairment, lower income, lower education, and those in residential care facilities had a lower proportion of respondents, and systematically reported a lower health-related quality of life (HRQoL). The response pattern of patients influenced scores significantly, and the highest scores are found in patients reporting scores at all observation times. Conclusion. Hip fracture leads to a persistent reduction in measured HRQoL, up to 36 months. The patients’ health and socioeconomic status were associated with the proportion of patients returning PROM data for analysis, and affected the results reported. Observed EQ-5D-3L scores are affected by attrition and selection bias mechanisms and motivate the use of statistical modelling for adjustment. Cite this article: Bone Joint J 2024;106-B(4):394–400

Aims. Cross-table lateral (CTL) radiographs are commonly used to measure acetabular component anteversion after total hip arthroplasty (THA). The CTL measurements may differ by > 10° from CT scan measurements but the reasons for this discrepancy are poorly understood. Anteversion measurements from CTL radiographs and CT scans are compared to identify spinopelvic parameters predictive of inaccuracy. Methods. THA patients (n = 47; 27 males, 20 females; mean age 62.9 years (SD 6.95)) with preoperative spinopelvic mobility, radiological analysis, and postoperative CT scans were retrospectively reviewed. Acetabular component anteversion was measured on postoperative CTL radiographs and CT scans using 3D reconstructions of the pelvis. Two cohorts were identified based on a CTL-CT error of ≥ 10° (n = 11) or < 10° (n = 36). Spinopelvic mobility parameters were compared using independent-samples t-tests. Correlation between error and mobility parameters were assessed with Pearson’s coefficient. Results. Patients with CTL error > 10° (10° to 14°) had stiffer lumbar spines with less mean lumbar flexion (38.9°(SD 11.6°) vs 47.4° (SD 13.1°); p = 0.030), different sagittal balance measured by pelvic incidence-lumbar lordosis mismatch (5.9° (SD 18.8°) vs -1.7° (SD 9.8°); p = 0.042), more pelvic extension when seated (pelvic tilt -9.7° (SD 14.1°) vs -2.2° (SD 13.2°); p = 0.050), and greater change in pelvic tilt between supine and seated positions (12.6° (SD 12.1°) vs 4.7° (SD 12.5°); p = 0.036). The CTL measurement error showed a positive correlation with increased CTL anteversion (r = 0.5; p = 0.001), standing lordosis (r = 0.23; p = 0.050), seated lordosis (r = 0.4; p = 0.009), and pelvic tilt change between supine and step-up positions (r = 0.34; p = 0.010). Conclusion. Differences in spinopelvic mobility may explain the variability of acetabular anteversion measurements made on CTL radiographs. Patients with stiff spines and increased compensatory pelvic movement have less accurate measurements on CTL radiographs. Flexion of the contralateral hip is required to obtain clear CTL radiographs. In patients with lumbar stiffness, this movement may extend the pelvis and increase anteversion of the acetabulum on CTL views. Reliable analysis of acetabular component anteversion in this patient population may require advanced imaging with a CT scan. Cite this article: Bone Joint J 2021;103-B(7 Supple B):59–65

Aims. The aim of this study was to conduct a cross-sectional, observational cohort study of patients presenting for revision of a total hip, or total or unicompartmental knee arthroplasty, to understand current routes to revision surgery and explore differences in symptoms, healthcare use, reason for revision, and the revision surgery (surgical time, components, length of stay) between patients having regular follow-up and those without. Methods. Data were collected from participants and medical records for the 12 months prior to revision. Patients with previous revision, metal-on-metal articulations, or hip hemiarthroplasty were excluded. Participants were retrospectively classified as ‘Planned’ or ‘Unplanned’ revision. Multilevel regression and propensity score matching were used to compare the two groups. Results. Data were analyzed from 568 patients, recruited in 38 UK secondary care sites between October 2017 and October 2018 (43.5% male; mean (SD) age 71.86 years (9.93); 305 hips, 263 knees). No significant inclusion differences were identified between the two groups. For hip revision, time to revision > ten years (odds ratio (OR) 3.804, 95% confidence interval (CI) (1.353 to 10.694), p = 0.011), periprosthetic fracture (OR 20.309, 95% CI (4.574 to 90.179), p < 0.001), and dislocation (OR 12.953, 95% CI (4.014 to 41.794), p < 0.001), were associated with unplanned revision. For knee, there were no associations with route to revision. Revision after ten years was more likely for those who were younger at primary surgery, regardless of route to revision. No significant differences in cost outcomes, length of surgery time, and access to a health professional in the year prior to revision were found between the two groups. When periprosthetic fractures, dislocations, and infections were excluded, healthcare use was significantly higher in the unplanned revision group. Conclusion. Differences between characteristics for patients presenting for planned and unplanned revision are minimal. Although there was greater healthcare use in those having unplanned revision, it appears unlikely that routine orthopaedic review would have detected many of these issues. It may be safe to disinvest in standard follow-up provided there is rapid access to orthopaedic review. Cite this article: Bone Joint J 2022;104-B(1):59–67

Aims. The aims of this study were to compare the use of resources, costs, and quality of life outcomes associated with subacromial decompression, arthroscopy only (placebo surgery), and no treatment for subacromial pain in the United Kingdom National Health Service (NHS), and to estimate their cost-effectiveness. Patients and Methods. The use of resources, costs, and quality-adjusted life-years (QALYs) were assessed in the trial at six months and one year. Results were extrapolated to two years after randomization. Differences between treatment arms, based on the intention-to-treat principle, were adjusted for covariates and missing data were handled using multiple imputation. Incremental cost-effectiveness ratios were calculated, with uncertainty around the values estimated using bootstrapping. Results. Cumulative mean QALYs/mean costs of health care service use and surgery per patient from baseline to 12 months were estimated as 0.640 (standard error (. se. ) 0.024)/£3147 (. se. 166) in the decompression arm, 0.656 (. se. 0.020)/£2830 (. se. 183) in the arthroscopy only arm and 0.522 (. se. 0.029)/£1451 (. se. 151) in the no treatment arm. Statistically significant differences in cumulative QALYs and costs were found at six and 12 months for the decompression versus no treatment comparison only. The probabilities of decompression being cost-effective compared with no treatment at a willingness-to-pay threshold of £20 000 per QALY were close to 0% at six months and approximately 50% at one year, with this probability potentially increasing for the extrapolation to two years. Discussion. The evidence for cost-effectiveness at 12 months was inconclusive. Decompression could be cost-effective in the longer-term, but results of this analysis are sensitive to the assumptions made about how costs and QALYs are extrapolated beyond the follow-up of the trial

Aims. Vitamin E-diffused, highly crosslinked polyethylene (VEPE) and porous titanium-coated (PTC) shells were introduced in total hip arthroplasty (THA) to reduce the risk of aseptic loosening. The purpose of this study was: 1) to compare the wear properties of VEPE to moderately crosslinked polyethylene; 2) to assess the stability of PTC shells; and 3) to report their clinical outcomes at seven years. Patients and Methods. A total of 89 patients were enrolled into a prospective study. All patients received a PTC shell and were randomized to receive a VEPE liner (n = 44) or a moderately crosslinked polyethylene (ModXLPE) liner (n = 45). Radiostereometric analysis (RSA) was used to measure polyethylene wear and component migration. Differences in wear were assessed while adjusting for body mass index, activity level, acetabular inclination, anteversion, and head size. Plain radiographs were assessed for radiolucency and patient-reported outcome measures (PROMs) were administered at each follow-up. Results. In total, 73 patients (82%) completed the seven-year visit. Mean seven-year linear proximal penetration was -0.07 mm (. sd. 0.16) and 0.00 mm (. sd. 0.22) for the VEPE and ModXLPE cohorts, respectively (p = 0.116). PROMs (p = 0.310 to 0.807) and radiolucency incidence (p = 0.330) were not different between the polyethylene cohorts. The mean proximal shell migration rate was 0.04 mm per year (. sd. 0.09). At seven years, patients with radiolucency (34%) demonstrated greater migration (mean difference: 0.6 mm (. sd. 0.2); p < 0.001). PROMs were lower for patients with radiolucency and greater proximal migration (p = 0.009 to p = 0.045). No implants were revised for aseptic loosening. Conclusion. This is the first randomized controlled trial to report seven-year RSA results for VEPE. All wear rates were below the previously reported osteolysis threshold (0.1 mm per year). PTC shells demonstrated acceptable primary stability through seven years, as indicated by low migration and lack of aseptic loosening. However, patients with acetabular radiolucency were associated with higher shell migration and lower PROM scores. Cite this article: Bone Joint J 2019;101-B:760–767

Aims. The aim of the Scaphoid Magnetic Resonance Imaging in Trauma (SMaRT) trial was to evaluate the clinical and cost implications of using immediate MRI in the acute management of patients with a suspected fracture of the scaphoid with negative radiographs. Patients and Methods. Patients who presented to the emergency department (ED) with a suspected fracture of the scaphoid and negative radiographs were randomized to a control group, who did not undergo further imaging in the ED, or an intervention group, who had an MRI of the wrist as an additional test during the initial ED attendance. Most participants were male (52% control, 61% intervention), with a mean age of 36.2 years (18 to 73) in the control group and 38.2 years (20 to 71) in the intervention group. The primary outcome was total cost impact at three months post-recruitment. Secondary outcomes included total costs at six months, the assessment of clinical findings, diagnostic accuracy, and the participants’ self-reported level of satisfaction. Differences in cost were estimated using generalized linear models with gamma errors. Results. The mean cost up to three months post-recruitment per participant was £542.40 (. sd. £855.20, n = 65) for the control group and £368.40 (. sd. £338.60, n = 67) for the intervention group, leading to an estimated cost difference of £174 (95% confidence interval (CI) -£30 to £378; p = 0.094). The cost difference per participant increased to £266 (95% CI £3.30 to £528; p = 0.047) at six months. Overall, 6.2% of participants (4/65, control group) and 10.4% of participants (7/67, intervention group) had sustained a fracture of the scaphoid (p = 0.37). In addition, 7.7% of participants (5/65, control group) and 22.4% of participants (15/67, intervention group) had other fractures diagnosed (p = 0.019). The use of MRI was associated with higher diagnostic accuracy both in the diagnosis of a fracture of the scaphoid (100.0% vs 93.8%) and of any other fracture (98.5% vs 84.6%). Conclusion. The use of immediate MRI in the management of participants with a suspected fracture of the scaphoid and negative radiographs led to cost savings while improving the pathway’s diagnostic accuracy and patient satisfaction. Cite this article: Bone Joint J 2019;101-B:984–994

Aims. We investigated patient characteristics and outcomes of Vancouver type B periprosthetic fractures treated with femoral component revision and/or osteosynthesis. Patients and Methods. The study utilized data from the Swedish Hip Arthroplasty Register (SHAR) and information from patient records. We included all primary total hip arthroplasties (THAs) performed in Sweden since 1979, and undergoing further surgery due to Vancouver type B periprosthetic femoral fracture between 2001 and 2011. The primary outcome measure was any further reoperation between 2001 and 2013. Cross-referencing with the National Patient Register was performed in two stages, in order to identify all surgical procedures not recorded on the SHAR. Results. Out of 1381 Vancouver type B fractures that fulfilled the inclusion criteria, 257 underwent further reoperation by the end of 2013. Interprosthetic and Type B1 fractures had a higher risk for reoperation. For B1 fractures, the rate of reoperation did not differ (p = 0.322) after use of conventional (26%) or locking plate osteosynthesis (19%). No significant differences were observed between cemented, cementless monoblock, and cementless modular revision components for the treatment of type B2 and B3 fractures. Conclusion. In this country-specific study, the choice of locking or conventional plates for the treatment of type B1, and cemented or cementless femoral components fixation for B2 and B3 fractures, had no significant influence on risk for reoperation. Interprosthetic fractures adversely affected the outcome of treatment of type B fractures. Differences in the patient characteristics of the compared groups were observed. Cite this article: Bone Joint J 2019;101-B:1447–1458

Aims. The aim of this large registry-based study was to compare mid-term survival rates of cemented femoral stems of different designs used in hemiarthroplasty for a fracture of the femoral neck. Patients and Methods. From the Norwegian Hip Fracture Register (NHFR), 20 532 primary cemented bipolar hemiarthroplasties, which were undertaken in patients aged > 70 years with a femoral neck fracture between 2005 and 2016, were included. Polished tapered stems (n = 12 065) (Exeter and CPT), straight stems (n = 5545) (Charnley, Charnley Modular, and Spectron EF), and anatomical stems (n = 2922) (Lubinus SP2) were included. The survival of the implant with any reoperation as the endpoint was calculated using the Kaplan–Meier method and hazard ratios (HRs), and the different indications for reoperation were calculated using Cox regression analysis. Results. The one-year survival was 96.0% (95% confidence interval (CI) 95.6 to 96.4) for the Exeter stem, 97.0% (95% CI 96.4 to 97.6) for the Lubinus SP2 stem, 97.6% (95% CI 97.0 to 98.2) for the Charnley stem, 98.1% (95% CI 97.3 to 98.9) for the Spectron EF stem, and 96.4% (95% CI 95.6 to 97.2) for the Charnley Modular stem, respectively. The hazard ratio for reoperation after one year was lower for Lubinus SP2 (HR 0.77, 95% CI 0.60 to 0.97), Charnley (HR 0.64, 95% CI 0.48 to 0.86), and Spectron EF stems (HR 0.44, 95% CI 0.29 to 0.67) compared with the Exeter stem. Reoperation for periprosthetic fracture occurred almost exclusively after the use of polished tapered stems. Conclusion. We were able to confirm that implant survival after cemented hemiarthroplasty for a hip fracture is high. Differences in rates of reoperation seem to favour anatomical and straight stems compared with polished tapered stems, which had a higher risk of periprosthetic fracture

Aims. The purpose of this study was to evaluate spinopelvic mechanics from standing and sitting positions in subjects with and without femoroacetabular impingement (FAI). We hypothesize that FAI patients will experience less flexion at the lumbar spine and more flexion at the hip whilst changing from standing to sitting positions than subjects without FAI. This increase in hip flexion may contribute to symptomatology in FAI. Patients and Methods. Male subjects were prospectively enrolled to the study (n = 20). Mean age was 31 years old (22 to 41). All underwent clinical examination, plain radiographs, and dynamic imaging using EOS. Subjects were categorized into three groups: non-FAI (no radiographic or clinical FAI or pain), asymptomatic FAI (radiographic and clinical FAI but no pain), and symptomatic FAI (patients with both pain and radiographic FAI). FAI was defined as internal rotation less than 15° and alpha angle greater than 60°. Subjects underwent standing and sitting radiographs in order to measure spine and femoroacetabular flexion. Results. Compared with non-FAI controls, symptomatic patients with FAI had less flexion at the spine (mean 22°, . sd. 12°, vs mean 35°, . sd. 8°; p = 0.04) and more at the hip (mean 72°, . sd. 6°, vs mean 62°, . sd. 8°; p = 0.047). Subjects with asymptomatic FAI had more spine flexion and similar hip flexion when compared to symptomatic FAI patients. Both FAI groups also sat with more anterior pelvic tilt than control patients. There were no differences in standing alignment among groups. Conclusion. Symptomatic patients with FAI require more flexion at the hip to achieve sitting position due to their inability to compensate through the lumbar spine. With limited spine flexion, FAI patients sit with more anterior pelvic tilt, which may lead to impingement between the acetabulum and proximal femur. Differences in spinopelvic mechanics between FAI and non-FAI patients may contribute to the progression of FAI symptoms. Cite this article: Bone Joint J 2018;100-B:1275–9