Aims. The main aims were to identify risk factors predictive of a radiolucent line (RLL) around the acetabular component with an interface bioactive bone cement (IBBC) technique in the first year after THA, and evaluate whether these risk factors influence the development of RLLs at five and ten years after THA. Methods. A retrospective review was undertaken of 980 primary cemented THAs in 876 patients using cemented acetabular components with the IBBC technique. The outcome variable was any RLLs that could be observed around the acetabular component at the first year after THA. Univariate analyses with univariate logistic regression and multivariate analyses with exact logistic regression were performed to identify risk factors for any RLLs based on radiological classification of hip osteoarthritis. Results. RLLs were detected in 27.2% of patients one year postoperatively. In multivariate regression analysis controlling for confounders, atrophic osteoarthritis (odds ratio (OR) 2.17 (95% confidence interval (CI), 1.04 to 4.49); p = 0.038) and 26 mm (OR 3.23 (95% CI 1.85 to 5.66); p < 0.001) or 28 mm head diameter (OR 3.64 (95% CI 2.07 to 6.41); p < 0.001) had a significantly greater risk for any RLLs one year after surgery. Structural bone graft (OR 0.19 (95% CI 0.13 to 0.29) p < 0.001) and location of the hip centre within the true acetabular region (OR 0.15 (95% CI 0.09 to 0.24); p < 0.001) were significantly less prognostic. Improvement of the cement-bone interface including complete disappearance and poorly defined RLLs was identified in 15.1% of patients. Kaplan-Meier survival analysis for the acetabular component at ten years with revision of the acetabular component for aseptic loosening as the end point was 100.0% with a RLL and 99.1% without a RLL (95% CI 97.9 to 100). With revision of the acetabular component for any reason as the end point, the survival rate was 99.2% with a RLL (95% CI 97.6 to 100) and 96.5% without a RLL (95% CI 93.4 to 99.7). Conclusion. This study demonstrates that acetabular bone quality, head diameter, structural bone graft, and hip centre position may influence the presence of the any RLL. Cite this article: Bone Joint Open 2021;2(5):278–292

Radiolucent lines at the bone-cement interface beneath the tibial components were assessed in 91 consecutive Oxford meniscal knee replacements in 78 patients. Of 80 knees in which radio-opaque cement was used, a radiolucent line was observed in 77, with a radiodense line in the bone immediately adjoining. Radiolucent lines developed in the majority of patients within one year after operation. In 11 knees fixed with radiolucent cement (which precluded assessment of the radiolucent line) a radiodense line was observed beneath the lucent cement in all cases. Histological examination of the interface obtained from secure tibial components showed the lucent zone to be composed of fibrocartilaginous connective tissue and the radiodense line to be a thick lamella of bone. It is suggested that the living bone under a rigid prosthesis requires a layer of relatively compliant fibrocartilaginous material at its interface to accommodate load-bearing. Attention is drawn to the importance of the radiodense line: its presence may constitute positive evidence that healing at the level of bone section is complete and that equilibrium is established; its absence at a mature interface may indicate disequilibrium and impending failure

The radiographic and histological features of radiolucent areas at the cement-bone interface were correlated in 15 specimens retrieved at post-mortem from patients who had undergone cemented total hip arthroplasty, two weeks to 15 years prior to death. All but one of the components were securely fixed, as demonstrated by direct measurements of micromotion. Extensive radiolucencies were present in all but one case. In 11 of the 14 specimens with radiolucencies, histological examination showed that the radiolucent areas represented regions of osteoporosis and bone remodelling. The remodelling changes were characterised by osteoporosis, cancellisation and thinning of the endosteal cortex, and osteopenia of the trabecular bone. In two specimens the appearance of radiolucency was found to be due to fibrous tissue at the cement-bone interface and in one specimen there was a mixed picture of osteolysis and fibrosis. The study demonstrates that radiolucent lines can occur with well-fixed components and that they may commonly represent osteoporosis rather than the presence of a fibrous membrane at the cement-bone interface.

This study aims to implement and assess the inter and intra-reliability of a modernised radiolucency assessment system; the Radiolucency In cemented Stemmed Knee (RISK) arthroplasty classification. Furthermore, we assessed the distribution of regions affected by radiolucency in patients undergoing stemmed cemented knee arthroplasty.

Stemmed knee arthroplasty cases over 7-year period at a single institution were retrospectively identified and reviewed. The RISK classification system identifies five zones in the femur and five zones in the tibia in both the anteroposterior (AP) and lateral planes. Post-operative and follow-up radiographs were scored for radiolucency by four blinded reviewers at two distinct time points four weeks apart. Reliability was assessed using the kappa statistic. A heat map was generated to demonstrate the reported regions of radiolucency.

29 cases (63 radiographs) of stemmed knee arthroplasty were examined radiographically using the RISK system. Intra-reliability (0.83) and Inter-reliability (0.80) scores were both consistent with a strong level of agreement using the kappa scoring system. Radiolucency was more commonly associated with the tibial component (76.6%) compared to the femoral component (23.3%), and the tibial anterior-posterior (AP) region 1 (medial plateau) was the most affected (14.9%).

The RISK classification system is a reliable assessment tool for evaluating radiolucency around stemmed knee arthroplasty using defined zones on both AP and lateral radiographs. Zones of radiolucency identified in this study may be relevant to implant survival and corresponded well with zones of fixation, which may help inform future research.

Radiolucent lines (RL) are a common radiographic finding following Oxford Uni knee arthroplastv. These RL are commonly seen at the bone-cement interface under the tibial tray and can only be evaluated using screened radiographs. These lines occur during the first year, are well defined and remain constant for years. The clinical relevance of this phenomenon is unclear. Pulse lavage has the potential to thoroughly clean the trabecular bone by clearing the bone from bone marrow and debris and can thereby facilitate cement penetration and interdigitation into trabecular bone.

Pulse lavage can reduce the occurrence of radiolucent lines under the tibial tray by improving cement penetration and interdigitation.

Since 2001 we routinely use pulse lavage before cementing the Oxford uni implants at the Orthopä-dische Universitätsklinik Heidelberg (group A). At Nuffield Orthopeadic Center, Oxford conventional irrigation has been used before cementing (group B). At a minimum follow-up of 1 year 56 screened AP radiographs of the knee after Oxford UCA have been blinded and evaluated for radiolucency and cement penetration by an independent observer. For standardized evaluation the cement bone interface has been devided into 4 zones and a specific algorithm for evaluation of the radiographs has been developed.

Complete radiolucencies were detected in 2 cases (4%) in group A and in 13 cases (23%) in group B (p=0,001). Partial radiolucent lines were seen in 32 knees of group A (57%) and in 40 knees (71%) in group B. In zone 1 RLs were found in 31 tibias (55%) in group A, in 32 tibias (57%) in group B. In zone 2 17 (30%) group A, 29 (52%) group B. In Zone 3 4 (7%) in Gruppe A, 20 (36%) in group B. In Zone 4 6 (11%) group A, 30 (54%) group B. The differences between group A and B were significant (P=0.001) in zones 2, 3 and 4.

In group A in 14 cases (25%) RL were limited to one zone, in group B in 5 cases (9%), respectively. In 12 cases (21%) 2 zones were affected in group A (12 cases (21%) group B). RLs in 3 zones were found in 4 cases (7%) in group A and in 10 cases (18%) in group B.

Mean cement penetration (mm) was 2,3mm in group A and in 1,4mm in group B. The use of pulsed lavage led to an increase in cement penetration by a factor of 1,6 (cement penetration in group A/B zone 1: 1,4mm/0,8mm; zone 2: 2,4mm/1,5mm; zone 3: 1,4mm/0,7mm; zone 4: 4,0mm/2,4mm).

The use of pulsed lavage significantly decreases the appearance of RLs at a minimum of 1 year follow-up by increasing cement penetration into cancellous bone. Even though the clinical relevance of tibial RLs in unclear we recommend the use of pulse lavage to improve cement penetration and interdigitation with cancellous bone. Unnecessary revisions due to misinterpretation of RLs may be prevented.

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.

Aims

We aimed to evaluate the long-term outcome of highly cross-linked polyethylene (HXLPE) cemented acetabular components and assess whether any radiolucent lines (RLLs) which arose were progressive.

Introduction. We have investigated middle-term clinical results of total hip arthroplasty (THA) cemented socket with improved technique using hydroxyapatite (HA) granules. IBBC (interfacial bioactive bone cement method, Oonishi) (1) is an excellent technique for augmenting cement-bone fixation in the long term. However, the technique is difficult and there are concerns over some points, such as bleeding control, disturbance of cement intrusion to anchoring holes by granules, difficulty of the uniform granular dispersion to the acetabular bone. To improve the original technique, we have modified IBBC (M-IBBC), and investigated the middle-term clinical results and radiographic changes. Materials and Methods. K-MAX HS-3 THA (Kyocera, Japan), with tapered cemented stem with small collar and all polyethylene cemented socket, was used for THA implants (Fig.1). Basically the third generation cementing technique was used for THA using bone cement. The socket fixation was performed with bone cement (Endurance, DePuy) and HA granules (Ca10(PO4)6(OH)2, Boneceram P; G-2, 0.3–0.6mm in size, Olympus, Japan) (Fig.2). In original IBBC technique, HA granules were dispersed on reamed acetabulum before cementing. In M-IBBC technique, HA granules were attached to bone cement on plastic plate, then inserted to reamed acetabulum and pressurized (Fig.3). 112 hip joints (95 cases) were operated between June 2010 and March 2014, and followed. The average follow-up period was 6.5 years, and average age at operation was 66.5 years. The clinical results were evaluated by Japan Orthopaedic Association Hip Score (JOA score), and X-p findings were evaluated using antero-posterior radiographs. The locations of radiolucent lines were identified according to the zones described by Delee and Charnley for acetabular components, and Zone 1 was divided into two parts, outer Zone 1a and inner Zone 1b. Results and Discussion. Revision was not performed. JOA score improved from 47 to 88. Socket and stem loosening was not observed. X-p findings of sockets demonstrated radiolucent line in Zone 1a/1b/2/3 in 0.9/0/0/0% immediately after the operation, 6.3/1.8/0/0.9% at 2 years postoperatively. After 2 years there was no progressive change, however, improvement of radiolucent line in Zone 1a was observed in two cases after 3 years postoperatively. Accordingly, at 5 years radiolucent line in Zone 1a/1b was observed in 4.4/1.8%. Oonish has reported excellent clinical results of THA with IBBC (1). To easily perform IBBC, we have modified the technique, improving the problems of IBBC. In this study, radiolucent line was observed at the margin of the socket in a small number of cases, and there was no progressive change. In addition, improvement of radiolucent line was observed in M-IBBC in this study, which was not observed in conventional cementing technique. Conclusions. It is demonstrated that M-IBBC provides stable socket cement fixation for THA. The interesting finding in M-IBBC cases was the improvement of radiolucent line, suggesting osteoconductive property of hydroxyapatite granules at the interface after the operations. The promising long-term clinical results of M-IBBC method, were expected. For any figures or tables, please contact the authors directly

Aims. There are concerns regarding complications and longevity of total elbow arthroplasty (TEA) in young patients, and the few previous publications are mainly limited to reports on linked elbow devices. We investigated the clinical outcome of unlinked TEA for patients aged less than 50 years with rheumatoid arthritis (RA). Methods. We retrospectively reviewed the records of 26 elbows of 21 patients with RA who were aged less than 50 years who underwent primary TEA with an unlinked elbow prosthesis. The mean patient age was 46 years (35 to 49), and the mean follow-up period was 13.6 years (6 to 27). Outcome measures included pain, range of motion, Mayo Elbow Performance Score (MEPS), radiological evaluation for radiolucent line and loosening, complications, and revision surgery with or without implant removal. Results. The mean MEPS significantly improved from 47 (15 to 70) points preoperatively to 95 (70 to 100) points at final follow-up (p < 0.001). Complications were noted in six elbows (23%) in six patients, and of these, four with an ulnar neuropathy and one elbow with postoperative traumatic fracture required additional surgeries. There was no revision with implant removal, and there was no radiological evidence of loosening around the components. With any revision surgery as the endpoint, the survival rates up to 25 years were 78.1% (95% confidence interval 52.8 to 90.6) as determined by Kaplan-Meier analysis. Conclusion. The clinical outcome of primary unlinked TEA for young patients with RA was satisfactory and comparable with that for elderly patients. A favourable survival rate without implant removal might support the use of unlinked devices for young patients with this disease entity, with a caution of a relatively high complication rate regarding ulnar neuropathy. Level of Evidence: Therapeutic Level IV. Cite this article: Bone Jt Open 2023;4(1):19–26

Aims. The use and variety of stemless humeral components in anatomical total shoulder arthroplasty (TSA) have proliferated since their advent in 2004. Early outcomes are reassuring but independent mid-term results are scarce. This independent study reports a consecutive series of 143 Eclipse stemless shoulder prostheses with a minimum five-year (5 to 10) follow-up. Methods. Outcomes of 143 procedures undertaken for all indications in 131 patients were reviewed, with subset analysis of those for osteoarthritis (OA) (n = 99). The primary outcome was the Oxford Shoulder Score (OSS) at a minimum of five years. Secondary outcomes were ranges of motion and radiological analysis of humeral radiolucency, rotator cuff failure, and glenoid loosening. Results. Mean OSS at mean follow-up of 6.67 years (5.0 to 10.74) was 40.12 (9 to 48), with no statistically significant difference between those implanted for a non-OA indication and those for OA (p = 0.056) or time-dependent deterioration between two years and five years (p = 0.206). Ranges of motion significantly improved compared with preoperative findings and were maintained between two and five years with a mean external rotation of 38° (SD 18.1, 0 to 100) and forward elevation of 152° (SD 29.9, 90 to 180). Of those components with radiographs suitable for analysis (n = 83), 23 (28%) were found to have a least one humeral radiolucent line, which were predominantly incomplete, less than 2 mm, and in a single anatomical zone. No humeral components were loose. A radiolucent line was present around 22 (15%) of glenoid components, and 15 (10%) of components had failed. Rotator cuff failure was found in 21 (15%) components. The mean time to either glenoid or rotator cuff failure was greater than three years following implantation. Survivorship was 96.4% (95% CI 91.6 to 98.5, number at risk 128) at five years, and 94.3% (95% CI 88.2 to 97.3, number at risk 76) at seven years, both of which compare favourably with best results taken from available registries. Conclusion. Functional and radiological outcomes of the Eclipse stemless TSA are excellent, with no loose humeral components at minimum five-year follow-up. The presence of radiolucent lines is of interest and requires long-term observation but does not impact on the clinical results. Of the eight revisions required, this was predominantly for glenoid and rotator cuff failure. Cite this article: Bone Joint J 2022;104-B(1):83–90

Introduction. IBBC (interfacial bioactive bone cement method, Oonishi) (1) is an excellent technique for augmenting cement-bone fixation in the long term. However, the technique is difficult and there are concerns over some points, such as bleeding control, disturbance of cement intrusion to anchoring holes by granules, difficulty of the uniform granular dispersion to the acetabular bone (Zone 1 in particular). To improve this technique, we have modified IBBC (M-IBBC), and investigated the short-term clinical results and radiographic changes. Materials and Methods. K-MAX HS-3 THA (Kyocera Medical, Japan), with cemented stem and all polyethylene cemented socket, was used for THA implants. Basically the third generation cementing technique was used for THA using bone cement. The socket fixation was performed with bone cement (Endurance, DePuy) and hydroxyapatite (HA) granules (Ca10(PO4)6(OH)2, Boneceram P; G-2, Olympus, Japan). In original IBBC technique, HA granules were dispersed on reamed acetabulum before cementing. In M-IBBC technique, HA granules were attached to bone cement on plastic plate, then inserted to reamed acetabulum and pressurized. HA granules (G-2) are 0.3–0.6mm in size, with 35–38% porosity and sintered at 1150â��. 51 hip joints (49 cases) were operated between June 2010 and December 2011, and followed. The average follow-up was 3.9 years, and average age at operation was 66.5 years. The clinical results were evaluated by Japan Orthopaedic Association Hip Score (JOA score), and X-p findings were evaluated using antero-posterior radiographs. The locations of radiolucent lines were identified according to the zones described by Delee and Charnley for acetabular components, and Zone 1 was divided into two parts, outer Zone 1a and inner Zone 1b. Results and Discussion. Revision was not performed. Japanese orthopaedic association (JOA) score improved from 48 to 87. Socket and stem loosening was not observed. X-p findings of sockets demonstrated radiolucent line in Zone 1a/1b/2/3 in 2/0/0/0% immediately after the operation, 9.8/2/0/2% at 1 year postoperatively. After 1 year there was no progressive change, however, improvement of radiolucent line in Zone 1a was observed in two cases after 3 years postoperatively. Accordingly, after 3 years radiolucent line in Zone 1a/1b was observed in 5.9/2%. Oonish has reported excellent clinical results of THA with IBBC (1). To easily perform IBBC, we have modified the technique, improving the problems of IBBC. In our previous report, we reported improvement of radiolucent line in IBBC (2). In this report, the similar radiographic behavior was observed in M-IBBC, which was not observed in conventional cementing technique. This finding suggests osteoconductive property of hydroxyapatite granules at the interface after the operations. Conclusions. The interesting finding in M-IBBC cases was the improvement of radiolucent line, which was observed in IBBC cases. The promising long-term clinical results of M-IBBC method, similar to IBBC cases, were expected

Introduction & Aim. The use of All-Poly Tibia has been in practice since the early 1970's. Recently due to the reports on wear and osteolysis in other articulations, this component has generated significant interest. In the current study we aim to report early medium-term results of All-poly Tibial components in elderly (>70 years) patients. Method. Study of 455 cases done between 2005-2020. All the cases were performed by a single surgeon. All-Poly Tibial component implantations were performed using Standard mechanical jigs and the same posterior-stabilized implant was used for all cases. Results. 20 cases were lost to follow-up. 25 patients died due to natural causes. Mean age at index surgery was 74 years (70 - 91 years). Preop KSS average was 47 (31- 62). Post operative at the last follow up was 87 (71- 93). Of the 410 cases there were 8 revisions, 6 for deep sepsis and 2 for periprosthetic fractures. There were no revisions for aseptic loosening or osteolysis. All cases are performing well functionally and clinically. 18 cases had a non-progressive radiolucent line beneath the Tibial component. The combination of perfect alignment and soft tissue balance creates an environment for a successful TKR. The choice of the All-Poly Tibial component for functionally low demand age group patients reduces the chances of premature wear and osteolysis. In elderly patients the implant should outlive the patient. Here it is observed that at 5-7 years aseptic loosening and subsequent revision chances are low. The all-poly Tibial component is significantly cheaper as compared to its metal back counterpart. Conclusion. An excellent clinical result in our hands for this group of patients supports the continued use of this implant strongly

Introduction. The clinical impact of radiolucent glenoid lines is controversial, where the presence of a radiolucent glenoid lines has been suggested to be an indicator of clinical glenoid loosening. The goal of this database analysis is to quantify and compare the pre- and post-operative outcomes of 427 patients who received a primary aTSA with one specific prosthesis and were sorted based upon the radiographic presence of a radiolucent glenoid line at latest clinical followup. Methods. 427 patients (mean age: 67.0yrs) with an average follow-up of 49.4 months was treated with aTSA for OA by 14 fellowship trained orthopaedic surgeons. Of these 427 patients, 293 had a cemented keel glenoids (avg follow-up = 50.8 months) and 134 had a cemented pegged glenoids (avg follow-up = 48.7 months). Cemented peg and keel glenoid patients were analyzed separately and also combined into 1 cohort: 288 patients (158 female, avg: 68.7 yrs; 130 male, avg: 64.9 yrs) did not have a radiolucent glenoid line (avg follow-up = 46.9 months); whereas, 139 patients (83 female, avg: 68.5 yrs; 56 male, avg: 64.6 yrs) had a radiolucent glenoid line (avg follow-up = 54.4 months). Outcomes were scored using SST, UCLA, ASES, Constant, and SPADI metrics; active ROM also measured. A two-tailed, unpaired t-test identified differences (p<0.05) in pre-operative, post-operative, and pre-to-post improvements. Results. The overall rate of radiolucent line formation in the glenoid for the combined peg and keel glenoid aTSA cohort was 32.6% (139 of 427 patients). The rate of radiolucent lines for the keel and peg glenoids was similar at nearly the same followup (∼50 months): 96 of 293 peg patients (32.8%) and 43 of 134 keel patients (32.1%) had a radiolucent glenoid line. Patients with cemented keeled glenoids had an average radiographic line score of 2.4 ± 1.3 which trended larger (p = 0.0875) than the average radiographic line score of 2.0 ± 1.1 of patients with cemented peg glenoids. Pre-operatively, no difference was noted between patients with and without radiolucent glenoid lines. (Figure 1) However post-operatively, patients with radiolucent glenoid lines were associated with significantly poorer clinical outcome scores according to all 5 clinical metrics and also had significantly less improvements in outcomes according to 4 of 5 outcome metrics; (Figure 2) poorer outcomes were observed for the combined cemented keeled and pegged glenoid cohorts and when each glenoid prosthesis type is analyzed separately. Additionally, patients with glenoid radiolucent lines were associated with significantly lower improvements in outcomes. (Figure 3) Finally, 24 complications were reported (5.6%), 14 for patients without radiolucent glenoid lines (4.9%) and 10 for patients with radiolucent glenoid lines (7.2%). Conclusions. This large-scale clinical outcome study demonstrated that aTSA patients with radiolucent glenoid lines were associated with significantly poorer clinical outcomes and a higher complication rate as compared to aTSA patients without radiolucent glenoid lines. The overall radiolucent line rate and the negative impact of radiolucent lines were no different between cemented keeled and cemented pegged glenoid components. Additional and longer-term follow-up is needed to confirm these conclusions. For figures/tables, please contact authors directly.

Purpose. Short metaphyseal fitting femoral stems convey stress to proximal femur and have no distal fixation. They have advantages in that there is no thigh pain and no bone loss due to stress shielding, but there is a concern for weakened fixation. So the authors evaluated whether short metaphyseal fitting femoral stems, which have only metaphyseal and no diaphyseal fixation, can acquire sufficient stability. Materials & methods. 39 cases of 36 patients who undervent uncemented total hip arthroplasty with DePuy Proxima. TM. (Johnson & Johnson orthopaedics, New Milton, UK) short metaphyseal fitting femoral stems from August 2009 to September 2011 were retrospectively evaluated. There were 19 male and 20 female cases. The mean follow-up period was 35.8(21.8∼49.2) months. Harris hip scores, WOMAC scores, UCLA scores, and presence of femoral pain were evaluated to assess clinical outcome. Femoral radiolucency in coronal and sagittal views of the hip, femoral stem loosening, and displacement was measured to evaluate radiological outcome. Distance between femoral stem and cortical bone was also measured to assess the relationship with radiolucency and loosening according to degree of contact. Results. Harris hip score before and after operation was 49.8(37–59) and 96.0(71–100) on average. WOMAC score improved from 44.1(31.9–56.3) to 91.8(62.3–100)after operation. UCLA activity score improved from 3.8(2–5) to 7.5(4–9) after operation. When assessed with 1mm as the standard, radiolucent line was shown in 5 cases(12.8%). When the area around the stem was divided into 5 sections, there were 3 cases in which radiolucent line was observed in all 5 sections, 1 case in which radiolucent line was found in only section 4, and 1 case in which radiolucent line was found only in section 5. There was 1 case(2.6%) that required revision THA due to femoral stem loosening. Femoral radiolucency and loosening on coronal and sagittal views increased with greater distance between femoral stem and cortical bone (p=0.002). Conclusion. In uncemented total hip arthroplasty with short metaphyseal fitting femoral stem, it is important to fill the femoral metaphyseal medullary cavity completely with the femoral stem. Therefore, there is severe loss of cancellous bone at proximal femur. Stability varies with differing degree of contact between femoral stem and proximal femoral cortical bone observed on postoperative coronal and sagittal views. When short metaphyseal fitting femoral stems are used, adequate early fixation can be achieved only with understanding of such characteristics as well as sufficient proficiency of the operator

In order to eliminate the “conflict” that can occur with physiological roll back of the femur on the tibia, most modern knee arthroplasty prostheses are designed to have little conformity between the femoral and tibial surfaces. However, a consequence of this design is paradoxical anterior sliding of the femur on tibia, which can result in clinically significant gait abnormalities. Recent studies show that during movement of the knee, the medial side remains very nearly stable like a ball-in-socket joint, whilst the lateral side moves front to back, rotating around the centre of the medial side. A total knee joint prosthesis designed with these same kinematics may therefore be advantageous. The objective of this study was to investigate the hypothesis that the increased constraint of a medial pivot knee promotes earlier loosening of the prosthesis. METHODS: This was a retrospective radiographic cohort study. Using our unit’s knee arthroplasty database, all patients with a Freeman-Samuelson 1000 knee arthroplasty (medial pivot design) or a Freeman-Samuelson Modular knee arthroplasty with a minimum follow-up of 2 years were identified, and matched as closely as possible for age, length of follow-up and pre-operative diagnosis (Osteoarthritis, Rheumatoid arthritis or Post-traumatic arthritis). This was a single surgeon series using a standard surgical approach with a posterior cruciate sacrificing technique. Standardised anteroposterior and lateral radiographs taken postoperatively, at 6 months, 1 year and then at yearly intervals, were examined systematically and independently of the senior surgeon (GS). Component migration and radiolucent line scores were allocated as recommended by the Knee Society. RESULTS: Group 1 (n=55),–Freeman Samuelson Modular design, mean age–70.3 years, mean length of follow-up–4.5 years. Group 2 (n=48),–Freeman Samuelson 1000 design (Medial pivot), mean age–70.4 years, mean length of follow-up–4.3 years. There were no failures in group 1. There was one failure requiring revision of the femoral component in group 2. Radiolucent lines were more prominent and frequent in the tibia, particularly under the medial and lateral plateau’s (KSS zone 1 and 6). There was no significant difference in the overall radiolucent line scores between the two groups (p=0.39, Mann Whitney U test). Similarly we found no difference between radiolucent line progression in the specific tibial zones (1–6 KSS system). Radiolucent lines in the femur were infrequent and insignificant. CONCLUSION: We found no statistically significant difference between the two designs of knee prosthesis in terms of either total radiolucent line score or rate of radiolucent line progression. The increased constraint of the medial pivot knee prosthesis does not appear to result in an increased incidence of radiographic loosening

Aims. Limb salvage in bone tumour patients replaces the bone with massive segmental prostheses where achieving bone integration at the shoulder of the implant through extracortical bone growth has been shown to prevent loosening. This study investigates the effect of multidrug chemotherapy on extracortical bone growth and early radiological signs of aseptic loosening in patients with massive distal femoral prostheses. Methods. A retrospective radiological analysis was performed on adult patients with distal femoral arthroplasties. In all, 16 patients were included in the chemotherapy group with 18 patients in the non-chemotherapy control group. Annual radiographs were analyzed for three years postoperatively. Dimensions of the bony pedicle, osseointegration of the hydroxyapatite (HA) collar surface, bone resorption at the implant shoulder, and radiolucent line (RLL) formation around the cemented component were analyzed. Results. A greater RLL score (p = 0.041) was observed at three years postoperatively, with those receiving chemotherapy showing greater radiological loosening compared with those not receiving chemotherapy. Chemotherapy patients experience osteolysis at the shoulder of the ingrowth collar over time (p < 0.001) compared with non-chemotherapy patients where osteolysis was not observed. A greater median percentage integration of the collar surface was observed in the non-chemotherapy group (8.6%, interquartile range (IQR) 0.0% to 37.9%; p = 0.021) at three years. Bone growth around the collar was observed in both groups, and no statistical difference in amount of extracortical bony bridging was seen. Conclusion. Multidrug chemotherapy affects the osseointegration of ingrowth collars and accelerates signs of radiological loosening. This may increase the risk of aseptic loosening in patients with massive segmental implants used to treat bone cancer. Cite this article: Bone Joint Res 2020;9(7):333–340

Aims. The use of vitamin E-infused highly crosslinked polyethylene (HXLPE) in total knee prostheses is controversial. In this paper we have compared the clinical and radiological results between conventional polyethylene and vitamin E-infused HXLPE inserts in total knee arthroplasty (TKA). Patients and Methods. The study included 200 knees (175 patients) that underwent TKA using the same total knee prostheses. In all, 100 knees (77 patients) had a vitamin E-infused HXLPE insert (study group) and 100 knees (98 patients) had a conventional polyethylene insert (control group). There were no significant differences in age, sex, diagnosis, preoperative knee range of movement (ROM), and preoperative Knee Society Score (KSS) between the two groups. Clinical and radiological results were evaluated at two years postoperatively. Results. Differences in postoperative ROM and KSS were not statistically significant between the study and control groups. No knee exhibited osteolysis, aseptic loosening, or polyethylene failure. Additionally, there was no significant difference in the incidence of a radiolucent line between the two groups. One patient from the study group required irrigation and debridement, due to deep infection, at six months postoperatively. Conclusion. Clinical results were comparable between vitamin E-infused HXLPE inserts and conventional polyethylene inserts at two years after TKA, without any significant clinical failure. Cite this article: Bone Joint J 2019;101-B:559–564

Purpose. To evaluate the radiographic long-term result of femoral revision hip arthroplasty using impacted cancellous allograft combined with cemented, collarless, polished and tapered stem. Materials and methods. Among 28 patients with impacted cancellous allograft with a cemented stem, 28 hips from 26 consecutive patients were analyzed retrospectively. The average patient age was 59 years. The follow-up period ranged 9 years 6 months to 14 years 5 months (mean, 12, 5 years). Radiographic parameters analyzed in this study included subsidence of the stem in the cement, subsidence of the cement mantle in the femur, bone remodeling of the femur, radiolucent line, and osteolysis. Results. Radiographic analysis showed very stable stem initially. 27 stems showed minimal subsidence (less than 5 mm) and 1 stem showed moderate subsidence (about 10 mm) in the cement. But there was no mechanical failure and subsidence at the composit-femur interface. Evidence of cortical and trabecular remodeling were observed in all cases. No radiolucent line or osteolysis were found in the follow-up period. There were 4 proximal femoral cracks and 1 distal femoral splitting during operation. Conclusion. The result of cemented stem revision with the use of impacted cancellous allograft was good long-terand femoral bone stock deficiency may be reconstructed successfully

Purpose. To evaluate the radiological changes after metal on metal resurfacing arthroplasty. Materials and Methods. Between December 1998 and August 2004, 166 hips in 150 patients who underwent metal resurfacing arthroplasty and followed up more than 4 years. Their mean age at the time of operation was 37.3 years(range, 15–68 years) and mean period of follow-up was 6.1 years(range, 48–95 months). The cause of arthroplasty included 115 avascular necrosis, 43 osteoarthritis, 7 ankylosing spondylitis, 1 haemophilic arthropathy. All patients had anteroposterior, translateral radiographs of the hip made preoperatively and each follow-up visit, and we analyzed radiographic findings such as radiolucencies or impingement signs around implant, neck narrowing and heterotopic ossification. Results. There was a no significant difference between preoperative and postoperative Harris hip score and range of motion. The mean stem-shaft angle was 137.4°, and 55.4% were ranged 130° to 140°. The mean inclination of acetabular component was 44.9°. There were no radiolucent lines or osteolytic lesion around the acetabular components, but 3 hips showed radiolucency around the head-neck junction(1.8%) and 4 hips showed radiolucent line around the stem (2.4%). 12 hips had impingement signs around the head-neck junction (7.2%), and 2 cases showed neck narrowing (1.2%). 3 cases had some heterotopic ossification (1.8%). In 12 cases with impingement signs, the stem-shaft angle and inclination of acetabular component were lower than control group. Pseudotumor was not found in this cohort. Conclusions. This study demonstrates no serious radiological problems till the midterm follow-up after resurfacing arthroplasty, but osteolytic lesion such as radiolucent line around head-neck junction, neck narrowing can be a potential cause of failure in future. Even though the radiolucent line around stem of femoral component revealed no subjective symptom yet, it suggests the micromotion of femoral component which can lead to femoral component loosening. The most common radiological findings, impingement signs, seem not to have clinical significance

Purpose. We have compared the short-term clinical results of total hip arthroplasty (THA) using PMMA bone cement and hydroxyapatite (HA) granules (interfacial bioactive bone cement method; IBBC) with the results of conventional method using PMMA bone cement. Materials and Methods. K-MAX HS-3 THA (JMM, Japan), with cemented titanium alloy stem and all polyethylene cemented socket, was used for THA implants. The third generation cement technique was used for the conventional THA (Group C) using bone cement (Endurance, DePuy). In the IBBC group (Group BC), the socket fixation was performed by the third generation cement technique with HA granules (Boneceram P; G-2, Olympus, Japan) according to the Ohnishi's method. In both groups, the stems were fixed by conventional cementing technique using cement gun. 76 hip joins (69 cases) were operated between April 2005 and August 2007, and followed. The group C (22 hips, 19 cases, average follow-up; 5.6 years, average age at operation; 64 years) and the group BC (54 hips, 50 cases, 5.4 years, 65 years) were investigated. Results. One revision was performed in BC group due to late infection. Japanese orthopaedic association (JOA) score improved from 42/48 to 85/87 in Group C/BC. Socket loosening was not observed radiographically. X-p findings of Group C/BC demonstrated radiolucent line in the outer part of Zone 1 in 18%/16% immediately after operation, 24%/23% at 2 years postoperatively. After 2 years there was no change in Group C, however, improvement of radiolucent line (gap filling) with bone remodeling was observed in two cases in Group BC at 3 years postoperatively. Conclusions. The short-term clinical results of Group BC using IBBC method and Group C using conventional method were equally satisfactory. The interesting finding in Group BC case was the improvement of radiolucent line (gap filling), suggesting osteoconductive property of hydroxyapatite granules at the interface after the operations. The promising clinical results of IBBC method in the long term were expected