Objectives. Few studies have assessed outcomes following non-metal-on-metal hip arthroplasty (non-MoMHA) revision surgery performed for adverse reactions to metal debris (ARMD). We assessed outcomes following non-MoMHA revision surgery performed for ARMD, and identified predictors of re-revision. Methods. We performed a retrospective observational study using data from the National Joint Registry for England and Wales. All non-MoMHAs undergoing revision surgery for ARMD between 2008 and 2014 were included (185 hips in 185 patients). Outcome measures following ARMD revision were intra-operative complications, mortality and re-revision surgery. Predictors of re-revision were identified using Cox regression. Results. Intra-operative complications occurred in 6.0% (n = 11) of the 185 cases. The cumulative four-year patient survival rate was 98.2% (95% CI 92.9 to 99.5). Re-revision surgery was performed in 13.5% (n = 25) of hips at a mean time of 1.2 years (0.1 to 3.1 years) following ARMD revision. Infection (32%; n = 8), dislocation/subluxation (24%; n = 6), and aseptic loosening (24%; n = 6) were the most common re-revision indications. The cumulative four-year implant survival rate was 83.8% (95% CI 76.7 to 88.9). Multivariable analysis identified three predictors of re-revision: multiple revision indications (hazard ratio (HR) = 2.78; 95% CI 1.03 to 7.49; p = 0.043); selective component revisions (HR = 5.76; 95% CI 1.28 to 25.9; p = 0.022); and ceramic-on-polyethylene revision bearings (HR = 3.08; 95% CI 1.01 to 9.36; p = 0.047). Conclusions. Non-MoMHAs revised for ARMD have a high short-term risk of re-revision, with important predictors of future re-revision including selective component revision, multiple revision indications, and ceramic-on-polyethylene revision bearings. Our findings may help counsel patients about the risks of ARMD revision, and guide reconstructive decisions. Future studies attempting to validate the predictors identified should also assess the effects of implant design (metallurgy and modularity), given that this was an important study limitation potentially influencing the reported prognostic factors. Cite this article: G. S. Matharu, A. Judge, D. W. Murray, H. G. Pandit. Outcomes following revision surgery performed for adverse reactions to metal debris in non-metal-on-metal hip arthroplasty patients: Analysis of 185 revisions from the National Joint Registry for England and Wales. Bone Joint Res 2017;6:405–413. DOI: 10.1302/2046-3758.67.BJR-2017-0017.R2

Aims. We report the long-term clinical and radiological outcomes of a consecutive series of 200 total ankle arthroplasties (TAAs, 184 patients) at a single centre using the Scandinavian Total Ankle Replacement (STAR) implants. Patients and Methods. Between November 1993 and February 2000, 200 consecutive STAR prostheses were implanted in 184 patients by a single surgeon. Demographic and clinical data were collected prospectively and the last available status was recorded for further survival analysis. All surviving patients underwent regular clinical and radiological review. Pain and function were assessed using the American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot scoring system. The principal endpoint of the study was failure of the implant requiring revision of one or all of the components. Kaplan–Meier survival curves were generated with 95% confidence intervals and the rate of failure calculated for each year. Results. A total of 84 patients (87 ankles) were alive by the end of this study. Of the surviving 84 patients (87 ankles; rheumatoid arthritis (RA), n = 40; OA, n = 47), 45 were women and 39 were men, with a mean age of 54 years (18 to 72 years) at the time of surgery. A total of 32 implants failed (16%), requiring revision surgery. The mean time to revision was 80 months (2 to 257). The implant survival at 15.8 years, using revision as an endpoint, was 76.16% (95% confidence interval (CI) 64.41 to 87.91). We found a steady but low decrease in survival over the study period. The mean AOFAS score improved from 28 (10 to 52) preoperatively to 61 (20 to 90) at long-term follow-up. Conclusion. STAR prostheses in the United Kingdom have now been largely superseded by newer design TAAs, potentially with improved characteristics and surgical techniques. The long-term survivorship for the STAR prosthesis can provide a benchmark for these later designs of ankle arthroplasty

Aims. To assess how the cost-effectiveness of total hip arthroplasty (THA) and total knee arthroplasty (TKA) varies with age, sex, and preoperative Oxford Hip or Knee Score (OHS/OKS); and to identify the patient groups for whom THA/TKA is cost-effective. Methods. We conducted a cost-effectiveness analysis using a Markov model from a United Kingdom NHS perspective, informed by published analyses of patient-level data. We assessed the cost-effectiveness of THA and TKA in adults with hip or knee osteoarthritis compared with having no arthroplasty surgery during the ten-year time horizon. Results. THA and TKA cost < £7,000 per quality-adjusted life-year (QALY) gained at all preoperative scores below the absolute referral thresholds calculated previously (40 for OHS and 41 for OKS). Furthermore, THA cost < £20,000/QALY for patients with OHS of ≤ 45, while TKA was cost-effective for patients with OKS of ≤ 43, since the small improvements in quality of life outweighed the cost of surgery and any subsequent revisions. Probabilistic and one-way sensitivity analyses demonstrated that there is little uncertainty around the conclusions. Conclusion. If society is willing to pay £20,000 per QALY gained, THA and TKA are cost-effective for nearly all patients who currently undergo surgery, including all patients at and above our calculated absolute referral thresholds. Cite this article: Bone Joint J 2020;102-B(7):950–958

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.

Aims. Magnetically controlled growing rods (MCGR) have been gaining popularity in the management of early-onset scoliosis (EOS) over the past decade. We present our experience with the first 44 MCGR consecutive cases treated at our institution. Methods. This is a retrospective review of consecutive cases of MCGR performed in our institution between 2012 and 2018. This cohort consisted of 44 children (25 females and 19 males), with a mean age of 7.9 years (3.7 to 13.6). There were 41 primary cases and three revisions from other rod systems. The majority (38 children) had dual rods. The group represents a mixed aetiology including idiopathic (20), neuromuscular (13), syndromic (9), and congenital (2). The mean follow-up was 4.1 years, with a minimum of two years. Nine children graduated to definitive fusion. We evaluated radiological parameters of deformity correction (Cobb angle), and spinal growth (T1-T12 and T1-S1 heights), as well as complications during the course of treatment. Results. The mean Cobb angles pre-operatively, postoperatively, and at last follow-up were 70° (53 to 103), 35° (15 to 71) and 39° (15 to 65) respectively (p < 0.001). Further, there was a mean of 14° (-6 to 27) of additional Cobb angle correction upon graduation from MCGR to definitive fusion. Both T1-T12 and T1-S1 showed significant increase in heights of 27 mm and 45 mm respectively at last follow-up (p < 0.001). Ten children (23%) developed 18 complications requiring 21 unplanned operations. Independent risk factors for developing a complication were single rod constructs and previous revision surgery. Conclusion. MCGR has the benefit of avoiding multiple surgeries, and is an effective tool in treatment of early-onset scoliosis. It also maintains the flexibility of the spine, allowing further correction at the time of definitive fusion. Cite this article: Bone Joint Open 2020;1-7:405–414

Aims. The aim of this study was to analyze the effect of a lateral rim mesh on the survival of primary total hip arthroplasty (THA) in young patients, aged 50 years or younger. Patients and Methods. We compared a study group of 235 patients (257 hips) who received a primary THA with the use of impaction bone grafting (IBG) with an additional lateral rim mesh with a group of 306 patients (343 hips) who received IBG in the absence of a lateral rim mesh during the same period from 1988 to 2015. In the mesh group, there were 74 male and 183 female patients, with a mean age of 35 years (13 to 50). In the no-mesh group, there were 173 male and 170 female patients, with a mean age of 38 years (12.6 to 50). Cox regression analyses were performed to study the effect of a lateral rim mesh on acetabular component survival. Kaplan–Meier analyses with 95% confidence intervals (CIs) were performed to estimate the survival of the acetabular implant. Results. The hazard ratio for the use of lateral rim mesh, adjusted for potential confounders, for acetabular revision for any reason was 0.50 (95% CI 0.13 to 1.93; p = 0.31) and for acetabular revision for aseptic loosening was 0.29 (95% CI 0.020 to 4.04; p = 0.35). The Kaplan–Meier analysis showed a ten-year survival for aseptic loosening of the acetabular of 98% (95% CI 95 to 100, n = 65 at risk) in the mesh group and 94% (89 to 98, n = 76 at risk) in the no-mesh group. The 15-year survival for aseptic acetabular loosening was 90% (81 to 100, n = 35 at risk) in the mesh group and 85% (77 to 94, n = 45 at risk) in the no-mesh group (p = 0.23). Conclusion. This study shows that the use of a lateral rim mesh in primary THA in young patients is not associated with a higher risk of revision of the acetabular component. Therefore, we consider a lateral rim mesh combined with IBG to be effective in reconstructing segmental acetabular defects in primary THA

Aims

Treatment of end-stage anteromedial osteoarthritis (AMOA) of the knee is commonly approached using one of two surgical strategies: medial unicompartmental knee arthroplasty (UKA) or total knee arthroplasty (TKA). In this study we aim to investigate if there is any difference in outcome for patients undergoing UKA or TKA, when treated by high-volume surgeons, in high-volume centres, using two different clinical guidelines. The two strategies are ‘UKA whenever possible’ vs TKA for all patients with AMOA.

Aims. Little is known about the relative outcomes of revision of unicompartmental knee arthroplasty (UKA) and high tibial osteotomy (HTO) to total knee arthroplasty (TKA). The aim of this study is to compare the outcomes of revision surgery for the two procedures in terms of complications, re-revision and patient-reported outcome measures (PROMs) at a minimum of two years follow-up. Patients and Methods. This study was a retrospective review of data from an institutional arthroplasty registry for cases performed between 2001 and 2014. A total of 292 patients were identified, of which 217 had a revision of HTO to TKA, and 75 had revision of UKA to TKA. While mean follow-up was longer for the HTO group compared with the UKA group, patient demographics (age, body mass index and Charlson co-morbidity index) and PROMs (Short Form-36, Oxford Knee Score, Knee Society Score, both objective and functional) were similar in the two groups prior to revision surgery. Outcomes included the rate of complications and re-operation, PROMS and patient-reported satisfaction at six months and two years post-operatively. We also compared the duration of surgery and the need for revision implants in the two groups. . Results . At two-year follow-up, both groups of patients had made significant improvement in terms of PROMs compared with pre-operative scores. PROMs and satisfaction rates were similar in the two groups. Complications requiring re-operation were significantly more frequent in the HTO group whilst more revision implants were used in the UKA group, resulting in a longer operative duration. . Conclusion. Revision of HTO and UKA achieve similar post-operative PROMs and satisfaction. Revision of UKA more frequently requires revision components with increased operation duration but fewer complications requiring re-operation compared with revision of HTO. . Cite this article: Bone Joint J 2017;99-B:1329–34

Aims

This systematic review aims to compare the precision of component positioning, patient-reported outcome measures (PROMs), complications, survivorship, cost-effectiveness, and learning curves of MAKO robotic arm-assisted unicompartmental knee arthroplasty (RAUKA) with manual medial unicompartmental knee arthroplasty (mUKA).

Aims

Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are common orthopaedic procedures requiring postoperative radiographs to confirm implant positioning and identify complications. Artificial intelligence (AI)-based image analysis has the potential to automate this postoperative surveillance. The aim of this study was to prepare a scoping review to investigate how AI is being used in the analysis of radiographs following THA and TKA, and how accurate these tools are.

Aims. Between 15% and 20% of patients remain dissatisfied following total knee arthroplasty (TKA). The SAIPH knee system (MatOrtho, Surrey, United Kingdom) is a medial ball and socket TKA that has been designed to replicate native knee kinematics in order to maximize the range of movement, stability, and function. This system is being progressively introduced in a stepwise fashion, with this study reporting the mid-term clinical and radiological outcomes. Patients and Methods. A retrospective review was undertaken of the first 100 consecutive patients with five-year follow-up following SAIPH TKA performed by the senior authors. The data that were collected included the demographics of the patients, clinical findings, the rate of intraoperative ligamentous release, patient-reported outcome measures (PROMS), radiological assessment, complications, and all-cause revision. Revision data were cross-checked with a national registry. Results. A total of 100 TKAs in 92 patients were included. Three patients died (three TKAs) and a further two TKAs were revised. Of the remaining 95 TKAs, five-year follow-up data were available for 81 TKAs (85%) in 87 patients. There were significant improvements in all PROMs and high satisfaction. The mean ROM at final follow-up was from 0° (full extension) to 124° flexion. There were seven major complications (7%): one infection, two deep vein thromboses, one cerebrovascular event, and two patients with stiffness requiring a manipulation under anaesthesia. Two patients required a lateral retinacular release to optimize patellar tracking in valgus knees; no additional ligament releases were performed in any patient. Radiological analysis demonstrated no evidence of implant-related complications. Conclusion. These results demonstrate satisfactory clinical and radiological outcomes at five years following a medial ball and socket TKA. The complication and revision rates are consistent with those previously reported for patients undergoing TKA. These results demonstrate the safety and efficacy of the SAIPH Knee TKA system and support its wider use

Aims. Despite few good-quality studies on the subject, total hip arthroplasty (THA) is increasingly being performed for displaced intracapsular fractures of the neck of femur. We compared outcomes of all patients with displacement of these fractures treated surgically over a ten-year period in one institution. Methods. A total of 2,721 patients with intracapsular fractures of the femoral neck treated with either a cemented hemiarthroplasty or a THA at a single centre were retrospectively reviewed. The primary outcomes analyzed were readmission for any reason and revision surgery. We secondarily looked at mortality rates. Results. We found no difference in the overall revision rate or rate of infection. However, the rates of readmission due to dislocation, pain, and trochanteric bursitis were significantly higher in the THA group (p = 0.001, p < 0.001, p < 0.001, and p = 0.001, respectively). Conclusion. Our study, comparing the outcomes of neck of femur fractures treated with a cemented hemiarthroplasty and THA, revealed the perceived superiority of THA was not borne out by our results. This should be carefully considered before any radical change in practice regarding the use of THA for displaced intracapsular fractures of the femoral neck. Cite this article: Bone Joint J 2020;102-B(6):693–698

Aims. The purpose of this study was to compare the radiological outcomes of manual versus robotic-assisted medial unicompartmental knee arthroplasty (UKA). Methods. Postoperative radiological outcomes from 86 consecutive robotic-assisted UKAs (RAUKA group) from a single academic centre were retrospectively reviewed and compared to 253 manual UKAs (MUKA group) drawn from a prior study at our institution. Femoral coronal and sagittal angles (FCA, FSA), tibial coronal and sagittal angles (TCA, TSA), and implant overhang were radiologically measured to identify outliers. Results. When assessing the accuracy of RAUKAs, 91.6% of all alignment measurements and 99.2% of all overhang measurements were within the target range. All alignment and overhang targets were simultaneously met in 68.6% of RAUKAs. When comparing radiological outcomes between the RAUKA and MUKA groups, statistically significant differences were identified for combined outliers in FCA (2.3% vs 12.6%; p = 0.006), FSA (17.4% vs 50.2%; p < 0.001), TCA (5.8% vs 41.5%; p < 0.001), and TSA (8.1% vs 18.6%; p = 0.023), as well as anterior (0.0% vs 4.7%; p = 0.042), posterior (1.2% vs 13.4%; p = 0.001), and medial (1.2% vs 14.2%; p < 0.001) overhang outliers. Conclusion. Robotic system navigation decreases alignment and overhang outliers compared to manual UKA. Given the association between component placement errors and revision in UKA, this strong significant improvement in accuracy may improve implant survival. Level of Evidence: III. Cite this article: Bone Jt Open 2021;2-3:191–197

Objectives. Preclinical data showed poly(methyl methacrylate) (PMMA) loaded with microsilver to be effective against a variety of bacteria. The purpose of this study was to assess patient safety of PMMA spacers with microsilver in prosthetic hip infections in a prospective cohort study. Methods. A total of 12 patients with prosthetic hip infections were included for a three-stage revision procedure. All patients received either a gentamicin-PMMA spacer (80 g to 160 g PMMA depending on hip joint dimension) with additional loading of 1% (w/w) of microsilver (0.8 g to 1.6 g per spacer) at surgery 1 followed by a gentamicin-PMMA spacer without microsilver at surgery 2 or vice versa. Implantation of the revision prosthesis was carried out at surgery 3. Results. In total, 11 of the 12 patients completed the study. No argyria or considerable differences in laboratory parameters were detected. Silver blood concentrations were below or around the detection limit of 1 ppb in ten of the 11 patients. A maximum of 5.6 ppb at 48 hours after implantation of the silver spacer, which is below the recommended maximum level of 10 ppb, was found in one patient. No silver was detected in the urine. Drainage fluids showed concentrations between 16.1 ppb and 23.3 ppb at 12 hours after implantation of the silver spacers, and between 16.8 ppb to 25.1 ppb at 48 hours after implantation. Pathohistological assessment of the periprosthetic membrane did not reveal any differences between the two groups. Conclusion. Microsilver-loaded gentamicin-PMMA spacers showed good biocompatibility and the broad antimicrobial activity warrants further clinical research to assess its effectivity in reducing infection rates in prosthetic joint infection. Cite this article: V. Alt, M. Rupp, K. Lemberger, T. Bechert, T. Konradt, P. Steinrücke, R. Schnettler, S. Söder, R. Ascherl. Safety assessment of microsilver-loaded poly(methyl methacrylate) (PMMA) cement spacers in patients with prosthetic hip infections: Results of a prospective cohort study. Bone Joint Res 2019;8:387–396. DOI: 10.1302/2046-3758.88.BJR-2018-0270.R1

Aims. The aim of this study was to evaluate the diagnostic accuracy of the synovial alpha-defensin enzyme-linked immunosorbent assay (ELISA) for the diagnosis of prosthetic joint infection (PJI) in the work-up prior to revision of total hip (THA) and knee arthroplasty (TKA). Patients and Methods. Inclusion criteria for this prospective cohort study were acute or chronic symptoms of the index joint without specific exclusion criteria. Synovial fluid aspirates of 202 patients were analyzed and semiquantitative laboratory alpha-defensin ELISA was performed. Final diagnosis of PJI was established by examination of samples obtained during revision surgery. Results. Sensitivity and specificity of the alpha-defensin ELISA for PJI were 78.2% (95% confidence interval (CI) 66.7 to 88.5) and 96.6% (95% CI 93.0 to 99.3). Positive and negative predictive values were 89.6% (95% CI 80.6 to 97.8) and 92.2% (95% CI 87.5 to 96.1). The test remained false-negative in 22% of septic revisions, most of which were due to coagulase-negative staphylococci all occurring in either late-chronic or early-postoperative PJI. Conclusion. The routine use of synovial fluid alpha-defensin laboratory ELISA in the preoperative evaluation of symptomatic THAs and TKAs is insufficient to accurately diagnose PJI. Particularly in cases involving low-virulence organisms, such as coagulase-negative staphylococci, there remains a need for tests with a higher sensitivity. Cite this article: Bone Joint J 2019;101-B:970–977

Aims

A functional anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL) has been assumed to be required for patients undergoing unicompartmental knee arthroplasty (UKA). However, this assumption has not been thoroughly tested. Therefore, this study aimed to assess the biomechanical effects exerted by cruciate ligament-deficient knees with medial UKAs regarding different posterior tibial slopes.