Effects of recurrent intra-articular corticosteroid injections for osteoarthritis at 3 months and beyond: a systematic review and meta-analysis in comparison to other injectables.

OBJECTIVE: Intra-articular corticosteroid injections (IACIs) provide temporary symptom relief in osteoarthritis (OA). This meta-analysis investigated the effects of recurrent IACIs at 3 months and beyond. DESIGN: We searched Medline, Embase and Cochrane from inception to January 2021 for randomised controlled trials (RCTs) of patients with OA who received recurrent IACIs compared with other injectables, placebo or no treatment (primary outcomes: pain, function). Mean differences (MDs) with 95% confidence intervals were reported. RESULTS: Ten RCTs were included (eight knee OA (n = 763), two trapeziometacarpal OA (n = 121)). Patients received between 2 and 8 injections, varying by trial. Trials compared recurrent IACIs with hyaluronic acid (HA), platelet-rich plasma (PRP), saline or orgotein (follow-up 3-24 months). Greater improvements in pain, function and QoL at 3-24 months were noted for the comparators than with IACIs, with comparators demonstrating an equal or superior effect, or the intervention effect attenuated during follow-up. Recurrent IACIs demonstrated no benefits in pain or function over placebo at 12-24 months. No serious adverse events were recorded. No studies reported on time-to-future interventions, risk of future prosthetic joint infection or other adverse events associated with subsequent joint replacement. CONCLUSIONS: Recurrent IACIs often provide inferior (or non-superior) symptom relief compared with other injectables (including placebo) at 3 months and beyond. Other injectables (HA, PRP) often yielded greater improvements in pain and function up to 24 months post-injection. Existing RCTs on recurrent IACIs lack sufficient follow-up data to assess disease progression and time-to-future interventions.

Systematic review of the safety and efficacy of osseointegration prosthesis after limb amputation.

BACKGROUND: Osseointegration, an approach for direct skeletal attachment of a prosthesis to an amputated limb, may address many of the problems associated with socket prostheses. The safety of osseointegration remains uncertain. The aim of this study was to summarize evidence on functional and clinical outcomes, as well as adverse effects of osseointegration for patients with a limb amputation. METHODS: MEDLINE, Embase, Web of Science and the Cochrane Library were searched to April 2018. Eligible studies were observational, case and qualitative studies, and RCTs conducted in patients with a limb amputation, who were managed with osseointegrated prostheses and had follow-up data. RESULTS: Twenty-two eligible articles comprising 13 unique studies were included. No RCT was identified. Apart from three case reports that comprised one to five patients, the sample size of studies ranged from 11 to 100 participants. All relevant studies reported improvement in functional outcomes (walking ability, prosthetic use and mobility), satisfaction and quality of life following osseointegration, compared with their preoperative status or when using a conventional socket prosthesis. Infection rates ranged from 1 (95 per cent c.i. 0 to 5) to 77 (59 to 88) per cent. The majority of infections were described as low-grade soft tissue or superficial infections related to the skin-implant interface, and were treated effectively with antibiotics. None of the studies reported additional amputation or death as a result of osseointegration. CONCLUSION: Osseointegration after limb amputation improves prosthetic use, comfort when sitting, walking ability, mobility, gait and quality of life. However, it is associated with an increased risk of soft tissue infection.

Rates of hip and knee joint replacement amongst different ethnic groups in England: an analysis of National Joint Registry data.

OBJECTIVE: Despite a health care system that is free at the point of delivery, ethnic minorities may not always get care equitable to that of White patients in England. We examined whether ethnic differences exist in joint replacement rates and surgical practice in England. DESIGN: 373,613 hip and 428,936 knee National Joint Registry (NJR) primary replacement patients had coded ethnicity in Hospital Episode Statistics (HES). Age and gender adjusted observed/expected ratios of hip and knee replacements amongst ethnic groups were compared using indirect standardisation. Associations between ethnic group and type of procedure were explored and effects of demographic, clinical and hospital-related factors examined using multivariable logistic regression. RESULTS: Adjusted standardised observed/expected ratios were substantially lower in Blacks and Asians than Whites for hip replacement (Blacks 0.33 [95% CI, 0.31-0.35], Asians 0.20 [CI, 0.19-0.21]) and knee replacement (Blacks 0.64 [CI, 0.61-0.67], Asians 0.86 % [CI, 0.84-0.88]). Blacks were more likely to receive uncemented hip replacements (Blacks 52%, Whites 37%, Asians 44%; P < 0.001). Black men and women aged <70 years were less likely to receive unicondylar or patellofemoral knee replacements than Whites (men 10% vs 15%, P = 0.001; women 6% vs 14%, P < 0.001). After adjustment for demographic, clinical and hospital-related factors, Blacks were more likely to receive uncemented hip replacement (OR 1.43 [CI, 1.11-1.84]). CONCLUSIONS: In England, hip and knee replacement rates and prosthesis type given differ amongst ethnic groups. Whether these reflect differences in clinical need or differential access to treatment requires urgent investigation.

Systematic review of risk prediction scores for surgical site infection or periprosthetic joint infection following joint arthroplasty.

Accurate identification of individuals at high risk of surgical site infections (SSIs) or periprosthetic joint infections (PJIs) influences clinical decisions and development of preventive strategies. We aimed to determine progress in the development and validation of risk prediction models for SSI or PJI using a systematic review. We searched for studies that have developed or validated a risk prediction tool for SSI or PJI following joint replacement in MEDLINE, EMBASE, Web of Science and Cochrane databases; trial registers and reference lists of studies up to September 2016. Nine studies describing 16 risk scores for SSI or PJI were identified. The number of component variables in a risk score ranged from 4 to 45. The C-index ranged from 0·56 to 0·74, with only three risk scores reporting a discriminative ability of >0·70. Five risk scores were validated internally. The National Healthcare Safety Network SSIs risk models for hip and knee arthroplasties (HPRO and KPRO) were the only scores to be externally validated. Except for HPRO which shows some promise for use in a clinical setting (based on predictive performance and external validation), none of the identified risk scores can be considered ready for use. Further research is urgently warranted within the field.

Osteonecrosis with the use of polymethylmethacrylate cement for hip replacement: thermal-induced damage evidenced in vivo by decreased osteocyte viability.

Thermal damage to host bone is a possible source of compromise of fixation in patients undergoing cemented total hip replacement (THR). Data on the subject to date are derived from mathematical modelling powered by animal studies. The aim of this study was to assess the effect of cement thickness on osteocyte viability in a population of patients undergoing cemented THR. An in vivo model was designed and validated by means of a finite element analysis. During standard hip joint replacement in 14 patients, the femoral necks were exposed before final resection to the heat of a curing cement mantle equivalent to 2.5 (Group 1) or 5 mm (Group 2) in vivo in the cemented acetabulum. Matched controls were collected for each patient. Osteocyte counts and viability were assessed by means of haematoxylin and eosin (H&E) stain and lactate dehydrogenase (LDH) assay. Ex vivo experiments were performed to determine the extent of thermal insult. H&E staining proved unreliable for assessing thermal insult in the short term. The LDH assay was reliable and demonstrated a significant reduction in osteocyte viability to a depth of 2.19 mm in group 1 and 9.19 mm in group 2. There was a significant difference between the groups at all depths. The ex vivo experiments revealed thermoclines indicating that host bone in the population undergoing cemented THR is more sensitive to the thermal insult delivered by curing polymethylmethacrylate cement than previously believed. This thermal insult may weaken the fixation between bone and cement and contribute towards aseptic loosening, the commonest cause of failure of THRs.

Wearable sensor-based measures of step-up transfers are supplementary to patient-reported outcome measures following total joint arthroplasty.

PURPOSE: This study investigated the longitudinal assessment of step-up performance in patients undergoing total joint arthroplasty (TJA) and correlation with subjective patient reported outcome measures (PROMs). METHODS: In this sub-analysis of the ADAPT study, PROMs were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Block step-up (BS) transfers were assessed by wearable-derived measures of time. 76 patients undergoing TJA were included. Subgroups were formed isolating the worst performing quartile (low functioning (LF)) from the high functioning (HF), and outcomes were compared. RESULTS: One-year post-surgery, WOMAC function demonstrated strong correlations to WOMAC pain (Pearson's r = 0.67-0.84) and moderate correlations to BS performance (Pearson's r = 0.31-0.54). Both WOMAC and BS significantly improved with a larger effect size for the HF subgroup (0.62 vs. 0.43; p < 0.05). Patients designated to the LF subgroup at 3 months had increased odds of representing the LF subgroup at 12 months (WOMAC = 19; BS = 4). WOMAC defined 18 LF patients at 12 months follow-up. BS performance identified 9 additional LF patients. CONCLUSIONS: WOMAC function scores seem pain dominated. Measures of BS performance allow assessment of otherwise hidden residual functional impairment. Lower functioning 3 months post-surgery is predictive of longer-term impairment.

Severe hip or knee osteoarthritis is a disabling condition which not only impacts patients' mobility but restricts quality of life due to constant pain and consequential lifestyle changes.Total joint arthroplasty (TJA) has developed into a successful intervention for patients with advanced hip or knee osteoarthritis.Some patients are dissatisfied after TJA due to residual functional impairment and the inclusion of performance-based tests in the post-operative evaluation and rehabilitation allows for the assessment of otherwise hidden residual impairment.Early detection of functional impairment using the repeated block step-up (BS) transfers allows to facilitate more targeted rehabilitation for better functional outcomes.

Does the publication of NICE guidelines for venous thromboembolism chemical prophylaxis influence the prescribing patterns of UK hip and knee surgeons?

INTRODUCTION: We assessed the practice of surgeons regarding venous thromboembolism (VTE) chemical prophylaxis for total hip replacement (THR) and total knee replacement (TKR), before and after issuing of updated National Institute for Health and Care Excellence (NICE) guidance in 2018. METHODS: A survey, circulated through the British Hip Society and regional trainee networks/collaboratives, was completed by 306 UK surgeons at 187 units. VTE chemical prophylaxis prescribing patterns for surgeons carrying out primary THR (n=258) and TKR (n=253) in low-risk patients was assessed after publication of 2018 NICE recommendations. Prescribing patterns before and after the NICE publication were subsequently explored. RESULTS: Following the new guidance, 34% (n=87) used low-molecular-weight heparin (LMWH) alone, 33% (n=85) aspirin (commonly preceded by LMWH) and 31% (n=81) direct oral anticoagulants (DOACs: with/without preceding LMWH) for THR. For TKR, 42% (n=105) used aspirin (usually monotherapy), 31% (n=78) LMWH alone and 27% (n=68) DOAC (with/without preceding LMWH). NICE guidance changed the practice of 34% of hip surgeons and 41% of knee surgeons, with significantly increased use of aspirin preceded by LMWH for THR (before=25% vs after=73%; p<0.001), and aspirin for TKR (before=18% vs after=84%; p<0.001). Significantly more regimens were NICE guidance compliant after the 2018 update for THR (before=85.7% vs after=92.6%; p=0.011) and TKR (before=87.0% vs after=98.8%; p<0.001). CONCLUSION: Over one-third of surveyed surgeons changed their VTE chemical prophylaxis in response to 2018 NICE recommendations, with more THR and TKR surgeons now compliant with latest NICE guidance. The major change in practice was an increased use of aspirin for VTE chemical prophylaxis.

Projections for primary hip and knee replacement surgery up to the year 2060: an analysis based on data from The National Joint Registry for England, Wales, Northern Ireland and the Isle of Man.

INTRODUCTION: We estimated the number of primary total hip and knee replacements (THR and TKR) that will need to be performed up to the year 2060. METHODS: We used data from The National Joint Registry for England, Wales, Northern Ireland and the Isle of Man on the volume of primary THRs (n=94,936) and TKRs (n=100,547) performed in 2018. We projected future numbers of THR and TKR using a static estimated rate from 2018 applied to population growth forecast data from the UK Office for National Statistics up to 2060. RESULTS: By 2060, THR and TKR volume would increase from 2018 levels by an estimated 37.7% (n=130,766) and 36.6% (n=137,341), respectively. For both males and females demand for surgery was also higher for patients aged 70 and over, with older patients having the biggest relative increase in volume over time: 70-79 years (44.6% males, 41.2% females); 80-89 years (112.4% males, 85.6% females); 90 years and older (348.0% males, 198.2% females). CONCLUSION: By 2060 demand for hip and knee joint replacement is estimated to increase by almost 40%. Demand will be greatest in older patients (70+ years), which will have significant implications for the health service requiring forward planning given that morbidity and resource use is higher in this population. These issues, coupled with two waves of COVID-19, will impact the ability of health services to deliver timely joint replacement to many patients for a number of years, requiring urgent planning.

Role of early intravenous to oral antibiotic switch therapy in the management of prosthetic hip infection treated with one- or two-stage replacement.

OBJECTIVES: To determine outcomes for an antibiotic regimen using early switch to oral antibiotics for treatment of infected total hip replacement (THR) treated by either a one-stage or two-stage procedure. METHODS: Cases of infected THR were identified from the microbiology records on all orthopaedic infections in a 24 month period. Diagnosis was made by microbiological culture of theatre specimens and findings at the time of surgery. A standard approach of 10-14 days intravenous (iv) antibiotic followed by a switch to oral antibiotics either for 6-8 weeks until second-stage re-implantation or for up to 3 months following a one-stage procedure was used. The exact date of oral switch and antibiotic duration was determined by clinical resolution and C-reactive protein (CRP). Outcome was recorded as no microbiological or clinical evidence of relapse of infection or relapse after completing the antibiotic course. Follow-up duration for all cases at the time of study was 24-36 months after completion of antibiotic treatment. RESULTS: In 24 months, 19 patients underwent two-stage THR for infection, of which 17 were treated with oral antibiotics after a median of 14 days initial iv antibiotics. None relapsed. Four patients underwent one-stage THR and had 12-20 days iv then 6-26 weeks oral antibiotics with no relapse. CONCLUSIONS: Early oral antibiotic switch therapy was effective in patients treated at the Avon Orthopaedic Centre with infected THR and plays an important role in enabling patients to return to independence after revision surgery and avoid complications of prolonged iv access.

Lysophosphatidic acid and calcitriol co-operate to promote human osteoblastogenesis: requirement of albumin-bound LPA.

Lysophosphatidic acid (LPA), a pleiotropic signalling lipid is assuming growing significance in osteoblast biology. Although committed osteoblasts from several mammalian species are receptive to LPA far less is known about the potential for LPA to influence osteoblast formation from their mesenchymal progenitors. An essential factor for both bone development and post-natal bone growth and homeostasis is the active metabolite of vitamin D3, calcitriol (D3). Previously we reported how a combination of LPA and D3 synergistically co-operated to enhance the differentiation of immature human osteoblasts. Herein we provide evidence for the formation of human osteoblasts from multiple, primary human bone marrow derived stromal (stem) cells (hBMSCs). Importantly osteoblast development from hBMSCs only occurred when LPA was administered as a complex with albumin, its natural carrier. Collectively our findings support a co-operative role of LPA and D3 in osteoblastogenesis, findings which may aid the development of novel treatment strategies for bone repair.

Clinical outcomes and fusion success associated with the use of BoneSave in spinal surgery.

BACKGROUND: Achieving spinal fusion is the guiding principle behind surgical treatment for a range of spinal pathologies, often requiring a substantial amount of bone-graft. Iliac crest autograft represents the gold standard although associated morbidities and limited graft material have led to the development of alternatives. BoneSave (Stryker, UK), a porous tricalcium phosphate-hydroxyapatite ceramic, is one such alternative, employed in spinal fusion over the past few years. Very little research exists into the clinical outcomes associated with its use. METHODS: Clinical data was collected retrospectively from the case notes of 45 patients who underwent posterolateral inter-transverse spinal fusion involving the application of BoneSave between June 2003 and January 2005. Latest follow-up information was collected via a postal questionnaire (average follow-up of 46 months). Validated outcome instruments employed included the Short Form 36 and Oswestry Disability Index. In addition visual analogue scales for pain, patient global impression of change, work status, persisting symptoms and patient satisfaction data were collected. Radiological evaluation of fusion was carried out from the most recent spinal radiographs available for each patient. RESULTS: Qualitative post-operative data was available in 96%, with a questionnaire response rate of 68.4%. Radiographical evaluation was possible in 67%. Significant post-operative improvements were seen across all outcome measures in the large majority of cases. Successful fusion was achieved in 56.7% of cases. CONCLUSIONS: The clinical outcomes associated with the use of BoneSave in spinal fusion are comparable to those available in the literature for more conventional techniques. The fusion rate was not significantly lower.

Effects of presurgical interventions on chronic pain after total knee replacement: a systematic review and meta-analysis of randomised controlled trials.

OBJECTIVE: Nearly 100 000 primary total knee replacements (TKR) are performed in the UK annually. The primary aim of TKR is pain relief, but 10%-34% of patients report chronic pain. The aim of this systematic review was to evaluate the effectiveness of presurgical interventions in preventing chronic pain after TKR. DESIGN: MEDLINE, Embase, CINAHL, The Cochrane Library and PsycINFO were searched from inception to December 2018. Screening and data extraction were performed by two authors. Meta-analysis was conducted using a random effects model. Risk of bias was assessed using the Cochrane tool and quality of evidence was assessed by Grading of Recommendations Assessment, Development and Evaluation. PRIMARY AND SECONDARY OUTCOMES: Pain at 6 months or longer; adverse events. INTERVENTIONS: Presurgical interventions aimed at improving TKR outcomes. RESULTS: Eight randomised controlled trials (RCTs) with data from 960 participants were included. The studies involved nine eligible comparisons. We found moderate-quality evidence of no effect of exercise programmes on chronic pain after TKR, based on a meta-analysis of 6 interventions with 229 participants (standardised mean difference 0.20, 95% CI -0.06 to 0.47, I2=0%). Sensitivity analysis restricted to studies at overall low risk of bias confirmed findings. Another RCT of exercise with no data available for meta-analysis showed no benefit. Studies evaluating combined exercise and education intervention (n=1) and education alone (n=1) suggested similar findings. Adverse event data were reported by most studies, but events were too few to draw conclusions. CONCLUSIONS: We found low to moderate-quality evidence to suggest that neither preoperative exercise, education nor a combination of both is effective in preventing chronic pain after TKR. This review also identified a lack of evaluations of other preoperative interventions, such as multimodal pain management, which may improve long-term pain outcomes after TKR. PROSPERO REGISTRATION NUMBER: CRD42017041382.

Prevalence and functional impact of patient-perceived leg length discrepancy after hip replacement.

The aim of this postal survey was to determine the prevalence and impact of patient-perceived leg length discrepancy (LLD) at 5-8 years after primary total hip replacement (THR). A postal audit survey was undertaken of all consecutive patients who had a primary unilateral THR at one elective orthopaedic centre between April 1993 and April 1996. The questionnaire included the Oxford hip score (OHS) and questions about LLD. Questionnaires were received from 1,114 patients. In total, 329 THR patients (30%) reported an LLD, although radiographic analysis revealed that only 36% of these patients had anatomical LLD. Patients with a perceived LLD had a significantly poorer OHS (p < 0.001) and reported more limping than those patients without a perceived LLD. This study found that a third of patients perceived an LLD after THR and that perceived LLD was associated with a significantly poorer midterm functional outcome.

Is social support associated with patient-reported outcomes after joint replacement? A systematic review and meta-analysis.

BACKGROUND: Identifying prognostic factors for outcomes after joint replacement could improve the provision of stratified care. This systematic review evaluated whether social support is a prognostic factor for better patient-reported outcomes after total hip replacement (THR) and total knee replacement (TKR). METHODS: MEDLINE, Embase and PsycINFO were searched from inception to April 2019. Cohort studies evaluating the association between social support and patient-reported outcomes at three months or longer after THR or TKR were included. Data were extracted from study reports. Study quality was assessed using the QUIPS tool. Data were synthesized using meta-analysis and narrative synthesis. The review was registered on PROSPERO (CRD42016041485). FINDINGS: Searches identified 5,810 articles and 56 studies with data from 119,165 patients were included. In meta-analysis, the presence of social support had a beneficial effect on long-term post-operative WOMAC (mean difference 2.88; 95% CIs 1.30; 4.46) and Oxford Knee Score (0.29; 0.12, 0.45). Social support measured using a validated questionnaire was found to be associated with WOMAC pain (0.04; 0.00, 0.08) but not WOMAC function (-0.01; -0.12, 0.11). The presence of social support had a positive association with some SF-36 subscales but not others. For all outcomes, results of narrative synthesis were inconsistent. INTERPRETATION: There is evidence that social support is a prognostic factor for some outcomes after joint replacement. Development and evaluation of complex interventions to improve social support and social integration is warranted. FUNDING: This study was supported by the NIHR Biomedical Research Centre at University Hospitals Bristol NHS Foundation Trust and the University of Bristol.

Ninety-day mortality after elective total hip replacement: 1549 patients using aspirin as a thromboprophylactic agent.

Thromboprophylaxis after elective orthopaedic surgery remains controversial. Recent guidelines from the National Institute for Clinical Excellence (NICE) have suggested that low molecular weight heparin should be given to all patients undergoing total hip replacement. The British Orthopaedic Association is currently debating this guideline with NICE, as it is not clear whether published evidence supports this view. We present the early mortality in our unit after total hip replacement using aspirin as chemical thromboprophylaxis. The 30-day and 90-day mortality after primary total hip arthroplasty was zero. We compare this with that reported previously from our unit without using chemical thromboprophylaxis. With the introduction of routine aspirin thromboprophylaxis, deaths from cardiovascular causes have dropped from 0.75% to zero. These results demonstrate that there is a strong argument for the routine administration of aspirin after elective total hip replacement.

Using home sensing technology to assess outcome and recovery after hip and knee replacement in the UK: the HEmiSPHERE study protocol.

INTRODUCTION: Over 160 000 people with severe hip or knee pain caused by osteoarthritis undergo total hip (THR) or knee replacement (TKR) surgery each year in the UK within the National Health Service (NHS), and this number is expected to increase. Innovative approaches to evaluating surgical outcomes will be needed to respond to the increasing burden of joint replacement surgery. The Sensor Platform for Healthcare in a Residential Environment, Interdisciplinary Research Collaboration (SPHERE-IRC) have developed a system of sensors that can monitor the health-related behaviours of people living at home. The system includes sensors for the home environment (measuring temperature, humidity, room occupancy, water and electricity usage), a wristband body-worn activity monitor and silhouette (body outline) sensors. The aim of HEmiSPHERE (Hip and knEe study of a Sensor Platform of HEalthcare in a Residential Environment) is to (1) determine the accuracy and feasibility of the sensory data as it compares with conventional assessment of health outcomes after surgery using patient self-reported questionnaires, and (2) to explore how the SPHERE system is useful for everyday clinical decision-making. METHODS AND ANALYSIS: A feasibility study recruiting and installing the SPHERE system in the homes of up to 30 NHS adult patients as they undergo a THR or TKR. Through a mixed-methods design, the SPHERE system will monitor and record continuous measurements of daily behaviour. Main outcomes will assess the relationships between environmental, behavioural and movement data and the parameters of interest from the standard clinical assessments measuring patient outcomes over time. Patient interviews and focus groups with consultant orthopaedic surgeons will provide in-depth understanding of the acceptability, feasibility and accuracy of the data. ETHICS AND DISSEMINATION: We aim to disseminate the findings through regional talks and seminars, international conferences and peer-reviewed journals and social media.

Is the rate of revision of 36 mm metal-on-metal total hip arthroplasties with Pinnacle acetabular components related to the year of the initial operation? an interrupted time-series analysis using data from the National Joint Registry for England and Wales.

AIMS: The aim of this study was to determine whether the rates of revision for metal-on-metal (MoM) total hip arthroplasties (THAs) with Pinnacle components varied according to the year of the initial operation, and compare these with the rates of revision for other designs of MoM THA. PATIENTS AND METHODS: Data from the National Joint Registry for England and Wales included 36 mm MoM THAs with Pinnacle acetabular components which were undertaken between 2003 and 2012 with follow-up for at least five years (n = 10 776) and a control group of other MoM THAs (n = 13 817). The effect of the year of the primary operation on all-cause rates of revision was assessed using Cox regression and interrupted time-series analysis. RESULTS: For MoM THAs involving Pinnacle components, those undertaken between 2007 and 2012 had higher rates of revision compared with those undertaken between 2004 and 2006 (hazard ratio (HR) 2.01; 95% confidence interval (CI) 1.57 to 2.57; p < 0.001). For THAs undertaken during and after 2007, the number of revisions per 1000 implant-years at risk significantly increased by 5.20 (95% CI 0.52 to 9.89; p = 0.033) compared with those undertaken before this time. In the control group, THAs undertaken between 2007 and 2012 also had higher rates of revision (HR 1.77; 95% CI 1.49 to 2.10; p < 0.001), with revisions per 1000 implant-years for those undertaken during and after 2007 significantly increasing by 6.13 (95% CI 1.42 to 10.83; p = 0.016). CONCLUSION: The five-year revision rates were significantly increased for all primary MoM THAs undertaken from 2007 onwards. Contrary to recent reports, this finding was not specific to those involving Pinnacle acetabular components and may be explained by increased surveillance and recent lowering of the threshold for revision. Cite this article: Bone Joint J 2018;100-B:33-41.

Resistance of disposable drapes to bacterial penetration.

PURPOSE: To test the bacterial penetrability of disposable non-woven drapes used specifically for total hip arthroplasty. METHODS: 12 round agar plates were inoculated with 107 colony-forming units/ml of coagulase-negative staphylococci (CNS) and incubated in air at 37 degrees Celsius for 18 hours to obtain a semi-confluent growth of organisms. Six brands of disposable drapes were tested; each was assigned to 2 plates. Each disposable drape was placed between a round agar plate and an inverted square agar plate filled with blood agar. After 30 and 90 minutes, the square agar plates were removed and incubated for 48 hours and inspected for growth of CNS. RESULTS: Bacterial penetration was time dependant. Certain brands of drapes were more impenetrable than others; none was impenetrable at all time points, but most remained so or allowed passage of fewer than 100 colony-forming units at 90 minutes. CONCLUSION: It is recommended that drapes be rigorously tested with regard to their resistance to bacterial penetration.

Reproducibility of the Gartland classification for supracondylar humeral fractures in children.

PURPOSE: To evaluate the intra- and inter-observer reproducibility of the Gartland radiographic classification for supracondylar humeral fractures in children. METHODS: Anteroposterior and lateral radiographs of 50 supracondylar humeral fractures in children were graded on 2 separate occasions by 4 orthopaedic surgeons according to the Wilkins modification of the Gartland classification. Data were analysed by calculating the Kappa values for intra- and inter-observer agreement to indicate the reproducibility of the classification. RESULTS: There was moderate inter-observer agreement, except for poor agreement over type I fractures. Type II fractures only showed fair to moderate agreement. Type III fractures and the flexion group showed good to very good agreement. Intra-observer agreement was good to very good. CONCLUSION: Surgeons should treat paediatric supracondylar humeral fractures based on an assessment of the degree of displacement rather than by employing the Gartland classification.

Omnifit acetabular component: a solution to preventing and treating dislocation.

PURPOSE: To assess short- to medium-term outcome of the Omnifit constrained acetabular component in preventing dislocation in at-risk patients after total hip arthroplasty (THA). METHODS: 81 patients (mean age, 77 years) underwent either primary or revision THA with an Omnifit constrained acetabular component and were followed up clinically and radiologically for a mean period of 24 months. RESULTS: There was one dislocation and one revision for avulsion of the acetabulum. The remaining prostheses remained well fixed. CONCLUSIONS: In the short- to medium-term, the Omnifit constrained acetabular component is effective in preventing primary and recurrent dislocation in at-risk patients. Long-term follow-up is needed to assess whether good fixation is maintained. The Omnifit acetabular cup is recommended for elderly patients with limited life expectancy and functional demands.