Blood metal ions have been widely used to investigate metal-on-metal hip replacements, but their ability to discriminate between well-functioning and failed hips is not known. The Medicines and Healthcare products Regulatory Agency (MHRA) has suggested a cut-off level of 7 parts per billion (ppb). We performed a pair-matched, case-control study to investigate the sensitivity and specificity of blood metal ion levels for diagnosing failure in 176 patients with a unilateral metal-on-metal hip replacement. We recruited 88 cases with a pre-revision, unexplained failed hip and an equal number of matching controls with a well-functioning hip. We investigated the 7 ppb cut-off level for the maximum of cobalt or chromium and determined optimal mathematical cut-off levels from receiver-operating characteristic curves. The 7 ppb cut-off level for the maximum of cobalt or chromium had a specificity of 89% and sensitivity 52% for detecting a pre-operative unexplained failed metal on metal hip replacement. The optimal cut-off level for the maximum of cobalt or chromium was 4.97 ppb and had sensitivity 63% and specificity 86%. Blood metal ions had good discriminant ability to separate failed from well-functioning hip replacements. The MHRA cut-off level of 7 ppb provides a specific test but has poor sensitivity.

Aims

This study aimed to describe the use of revision knee arthroplasty in Australia and examine changes in lifetime risk over a decade.

Aims. To investigate whether elective joint arthroplasty performed at the weekend is associated with a different 30-day mortality versus that performed between Monday and Friday. Patients and Methods. We examined the 30-day cumulative mortality rate (Kaplan-Meier) for all elective hip and knee arthroplasties performed in England and Wales between 1st April 2003 and 31st December 2014, comprising 118 096 episodes undertaken at the weekend and 1 233 882 episodes performed on a weekday. We used Cox proportional-hazards regression models to assess for time-dependent variation and adjusted for identified risk factors for mortality. Results. The cumulative 30-day mortality for hip arthroplasty was 0.15% (95% confidence interval (CI) 0.12 to 0.19) for patients operated on at the weekend versus 0.20% (95% CI 0.19 to 0.21) for patients undergoing surgery during the normal working week. For knee arthroplasty, the cumulative 30-day mortality was 0.14% (95% CI 0.11 to 0.17) for weekend-operated patients versus 0.18% (95% CI 0.17 to 0.19) for weekday-operated patients. These differences were independent of any differences in patient age, gender, American Society of Anaesthesiologists grade, surgeon seniority, surgical and anaesthetic practices, and thromboprophylaxis choice in weekend versus weekday-operated patients. Conclusion. The 30-day mortality rate after elective joint arthroplasty is low. Surgery performed at the weekend is associated with lower post-operative mortality versus operations performed on a weekday. Cite this article: Bone Joint J 2017;99-B:1618–28

Aims

The aim of this study was to estimate the clinical and economic burden of dislocation following primary total hip arthroplasty (THA) in England.

Aims. The aim of this study was to assess the effect of multimorbidity on improvements in health-related quality of life (HRQoL) following total hip arthroplasty (THA) and total knee arthroplasty (TKA). Patients and Methods. Using data from a regional joint registry for 14 573 patients, HRQoL was measured prior and one year following surgery using the Oxford Hip Score (OHS) and Oxford Knee Score (OKS), and the 12-Item Short-Form Health Survey Physical and Mental Component Summary scores (PCS and MCS, respectively). Multimorbidity was defined as the concurrence of two or more self-reported chronic conditions. A linear mixed-effects model was used to test the effects of multimorbidity and the number of chronic conditions on improvements in HRQoL. Results. Almost two-thirds of patients had multimorbidity, which adversely effected improvements in HRQoL. For THA, mean improvements in HRQoL scores were reduced by 2.21 points in OHS, 1.62 in PCS, and 4.14 in MCS; for TKA, the mean improvements were reduced by 1.71 points in OKS, 1.92 in PCS, and 3.55 in MCS (all p < 0.0001). An increase in the number of chronic conditions was associated with increasing reductions in HRQoL improvements. Conclusion. Multimorbidity adversely effects improvements in HRQoL following THA and TKA. Our findings are relevant to healthcare providers focused on the management of patients with chronic conditions and for administrators reporting and monitoring the outcomes of THA and TKA. Cite this article: Bone Joint J 2018;100-B:1168–74

We performed a systematic review and meta-analysis to compare the efficacy of intermittent mechanical compression combined with pharmacological thromboprophylaxis, against either mechanical compression or pharmacological prophylaxis in preventing deep-vein thrombosis (DVT) and pulmonary embolism in patients undergoing hip or knee replacement. A total of six randomised controlled trials, evaluating a total of 1399 patients, were identified. In knee arthroplasty, the rate of DVT was reduced from 18.7% with anticoagulation alone to 3.7% with combined modalities (risk ratio (RR) 0.27, p = 0.03; number needed to treat: seven). There was moderate, albeit non-significant, heterogeneity (I. 2. = 42%). In hip replacement, there was a non-significant reduction in DVT from 8.7% with mechanical compression alone to 7.2% with additional pharmacological prophylaxis (RR 0.84) and a significant reduction in DVT from 9.7% with anticoagulation alone to 0.9% with additional mechanical compression (RR 0.17, p < 0.001; number needed to treat: 12), with no heterogeneity (I. 2. = 0%). The included studies had insufficient power to demonstrate an effect on pulmonary embolism. We conclude that the addition of intermittent mechanical leg compression augments the efficacy of anticoagulation in preventing DVT in patients undergoing both knee and hip replacement. Further research on the role of combined modalities in thromboprophylaxis in joint replacement and in other high-risk situations, such as fracture of the hip, is warranted

Aims

Navigation devices are designed to improve a surgeon’s accuracy in positioning the acetabular and femoral components in total hip arthroplasty (THA). The purpose of this study was to both evaluate the accuracy of an optical computer-assisted surgery (CAS) navigation system and determine whether preoperative spinopelvic mobility (categorized as hypermobile, normal, or stiff) increased the risk of acetabular component placement error.

Cartilage defects of the hip cause significant pain and may lead to arthritic changes that necessitate hip replacement. We propose the use of fresh osteochondral allografts as an option for the treatment of such defects in young patients. Here we present the results of fresh osteochondral allografts for cartilage defects in 17 patients in a prospective study. The underlying diagnoses for the cartilage defects were osteochondritis dissecans in eight and avascular necrosis in six. Two had Legg-Calve-Perthes and one a femoral head fracture. Pre-operatively, an MRI was used to determine the size of the cartilage defect and the femoral head diameter. All patients underwent surgical hip dislocation with a trochanteric slide osteotomy for placement of the allograft. The mean age at surgery was 25.9 years (17 to 44) and mean follow-up was 41.6 months (3 to 74). The mean Harris hip score was significantly better after surgery (p < 0.01) and 13 patients had fair to good outcomes. One patient required a repeat allograft, one patient underwent hip replacement and two patients are awaiting hip replacement. Fresh osteochondral allograft is a reasonable treatment option for hip cartilage defects in young patients. Cite this article: Bone Joint J 2014;96-B(11 Supple A):11–16

The purpose of this study was to evaluate whether concerns about the release of metal ions in metal-on-metal total hip replacements (THR) should be extended to patients with metal-bearing total disc replacements (TDR). Cobalt and chromium levels in whole blood and serum were measured in ten patients with a single-level TDR after a mean follow-up of 34.5 months (13 to 61) using inductively-coupled plasma mass spectrometry. These metal ion levels were compared with pre-operative control levels in 81 patients and with metal ion levels 12 months after metal-on-metal THR (n = 21) and resurfacing hip replacement (n = 36). Flexion-extension radiographs were used to verify movement of the TDR. Cobalt levels in whole blood and serum were significantly lower in the TDR group than in either the THR (p = 0.007) or the resurfacing group (p < 0.001). Both chromium levels were also significantly lower after TDR versus hip resurfacing (p < 0.001), whereas compared with THR this difference was only significant for serum levels (p = 0.008). All metal ion levels in the THR and resurfacing groups were significantly higher than in the control group (p < 0.001). In the TDR group only cobalt in whole blood appeared to be significantly higher (p < 0.001). The median range of movement of the TDR was 15.5° (10° to 22°). These results suggest that there is minimal cause for concern about high metal ion concentrations after TDR, as the levels appear to be only moderately elevated. However, spinal surgeons using a metal-on-metal TDR should still be aware of concerns expressed in the hip replacement literature about toxicity from elevated metal ion levels, and inform their patients appropriately

While an increasing amount of arthroplasty articles report comorbidity measures, none have been validated for outcomes. In this study, we compared commonly used International Classification of Diseases-based comorbidity measures with re-operation rates after total hip replacement (THR). Scores used included the Charlson, the Royal College of Surgeons Charlson, and the Elixhauser comorbidity score. We identified a nationwide cohort of 134 423 THRs from the Swedish Hip Arthroplasty Register. Re-operations were registered post-operatively for up to 12 years. The hazard ratio was estimated by Cox’s proportional hazards regression, and we used C-statistics to assess each measure’s ability to predict re-operation. Confounding variables were age, gender, type of implant fixation, hospital category, hospital implant volume and year of surgery. In the first two years only the Elixhauser score showed any significant relationship with increased risk of re-operation, with increased scores for both one to two and three or more comorbidities. However, the predictive C-statistic in this period for the Elixhauser score was poor (0.52). None of the measures proved to be of any value between two and 12 years. They might be of value in large cohort or registry studies, but not for the individual patient. Cite this article: Bone Joint J 2013;95-B:1184–91

Aims. The aim of this study was to evaluate the long-term clinical and radiographic outcomes of the Birmingham Interlocking Pelvic Osteotomy (BIPO). Patients and Methods. In this prospective study, we report the mid- to long-term clinical outcomes of the first 100 consecutive patients (116 hips; 88 in women, 28 in men) undergoing BIPO, reflecting the surgeon’s learning curve. Failure was defined as conversion to hip arthroplasty. The mean age at operation was 31 years (7 to 57). Three patients (three hips) were lost to follow-up. Results. Survivorship was 76% at ten years and 57% at a mean of 17 years. Younger patients (< 20 years) had the best survivorship (20 hips at risk; 90% at 17 years; 95% confidence interval 65 to 97). Post-operative complications occurred after 12 operations (10.4%) over the duration of the study. Increasing patient age and hip arthritis grade were primary determinants of surgical failure. Conclusion. BIPO provides good to excellent survivorship in appropriately selected patients, with a relatively low rate of complications. Our results are comparable with other established methods of periacetabular osteotomy (PAO), such as the Bernese PAO, even during the surgeon’s initial learning curve. Cite this article: Bone Joint J 2017;99-B:724–31

Aims

A recent report from France suggested an association between the use of cobalt-chrome (CoCr) femoral heads in total hip arthroplasties (THAs) and an increased risk of dilated cardiomyopathy and heart failure. CoCr is a commonly used material in orthopaedic implants. If the reported association is causal, the consequences would be significant given the millions of joint arthroplasties and other orthopaedic procedures in which CoCr is used annually. We examined whether CoCr-containing THAs were associated with an increased risk of all-cause mortality, heart outcomes, cancer, and neurodegenerative disorders in a large national database.

Aims

The aim of this study was to determine whether total hip arthroplasty (THA) for chronic hip pain due to unilateral primary osteoarthritis (OA) has a beneficial effect on cognitive performance.

We report an audit of 208 patients with a mean age of 39 years (16 to 65) attending the Orthopaedic Assessment Unit at the Wellington Hospital between January 2006 and December 2007 with an injury of the tendo Achillis requiring immobilisation in a cast. Information on assessment of venous thromboembolism (VTE) risk, prophylactic measures and VTE events for all patients was obtained from the medical records. A VTE risk factor was documented in the records of three (1%) patients. One of the 208 patients received aspirin prophylaxis; none received low molecular weight heparin. In all, 13 patients (6.3%, 95% confidence interval 3.4 to 10.5) developed symptomatic VTE during immobilisation in a cast, including six with a distal deep-vein thrombosis (DVT), four with a proximal DVT, and three with a confirmed pulmonary embolus. This incidence of symptomatic VTE is similar to that reported following elective hip replacement. We propose that consideration is given to VTE prophylaxis during prolonged immobilisation of the lower limbs in a cast, to ensure that the same level of protection is provided as for patients undergoing elective hip replacement

Aims

Perthes’ disease is an uncommon hip disorder with limited data on the long-term outcomes in adulthood. We partnered with community-based foundations and utilized web-based survey methodology to develop the Adult Perthes Survey, which includes demographics, childhood and adult Perthes’ disease history, the University of California Los Angeles (UCLA) Activity Scale item, Short Form-36, the Hip disability and Osteoarthritis Outcome Score, and a body pain diagram. Here we investigate the following questions: 1) what is the feasibility of obtaining > 1,000 survey responses from adults who had Perthes’ disease using a web-based platform?; and 2) what are the baseline characteristics and demographic composition of our sample?