Ceramic-on-metal (CoM) is a relatively new bearing combination for total hip arthroplasty (THA) with few reported outcomes. A total of 287 CoM THAs were carried out in 271 patients (mean age 55.6 years (20 to 77), 150 THAs in female patients, 137 in male) under the care of a single surgeon between October 2007 and October 2009. With the issues surrounding metal-on-metal bearings the decision was taken to review these patients between March and November 2011, at a mean follow-up of 34 months (23 to 45) and to record pain, outcome scores, radiological analysis and blood ion levels. The mean Oxford Hip Score was 19.2 (12 to 53), 254 patients with 268 hips (95%) had mild/very mild/no pain, the mean angle of inclination of the acetabular component was 44.8^o (28^o to 63^o), 82 stems (29%) had evidence of radiolucent lines of > 1 mm in at least one Gruen zone and the median levels of cobalt and chromium ions in the blood were 0.83 μg/L (0.24 μg/L to 27.56 μg/L) and 0.78 μg/L (0.21 μg/L to 8.84 μg/L), respectively. The five-year survival rate is 96.9% (95% confidence interval 94.7% to 99%).

Due to the presence of radiolucent lines and the higher than expected levels of metal ions in the blood, we would not recommend the use of CoM THA without further long-term follow-up. We plan to monitor all these patients regularly.

Cite this article: Bone Joint J 2015;97-B:300–5.

Many different designs of total hip arthroplasty (THA) with varying performance and cost are available. The identification of those which are the most cost-effective could allow significant cost-savings. We used an established Markov model to examine the cost effectiveness of five frequently used categories of THA which differed according to bearing surface and mode of fixation, using data from the National Joint Registry for England and Wales. Kaplan–Meier analyses of rates of revision for men and women were modelled with parametric distributions. Costs of devices were provided by the NHS Supply Chain and associated costs were taken from existing studies. Lifetime costs, lifetime quality-adjusted-life-years (QALYs) and the probability of a device being cost effective at a willingness to pay £20 000/QALY were included in the models.

The differences in QALYs between different categories of implant were extremely small (<  0.0039 QALYs for men or women over the patient’s lifetime) and differences in cost were also marginal (£2500 to £3000 in the same time period). As a result, the probability of any particular device being the most cost effective was very sensitive to small, plausible changes in quality of life estimates and cost.

Our results suggest that available evidence does not support recommending a particular device on cost effectiveness grounds alone. We would recommend that the choice of prosthesis should be determined by the rate of revision, local costs and the preferences of the surgeon and patient.

Cite this article: Bone Joint J 2015;97-B:449–57.

This is the second of a series of reviews of registries. This review looks specifically at worldwide registry data that have been collected on knee arthroplasty, what we have learned from their reports, and what the limitations are as to what we currently know.

This editorial considers the shortcomings of assessing outcome after joint replacement only by the survival of the implant.

The Oxford knee score (OKS) is a validated and widely accepted disease-specific patient-reported outcome measure, but there is limited evidence regarding any long-term trends in the score. We reviewed 5600 individual OKS questionnaires (1547 patients) from a prospectively-collected knee replacement database, to determine the trends in OKS over a ten-year period following total knee replacement. The mean OKS pre-operatively was 19.5 (95% confidence interval (CI) 18.8 to 20.2). The maximum post-operative OKS was observed at two years (mean score 34.4 (95% CI 33.7 to 35.2)), following which a gradual but significant decline was observed through to the ten-year assessment (mean score 30.1 (95% CI 29.1 to 31.1)) (p < 0.001). A similar trend was observed for most of the individual OKS components (p < 0.001). Kneeling ability initially improved in the first year but was then followed by rapid deterioration (p < 0.001). Pain severity exhibited the greatest improvement, although residual pain was reported in over two-thirds of patients post-operatively, and peak improvement in the night pain component did not occur until year four. Post-operative OKS was lower for women (p < 0.001), those aged < 60 years (p < 0.003) and those with a body mass index > 35 kg/m² (p < 0.014), although similar changes in scores were observed. This information may assist surgeons in advising patients of their expected outcomes, as well as providing a comparative benchmark for evaluating longer-term outcomes following knee replacement.

Cite this article: Bone Joint J 2013;95-B:45–51.

We assessed the effect of social deprivation upon the Oxford knee score (OKS), the Short-Form 12 (SF-12) and patient satisfaction after total knee replacement (TKR). An analysis of 966 patients undergoing primary TKR for symptomatic osteoarthritis (OA) was performed. Social deprivation was assessed using the Scottish Index of Multiple Deprivation. Those patients that were most deprived underwent surgery at an earlier age (p = 0.018), were more likely to be female (p = 0.046), to endure more comorbidities (p = 0.04) and to suffer worse pain and function according to the OKS (p < 0.001). In addition, deprivation was also associated with poor mental health (p = 0.002), which was assessed using the mental component (MCS) of the SF-12 score. Multivariable analysis was used to identify independent predictors of outcome at one year. Pre-operative OKS, SF-12 MCS, back pain, and four or more comorbidities were independent predictors of improvement in the OKS (all p < 0.001). Pre-operative OKS and improvement in the OKS were independent predictors of dissatisfaction (p = 0.003 and p < 0.001, respectively). Although improvement in the OKS and dissatisfaction after TKR were not significantly associated with social deprivation per se, factors more prevalent within the most deprived groups significantly diminished their improvement in OKS and increased their rate of dissatisfaction following TKR.

Cite this article: Bone Joint J 2013;95-B:52–8.

As part of the national initiative to reduce waiting times for joint replacement surgery in Wales, the Cardiff and Vale NHS Trust referred 224 patients to the NHS Treatment Centre in Weston-Super-Mare for total knee replacement (TKR). A total of 258 Kinemax TKRs were performed between November 2004 and August 2006. Of these, a total of 199 patients (232 TKRs, 90%) have been followed up for five years. This cohort was compared with 258 consecutive TKRs in 250 patients, performed at Cardiff and Vale Orthopaedic Centre (CAVOC) over a similar time period. The five year cumulative survival rate was 80.6% (95% confidence interval (CI) 74.0 to 86.0) in the Weston-Super-Mare cohort and 95.0% (95% CI 90.2 to 98.2) in the CAVOC cohort with revision for any reason as the endpoint. The relative risk for revision at Weston-Super-Mare compared with CAVOC was 3.88 (p < 0.001). For implants surviving five years, the mean Oxford knee scores (OKS) and mean EuroQol (EQ-5D) scores were similar (OKS: Weston-Super-Mare 29 (2 to 47) vs CAVOC 29.8 (3 to 48), p = 0.61; EQ-5D: Weston-Super-Mare 0.53 (-0.38 to 1.00) vs CAVOC 0.55 (-0.32 to 1.00), p = 0.79). Patients with revised TKRs had significantly lower Oxford knee and EQ-5D scores (p < 0.001).

The results show a higher revision rate for patients operated at Weston-Super-Mare Treatment Centre, with a reduction in functional outcome and quality of life after revision. This further confirms that patients moved from one area to another for joint replacement surgery fare poorly.

We obtained information from the Elective Orthopaedic Centre on 1523 patients with baseline and six-month Oxford hip scores (OHS) after undergoing primary hip replacement (THR) and 1784 patients with Oxford knee scores (OKS) for primary knee replacement (TKR) who completed a six-month satisfaction questionnaire.

Receiver operating characteristic curves identified an absolute change in OHS of 14 points or more as the point that discriminates best between patients’ satisfaction levels and an 11-point change for the OKS. Satisfaction is highest (97.6%) in patients with an absolute change in OHS of 14 points or more, compared with lower levels of satisfaction (81.8%) below this threshold. Similarly, an 11-point absolute change in OKS was associated with 95.4% satisfaction compared with 76.5% below this threshold. For the six-month OHS a score of 35 points or more distinguished patients with the highest satisfaction level, and for the six-month OKS 30 points or more identified the highest level of satisfaction. The thresholds varied according to patients’ pre-operative score, where those with severe pre-operative pain/function required a lower six-month score to achieve the highest levels of satisfaction.

Our data suggest that the choice of a six-month follow-up to assess patient-reported outcomes of THR/TKR is acceptable. The thresholds help to differentiate between patients with different levels of satisfaction, but external validation will be required prior to general implementation in clinical practice.

The responsiveness of the Manchester–Oxford Foot Questionnaire (MOXFQ) was compared with foot/ankle-specific and generic outcome measures used to assess all surgery of the foot and ankle. We recruited 671 consecutive adult patients awaiting foot or ankle surgery, of whom 427 (63.6%) were female, with a mean age of 52.8 years (18 to 89). They independently completed the MOXFQ, Short-Form 36 (SF-36) and EuroQol (EQ-5D) questionnaires pre-operatively and at a mean of nine months (3.8 to 14.4) post-operatively. Foot/ankle surgeons assessed American Orthopaedic Foot and Ankle Society (AOFAS) scores corresponding to four foot/ankle regions. A transition item measured perceived changes in foot/ankle problems post-surgery. Of 628 eligible patients proceeding to surgery, 491 (78%) completed questionnaires and 262 (42%) received clinical assessments both pre- and post-operatively. The regions receiving surgery were: multiple/whole foot in eight (1.3%), ankle/hindfoot in 292 (46.5%), mid-foot in 21 (3.3%), hallux in 196 (31.2%), and lesser toes in 111 (17.7%). Foot/ankle-specific MOXFQ, AOFAS and EQ-5D domains produced larger effect sizes (> 0.8) than any SF-36 domains, suggesting superior responsiveness. In analyses that anchored change in scores and effect sizes to patients’ responses to a transition item about their foot/ankle problems, the MOXFQ performed well. The SF-36 and EQ-5D performed poorly. Similar analyses, conducted within foot-region based sub-groups of patients, found that the responsiveness of the MOXFQ was good compared with the AOFAS.

This evidence supports the MOXFQ’s suitability for assessing all foot and ankle surgery.

This prospective study assessed the effect of social deprivation on the Oxford hip score at one year after total hip replacement. An analysis of 1312 patients undergoing 1359 primary total hip replacements for symptomatic osteoarthritis was performed over a 35-month period. Social deprivation was assessed using the Carstairs index. Those patients who were most deprived underwent surgery at an earlier age (p = 0.04), had more comorbidities (p = 0.02), increased severity of symptoms at presentation (p = 0.001), and were not as satisfied with their outcome (p = 0.03) compared with more affluent patients. There was a significant improvement in Oxford scores at 12 months relative to pre-operative scores for all socioeconomic categories (p < 0.001). Social deprivation was a significant independent predictor of mean improvement in Oxford scores at 12 months, after adjusting for confounding variables (p = 0.001). Deprivation was also associated with an increased risk of dislocation (odds ratio 5.3, p < 0.001) and mortality at 90 days (odds ratio 3.2, p = 0.02).

Outcome, risk of dislocation and early mortality after a total hip replacement are affected by the socioeconomic status of the patient