No abstract

Oxidised zirconium (OxZi) has been developed as an alternative bearing surface for femoral heads in total hip arthroplasty (THA). This study has investigated polyethylene wear, functional outcomes and complications, comparing OxZi and cobalt-chrome (CoCr) as part of a three-arm, multicentre randomised controlled trial. Patients undergoing THA from four institutions were prospectively randomised into three groups. Group A received a CoCr femoral head and highly cross-linked polyethylene (XLPE) liner; Group B received an OxZi femoral head and XLPE liner; Group C received an OxZi femoral head and ultra-high molecular weight polyethylene (UHMWPE) liner. At five years, 368 patients had no statistically significant differences in short-form-36 (p = 0.176 mental, p = 0.756 physical), Western Ontario and McMaster Universities Osteoarthritis Index (p = 0.847), pain scores (p = 0.458) or complications. The mean rate of linear wear was 0.028 mm/year (standard deviation (SD) 0.010) for Group A, 0.023 mm/year (SD 0.010) for Group B, and 0.09 mm/year (SD 0.045) for Group C. Penetration was significantly higher in the UHMWPE liner group compared with both XLPE liner groups (p < 0.001) but no significant difference was noted between CoCr and OxZi when articulating with XLPE (p = 0.153). In this, the largest randomised study of this bearing surface, it appears that using a XLPE acetabular liner is more important in reducing THA component wear than the choice of femoral head bearing, at mid-term follow-up. There is a non-significant trend towards lower wear, coupling OxZi rather than CoCr with XLPE but long-term analysis is required to see if this observation changes with time and becomes significant.

BackgroundTechnology in orthopaedic surgery has become more widespread in the past 20 years, with emerging evidence of its benefits in arthroplasty. Although patients are aware of benefits of conventional joint replacement, little is known on patients' knowledge of the prevalence, benefits or drawbacks of surgery involving navigation or robotic systems.MethodsIn an outpatient arthroplasty clinic, 100 consecutive patients were approached and given questionnaires to assess their knowledge of navigation and robotics in orthopaedic surgery. Participation in the survey was voluntary.ResultsNinety-eight patients volunteered to participate in the survey, mean age 56.2 years (range, 19 to 88 years; 52 female, 46 male). Forty percent of patients thought more than 30% of National Health Service (NHS) orthopaedic operations involved navigation or robotics; 80% believed this was the same level or less than the private sector. One-third believed most of an operation could be performed independently by a robotic/navigation system. Amongst perceived benefits of navigation/robotic surgery was more accurate surgery (47%), quicker surgery (50%), and making the surgeon's job easier (52%). Sixty-nine percent believed navigation/robotics was more expensive and 20% believed it held no benefit against conventional surgery, with only 9% believing it led to longer surgery. Almost 50% would not mind at least some of their operation being performed with use of robotics/navigation.ConclusionsAlthough few patients were familiar with this new technology, there appeared to be a strong consensus it was quicker and more accurate than conventional surgery. Many patients appear to believe navigation and robotics in orthopaedic surgery is largely the preserve of the private sector. This study demonstrates public knowledge of such new technologies is limited and a need to inform patients of the relative merits and drawbacks of such surgery prior to their more widespread implementation.

In this systematic review, our aim was to explore whether or not patients are able to return to athletic activity following lower limb joint replacement. We also investigated any evidence as to whether participation in athletic activity post-joint replacement increases complications and reduces implant survival. A PubMed, Embase and Sports Discus search was performed using the MeSH terms 'Sport', 'Athletic', 'Athlete', 'Physical', 'Activity', 'Arthroplasty', 'Total Hip Replacement', 'Hip Resurfacing', 'Total Knee Replacement', 'Unicompartmental Knee Replacement' and 'Unicondylar Knee Replacement'. From this search, duplications were excluded, the remaining abstracts were reviewed and any unrelated to the search terms were excluded. The remaining abstracts had their full papers reviewed. Following joint replacement, participation in sporting activity is common principally determined by pre-operative patient activity levels, BMI and patient age. The type of joint replaced is of less significance. Total time spent performing activity does not change but tends to be at a lower intensity. There is little evidence in the literature of an association between high activity levels and early implant failure.