Within an ageing population, the morbidity and mortality burden of neck of femur fractures will only worsen. Financially incentivising acute Trusts via the Best Practice Tariff for inpatient care has yielded good results(1,2,3,4) but post-discharge care is still variable. Most importantly, restoring patients to their pre-fracture mobility is key to their quality of life(5,6) and reducing both readmissions to hospital(7,8) and expensive local authority residential care. Unfortunately, physiotherapist vacancies are in their thousands(9,10) leading to waiting times of around three months once discharged(11).

In 2019, the Royal Derby Hospital created a novel Hip Fracture Patient Advocate (HFPA) to observe those who have fallen through gaps in community services. It involves monitoring patients’ progression, signposting to appropriate services, flagging issues to the responsible consultant and assisting in physical mobilisation.

A retrospective review examined data from patients discharged to their own homes. This included demographics, residential status and mobility, both pre-fracture and at 120 days post-fracture. Mobility was classified into five categories, in line with the national hip fracture database.

In 2018, of 238 patients, 41.2% returned to their baseline or increased mobility, and, after the introduction of the HFPA in 2019, this figure increased to 48.2%.

In one year, there was a 7% increase in patients recovering their baseline mobility. This is a cost-effective intervention that can successfully improve mobility, leading to improved long-term outcomes. This includes the potential to reduce acute readmissions and the need for residential care, appealing to Integrated Care Boards. It also bridges the gap to primary care to optimise medical management and after further development, could be financially-incentivised via the Best Practice Tariff. Rather than thinking more expensive clinicians are required, this study proposes that a HFPA can garner better outcomes for both the patient and the wider system.

Aims

This study reports the ten-year wear rates, incidence of osteolysis, clinical outcomes, and complications of a multicentre randomized controlled trial comparing oxidized zirconium (OxZr) versus cobalt-chrome (CoCr) femoral heads with ultra-high molecular weight polyethylene (UHMWPE) and highly cross-linked polyethylene (XLPE) liners in total hip arthroplasty (THA).

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.

Cite this article: Bone Joint J 2015;97-B:883–9.

Introduction

In Total Hip Arthroplasty (THA), polyethylene wear reduction is key to implant longevity. Oxidized Zirconium (OxZi) unites properties of a ceramic bearing surface and metal head, producing less wear in comparison to standard Cobalt-Chromium (CoCr) when articulating with Cross-linked polyethylene (XLPE) in vitro. This study investigates in vivo polyethylene (PE) wear, outcomes and complications for these two bearing couples in patients at 5 year follow-up