Purpose

Despite the increasing interest and subsequent published literature on hip resurfacing arthroplasty, little is known about the prevalence of its complications and in particular the less common modes of failure. The aim of this study was to identify the prevalence of failure of hip resurfacing arthroplasty and to analyse the reasons for it.

Despite the increasing interest and subsequent published literature on hip resurfacing arthroplasty, little is known about the prevalence of its complications and in particular the less common modes of failure. The aim of this study was to identify the prevalence of failure of hip resurfacing arthroplasty and to analyse the reasons for it.

From a multi-surgeon series (141 surgeons) of 5000 Birmingham hip resurfacings we have analysed the modes, prevalence, gender differences and times to failure of any hip requiring revision. To date 182 hips have been revised (3.6%). The most common cause for revision was a fracture of the neck of the femur (54 hips, prevalence 1.1%), followed by loosening of the acetabular component (32 hips, 0.6%), collapse of the femoral head/avascular necrosis (30 hips, 0.6%), loosening of the femoral component (19 hips, 0.4%), infection (17 hips, 0.3%), pain with aseptic lymphocytic vascular and associated lesions (ALVAL)/metallosis (15 hips, 0.3%), loosening of both components (five hips, 0.1%), dislocation (five hips, 0.1%) and malposition of the acetabular component (three hips, 0.1%). In two cases the cause of failure was unknown.

Comparing men with women, we found the prevalence of revision to be significantly higher in women (women = 5.7%; men = 2.6%, p < 0.001). When analysing the individual modes of failure women had significantly more revisions for loosening of the acetabular component, dislocation, infection and pain/ALVAL/metallosis (p < 0.001, p = 0.004, p = 0.008, p = 0.01 respectively).

The mean time to failure was 2.9 years (0.003 to 11.0) for all causes, with revision for fracture of the neck of the femur occurring earlier than other causes (mean 1.5 years, 0.02 to 11.0). There was a significantly shorter time to failure in men (mean 2.1 years, 0.4 to 8.7) compared with women (mean 3.6 years, 0.003 to 11.0) (p < 0.001).

The St Leger total knee replacement is a bicondylar prosthesis developed as an cheaper alternative to other similar implants of its time. Between October 1993 and June 1999, 144 St Leger total knee replacements were implanted in 114 patients.

The aim of this study was to clinically and radiologically assess these patients after a mean follow up of 10.22 years.

Between February and July 2007 ninety-one patients recalled for clinical evaluation (using functional and objective American Knee Society Scores) and radiological assessment (using the American Knee Society Scoring System). 11 patients had died and 12 were lost to follow up or were medically unfit to attend evaluation. Of the ninety-one patients recalled, 18 had had their prostheses revised (19 knees). 63% of prostheses had survived 10 years or more.

Of the patients with St Leger knees in situ (99 knees) the American Knee Scores showed 78% poor, 10% fair, 6% good and 6% excellent results. Radiological assessment identified 12 arthroplasties that had failed (5 femoral components, 5 tibial components and 4 patellae,) 58 that needed close follow up (18 femoral components, 31 tibial components and 38 patellae) and 29 that were well fixed. A best-case Kaplan-Meier cumulative survivorship was 87% at 10 years. (Worst-case was 71% at 10 years)

These 10 year results showed that the St Leger total knee prosthesis did not perform as well as other bicondylar prostheses of the same generation and had a higher revision rate. Despite favourable published mid-term results, the long-term results for the St Leger total knee replacement have shown it to be unreliable and not worth the initial financial saving.