The articular surface replacement implant recall: a United Kingdom district hospital experience

We present our experience of the articular surface replacement (ASR) hip and the implant recall process. One hundred and twenty-one ASR components were implanted (21 resurfacing hip arthroplasty (RHA) and 100 ASR/XL modular total hip replacements). At the time of the implant recall in August 2010 there were 111 surviving hips (92%) with a mean follow-up of 44 months. Nine hips had been revised and one had been listed for revision surgery. Ninety-two percent of surviving implants were reviewed in the recall clinics, and blood metal ion levels or ultrasound scans were indicated in 38 hips (34%). Immediately after the recall process seven hips (6 ASR/XL and 1 RHA) were listed for revision and a further 9 were kept under close surveillance. One year after completion of the recall process 23 hips (19 ASR/XL and 4 RHA's) had been revised. A diagnosis of adverse reaction to metal debris (ARMD) was made at surgery in all but two hips. Our current revision rate for ASR RHA is 19% (mean follow-up 62 months, range 29-80) and for the ASR/XL is 19% (mean follow-up 53 months, range 10-80). The 5-year cumulative survival rates with revision for any reason for the ASR/XL, was 80.8% (95% confidence interval 72.0 - 89.5). Given experience elsewhere we expect this rate may increase significantly with time.