Hip Arthroplasty: Back to the Future?

Introduction

Having been named the “operation of the century” by the Lancet,¹ then commemorated with a stamp by the Royal Mail and acknowledged as one of the most cost-effective surgical procedures in terms of improvement in quality of life,² total hip arthroplasty (THA) is universally regarded as a surgical success story. Last year over 76,000 primary THAs were performed in England & Wales.³

Against that positive background however, there have been dark days. In the 1990s, the Capital Hip (3M, Loughborough, UK) was widely implanted partly on the back of its similarity to an established device, but also perhaps because it was cheaper. There was a national scandal when it was subsequently found to have a high failure rate.^4,5 The National Joint Registry in England & Wales (NJR) was founded, in part, as a response to concerns raised by this issue. More recently, the search for a more durable bearing surface and a reduced rate of dislocation led to the widespread increased use of large head metal-on-metal articulations resulting in well-documented problems and a significant number of catastrophic outcomes for our patients.⁶ While more implants are introduced to the market, others are withdrawn and one wonders whether the lessons of the Capital hip have not been learnt. The primary lesson in both these situations is that implants and bearing surface combinations must be properly evaluated before they are introduced. Similarly, it cannot be assumed that a ‘me-too’ implant will function in the same way as the design on which it is based.

As we move into the 21st Century, with an increasingly ageing yet active population, against a background of increasing medical co-morbidity and obesity our patients will, understandably, demand and require improved clinical outcomes and reliable longevity. This review examines some of the current issues and the future of THA, aiming to avoid past mistakes.