The era of phased introduction of new implants

At present, most new designs for total knee (TKP) and total hip prostheses (THP) are approved and distributed on the market without extensive safety and effectiveness testing via the 510(k) pathway in the United States and regulation via notified bodies in Europe (Directive 93/42/EEC).^1,2 In 2007, the European Union reclassified total hip, total knee and total shoulder prostheses to “class III medical devices” (Directive 2005/50/EC). Class III medical devices are high risk and require pre-marketing testing in patients.³ Nevertheless, the 510(k) pathway in the United States and the reviews of device reliability via notified bodies in Europe have created an environment in which unsafe TKP and THP can reach the market.⁴ This lack of adequate regulation has led to the widespread use of potentially unsafe TKP and THP, with failure rates two to ten times the standard of national joint registries (i.e. 5% failures at ten years follow-up).^2,5–10 Furthermore, problems with new methods of fixation of orthopaedic implants such as Boneloc cement (Biomet Inc., Warsaw, Indiana), have also resulted in revision rates that were 14 times higher than normal.¹¹ Taking the above into consideration, the selection of any new implant, fixation method but also new surgical technique should be evaluated to have the optimal patient safety. The IDEAL consortium is an important proponent of this.¹² Do the potential advantages of new techniques outweigh the potential risks?¹³