A hip resurfacing system is intended to be just that - a coherent system comprised of elements which are carefully designed by the manufacturer to be used together.
The purpose of this page is to provide a brief overview of one potential root cause of failed hip surgery. It is a very basic mistake on the part of the orthopedic surgeon which thankfully is not made often, and could be easily avoided. In reality it should never happen at all.
The mistake occurs when the surgeon, contrary to instructions & warnings supplied with the product, mixes a component drawn from one manufacturer's hip resurfacing system with a component drawn from another manufacturer's system - effectively creating a 'mix and match' joint.
Manufacturers of hip implants typically supply and market a complete hip resurfacing system comprised of a range of components in different sizes, such as a metal acetabular cups to be fitted in to the hip socket; and metal caps to be fitted to the top of the femoral head.
Subject to the manufacturer's instructions, hip resurfacing systems should be regarded as standalone 'kits' where components should only be taken from one marketed kit or system. Or, put another way, components should not be mixed from the hip resurfacing systems of different manufacturers.
Each hip replacement system will have it's own design specification and metallurgy and therefore it is important that all components and any associated / bespoke instruments, fixings or tools be taken from the same system, if and as prescribed by the manufacturer.
Failure on part of the orthopedic surgeon to read, understand or adhere to the instructions supplied by a manufacturer may be the only explanation for this mistake.
It has to be said that such an error should it occur would be judged by most people to be fundamental and basic; there really can be no excuse for such a mistake.
An analogy might be a motor mechanic fitting a steering component from one brand of vehicle, to the front wheel and chassis of another brand of vehicle. The dimensions, strength and engineering tolerances of the components will be different. They have not been designed to be used together. Consequently, the probability of the steering and suspension system operating effectively and safely as a coherent whole once the vehicle is back on the road would be very low.
There are differences between countries in the extent to which mixing and matching between different implant systems takes place. In some countries there are unequivocal recommendations for surgeons by regulatory bodies that mixing & matching should not take place. Guidance in other countries may be different or completely absent.
Regardless, the manufacturer's instructions should be followed irrespective of geography or jurisdiction.
This requirement would appear to most people to be simple common sense. Accordingly, some people I have spoken with are surprised that such basic guidance needs to be published on the websites of some Regulators.
Conversely, of course it is essential that the most basic and common requirements for safe hip replacement and hip resurfacing surgery are set out plainly and clearly for any medical practitioner to refer to. However, the mere fact that something so basic needs to be published does raise concerns that there may be some surgeons practicing who may not be adhering to product instructions.
Bottom line - surgeons and other health care professionals should read and adhere to the manufacturers' instructions.