Hip Resurfacing

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In hip resurfacing the aim of the surgery is to provide new bearing surfaces for the hip. These surfaces are today made of metals, chrome cobalt alloys.

The concept of resurfacing is not new at all; it was first brought to the fore in the 1960s by Charnley who first undertook this operation using Teflon. His idea was that the fundamental problem in osteoarthritis was the loss of the cartilage surface on the bones (the bearing surface) and therefore their replacement would be less destructive than a total hip replacement. Unfortunately Teflon is not strong enough to cope with the loads produced within the hip and these all failed and had to be revised.

In the late 1970s and the 1980s the concept was resurrected by a number of surgeons around the world, predominantly Freeman in the UK and Wagner in Germany. These joints were constructed of a metal surface to cover the head of the femur (the ball of the hip joint) and a plastic liner to the acetabulum (the socket of the hip joint).  Because the plastic liner could be little more than 3 mm in thickness and because of the large surface area the plastic wore very badly and often ripped, the plastic wear debris doing a great deal of damage to the bone of the femur which was supporting the metal surface component causing it to fail.

Resurfacing therefore fell into disrepute for a number of years.

During the 1990s McMinn in Birmingham resurrected the concept using metal on metal bearings.

Metal on metal bearings were not new either. They had been in use since the 1950s in total joint replacements particularly by surgeons such as McKee and later by Peter Ring in Redhill, Surrey. Examples of these joints with survivorships of over 20 years still abound and remain pain free and fully functional with no bone destruction from wear debris. A lot of research was undertaken to determine the best metallurgy and engineering configurations to employ and the Birmingham Hip Resurfacing was launched. This has proved to be very successful and as a result further developments were undertaken to improve fixation and ease of implantation and the Adept system of joint resurfacing and replacement were marketed. Rowan Pool was involved in the design and development of the instrumentation for implantation which has eased the difficulties inherent in this aspect of the surgery.

There do remain some concerns about the wear debris created by these articulations. Blood levels of chrome and cobalt do rise in the blood of patients who have these components. However over the large number of years that these bearings have been around there are no reports of cancerous changes being observed. However currently there is some concern that the rare patient may appear who is allergic to these metal ions in their tissues and research is ongoing looking at this aspect.

Generally though the results of this operation are as good in the short to medium term as total hip replacement but long term results are awaited, the longest follow up of current design and production components is only around 7 to 8 years.

The overall concept though is an attractive one. Only the surfaces of the joint are replaced therefore all the main part of the thigh bone is retained untouched and the length of the leg is restored along with the other aspects of the mechanics of the hip to restore the hip to its pre-disease state. Later if a revision of this joint is required it is much easier to do as more bone is available for resection to convert the joint to a total joint replacement. Ease of revision is important when a patient is getting older and the more risky a revision procedure becomes.

Because the joint is restored to normal mechanics with a large diameter articulation it is more stable and therefore patients can undertake activities that may be precluded with a conventional total joint replacement with a relatively small bearing. Therefore one can aim to return to all previous levels of activity, e.g. squash and badminton and postoperatively patients can mobilise fully weight bearing and sit and lie in whichever position is comfortable for them, with no restrictions applied to reduce the dislocation risk as happens with the aftercare of most conventional replacements.

The aim of this operation is to restore normal quality of life for each individual.

Pre Operative X-ray of Osteoarthritic Left Hip





Pre Operative Lateral X-ray of Osteoarthritic Left Hip

Post Op X-ray of Resurfaced Left Hip