Resurfacing of the hip

Hip resurfacing is a specialised kind of hip replacement where the minimal amount of bone is removed from the head of the femur.

Advantages of this implant are preservation of bone and anatomy, a hardwearing bearing, hip stability, and potential for very high levels of patient activity. It is the only hip that potentially allows the patient to return to any activity including running, climbing etc.

Fig 1: Resurfacing implant compared to conventional THR.

Resurfacing is best suited to high activity, young, male patients without significant bony deformity. It has become apparent that the cause of hip arthritis in the majority of these young athletic males is femoro-acetabular impingement, and resurfacing is ideally suited to deal with the pattern of arthritis that this causes.

Fig 2: High activity patient after hip resurfacing.

Benefits of hip resurfacing:

Benefits of MoM bearings
Very high activity possible
Bone preservation femur
Restores function
Results >15 years
Easy revision after femoral failure.

Benefits of MoM:

Low wear
Tough
>20 years experience of modern MoM bearings
Allows use of very large heads.

The surgery is more demanding than conventional THR, and the results are very dependent on patient selection, implant selection and surgical technique. Despite the bigger incision required for this procedure, patients recover exceptionally quickly. It is a metal on metal (MoM) bearing, made from cobalt chrome. MoM combinations were first tried as far back as 1938, but were used in large numbers of hip replacements in the 1960s and 1970s. It went out of favour in the 1980s, but returned in the 1990s in conjunction with the development of modern hip resurfacing. It is a very hard material, and can be safely manufactured into relatively thin cups, allowing the use of very large heads and hip resurfacing.

There have been many concerns over the use of MoM bearings, relating to metal allergy, theoretical links with cancer, and technical problems in implantation. However, with careful patient selection and good surgical technique, the results are excellent, especially in the young active male.

Problems of hip resurfacing:

Problems of MoM bearings
Neck fracture 1%
Larger incision
Neck thinning (usually females)
More demanding operation.

Problems with MoM bearings:

Metal allergy, and ALVAL/ARMD, especially in young females
Unexplained pain, especially in young females
Worries over cancer risk (unfounded)
Wear particles cross the placenta
Sensitive to surgical error in placement.

Orthopaedics WA’s Professor Yates and Gareth Prosser have been performing hip resurfacing for more than 13 years, and were trained by one of the most experienced resurfacing surgeons in the World, in the UK, and have published several research papers on the subject.

Professor Yates has performed several hundred of these operations, and has frequently taught other specialists and other health professionals about this procedure.

Fig 4: Bilateral hip resurfacing in a 44-year-old.

The procedure

Preparation for the surgery is very similar to that of total hip replacement (see Pathway for total hip replacement and resurfacing hip replacement).

The set up in theatre is the same, as is the anaesthetic. The operation takes about 45 minutes to one hour. Most patients are able to stand on the day of surgery, and are ready for discharge home on the second or third post operative day. Sometimes, Orthopaedics WA will ask patients to remain on crutches for a few weeks after this operation, to protect the bone while it remodels. Postoperative care is the same as for a THR.