Hip resurfacing vs total hip replacement

Both operations treat end-stage hip arthritis when pain and stiffness have not improved with non-surgical care. In total hip replacement, the arthritic ball is removed and replaced by a smaller prosthetic head fixed to a stem in the thigh bone, with a lining placed in the socket. In hip resurfacing, the surface of the ball is trimmed and capped with a metal covering, keeping the femoral neck and most of the bone, and a metal cup lines the socket.

Resurfacing was developed to preserve bone for younger active patients who might need more than one operation in their lifetime, and to allow a larger ball with a lower risk of dislocation.

Resurfacing is almost always metal-on-metal. Some designs released metal particles that caused reactions in surrounding tissue and, in some patients, failure of the implant. National regulators and the National Joint Registry issued alerts and advised monitoring for people with such implants. The design, the surgeon's experience and the size of the components all affect outcomes, and some products were withdrawn.

Because of these experiences, resurfacing is now offered to a narrower group, typically at specialist centres with experience in the technique, and with implants that have a good track record in registry data.

NICE TA304 on total hip replacement and resurfacing arthroplasty recommends prostheses as treatment options only if they have a revision rate of 5% or less at 10 years, and notes that comparative studies found a higher revision rate for resurfacing than for total hip replacement. The National Joint Registry publishes implant-level results.

In practice, most surgeons recommend a conventional total hip replacement, with resurfacing discussed for selected patients, commonly men with large hips and good bone, who are keen to remain active, and treated by surgeons who do the operation regularly.

• Average build or smaller, female, osteoporosis, or kidney problems: total hip replacement is usually advised.

• Younger, active man with good bone and a large femoral head: ask whether resurfacing could suit and about the specific implant's registry results.

• Concerned about metal exposure: tell the surgeon and ask about ceramic or other bearings.

• Previous resurfacing with pain, a limp or groin swelling: seek review, since this can indicate a reaction to metal.

• Not sure: ask for the surgeon's own numbers and the implant's National Joint Registry data.

Resurfacing is not a "keyhole" or gentler operation; it is a major hip operation and requires a similar recovery. Nor is it automatically better for sport. And metal-on-metal problems do not affect all resurfacing patients; many implants do well, which is why individual monitoring matters.

A total hip replacement is also not an old-fashioned option; modern bearings and techniques have good long-term results in registry data.

• Which implant do you propose and what are its registry results?

• How many resurfacings do you perform each year?

• What is the bearing, and will I need follow-up blood tests for metal ions?

• What would a revision involve if it were ever needed?