While it's not uncommon for older people to get total hip replacements, doctors now often go with hip resurfacing implants for younger patients who have conditions such as osteoarthritis. The devices can cause problems, however, plus they can't be used on women. A new type of implant may change that, as it's made out of ceramic instead of the traditional metal.

In a total hip replacement, the entire hip joint is replaced with an artificial one. That's generally OK for seniors, but not for younger more active people – problems can arise from the artificial hip's stiff metal stem sitting inside of the patient's own more flexible thigh bone.

That's where hip resurfacing comes in. It involves replacing only the diseased cartilage in the hip joint with a metal-on-metal, ball-and-socket implant. This leaves more of the patient's hip bone intact, allowing them to be more active after surgery, plus it lasts longer than a full artificial hip. It can have problems too, though.

Sometimes, tiny particles of metal are released by the implant, resulting in swelling and soreness in the surrounding tissue. Additionally, the metal implants don't fit women's hip bones, leaving them with no option but to get a total hip replacement.

Developed at Imperial College London, the experimental H1 hip resurfacing implant is designed to get around these shortcomings. It's made out of a strong, low wearing and non-toxic ceramic that shouldn't cause problems in the surrounding tissue, plus it fits the contours of both male and female hips.

In a recent trial that was started at Charing Cross Hospital, 15 test subjects of both sexes (aged 18 to 70) received H1 implants. The early results are promising – the patients were able to return to physical activities such as swimming, cycling and walking within six weeks of their operation, and after three months were able to return to activities they couldn't do before, such as dancing, yoga and gym work.

The next phase of the trial will be carried out at hospitals across the UK and Europe, involving a total of 250 test subjects who will be followed for ten years to assess how their implants are performing.

Source: Imperial College London