Case history: Total ankle replacement

PUBLISHED : Tuesday, 26 February, 2013, 12:00am
UPDATED : Tuesday, 26 February, 2013, 9:03am

Graeme Collins, 63, a retired ballet dancer who now teaches, knew he was in dire straits when he first felt his ankle joint getting stiff about 14 years ago. "My left ankle was a mess," he says.

At the time, he was the head of ballet at the Hong Kong Academy for Performing Arts, after a successful 17-year career as a professional dancer in Australia, London, Sweden and South Africa. "I had sprained my ankle a number of times as a dancer," he recalls.

After retiring from dancing, he developed an interest in long-distance hiking and squash, and those activities caused a few more sprains on his now-weary ankle.

About five years ago, Collins felt his ankle becoming increasingly immobile and painful, and he started to walk with a limp. He iced and strapped it, and saw the physiotherapist at the Academy. It didn't help much.

He lived with the pain for a while more, but when it became tougher to demonstrate dance moves in class, he decided to take further action. His general practitioner did an X-ray of the ankle and confirmed it was deformed. The physician referred him to Dr Yeung Yeung, a specialist in orthopaedics and traumatology at Matilda International Hospital.

"Mr Collins couldn't put his left foot flat on the floor because of the ankle deformity. He was walking on the outside of the foot and was in a lot of pain," Yeung recalls of her first meeting with him. "Repeated injury to the outer ligament of the ankle meant it could no longer support the joint."

Yeung, a sub-specialist in foot and ankle surgery, fitted Collins with orthotics for six months - a "conservative way" to try to control the pain and prevent the injury from worsening. That didn't help either, so surgery was discussed.

The gold standard for advanced ankle arthritis is fusion surgery, which fuses the ankle joint solidly together to keep it stable and pain-free when bearing weight (such as during walking and standing). However, the ankle joint becomes stiff and motionless afterwards. Some patients may develop arthritis in adjacent joints about 10 years after the initial surgery.

The other surgical option is Total Ankle Replacement (TAR), which removes the diseased joint cartilage and replaces it with an artificial implant that mimics the function of the ankle joint. TAR preserves the functional range of motion of the ankle, allowing patients to better perform daily activities and possibly resume athletic activities. It also has a shorter rehabilitation period of four to six weeks, compared with four to six months for fusion surgery.

TAR has been performed in Europe and the US in the past decade and is an evolving technology. Early designs of implanted prostheses were largely unsuccessful, with high complication and failure rates. Problems included excessive wear and constraint and a lack of stability.

New designs of implants have had favourable clinical results. Yeung had researched the designs intensively and found one developed by Pascal Rippstein, a Swiss surgeon, to be the best option. It consists of an implant made of a metal alloy and polyethylene spacer.

It's been getting better and better. It's nowhere near the level of pain I used to feel
Graeme Collins, Ballet teacher

Yeung travelled to Switzerland to learn from Rippstein at his Department of Orthopaedic Surgery at Schulthess Clinic's Foot and Ankle Centre in Zurich, where Rippstein confirmed he was a suitable candidate for TAR surgery.

Matilda's executive medical director, Dr Hans Schrader, says a TAR package with the hospital costs between HK$75,000 and HK$100,000, while a fusion surgery package costs HK$55,000 to HK$70,000. Between the two, the choice was clear for Collins.

"My criteria were that I wanted to be able to walk, hike and continue teaching ballet after the surgery," he says. "TAR would give me mobility."

In June last year, Yeung - overseen by Rippstein, who was visiting - operated for 90 minutes on Collins at Matilda, which is the first and only private hospital in Hong Kong to be equipped with the skills and instruments for a TAR procedure.

Collins' foot was kept in a cast for two weeks. After the plaster was removed, rehabilitation and physiotherapy followed, first with gentle movements and exercises to boost circulation to the joint. After four weeks, Collins began learning to walk again with the proper gait, and progressively increased the weight bearing on the joint. After three months, he slowly eased back into gentle physical activity.

"It's been getting better and better," says Collins. "It's nowhere near the level of pain I used to feel."

He will have to have annual check-ups using X-rays to ensure that his foot, its bones and the joint implant continue to be in good shape. There is the possibility of complications, including a loosening of the implant and an allergic reaction to it, says Yeung, "but it's not a major concern".

She says TAR may not be suitable for young and active patients, nor those with a history of infections, those suffering from peripheral vascular disease or from neuromuscular disease with poor muscle control, as well as patients whose daily life or work requires a lot of heavy loading on the joint.

Worldwide, four in every 1,000 people over 65 will suffer from some form of ankle degeneration, says Yeung. She advises that recurrent ankle injuries are treated early and the ankle realigned properly. This will prevent further cartilage wear and tear, and ankle deformation.

Collins recently returned from a trip to Australia and Fiji, where he says he did quite a lot of walking. He plans to hike the hills around his home in Lantau soon.

The only inconvenience that he's experienced recently is setting off sensors repeatedly while going through airport security in London. He told security staff that he had an implant fitted and showed his scar to prove it - and was then allowed through, fancy footwork and all.