Goodhealth with Dr Melanie Wynne-Jones

Cutting edge: Knee replacements

In the early days, knee replacement used to be the last resort for people with severe knee pain and difficulty in walking. However over the last ten years they have become phenomenally successful, thanks to better technology and a better understanding of how the new knee should be fixed in place.

In fact, we do more knee than hip replacements in this country now, and the results are excellent. If patients aren’t sure, I ask them whether things are bad enough to risk a one-in-50 chance that their symptoms could get worse.

Mini-incision surgery (MIS) came in about five years ago; it was a big advance, as it involves much less cutting through muscles to get to the joint. However, we’ll never be able to do keyhole surgery, as any knee replacement involves inserting a lump of metal the size of the patient’s clenched fist into their knee!

MIS has helped to reduce hospital stays from a week to three or four days, with patients able to climb stairs as soon as they get home, and drive after four weeks.

The difference between men and women

Surgeons who were doing lots of replacements started to notice a subtle difference in the results for men and women. Men were doing slightly better on pain scores, and some women complained of pain at the front of the knee – not a lot, but enough to make us want to find out why this was. It turned out that women’s thigh bones (femurs) are a different shape from men’s.

For decades, knee replacements were based on men’s femoral measurements, but we discovered that women’s femurs are slightly narrower from side to side than men’s, and the bone at the front of their knees is subtly different. This means that up to half of women having a standard “unisex” replacement are left with a small overhang that can press on surrounding ligaments and tendons and cause pain.

The Gender Solution’s knee replacement, which was introduced to the UK in May 2007 and which I have been using ever since, was specifically designed to give women a “personalised” implant that gives a better fit and allows more natural movement. We expect that it will reduce post-operative pain even further; the results look good, but it will take years to see all the benefits.

Using a general or spinal anaesthetic, the worn-down surfaces at the bottom end of the femur (thigh bone) and the top of the tibia (shin bone) are replaced with metal implants, which are cemented into place. Physiotherapy exercises are started in hospital and continue at home. People are often back at work in a few weeks, but pain can take several months to fully settle.

Ninety per cent of patients can go back to normal activities, such as tennis, golf and even skiing, but not high-impact sports such as football. A further eight per cent may still have some discomfort, but improve enough to get back to more activities.

Who needs a knee replacement?

Osteoarthritis is the main reason for almost all knee replacements. As joint surface cartilage wears out, the bottom of the thigh bone starts rubbing on the top of the shin bone, causing pain and difficulty in walking. More women than men have knee replacements, and most are around retirement age. But the operation is increasingly being offered to younger people who want to carry on being active.

Up to 95 per cent of knee replacements last ten years, and many will last more than 20 years, depending on what activities their owners do. Second or even third replacements are usually successful, but being overweight can make pain worse, and increase the risk of complications.

Nick London and Stuart Calder, surgeons at the Yorkshire Knee Clinic, look at the risks posed by the annual winter sports season.

Over the next few weeks, thousands of people from Yorkshire will be heading for the ski slopes. Many will hobble home with badly damaged knees, victims of the so-called half-term syndrome.

Traditional surgery for damaged knee cartilage doesn't always work, but a new treatment replaces damaged tissue with cartilage harvested from elsewhere in the knee.

Peter Dodds, 37, from Driffield, East Yorkshire, talks to ANGELA BROOKS about his experience, while his surgeon, Stuart Calder, explains the procedure...

ROB VICKERMAN can easily identify the lowest point in his career.

It came at Worcester in a Leeds Tykes reserve match 53 weeks ago. The young centre, a week short of his 21st birthday, was making his comeback after eight months out with a ruptured anterior cruciate ligament (ACL) in his knee.

Vaughan has been plagued by injuries to such a degree that he must have been close to despair at times but his resolve has seen him through and it was typical of the man that he had invited Nick London, the surgeon who saved his career with a knee operation, to watch the match.

"It was a funny celebration, a lot of the team know what I've been through," Vaughan said. "It was a long road, and it's been very hard. It almost felt like destiny to score a hundred on my comeback on my home ground, and my knee surgeon, Nick London, was here to watch it."

Since he last appeared for England, against Pakistan, Vaughan has been troubled by a persistent knee problem, which has required four operations, as well as a hamstring injury and that broken finger. Yesterday was all the sweeter for Vaughan as he was watched by Nick London, the surgeon who performed the last of those four operations.

Michael Vaughan, the returning England captain, said after his test comeback that his hundred in his first Test since December 2005 was "as fine a feeling as I've ever felt in the game", adding that it seemed like destiny to make it at his home ground.

"To go out there and produce it when it seemed the whole country was looking to see how Michael Vaughan was going to react this week was really pleasing," he said. "My celebration was a mixture of lots of emotions. To have the crowd cheering was a feeling I haven't had for a long time, and it's what you play the game for. That's as fine a feeling as I've ever felt in the game. I felt all week I was going to get some runs. I could envisage myself scoring a hundred. I just had this sense it was going to happen. I got to 20 and thought, there's a 100 in me today."

Vaughan, who made his runs in front of Nick London, the surgeon who operated on his knee last year, spoke of a long, dark road to recovery and admitted that his enforced break from Test cricket, stretching back to the third Test against Pakistan in Lahore in November 2005, had at times led him to question himself.

"You have to prove to yourself that you can play at this level," he said. "I know I'm a good player but when you've had an 18-month lay-off there are always doubts in the back of your mind about whether you're going to see the ball, whether you're going to react, whether your feet are going to move. To score a hundred under pressure is probably the most pleasing aspect.

"In terms of innings I've played, I put that right up there just for the pressure. It stands with the innings I played against Australia at Old Trafford in 2005. I knew by coming in having not played for three weeks I was under pressure. But I'd rather play under that amount of pressure than take the easy option of getting myself into great nick first. I feel I'm due a bit of luck with my injuries and hopefully this is the start of a long run in the team."

Among the many fans that stood to applaud Vaughan's achievement was one man who was singled out for a special mention - Nick London, the surgeon who reconstructed Vaughan's knee and made the emotions of the day possible. "It's quite ironic that he was here today," Vaughan added. "It's the first time he's seen me play."

Gender Knee

Orthopaedic Surgeon Nick London is rolling out this pioneering surgery at Harrogate District Hospital and the town's Nuffield hospital - describing it as a "significant advance" in knee replacement operations.

Mr London believes the new replacements could help reduce the pain suffered by some women after their operations, as well as improving mobility.

He says some women suffer because previous knee replacements did not properly fit their femurs, or thigh bones, which are narrower than men's.

"Around two thirds of all knee replacements worldwide are for women but although they suit both genders, traditionally they are probably more suited to the male knee than the female shape." Mr London said.

"It is a significant advance because it is the first knee replacement specifically designed for women.

"Knee replacements have become a phenomenal success, but surgeons have noticed in the last few years that men and women are behaving differently after the operations.

"For a lot or women, the replacement doesn't quite match the end of the femur, and in the last few years that has made a difference to their pain."

The knee implant, designed by Zimmer Gender Solutions, replaces the thighbone portion of the knee and is based on years of research which has shown that a good implant fit is about shape as well as size.

It is the only implant to be specifically designed for women.

Researchers also believe the design leads to improved movement and the implants could last longer than traditional ones.

The operation, which is available both privately and on the NHS, is exactly the same as the traditional replacement and Mr London said any increased costs would be "marginal" to cover initial development costs.

One of the first women to undergo the surgery in Britain was June Connor, 67, from Thorner in West Yorkshire, who had the operation at Harrogate and District Hospital last Tuesday.

She said: "I thought having the new replacement would help other people in the future, so I went ahead with it.

"It has been very painful over the last year, but now the new knee will give a better degree of movement and will be totally pain-free once I've recovered from the operation."