Joint responsibility

Published on Wednesday 9 July 2008 15:53

IT'S an easy excuse for the less fit among us to look around at those who spend a fortune in time and money down at the gym or pounding the streets and point out how often they're laid up injured.

One of the downsides of being sporty is that it's all too easy to overdo it, and nowhere is this more apparent than in the body's biggest joint, the knee, which is very prone to painful damage. At one time, surgery to replace the joints was the only solution, but nowadays there are alternatives.

A lifetime of running, skiing, football, cycling or dancing can take its toll on the knees, with surrounding ligaments and muscles prone to tears and sprains as well as early-onset osteoarthritis, which destroys the cartilage. Sticking to one activity overworks some muscles, for example the calves, and ignores others, such as the hamstrings and hips. Yet these are the very parts that should be worked to help keep pressure off the knee and avoid injury.

According to experts, knee patients fall into two camps. Younger athletes tend to damage their joints with acute trauma, while older sportspeople will have worn-down cartilage thanks to minor injuries to the knee joint over time and may end up suffering the excruciating pain of bone grinding on bone.

Kirsten Lord, managing director at the Edinburgh Physiotherapy Centre, says, "Anyone can suffer from premature knee pain, although the more sporty you've been in your youth, the more likely you are to suffer.

"We often see people who have suffered an injury during sport, usually with a forced twist, and particularly with rugby, football and jogging. And people who are overweight or whose jobs involve a lot of kneeling, such as builders and carpet-layers, are also susceptible."

Keeping the knees flexible and strong, strengthening the muscles that go across the joint with a range of movements, is the way to avoid injury. Building up the strength in the thigh muscles by cycling up and down hills or walking on a treadmill is a good way to help protect the ligaments that guide the kneecaps.

Variety is also important, and those who take part in a wide range of sporting activities are much less likely to end up with knee trouble than someone who has been pounding the pavements for several decades. So rather than a daily jog, taking up yoga or dance might be the key to all-round fitness, though if the knees are already damaged, the advice is to take it easy.

Susan Neal, of YogaScotland, says, "If you have never done yoga before, then maybe now is not a good time to begin! Certainly some simple movement and exercise will be beneficial, but although yoga poses (asanas) have beneficial side-effects, these are not the main aim of the poses. Yoga's aim is to unite body, mind and spirit.

"Having said that, strengthening movements could be simply bending and straightening of the knee, either from a sitting or supine position. In yoga, these would always be done in tune with the breath. Once the joint becomes stronger and more mobile from doing these 'joint-freeing' movements, some simple squatting moves can help. Stand with the feet hip-width apart and parallel. Use a chair for support, then squat down a little way, making sure the legs stay parallel and the knees do not move in or out. This is because the knee is a hinge and any movement which adds a twist can be unsafe," she says.

It's also important to remember that knee pain could be a symptom of an underlying problem that originates elsewhere in the body, the hip or ankle for instance. "If someone has injured a nearby joint, they often change the way they walk and move, which can result in increased stresses and strains through the knee," says Lord.

"Tension which develops in the calf muscle will often refer pain into the knee joint area. The lower back can also refer pain directly to the knee. Even when X-rays show gross degeneration, your pain may be coming from somewhere else."

Advances in diagnostic technology include the Core:Tx, a tool that senses moving during limb exercise, and a new procedure known as viscosupplementation, where hyaluronic acid is injected into the joint to lubricate the bones and keep them moving smoothly, absorb shocks and relieve pain.

Another method that doesn't involve surgery is biomechanical training of specific muscles, through the use of insoles that align the feet correctly or braces that force the knee to be slightly flexed and in the correct position during sport. This is particularly helpful for women, because they have a tendency to land more straight-legged when jumping and turning and are more likely to damage their tibia.

There are times when surgery is advisable, however. Traditional knee replacements made of metal and plastic have a lifespan of ten to 15 years and are mainly used in older patients, but more recent advances have seen the development of biological knee replacement, which involves using natural tissues to re-grow the surface of the articular cartilage. This is commonly used alongside meniscus transplant from a human donor.

If only part of the knee is damaged, patients can opt to have a half-knee replacement, more minor surgery that is suitable for older, less active people. Should a total knee replacement be required, a new technique being performed in around one in 20 knee replacements in the UK sees the size of the incision that needs to be made in the knee reduced by half, meaning less tissue damage, a smaller scar and a shorter stay in hospital.

According to the Scottish Arthroplasty Project, an NHS group that monitors joint replacement surgery, 6,181 patients, average age 69 years, underwent knee replacement surgery in 2006/07 in this country, 58% of them female. Their research indicates that knee joint replacement surgery is becoming increasingly common in Scotland, thanks to the success of the procedures.

But bear in mind that with common sense in training routines and variety in exercise, it's possible to avoid the agony of knee pain altogether. It might be time to enrol in that yoga class before it's too late – you may find it's not just your knees that benefit.

For more information about knee replacement in Scotland, check www.arthro.scot.nhs.uk

For more information on yoga classes, see www.yogascotland.org.uk