The hidden costs of jogging

For 30 years we've become a nation obsessed with our body image, pushing ourselves ever harder in a quest for perfect fitness. But now the "jogging generation", spurred on by the extraordinary growth of the fitness industry, is facing an even tougher challenge - wasted knees.

A generation of middle-aged men and women who didn't protect themselves properly, and a younger group of people who simply pushed themselves too hard on the sports field, on "fun runs" or the ski slope, are part of the 300,000 or so every year who complain of cracked knee caps, torn tendons and damaged ligaments.

But at the same time, medicine has seen an extraordinary development in the types of operations to correct knee injuries, with less-invasive techniques and faster recovery times. The problem is, how do you know what's right for you - and when should you consult a specialist rather than hope the problem mends itself ?

The past two years alone have seen a 25 per cent increase in knee injuries reported annually. More worryingly, total knee replacement surgery - which occurs only when all else has failed - is performed on one in 10 of those.

John Skinner, consultant orthopaedic surgeon at the Royal National Orthopaedic Hospital in Stanmore, Middlesex, says that the fitness revolution of the Seventies has certainly led to the huge increase in knee injuries and, as each generation joins in, the numbers will soar. The problem is that the kind of injury one gets while young can lead to the Zimmer frame 20 years on.

"We are now obsessed with sport," says Skinner. "But the kind of all-action activities we do now means that so much movement goes through the knees, rather than, for instance, the ankles. The enormous force that goes through the knee means that it can swell like a balloon and fill with fluid - usually blood.

"The three common injuries we see from any sport are a tear of the anterior cruciate ligament, tear of the meniscus (the cartilage) or an osteochondral fracture - when the surface of the joint is chipped, like a golfing divot.

"Modern training shoes are part of the problem. The old shoes such as Dunlop Green Flash used to slide - but trainers now are so good for gripping the ground that the foot stays rooted to the spot and that's when the bad force is transmitted." Because the cartilage acts as shockabsorbing material, a number of tears leading to repairs can mean that the cartilage is destroyed completely, resulting in total knee replacement. Yet even that doesn't mean the end, for replacements need to be replaced too, leaving the prospect that a patient who suffers a serious knee injury when young may need as many as three such operations before the age of 60.

"If a patient does not need the whole knee replaced," says Skinner, "then we can put in a Unicondylar, a half-knee replacement which means we can carry out operations without cutting into bone.

"But the most exciting innovation is a technique called cartilage transplantation. This allows patients to virtually grow a new knee. It has been successful in more than 70 per cent of 500 trial patients - mainly with sports injuries - aged between 15 and 45."

There are, however, several ways in which you can protect yourself:

But if you do need an operation, what's on offer?

Operations

These are the common operations, the NHS waiting lists are around nine months, private lists may be up to three months. Costs refer to private operations. Check individual insurance policies for what you are entitled to.

Arthroscopy: Keyhole surgery to look inside the knees and use the cutting instrument to take out the torn piece of meniscus (cartilage) and repair what's left.
Cost: £1,650 (day case). Recovery time: sore for a week or so.

Repair of Anterior Cruciate Ligament: This can be reconstructed with tendon from the hamstring to run from the knee cap to shinbone. This works to stabilise the knee and lasts well.
Cost: £4,500. Recovery time: six weeks.

Micro-fracture surgery: The cartilage is white and shiny like a chicken leg knuckle. It is very smooth and slippery so the knee can bend without friction.

If healthy, the cartilage is squashy so if the knee is jarred, it absorbs shock and returns to its original shape like a sponge and protects the bone.

We don't make more cartilage as we get older, so there is not much repair potential and this leads to arthritis in the future. If a divot is made in the joint, then little holes are drilled in it to bring blood cells containing blood marrow to the surface. These cells grow and produce a material to cover the exposed bone.
Cost: £1,650 (day case). Recovery time: six weeks.

Unicondyler: The "Oxford Knee" is half a knee replacement - a little metal tray is placed at the top of the shinbone with a C-shaped attachment which fits on the end of the knee joint. It has a plastic spacer in between to give movement so the knee can straighten, bend and move from side to side.
Cost: £9,000. Recovery time: six to eight weeks.

Total knee replacement: A cobalt-and-chrome joint replaces the damaged one.
Cost: £9,000. Recovery time: six to eight weeks.

Cartilage transplantation: If the injury is suitable for transplantation, a small piece of cartilage is taken containing a few hundred cartilage cells and grown in the patient's own serum in a laboratory.

Within a month, these will have multiplied to 15-20 million cells and a second operation is necessary to open up the knee and sew in a special membrane behind which the cartilage cells are injected. This is then sealed with "fibre and glue" made from the patient's blood serum and the cells link with the surrounding cartilage.

It takes a year for the cells to re-grow fully. As the original cells have come from the patient's body, they will not be rejected when they are implanted.
Cost: first stage £1,650, second stage £8,100. Recovery time: four to six weeks.

Surgeons

There is no "league table" of specialists - however, these consultant orthopaedic surgeons, who specialise in knee surgery, work at top London teaching hospitals and individual clinics, and are recognised by their peers as among the best in the country. They all operate both on the NHS and privately.
St George's Hospital Tooting: Roger Vickers: 020 8672 1255.

Royal National Orthopaedic Hospital, Stanmore: John Skinner and Tim Briggs: 020 8954 2300.

Queen Mary's Hospital, Roehampton: Jonathan Bell and David Ward: 020 8789 6611.

King's College Hospital, Camberwell: Michael Wilkinson: 020 7737 4000.

Guy's and St Thomas' Hospital Trust: Peter Earnshaw, James Bliss, Andrew Davies (planned surgery at Guy's, emergency surgery at St Thomas'): 020 7188 7188.

Royal Free Hospital, Hampstead: George Dowd: 020 7794 0500.