Nerve-burning blast to ease creaky knees

ATWO-MINUTE nerve-blocking procedure could help improve mobility and pain in those with osteoarthritis of the knee. The procedure involves destroying a portion of nerve tissue in order to disrupt pain signals, and researchers say it could also help reduce or delay the need for a knee replacement. Osteoarthritis, commonly known as ‘wear and tear’ arthritis, occurs when the cartilage that provides cushioning between joints wears away, leaving the bone ends to rub against each other. This results in pain, swelling, stiffness and problems with mobility.

It affects nine million in the UK, with the knee the most commonly affected joint. In fact, 20 per cent of the over-45s are thought to have some degree of knee arthritis.

There is no cure, and the condition is normally managed in the earlier stages with painkillers or steroid injections. But as the damage to the joint increases, a knee replacement is usually required.

There are around 100,000 knee replacements carried out each year, according to national Joint Registry figures. However, the procedure involves a lengthy recovery, and younger patients may need a further replacement in the future.

The new treatment, known as radiofrequency ablation, may offer another option. It works by stopping the genicular nerves in the knee from sending pain signals to the brain.

To test whether a patient is likely to benefit, a temporary nerve block is first injected into the knee so that doctors can monitor how successful it is in reducing pain and improving movement.

The treatment itself involves having the needle-like radiofrequency equipment, which is loaded into a catheter (tube), inserted into an artery in the thigh and guided to the knee area using ultrasound. Once in place, two one-minute blasts of 80c radiowaves are fired to destroy a portion of nerve tissue.

Some small studies have shown the ablation treatment is effective, particularly on patients for whom physiotherapy, anti-inflammatory painkillers and steroid injections have provided little benefit. The treatment can cut pain symptoms by 70 to 80 per cent.

now a trial involving 50 patients with osteoarthritis of the knee is being held at mansoura university, in egypt. Some of the group will have the actual treatment, while the others will have a placebo treatment. Doctors will assess the effects on pain and movement for up to six months afterwards.

Previous studies have found that the effects can last up to a year or more and treatment can be repeated if necessary.

Commenting on the research, Roger Hackney, a consultant orthopaedic surgeon at Spire and nuffield hospitals in Leeds, said: ‘Any intervention that can extend the time of relative comfort for a patient is likely to be welcome. However, the risks need to be quantified, as introducing a device into an artery is not risk-free. If the pain relief proves to be prolonged, then there is a risk of the osteoarthritis changes to the knee progressing to the stage where surgery becomes more challenging.’