Injection of skin cells has been found effective in treating tennis elbow, UK researchers say.
The 15-minute procedure uses cells taken from a tiny piece of their own skin. They are then injected into the joint to regenerate the damaged tendon that causes the painful condition.
A pilot study on 12 patients has thrown up satisfying results.
Eleven were cured within weeks with no side effects and only one patient failed to respond.
The pioneering technique could also help treat tendon and ligament damage throughout the body - such as a torn Achilles tendon.
Tennis elbow, which is known in medical terms as lateral epicondylitis, is a degenerative condition thought to affect two million people in Britain - mainly between the ages of 40 and 55, reports Daily Mail.
It is caused by fraying of the tendon that joins the forearm muscle to the upper arm.
Repeated overuse of the arm is most often to blame, but it can also be triggered by an isolated incident - lifting something too heavy can be enough to trigger an attack.
Patients initially suffer feelings of stiffness in the elbow first thing in the morning, as well as severe pain on the bony outer side of the joint.
This pain can radiate up and down the arm, weakening the wrist so severely that some find even taking the lid off a jar impossible.
Doctors recommend rest, anti-inflammatories, a series of physiotherapy sessions and steroid injections - although steroids have recently been shown to be no more effective than rest.
It was found a few years ago that injecting patients with their own blood at the site encouraged the growth of new tissue, sealing the tears.
The problem is that this generates scar tissue, which is far less elastic than healthy tendon and so limits the range of movement.
In the new treatment, a 4mm piece of skin is taken from the hip and used to isolate special "stem" cells.
Stem cells are capable of morphing into any form of tissue.
Although adult stem cells tend to be less flexible than embryo stem cells, they can be coaxed into developing tissue similar to their site of origin, doctors say.
For instance, skin stem cells can be grown into muscle tendon or ligaments but not into liver or kidney cells.
The huge advantage they have over embryonic stem cells is that using the patients' own stem cells means they won't be rejected by the body.
The few stem cells taken from the skin are cultured until they have grown over one million cells. This takes between four and six weeks.
The cells are then injected under ultrasound guidance into the tendon defects.
This technique has been adapted from a treatment developed by veterinary surgeons four years ago to get champion racehorses back on track following serious tendon damage.
The work on horse injury was pioneered by Roger Smith, professor of equine orthopaedics at the Royal Veterinary College.
"There are many similarities between horses and humans," says Professor Smith. "They age and exercise in the same way and suffer from similar strain injuries."
A team working at the Royal National Orthopaedic Hospital in Stanmore, Middlesex, led by Dr David Connell, tested the technique in a pilot study last year.
One of the patients was Michael Arciero, 54, a hospital porter from Chessington in Surrey.
He had been diagnosed with tennis elbow in his left arm a year previously.
"Whenever I tried lifting anything, pain shot all the way down to my hand," he recalls.
"I was treated with blood injections, which worked although my arm took weeks to improve.
"But when the condition flared up in my right arm, it was much more debilitating, probably because I'm right-handed and rely on that side more.
"After the procedure, I was told to avoid lifting anything heavy for a fortnight, but within two days the pain had gone. A week later, I was back at the gym."
The first clinical trial of the treatment is under way, with half of the 50 testers being given injections of the stem cells and the others receiving injections of their own blood.
Commenting on the research, Simon Owen-Johnstone, a consultant orthopaedic surgeon at St Bartholomew's Hospital in London, said: "This appears to be a radical solution for tennis elbow, and I would welcome any new treatment that helps these patients."