Polyester patch to help boost shoulder mobility
APATCH made of polyester that ‘draws in’ water, could be an effective treatment for shoulder pain, a new study suggests.
The patch is used to augment the surgical repair of a damaged rotator cuff, and is designed to help prevent recurrence of the problem.
The shoulder is a complex ball and socket joint. It is formed by three main bones: the collarbone, shoulder blade and upper arm bone — the latter forms a ball, called the humeral head, which rests against a socket in the shoulder blade.
Although it is a ball and socket joint like the hip, the shoulder socket is shallower as it has to allow a wider range of movement. In contrast, the main purpose of the hip is to provide stability.
A group of muscles and tendons, known as the rotator cuff, keeps the ball in the socket. As the joint moves, the tendons hold the ball in place.
But these tendons often tear, particularly as we age. This restricts movement and causes pain. A tear can happen suddenly, for example when falling on an outstretched hand.
It is thought at least 50 per cent of people aged 60 and over suffer a rotator cuff tear sometime — the risk of one is 2 per cent at age 40, rising to over 70 per cent at 80.
Exercises to restore strength and range of motion, and steroid injections are among first-line treatments for a partial tear — where one of the rotator cuff muscles becomes frayed or damaged.
In a complete tear, the tendon is pulled off the bone and has to be stitched back.
Up to 50 per cent of rotator cuff repair surgeries fail in the first 12 months, which can end in longterm disability.
The bigger the tear, the lower the chances of the repaired tendon (which is about as thick as a little finger) healing.
Although patches have been used before, the new one — that is stitched over the surgical repair — provides a ‘scaffold’ for the repair to improve the fixing of the tendon to the bone.
It has thousands of tiny holes or perforations, into which new tissue can grow. The polyester itself is treated to make it hydrophilic, which means it attracts water. This encourages tissue cells which contain water, to attach.
The kind of polyester used in drip-dry shirts normally repels water.
The patch is designed both to strengthen a repair, and reduce the tension across the repair, a risk factor for the tear to recur.
A peer-reviewed study, yet to be published, involving 29 patients in Leeds, showed all improved after having the patch surgery. One patient went from near paralysis of the joint, to fully functioning. On average, there was a threefold improvement in movement and in pain.
Two other trials have found similar results. Further, larger studies are needed to see if the patch reduces tear recurrence.
Professor Chris Peach, a consultant elbow and shoulder surgeon at the OrthTeam Centre in Manchester, is leading a worldwide clinical trial to see if patches help the tendon heal better.
He said: ‘I think that biological augments such as this one are the future of rotator cuff tendon repair surgery. But it is incumbent upon us as responsible surgeons and scientists to prove this technology works through larger clinical trials before it is adopted more widely.’