New Implant To Relieve Joint Pain

by Karen Ott Mayer

New Implant To Relieve Joint Pain

The HemiCAP implant is a rounded, cap-like device.
Patients suffering from painful joints may now have an alternative treatment with the introduction of a new larger 35-millimeter HemiCAP (Contoured Articular Prosthetic) device.

Manufactured by Arthrosurface, a company located in Franklin Massachuetts, the device is part of the HemiCAP Resurfacing System which is a surgical method for treating localized lesions and defects in major joints such as the knee, hip and shoulder.

Joint pain occurs when the articular cartilage, the cartilage that covers the bones of a joint, is damaged. When the cartilage is damaged, it becomes rough or worn, thus preventing bones in a joint to slide smoothly against each other. Articular cartilage can be damaged through trauma or degenerative joint disease that can include damage from years of athletic activities and arthritis.

"Painful damage to the joint cartilage is a common problem for patients in their 40's and 50's. Repeated injury from sports, heavy work or a traumatic impact can damage a section of the joint's naturally smooth surface. When this happens, the bones grate against each other causing swelling, pain and limited motion," says local orthopeadic surgeon, Bret Sokoloff, M.D. of Methodist Healthcare and Memphis Orthopaedic Group.

The HemiCAP implant is a rounded, cap-like implant made from a cobalt chrome alloy. This metal possesses qualities that are similar to articular cartilage when implanted in a joint, mimicking the smooth articular surface which allows the bones to slide freely against each other once again. It is implanted by mapping the curves of each patient's joint during surgery, so the surgeon can select the most appropriate fit based on the patient's anatomy.

Sokoloff is one of just a few select physicians that has been trained on how to implant the new larger 35-millimeter HemiCAP.

"The traditional total joint replacement, unlike the HemiCAP device, removes a large amount of bone and sets the stage for later problems or more complicated revision surgery in the younger population. Patients may be too young for a full replacement, but need something to give them relief from the pain and allow them to resume their normal lifestyle," says Sokoloff.

By using the larger 35-millimeter HemiCAP implant, rather than the smaller 25 and 30-millimeter device, Sokoloff can now treat patients with more widespread arthritis or avascular necrosis (loss of blood supply to the bone) without limiting future options for the patient.

The procedure requires a smaller incision and less removal of bone than traditional joint replacement and patients experience less pain. The HemiCAP surgical procedure begins when two or more small incisions are made in order to access the joint. An arthroscope is inserted in one of the incisions. The second portal is used for instrumentation during surgery. When a defect is located, a component is implanted to establish a mechanism for the resurfacing implant. Special instruments are used to map the contours of the patient's articular cartilage. Once the site is prepared, the HemiCAP resurfacing implant is positioned and seated.

Patients recover quicker after the procedure and are allowed to return to normal activities sooner than with previous procedures.

"Some patients have described the surgery as phenomenal, reporting less crunching and an increased sense of strength and function relatively soon after surgery," says Sokoloff.

Patients like Richard Booker understand the meaning of joint pain. A horse trainer, he suffered a severe injury when a horse he was training jerked his right arm. After three months of cortisone shots that did not ease the pain, laser surgery revealed Booker's shoulder joint had severe cartilage damage.

"The pain was so bad I could hardly raise my arm," he said.

Not only were the bones in the joint rubbing against each other, there were also signs of arthritis. After discussing his options with Sokoloff, he decided to have the HemiCAP resurfacing implant. The procedure succeeded in relieving pain for Booker. With the help of physical therapy, he will soon be able to resume his normal activities.

For the young, active population, the HemiCAP means the possibility of avoiding total joint replacements and may delay further damage in the joint.

The U.S. Food and Drug Administration has approved the HemiCAP implant for use in the shoulder, hip and foot. It is currently being clinically evaluated for use in the knee.