Arthroscopic Shoulder Surgery:

Thermal Capsulorrhaphy

No joint has greater range of motion than the shoulder. But this flexibility is also a liability, because it makes the shoulder prone to dislocation and instability. The upper arm bone (humerus) sits in a saucer-shaped part of the shoulder blade (scapula) called the glenoid. A circle of ligaments, tendons, muscles and cartilage form a capsule around the joint to maintain stability.

Trauma or overuse can cause these soft tissues to stretch or tear. Then they can no longer provide the necessary support. A feeling of "looseness" may develop and the shoulder may "pop out" with some activities. Pain and weakness may interfere with daily activities such as work, sports, or sleep.

An emerging trend

In recent years, arthroscopic techniques that use heat to "shrink" and tighten the tissues have been developed to treat several types of shoulder instability. The new procedure, called thermal capsulorrhaphy (kap-sue-lore'-a-fee), works because the molecular structure of tissue changes in response to heat. Tendons and ligaments are primarily composed of collagen, a type of protein. When collagen is heated to the appropriate temperature, it contracts and "shrinks." The body perceives this as an injury and the tissues rebuild around the shorter collagen fibers, resulting in a tighter, and theoretically more stable, shoulder.

Initially, laser devices that used light to heat the tissues were developed, but the high cost of equipment and other concerns prompted researchers to investigate other methods. Today, radio frequencies inside the thermal probe can also be used to generate the necessary temperatures. These devices generate vibrations within the intracellular molecules, creating heat.

What to expect

Thermal capsulorrhaphy is an outpatient procedure performed while the patient is under general anesthetic. The surgeon makes two or three small incisions called portals through which to insert the pencil-sized arthroscopic instruments. One instrument enables the surgeon to view the joint and another provides the heat source. The surgeon is able to see changes in color and texture in the tissues as the thermal probe is brushed back and forth across them. The entire procedure usually takes less than 30 minutes.

After surgery, patients must wear a sling for at least three weeks. There is little postoperative pain, but the patient must be careful not to raise or turn the arm because this will stretch the tissues before they have healed in their shortened state. The physician will also prescribe a rehabilitation program designed to strengthen the muscles and restore a full range of motion. Patients may be able to safely return to certain sports in as little as four to six months.

Results

Early studies indicate that thermal capsulorrhaphy may be beneficial in treating several kinds of shoulder instability. However, the technique is so new that long-term results are not yet available. Some people may continue to experience shoulder instability and may eventually require open surgery to shorten and tighten the tendons. Others may develop a condition called capsulitis, which is a stiffening or tightness in the joint.

Thermal capsulorrhaphy is not appropriate for every patient. Your doctor will discuss various options with you based on the underlying cause and the degree of laxity in your shoulder. Overuse injuries can often be treated with an aggressive rehabilitation program, but if non-operative treatment fails, surgery may be recommended. Traumatic injuries may also require surgical repair. If the damage is significant, the orthopedic surgeon may use an open technique that tightens and reattaches the tissue. A hospital stay will be necessary in this case and rehabilitation can take 9 to 12 months.