Back in the Middle Ages, physicians treated a patient with an unstable, or loose, shoulder by placing a hot poker in the patient’s armpit. The tissue reacted by forming a large scar that limited motion of the shoulder, and thus, the shoulder was less likely to dislocate again. We have come a long way since then, but the idea of using heat, or thermal energy, to treat a disorder of the joint is alive and well.
Over the past ten years, orthopaedic surgeons have increasingly used thermal energy to treat various problems of the musculoskeletal system. Instead of the hot poker, we now use small probes no larger than a pencil. Almost always, thermal surgery is performed arthroscopically (through small incisions in the skin). This method allows fluid to flow continuously through the joint, helping to keep the temperature from getting too hot. Different temperatures are used to achieve different goals.
Thermal energy can be used in several ways. First, it is commonly used to remove unwanted tissue. For example, a torn cartilage in the knee can be removed by touching it with the heating probe. This method is very precise, and many surgeons feel they can “fine tune” the surgery better than with traditional methods. An additional benefit of thermal surgery is that the heat itself decreases bleeding by sealing the ends of small blood vessels. With less blood in the area, the surgeon can see better and the surgery takes less time.
Another use of thermal surgery is in treating mild cases of arthritis. The ends of your bones are covered with shiny, smooth tissue called articular cartilage. With wear and tear, this cartilage can become frayed and rough, causing arthritis. Thermal probes are used to treat the cartilage before it degenerates too much. The hope is to create a smoother, stable surface that is less likely to degenerate in the future.
Finally, one of the most popular uses of thermal surgery is to shrink the soft tissues of the joints to make them more stable. This technique is most commonly used in the shoulder but has been used in the ankle and hip as well. After an injury, a ligament can become stretched, causing the normally stable joint to “give way.” Applying the probe to the stretched ligament causes the ligament to become shorter and tighter, making the joint stable again. Thermally treated ligaments need to be protected for several weeks or they can stretch back out. For this reason, your doctor may significantly limit your activity for a period of time after the surgery.
As with any surgery, there are concerns such as infection. Problems can also occur from the thermal energy itself. If too much heat is applied, death of the cartilage, ligament, or bone can occur. There have also been reports of the skin being burned if the probe gets too close to the skin. Furthermore, if thermal energy fails to “tighten” a joint, the traditional surgery may be more difficult due to the thermally damaged tissue. However, when performed by an experienced orthopaedic surgeon, thermal surgery has a low risk of complications such as these.
Thermal surgery is definitely a “hot” topic in orthopaedic surgery. At the present time, it is primarily used for tissue removal and tissue shrinkage. Continued research will provide more answers and, we hope, make it safer and more effective.