Shockwave therapy is a relatively new treatment option in orthopedic and rehabilitation medicine. The effect of shockwaves was first documented during World War II when the lungs of castaways were noted to be damaged without any superficial evidence of trauma. It was discovered the shockwaves created by depth charges were responsible for the internal injuries. This created a great deal of interest and research into the biological effects of shockwaves on living tissue. The first medical treatment developed from this research was lithotripsy. This allowed focused shockwaves to essentially dissolve kidney stones without surgical intervention. Today, over 98% of all kidney stones are treated with this technology. The use of shockwaves to treat tendon related pain began in the early 1990s.
A clinical shockwave is nothing more than a controlled explosion that creates a sonic pulse, much like an airplane breaking the sound barrier. The primary effect of a shockwave is a direct mechanical force. The exact mechanism by which shockwave therapy acts to treat tendon pathology is not known. The leading explanation is based on the inflammatory healing response. It is felt the shockwaves cause microtrauma to the diseased tendon tissue. This results in inflammation, which allows the body to send healing cells and increase the blood flow to the injured site.
Shockwaves are used to treat many orthopedic conditions, including plantar fasciitis (heel spurs), patellar tendinitis (jumper’s knee), lateral epicondylitis (tennis elbow), medial epicondylitis (golfer’s elbow) and shoulder tendinitis. Multiple studies have been conducted to assess the efficacy of shockwave therapy. Many have shown a positive response versus placebo treatment and others have shown no benefit over placebo. No studies have reported any significant side effects when utilized for orthopedic conditions. Contraindications to shockwave therapy include bleeding disorders and pregnancy.
There are two main types of shockwave machines, low and high energy. High-energy treatments are administered in the operating room with regional or general anesthesia. Low-energy treatments are administered in the clinic and do not require anesthesia or injections. SCOI currently uses a low-energy machine. A technician places the probe on the area of greatest tenderness and the shockwaves are delivered over 10-20 minutes. Occasionally, patients will relate mild transient discomfort at the treatment site. Patients are usually treated with 3-5 sessions separated by a week. Between treatments, patients are able to perform all normal daily activities. Some patients report immediate pain relief but the healing response usually requires 6-8 weeks. Early results are encouraging and research continues at multiple sites around the country.
By Michael S. Hewitt, MD