My doctor told me I have tendinosis. How is this different than tendinitis?

Tendons function to transmit the force generated by our muscles to our bones, allowing us to move. When tendons are subjected to repetitive mechanical loads they can be compromised, possibly developing small tears, degenerative changes, collagen disruption, proliferation of certain cells (for example fibroblasts), inflammation or other abnormalities. When this happens the patient will develop tenderness, pain (especially against resistance when using the affected tendon), loss of function and/or other symptoms.

We usually use “-itis” to denote inflammation, but evaluation of surgical specimens of patients with tendon abnormalities show that inflammation of the tendon is actually not a large component of their condition. Some authors use tendinitis to mean an acute tendon injury and tendinosis to mean a more chronic condition, while other authors now refer to these injuries as tendinosis or tendinopathy and no longer use the term tendinitis.

Sports injuries are very common, with the incidence depending on the sport and the athlete. For example, it is estimated that as few as 2 per 100 to as many as 40 per 100 athletes participating in club gymnastics suffer a sports-related injury per year. It is estimated that half of all sports injuries involve tendons. So although many of these injuries are not reported thus it is not known how prevalent they are, tendon injuries are overall very common, especially by the time people reach middle age.

Common tendinopathies include (note that the injuries are not limited to the sport they are named after): tennis elbow (lateral epicondylitis); pitcher’s elbow (medical epicondylitis); rotator cuff injuries (involving the shoulder); bicipital injuries (involving the biceps tendons); jumper’s knee (patellar tendinopathy), as well as other knee conditions (such as iliotibial band syndrome); shin splints (medial tibial stress syndrome); Achilles tendon injuries; others.

The diagnosis of a tendon injury is made based on the injury and physical exam; X-rays are usually normal, and other imaging (such as ultrasound or MRI) are usually not needed unless the diagnosis is in question.

The goal of treatment for tendon injuries is to reduce pain and regain functionality. Acutely, rest (avoidance of activities that cause pain, specifically avoiding the activity suspected of leading to the condition and even possibly including use of a sling or other support to minimize use of the injured area), pain management with non-steroidal anti-inflammatory drugs (NSAIDs), and/or ice (for first one to two days) are often indicated. For more chronic symptoms, physical therapy (for example heavy load resistance training and stretching exercises) is usually recommended. Other treatment considerations may include topical nitroglycerin cream (although some studies note limited benefit there also seems to be minimal risk), acupuncture, pulsed ultrasound treatments and other treatments.

Although the overall prognosis is good, it may take many months for the patient to get back to their baseline, so it is important patients know they need to continue their physical therapy and/ other treatments. Complications may include tendon rupture, chronic pain/disability and/or loss of functionality (for example “frozen shoulder”). Surgical consultation should be considered in patients have not improved after six months despite diligent compliance with treatment recommendations.

Jeff Hersh, Ph.D., M.D., can be reached at DrHersh@juno.com.