What is tendinitis?

Causes and Symptoms

Tendons are fibrous cords that attach muscles to bones. Their function is to transmit force and coordinate the activity between muscles and bones. When too much stress is placed upon the tendons, they may become inflamed (tendinitis), or damaged, or both, from the chronic degeneration of tendon
collagen (tendinosis). The cause of such stress is usually poor technique, overuse, or repetitive movements in sports, recreational, and occupational activities. The injury usually follows the progression of multiple microscopic tears in the tendon tissue, eventually leading to acute inflammation and pain. The areas most commonly affected are the rotator cuff of the shoulder, the elbow (“tennis elbow” or “golfer’s elbow”), the
wrist/thumb (de Quervain’s disease), the knee (“jumper’s knee”), and the ankle (Achilles tendinitis).

Many athletic activities, such as racquet sports, baseball, running, and weight training, involve repetitive movements that may put excessive stress on the tendons. Many occupations also pose a risk; examples include performing assembly line work, playing a musical instrument, and using a keyboard. Tendinitis may also be caused by infection or by a buildup of calcium deposits (calcific tendinitis) or other materials in a joint as a result of a chronic illness such as diabetes or arthritis.

Pain is the usual complaint. It occurs when the patient moves the affected joint but may sometimes persist when the joint is at rest. In severe cases, simple activities such as raising a coffee cup or brushing teeth may cause pain. There may also be swelling, warmth, and redness in the affected area.

Treatment and Therapy

The term “tendinitis” has traditionally been used as a blanket term for all tendinopathies. However, medical professionals emphasize that tendinitis and tendinosis, while often occurring hand-in-hand, are separate conditions and must be treated accordingly. Tendon overuse conditions have been generally considered inflammatory processes (tendinitis), and therapy has been administered based on that conception. However, it is important to recognize that overuse tendon conditions are frequently caused by collagen damage and degeneration of tendon tissue (tendinosis), eventually leading to an acute inflammatory condition. Tendinosis requires a different approach to therapy once the initial inflammation is treated.

True tendinitis conditions are treated with therapy aimed at reducing inflammation. Rest and avoidance of the causative activity, alternative application of ice and heat, compression and elevation of the affected extremity, and immobilization with slings and splints are all helpful measures. Over-the-counter anti-inflammatory medications such as ibuprofen may be suggested. A method exists for delivering medication to inflamed tissue: iontophoresis, whereby a small electrical current delivers anti-inflammatory medication, such as dexamethasone, through the skin to the inflamed tissue. More severe cases may require corticosteroid injections. Tendinitis caused by infection is treated with antibiotics and sometimes surgery if first-course therapy is not effective. Recovery from tendinitis varies from a few to several weeks.

Tendinosis therapy is aimed at allowing the injured tendon tissue to heal. Rest and avoidance of the offending activity is most important. Icing, ultrasound, and electrical stimulation may enhance collagen production. Once the initial inflammation has been treated, anti-inflammatory medications and corticosteroid injections are not indicated and may actually impede healing. Ergonomic changes in the workplace and the correction of improper technique in sports activities are important. Physical therapy and strengthening exercises play key rehabilitative roles by helping to prevent future injury, and they may also improve collagen formation and thus speed healing. Surgery to remove damaged tissue is used only as a last resort when conservative management has failed. Recovery from tendinosis may take up to several months.

Perspective and Prospects

Tendinopathies have been regarded as conditions that are often recalcitrant to therapy, becoming chronic or frequently reoccurring. It is possible that this difficulty is in part attributable to the lack of distinction between tendinitis and tendinosis. It has been postulated that some of the therapies for tendinitis, when used on tendinosis, may cause further tissue deterioration and thus contribute to the chronic nature of the disorder. Additionally, once the initial inflammation is treated and pain is no longer felt, the injured individual will often begin the offending activity before healing is complete. This leads to further damage and weakened tissue, creating a frustrating cycle. It is therefore crucial that a proper diagnosis is made before treatment begins and that the injured individual follow the full course of therapy and rest to ensure optimal healing.

The investigation of new treatment modalities is ongoing. Extracorporeal shock wave therapy has been shown to have some positive benefits for both tendinosis and calcific tendinitis. The use of ultrasound and electrical stimulation has gained acceptance with some professionals.

Preventive measures can greatly reduce the risk of developing overuse tendinopathies. This approach is becoming more evident in the workplace, where proper ergonomic environments help to decrease employee injury, increase productivity, and reduce injury and absences. Conditioning and emphasis on correct technique in sports and recreational activities will greatly reduce the incidence of tendon overuse disorders.

Bibliography

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Khan, Karim M, et al. “Time to Abandon the ’Tendinitis’ Myth: Painful, Overuse Tendon Conditions Have a Non-inflammatory Pathology.” British Medical Journal 324, no. 7338 (March 16, 2002): 626–627.

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