Tendinitis and Tenosynovitis

ByDeepan S. Dalal, MD, MPH, Brown University
Reviewed/Revised Mar 2024
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Tendinitis is inflammation of a tendon, often developing after degeneration (tendinopathy). Tenosynovitis is tendinitis with inflammation of the tendon sheath lining. Symptoms usually include pain with active or resisted motion and tenderness with palpation. Chronic deterioration or inflammation of the tendon or tendon sheath can cause scars that restrict motion. Diagnosis is clinical, sometimes supplemented with imaging. Treatment includes rest, nonsteroidal anti-inflammatory drugs (NSAIDs), and sometimes corticosteroid injections.

Tendinopathy usually results from repeated small tears or degenerative changes (sometimes with calcium deposits) that occur over years in the tendon.

Tendinitis and tenosynovitis most commonly affect tendons associated with the shoulder (rotator cuff), the tendon of the long head of the biceps muscle (bicipital tendon), flexor carpi radialis or ulnaris, flexor digitorum, popliteus tendon, Achilles tendon (see Achilles Tendinitis), and the thumb's abductor pollicis longus and extensor pollicis brevis, which share a common fibrous sheath (the resulting disorder is De Quervain syndrome).

Etiology of Tendinitis and Tenosynovitis

The cause of tendinitis is often unknown. It usually occurs in people who are middle-aged or older as the vascularity of tendons decreases; repetitive microtrauma may contribute. Repeated or extreme trauma (short of rupture), strain, and excessive or unaccustomed exercise probably also contribute. Some fluoroquinolone antibiotics may increase the risk of tendinopathy and tendon rupture.

Risk of tendinitis may be increased by certain systemic disorders—most commonly rheumatoid arthritis, systemic sclerosis, gout, reactive arthritis, and diabetes or, very rarely, amyloidosis or markedly elevated blood cholesterol levels. In younger adults, particularly women, disseminated gonococcal infection may cause acute migratory tenosynovitis in the absence of localizing genitourinary symptoms. Nontuberculous mycobacteria, such as Mycobacterium marinum, have a predilection to cause local chronic infection of peripheral tendons, resulting in symptoms of tenosynovitis.

Fluoroquinolone antibiotic use has been associated with tendinopathies, including tendon rupture.

Symptoms and Signs of Tendinitis and Tenosynovitis

Affected tendons are usually painful when actively moved or when natural motion is resisted. For example, because the posterior tibial tendon helps invert the foot, passive eversion plus active, resisted inversion causes pain in patients with posterior tibial tendinitis. Occasionally, tendon sheaths become swollen and fluid accumulates, usually when patients have infection, rheumatoid arthritis, or gout. Swelling may be visible or only palpable. Along the tendon, palpation elicits localized tenderness of varying severity.

In systemic sclerosis, the tendon sheath may remain dry, but movement of the tendon in its sheath may cause friction, which can be felt or heard with a stethoscope.

Diagnosis of Tendinitis and Tenosynovitis

  • Clinical evaluation

  • Sometimes imaging

Usually, the diagnosis can be based on symptoms and physical examination, including palpation or specific maneuvers to assess pain. MRI or ultrasonography may be done to confirm the diagnosis, rule out other disorders, and detect tendon tears and inflammation.

Rotator cuff tendinopathy

Rotator cuff tendinopathy is the most common cause of shoulder pain. The rotator cuff is composed of four tendons, the supraspinatus, infraspinatus, subscapularis, and teres minor. The supraspinatus tendon is most frequently involved and the subscapularis is second. Active abduction in an arc of 40 to 120° and internal rotation cause pain (see also Rotator Cuff Injury/Subacromial Bursitis). Passive abduction causes less pain, but abduction against resistance can increase pain. Calcium deposits in the tendon just below the acromion are sometimes visible on radiograph. Ultrasonography or MRI may help with further evaluation (eg, if the diagnosis is otherwise unclear) and with treatment decisions (eg, presence of significant tears that might warrant surgical interventions).

Bicipital tendinitis

Pain in the biceps tendon is aggravated by shoulder flexion or resisted supination of the forearm. Examiners can elicit tenderness proximally over the bicipital groove of the humerus by rolling (flipping) the bicipital tendon under their thumb.

Volar flexor tenosynovitis (digital flexor tendinitis)

Volar flexor tenosynovitis (digital flexor tendinitis) is a common musculoskeletal disorder that is often overlooked. Pain occurs in the palm on the volar aspect of the thumb or other digits and may radiate distally. Palpation of the tendon and sheath elicits tenderness; swelling and sometimes a nodule are present. The affected digit may rest in a flexed position, and passive extension elicits pain. In later stages, the digit may lock when it is flexed, and forceful extension may cause a sudden release with a snap (trigger finger).

Gluteus medius tendinitis

Patients with greater trochanteric pain syndrome (formerly trochanteric bursitis) almost always have gluteus medius tendinitis. In patients with greater trochanteric pain syndrome, palpation over the lateral prominence of the greater trochanter elicits tenderness. Patients often have a history of chronic pressure on the joint, trauma, a change in gait (eg, due to osteoarthritis, stroke, or leg-length discrepancy), or inflammation at this site (eg, in rheumatoid arthritis).

Treatment of Tendinitis and Tenosynovitis

  • Rest or immobilization, heat or cold, followed by exercise

  • Nonsteroidal anti-inflammatory drugs (NSAIDs)

  • Sometimes corticosteroid injection

Symptoms are relieved by rest or immobilization (eg, splint or sling) of the tendon, application of heat (usually for chronic inflammation) or cold (usually for acute inflammation), and NSAIDs (see table NSAID Treatment of Rheumatoid Arthritisgout is the cause. After inflammation is controlled, exercises that gradually increase range of motion should be done several times a day, especially for the shoulder, which can develop contractures rapidly.

Pearls & Pitfalls

  • Do not inject corticosteroids into a tendon; doing so will weaken it, increasing risk of rupture.

Repeat injections and symptomatic treatment may be required. Rarely, for persistent cases, particularly rotator cuff tendinopathy, surgical exploration with removal of calcium deposits or tendon repair, followed by graded physical therapy, is needed. Occasionally, patients require surgery to release scars that limit function, remove part of a bone causing repetitive friction, or do tenosynovectomy to relieve chronic inflammation.

Key Points

  • Tendinitis and tenosynovitis, unlike tendinopathy (tendon degeneration), involve inflammation.

  • Pain, tenderness, and swelling tend to be maximal along the tendon's course.

  • Diagnose most cases by examination, including tendon-specific maneuvers, sometimes confirming the diagnosis with MRI or ultrasonography.

  • Treat with rest, heat or cold, NSAIDs, and sometimes corticosteroid injection.

Drugs Mentioned In This Article
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