(See also Overview and Evaluation of Hand Disorders.)
Digital flexor tendinitis and tenosynovitis are idiopathic but are common among patients with rheumatoid arthritis or diabetes mellitus. Repetitive use of the hands (as may occur when using heavy gardening shears) may contribute. In diabetes, they often coexist with carpal tunnel syndrome and occasionally with fibrosis of the palmar fascia. Pathologic changes begin with a thickening or nodule within the tendon; when located at the site of the tight first annular pulley, the thickening or nodule blocks smooth extension or flexion of the finger. The finger may lock in flexion, or “trigger,” suddenly extending with a snap.
Treatment of acute inflammation and pain includes splinting, moist heat, and anti-inflammatory doses of nonsteroidal anti-inflammatory drugs (NSAIDs).
If these measures fail, injection of a corticosteroid suspension into the flexor tendon sheath, along with splinting, may provide safe, rapid relief of pain and triggering. Operative release can be done if corticosteroid therapy fails.