Finger injuries are often seen in the primary care physician’s office. The evidence—and our experience in sports medicine—indicates that many of these injuries can be managed conservatively with bracing or injection; a subset, however, requires surgical referral. In this article, we provide a refresher on finger anatomy (see “A guide to the anatomic structures of the digits of the hand”1,2) and review the diagnosis and management of 4 common soft-tissue finger and thumb injuries in adults: trigger finger, jersey finger, mallet finger, and skier’s thumb (TABLE2-18).
Also called stenosing flexor tenosynovitis, trigger finger is caused by abnormal flexor tendon movement that results from impingement at the level of the A1 pulley.
Causes and incidence. Impingement usually occurs because of thickening of the A1 pulley but can also be caused by inflammation or a nodule on the flexor tendon.3,4 The A1 pulley at the metacarpal head is the most proximal part of the retinacular sheath and therefore experiences the greatest force upon finger flexion, making it the most common site of inflammation and constriction.4
Trigger finger occurs in 2% to 3% of the general population and in as many as 10% of people with diabetes.5 The condition typically affects the long and ring fingers of the dominant hand; most cases occur in women in the sixth and seventh decades.3-5
Multiple systemic conditions predispose to trigger finger, including endocrine disorders (eg, diabetes, hypothyroidism), inflammatory arthropathies (gout, pseudogout), and autoimmune disorders (rheumatoid arthritis, sarcoidosis).3,5 Diabetes commonly causes bilateral hand and multiple digit involvement, as well as more severe disease.3,5 Occupation is also a risk factor for trigger finger because repetitive movements and manual work can exacerbate triggering.4
Presentation and exam. Patients report pain at the metacarpal head or metacarpophalangeal (MCP) joint, difficulty grasping objects, and, possibly, clicking and catching of the digit and locking of the digit in flexion.3,5
On exam, there might be tenderness at the level of the A1 pulley over the volar MCP joint or a palpable nodule. In severe cases, the proximal interphalangeal (PIP) joint or entire finger can be fixed in flexion.5 Repeated compound finger flexion (eg, closing and opening a fist) or holding a fist for as long as 1 minute and then slowly opening it might provoke triggering.
More than 60% of patients with trigger finger also have carpal tunnel syndrome.5 This makes it important to assess for (1) sensory changes in the distribution of the median nerve and (2) nerve compression, by eliciting Phalen and Tinel signs.4,5
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