trigger finger/thumb

Introduction

Inability to re-extend the finger (generally 2nd or 3rd finger) after flexion, due to sticking of tendon in the metacarpal tendon sheath.

Etiology

• direct mechanical trauma to the joints of the fingers
• repetitive grasping action involving the fingers &/or thumb

Epidemiology

• 3% in the general population
• up to 10% in patients with diabetes mellitus

Pathology

• inflammation due to overuse of the superficial finger flexor tendons
• tendon nodules at the A1 pulley site (distal palmar area over the distal metacarpal head)
• sticking of tendon in the metacarpal tendon sheath

Clinical manifestations

• inability to re-extend the finger (generally 2nd or 3rd finger) after flexion
• making a fist may be difficult/painful
• the digit may finally extend with a painful click
• a nodule may be felt over the A1 pulley

Management

• steroid injection: 0.5 cc Kenalog (40 mg/mL)
  • 45% of patients with sustained benefit from a single injection after 10 years
    • women more likely to benefit than men
    • age & diabetes mellitus not factors in benefit
• surgical release

More general terms

• repetitive strain disorder