Description

Trigger finger, also known as stenosing flexor tenosynovitis, is disruption of smooth tendon gliding in the fingers/thumb that causes clicking, locking, catching, and pain with flexion and extension.

Epidemiology

Incidence

• Adult population: 2–3% of adults
  • Typically presents in the 5th and 6th decades of life
  • Female > male (6:1)
• Rare in children
  • Associated with mucopolysaccharidoses (MPS)
  • Female = male
• 10% of diabetic population
• Thumb is predominant digit

Prevalence
Lifetime prevalence in the general population is 2.6%.

Pediatric Considerations

• Successful treatment using nonoperative methods such as casting and splinting
• Surgical methods provided satisfactory resolution with those who failed conservative measures and are also used as initial therapy as well.

Etiology and Pathophysiology

• The result of fibrocartilaginous metaplasia of the tendon and/or pulley from prolonged inflammation causing narrowing around the pulley
• This can occur at any of the five pulleys along the flexor tendon—A1 pulley is the most common.
• If flexor tendon becomes nodular, the triggering phenomenon is worse because the nodule has difficulty passing under the A1 pulley.
• Because intrinsic flexor muscles are stronger than extensors, the finger can get stuck in the flexed position.
• No clear association with repetitive movements

Risk Factors

• Diabetes mellitus
• Rheumatoid arthritis
• Hypothyroidism
• Mucopolysaccharide disorders
• Amyloidosis

General Prevention

• Most cases are idiopathic.
• No clear association with occupational-related or repetitive activities

Commonly Associated Conditions

• Orthopedic conditions:
  • Rheumatoid arthritis
  • Calcific tendinitis
  • Septic tenosynovitis
  • Carpal tunnel syndrome
  • Congenital trigger thumb
• Medical conditions:
  • Diabetes
  • Amyloidosis
  • Hypothyroidism
  • Sarcoidosis
  • Gout
  • Pseudogout