Tenosynovitis

Tenosynovitis is the inflammation of a tendon (tendinitis) and its synovial sheath (synovitis). This inflammation is often due to tendon overuse (e.g., texting, typing), but can also be due to systemic diseases (e.g., rheumatoid arthritis, sarcoidosis) or infection following a penetrating injury (e.g., animal/human bites, thorn prick injury). The tendons of the hand and wrist are most commonly affected. Patients typically present with pain which is worsened by activity, edema of the affected tendons, and pain along the tendon course on stretching of the tendon. The diagnosis is established clinically but may require additional pathogen isolation for treatment planning in cases of bacterial tenosynovitis. Administration of NSAIDs and immobilization of the affected tendons is often sufficient for treating tenosynovitis. In cases of severe or persistent symptoms glucocorticoid injections into the tendon sheath are usually effective. Few cases require surgical splitting of the constricting ligaments of the affected tendons.

• Non-infectious tenosynovitis (most common)
  • Overuse tendinitis: repetitive use of the involved tendon (e.g., texting, typing, gaming)
  • Systemic diseases (e.g., rheumatoid arthritis, sarcoidosis, diabetes mellitus)
• Infectious tenosynovitis ^[1]
  • Direct inoculation following penetrating trauma
    • Animal/human bites
    • IV drug use
    • Thorn prick injuries
  • Hematogenous spread of infection
    • Neisseria gonorrhoeae
    • Mycobacterium tuberculosis

• Tendons of fingers and wrist are commonly affected ^[2]
• First sign: pain on passive extension of the affected tendon (affected fingers are slightly flexed at rest)
• Swelling
• Palpable crepitation
• Fever and erythema in the case of bacterial infections
• Late signs
  • Tenderness along the affected tendon
  • Sharp, stabbing pain worsened by activity, followed by constant dull ache at rest

Stenosing tenosynovitis (trigger finger) ^[2]

• Epidemiology ^[3]
  • Sex: ♀ > ♂ (6:1)
  • Age: > 40 years
• Etiology: usually idiopathic
• Pathophysiology: fibrocartilaginous metaplasia of the tendon sheath of the A1 annular pulley → loss of smooth gliding of the finger flexor tendons under the annular pulley → finger gets locked in flexed position ^[3]
• Clinical features ^[3]
  • Trigger finger: locking of a finger in flexed position which releases suddenly with a snap/pop on extension; often painful
  • Often associated with tenderness and a palpable nodule at the base of the metacarpophalangeal joint
  • Mostly affects thumbs and ring fingers
• Diagnostics: clinical diagnosis
• Treatment: see below

De Quervain tenosynovitis ^[4]

• Description: noninflammatory thickening of the tendons of the abductor pollicis longus and extensor pollicis brevis due to myxoid degeneration
• Epidemiology
  • Sex: ♀ > ♂
  • Age: 30–50 years
• Etiology
  • Repetitive/prolonged abduction and extension of the thumb: often seen in golfers and tennis players, individuals who text a lot, and young parents (due to the repeated strain of lifting the baby)
  • Inflammatory conditions such as rheumatoid arthritis
• Clinical features
  • Pain with or without swelling of the radial styloid
  • Pain may radiate to thumb or elbow, exacerbated by movement/grasping objects.
  • Positive Finkelstein test: examiner grasps the affected thumb and exerts longitudinal traction across the palm of the hand towards the ulnar side, which causes pain
• Diagnostics: clinical diagnosis
• Treatment: see below

Tenosynovitis is a clinical diagnosis with specific tests used to establish the etiology.

• Laboratory tests: in infectious synovitis
  • CBC (leukocytosis), CRP , ESR
  • Aspiration and analysis of synovial fluid (WBC count, Gram stain, culture)
• X-ray: assessment of possible bone involvement, detection of a foreign body in cases of penetrating trauma
• Other: tests for underlying disease if one is suspected (e.g., rheumatoid factor, cultures for gonococcal disease)

• Treatment of non-infectious tenosynovitis ^[3]
  • Conservative management (first-line)
    • NSAIDs
    • Splinting (immobilization) of the affected finger for 6 weeks
  • Interventions
    • Single (ultrasound-guided) glucocorticoid injection into the tendon sheath (effective in 90% cases, esp. if the tenosynovitis has been present for less than 6 months) .
    • Splitting of the constricting retinaculum/ligament
• Treatment of infectious tenosynovitis ^[1]
  • Analgesics and broad spectrum IV antibiotics (e.g., cephalosporins, clindamycin )
  • Splinting and elevation of the affected finger (to decrease the edema)
  • Surgery: incision and drainage, saline irrigation, and open debridement of necrotic/infected tissue