Definition
Tenosynovitis where the first dorsal compartment muscle bellies (APL and EPB) cross the second compartment tendons (ECRL and ECRB) in the distal forearm.
Aetiology
- Repetitive wrist flexion and extension
- Rowers, canoeists, weightlifters and skiers
Epidemiology
- Less common than de Quervain’s syndrome
- Young athletes and manual workers after a rise in training load
Pathology
- Stenosing tenosynovitis of the second dorsal compartment sheath
- Friction where APL and EPB cross the radial wrist extensors
- Crossing point 4 to 8 cm proximal to Lister’s tubercle
Clinical Features
- Pain and swelling over the dorsoradial distal forearm
- Palpable or audible crepitus, the squeaker’s wrist
- Tenderness proximal to the first dorsal compartment
- Finkelstein test may be mildly positive
- Pain on resisted wrist extension and thumb abduction
- Fusiform swelling may be visible in thin patients
Investigations
- Clinical diagnosis
- Ultrasound or MRI shows peritendinous oedema at the crossing point
- Radiographs normal, used to exclude fracture or arthritis
Differential Diagnosis
- De Quervain’s syndrome
- Wartenberg syndrome
- Scaphoid fracture
- Thumb CMC joint osteoarthritis
- Extensor tenosynovitis from inflammatory arthritis
Management
- Activity modification. Avoid the provoking wrist motion
- Splinting. Wrist in slight extension for 2 to 3 weeks
- NSAIDs. Symptom relief alongside rest
- Corticosteroid injection. Into the second compartment sheath at the crossing point
- Surgical release. Second dorsal compartment release and debridement for refractory symptoms
Prognosis
- Most settle with rest and splinting
- Recognition avoids an unnecessary first compartment release
Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 19 October 2026.