Extensor Tendinopathy of the Wrist

Degenerative or inflammatory overload of the extensor tendons that cross the dorsal wrist within the six dorsal compartments: extensor carpi ulnaris (sixth compartment, the commonest site of sports related wrist tendinopathy), extensor carpi radialis longus and brevis (second), extensor digitorum and extensor indicis (fourth), extensor digiti minimi (fifth), and extensor pollicis longus (third).

• Causes: repetitive wrist extension, deviation or rotation (tennis, golf, badminton, rowing, weightlifting, gymnastics, typing, manual work), sudden increase in load, direct trauma, and rheumatoid arthritis (tenosynovitis with a risk of rupture). Extensor carpi ulnaris tendon subluxation follows forearm supination with ulnar deviation and wrist flexion, as in a tennis forehand or golf swing.
• Extensor pollicis longus tendinopathy and rupture follow undisplaced distal radius fractures (ischaemia at Lister tubercle, rupture at 3 to 8 weeks), steroid injection, and rheumatoid arthritis.
• Risk factors: repetitive use, ulnar variance, inflammatory arthritis, corticosteroid or fluoroquinolone exposure, and previous wrist injury.
• Prognosis is good with early splinting and graded loading, and most patients recover in 6 to 12 weeks.

• Pain over the dorsum of the wrist, along the affected tendon, worse on resisted extension, gripping, lifting and repetitive use, with tenderness, local swelling and occasional crepitus.
• Extensor carpi ulnaris: ulnar sided dorsal wrist pain, tenderness in the groove beside the ulnar styloid, pain on resisted wrist extension with ulnar deviation, and a painful snap or pop when the forearm is supinated with the wrist flexed and ulnar deviated (subluxation from the groove).
• Extensor pollicis longus: pain over the dorsal wrist at Lister tubercle, radiating to the thumb, and inability to extend the thumb interphalangeal joint when it ruptures.
• Rheumatoid involvement: boggy dorsal swelling that moves with the tendons, with a risk of rupture of the ring and little finger extensors (inability to extend these fingers at the metacarpophalangeal joints).
• Differential diagnosis: triangular fibrocartilage complex tear, ulnocarpal impaction, lunotriquetral ligament injury, distal radioulnar joint instability, dorsal wrist ganglion, scapholunate injury, intersection syndrome, carpal boss, Kienbock disease, posterior interosseous nerve syndrome, and septic tenosynovitis.
• Red flags: sudden loss of finger or thumb extension (rupture), fever and warmth, persistent swelling with morning stiffness, and trauma with bony tenderness.
• Complications: tendon rupture, chronic tenosynovitis, instability, and persistent weakness.

• Clinical, with a full examination of the wrist, distal radioulnar joint and extensor function of each finger and the thumb.
• X-ray of the wrist to exclude fracture, arthritis, ulnar variance, and calcification.
• Ultrasound (dynamic) shows tendon thickening, effusion in the sheath, tears and subluxation. MRI shows tendon tears, sheath disease and associated triangular fibrocartilage or ligament injury.
• Blood tests (CRP, ESR, rheumatoid factor, anti-CCP antibodies, urate) when inflammatory arthritis or gout is suspected.

• Relative rest and activity modification for 2 to 4 weeks. Correct technique and equipment (grip size, racket string tension, tool handles, keyboard position).
• Splinting: for extensor carpi ulnaris, a wrist splint or short arm cast holding the wrist in slight extension and radial deviation with the forearm in pronation, for 3 to 6 weeks. For other tendons, a wrist splint in neutral to 20 degrees of extension for 2 to 4 weeks.
• Analgesia: paracetamol 1 g orally 6 hourly. Ibuprofen 400 mg orally 8 hourly with food (or naproxen 500 mg 12 hourly) for 1 to 2 weeks. Topical diclofenac 1% gel 2 to 4 g 3 to 4 times daily. Ice for 10 to 15 minutes after activity.
• Physiotherapy: progressive eccentric and isometric loading of the wrist extensors and ulnar deviators, grip strengthening, forearm stabilisation, and proprioceptive training, over 6 to 12 weeks, with graded return to sport.
• Corticosteroid injection for persistent pain after 4 weeks: triamcinolone acetonide 10 to 20 mg with lidocaine 1% 1 to 2 mL into the tendon sheath (not into the tendon), under ultrasound guidance. Avoid injection near the extensor pollicis longus and in rheumatoid disease because of the risk of rupture.
• Rheumatoid tenosynovitis: treat the underlying disease with disease modifying drugs under rheumatology, and arrange early surgical synovectomy for persistent tenosynovitis beyond 3 to 6 months to prevent rupture.
• Surgery:
  • Extensor carpi ulnaris subluxation: reconstruction of the fibro osseous sheath (subsheath) using a strip of retinaculum, for failure of 3 to 6 months of casting.
  • Chronic tenosynovitis: debridement and tenosynovectomy.
  • Tendon rupture: urgent hand surgery review. Extensor pollicis longus rupture is treated by extensor indicis proprius transfer, and rheumatoid finger extensor ruptures by tendon transfer or grafting, within the first weeks for best results.
• Special groups:
  • Athletes: graded return when pain free, with full grip strength and no snapping.
  • Pregnancy: splint, paracetamol and ice. Avoid NSAIDs after 20 weeks.
  • Diabetes: monitor glucose after injection.
  • Fluoroquinolone and corticosteroid users: review the drug if tendon pain occurs.
• Follow up: review at 2 to 3 weeks and at 6 weeks. Refer to hand surgery or rheumatology for suspected rupture, subluxation, rheumatoid disease or failure of 3 months of treatment.