De Quervain Tenosynovitis

De Quervain tenosynovitis is stenosing tenosynovitis of the first dorsal compartment of the wrist, which contains the abductor pollicis longus and extensor pollicis brevis. The retinaculum thickens, and the tendons glide poorly through the tight fibro osseous tunnel at the radial styloid. Histology shows myxoid degeneration and thickening rather than classic inflammation.

Prevalence is about 0.5% in men and 1.3% in women. The disorder is 6 to 10 times more common in women, peaks at 30 to 50 years, and is frequent in the last trimester of pregnancy and in the postpartum period (lifting an infant with the thumb abducted and the wrist ulnar deviated). Other risks are repetitive thumb and wrist use, gripping tools, racket sports, rheumatoid arthritis and direct trauma.

The compartment is divided by a septum in 30 to 60% of wrists, with the extensor pollicis brevis in a separate sub-compartment, which affects both injection and surgery. The course is variable. Many cases settle within months, especially in pregnancy, but some are persistent. Complications are chronic pain, superficial radial nerve irritation and, rarely, tendon rupture.

• Pain over the radial wrist, worse with thumb movement, gripping, pinching and wringing
• Swelling and tenderness over the radial styloid, sometimes crepitus
• Positive Finkelstein test (the patient flexes the thumb into the palm and the examiner ulnar deviates the wrist, reproducing sharp pain) and a positive wrist hyperflexion and thumb abduction test
• Pain on resisted thumb extension and abduction
• Red flags: numbness over the dorsal thumb (superficial radial nerve neuritis), fever, trauma, thenar wasting, bilateral disease with systemic inflammatory signs

• Clinical diagnosis from tenderness and the Finkelstein test.
• Ultrasound: thickened retinaculum, fluid in the tendon sheaths, thickened tendons, and the presence of a septum or a separate extensor pollicis brevis compartment.
• Radiographs of the wrist and thumb for carpometacarpal arthritis, scaphoid fracture and radial styloid pathology.
• Inflammatory markers and urate when synovitis is atypical or bilateral.

Differentials: intersection syndrome (pain and crepitus 4 to 6 cm proximal to the wrist), thumb carpometacarpal osteoarthritis, Wartenberg syndrome, scaphoid fracture, flexor carpi radialis tendinopathy, ganglion, rheumatoid arthritis, gout.

• Thumb spica splint (including the thumb interphalangeal joint is optional) full time for 3 weeks, then during activity for a further 3 weeks, with activity modification and avoidance of repeated pinching.
• Analgesia: paracetamol 1 g orally every 6 hours (maximum 4 g a day), ibuprofen 400 mg orally every 8 hours with food for up to 7 days, or diclofenac 1% gel 2 g to the radial wrist four times daily for up to 2 weeks.
• Corticosteroid injection (the most effective option, with success in about 60 to 90%): methylprednisolone acetate 40 mg or triamcinolone acetonide 10 to 20 mg with lidocaine 1% 1 mL into the first dorsal compartment sheath, ideally under ultrasound guidance, with both sub-compartments injected if a septum is present. May be repeated once after 4 to 6 weeks, to a maximum of 2 to 3 injections. Adverse effects: skin hypopigmentation and fat atrophy (more visible in dark skin), tendon rupture, superficial radial nerve injury, transient flare.
• Pregnancy and lactation: splint, activity modification and paracetamol. Steroid injection is safe to use in the postpartum period. Symptoms often resolve after delivery or weaning.
• Surgery (after 2 injections or 6 months of failed treatment, or a recurrent case): release of the first dorsal compartment through a transverse incision over the radial styloid, with dorsal side division of the retinaculum, release of every sub-compartment, and care to protect branches of the superficial radial nerve. Wide awake local anaesthesia with lidocaine 1% and adrenaline 1:100,000, 5 to 10 mL. Cefazolin 2 g IV before incision if a tourniquet and sedation are used. Immediate finger and thumb motion, with return to light use in 1 to 2 weeks.
• Complications of surgery: superficial radial nerve neuroma (up to 10%), volar tendon subluxation if the release is too volar, incomplete release from a missed septum, scar tenderness and complex regional pain syndrome.

Follow up at 4 to 6 weeks after injection and at 2 and 6 weeks after surgery. Counsel on modified lifting of infants, neutral wrist positions and ergonomic tool changes.