Flexor Tendinopathy of the Wrist

Overuse or degenerative disease of the flexor tendons at the wrist, mainly flexor carpi radialis (at the groove of the trapezium and its insertion on the base of the second metacarpal) and flexor carpi ulnaris (at the pisiform and its insertions on the hook of the hamate and fifth metacarpal). Palmaris longus and the finger flexors are involved less often.

• Causes: repetitive wrist flexion and gripping (racket sports, golf, rowing, weightlifting, gymnastics, cycling, manual work, musicians), trauma, scaphotrapeziotrapezoid osteoarthritis (flexor carpi radialis irritated by osteophytes in its tunnel), and inflammatory arthritis.
• Calcific tendinitis of flexor carpi ulnaris near the pisiform produces an acute, severe, self-limiting attack in adults aged 30 to 60, often mistaken for infection or gout.
• Flexor carpi radialis tendon rupture is rare and follows chronic tendinopathy or steroid injection.
• Prognosis is good, and most cases improve within 6 to 12 weeks with splinting and loading.

• Flexor carpi radialis: pain on the palmar radial wrist, at the proximal wrist crease and thenar base, worse with resisted wrist flexion and radial deviation and with gripping, with tenderness over the tendon and sometimes swelling, and pain on passive wrist extension.
• Flexor carpi ulnaris: pain on the palmar ulnar wrist near the pisiform, worse with resisted wrist flexion and ulnar deviation, with tenderness proximal to the pisiform and local swelling. Calcific tendinitis causes sudden severe pain, redness, warmth and swelling over the pisiform with marked tenderness and limited wrist movement, and may follow a fever like pattern with raised inflammatory markers.
• Differential diagnosis: carpal tunnel syndrome, ganglion, scaphoid fracture or scaphoid tubercle fracture, hook of the hamate fracture, pisotriquetral arthritis, thumb carpometacarpal and scaphotrapeziotrapezoid osteoarthritis, de Quervain tenosynovitis, ulnar tunnel (Guyon canal) syndrome, triangular fibrocartilage tear, septic arthritis or tenosynovitis, gout, pseudogout, and rheumatoid tenosynovitis.
• Red flags: fever, spreading redness, marked swelling and rapid onset (infection or crystal arthritis), numbness in the median or ulnar distribution, trauma with bony tenderness, and loss of flexion (rupture).
• Complications: chronic pain, tendon rupture, median or ulnar nerve irritation, and recurrence.

• Clinical examination of the wrist and hand, including resisted flexion testing, palpation of the carpal bones, and the median and ulnar nerves.
• X-ray of the wrist (including a carpal tunnel view and a 30 degree supinated oblique view for the pisiform) to show calcification in calcific tendinitis, osteoarthritis, fracture, and hook of the hamate abnormality.
• Ultrasound shows tendon thickening, tears, calcific deposits and fluid, and guides aspiration or injection. MRI or CT for suspected fracture of the hook of the hamate, scaphoid tubercle or pisiform, and for refractory disease.
• Blood tests: CRP, ESR, white cell count, urate, and calcium when acute calcific tendinitis, gout or infection is suspected. Joint or sheath aspiration if infection is possible.

• Relative rest and modification of aggravating activities for 2 to 4 weeks, with technique and equipment review.
• Splinting: a wrist splint in neutral position for 2 to 4 weeks (continuous in the acute phase, then during activity).
• 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, and for acute calcific tendinitis a full anti-inflammatory dose for 5 to 7 days (naproxen 500 mg 12 hourly). Topical diclofenac 1% gel. Ice for 10 to 15 minutes, 3 times daily.
• Physiotherapy: gentle range of movement, progressive isometric then eccentric loading of the wrist flexors (3 sets of 10 to 15), grip strengthening, and graded return to sport or work over 6 to 12 weeks.
• Corticosteroid injection for persistent pain: triamcinolone acetonide 10 to 20 mg (or methylprednisolone acetate 20 mg) with lidocaine 1% 1 to 2 mL around the tendon sheath, under ultrasound guidance, avoiding the median and ulnar nerves and the radial artery. Never inject into the tendon. Limit to 1 to 2 injections.
• Calcific tendinitis of flexor carpi ulnaris: usually resolves in 1 to 3 weeks with NSAIDs and a splint. Ultrasound guided needle lavage, aspiration of the calcific deposit and steroid injection give rapid relief in severe cases.
• Scaphotrapeziotrapezoid or pisotriquetral osteoarthritis: splint, steroid injection into the joint (triamcinolone 10 mg with lidocaine 1% 0.5 mL), and surgery (excision of the pisiform, or distal scaphoid excision or fusion) for failure.
• Surgery for refractory tendinopathy (after 6 months): tenosynovectomy, release of the flexor carpi radialis tunnel, excision of osteophytes, or pisiform excision for chronic flexor carpi ulnaris disease, with generally good results.
• Rupture: urgent hand surgery review for repair or reconstruction.
• Septic tenosynovitis: emergency drainage and IV antibiotics (flucloxacillin 2 g 6 hourly, adding vancomycin 15 to 20 mg/kg 8 to 12 hourly if MRSA is possible).
• Special groups:
  • Athletes and musicians: technique modification, grip changes, and graded return.
  • Pregnancy: splint, paracetamol and ice. Avoid NSAIDs after 20 weeks, and treat any median nerve symptoms with night splinting.
  • Diabetes: monitor glucose after injection.
  • Renal impairment and gastrointestinal disease: use topical agents instead of oral NSAIDs.
• Follow up: review at 2 to 3 weeks and at 6 weeks. Refer to hand surgery for rupture, suspected fracture, nerve compression, osteoarthritis needing surgery, or failure of 3 months of treatment.