Mallet Toe

Mallet toe is a flexion deformity at the distal interphalangeal joint of a lesser toe, with the proximal interphalangeal and metatarsophalangeal joints neutral. The second toe is affected most often, and the tip of the toe presses on the shoe or floor.

• Causes: a long toe cramped in a short or tight shoe, trauma (stubbing or a crush injury), tight flexor digitorum longus tendon, rheumatoid and psoriatic arthritis, neuromuscular disease, diabetes and previous surgery.
• It is less common than hammertoe, and commonly flexible at first and rigid later. Do not confuse it with mallet finger, which is a rupture of the extensor tendon at the finger tip.

• A toe tip pointing downward, with a painful corn or callus at the tip or dorsum of the distal interphalangeal joint, nail deformity or thickening from pressure, tenderness in shoes, and in neuropathic feet, tip ulceration.
• Examination: flexibility (passive correction of the distal joint), alignment of other joints, tip callus, nail changes, perfusion and sensation.
• Differential diagnosis: hammertoe, claw toe, subungual exostosis, onychomycosis, glomus tumour, corn from other causes, gout, osteomyelitis and infected corn.
• Red flags: tip ulcer, drainage, a warm swollen toe, diabetes with neuropathy, poor circulation and sudden painful deformity after trauma.
• Complications: tip corns, ulcer, infection, osteomyelitis, nail dystrophy and difficulty with footwear.

• Clinical. Check flexibility, neurovascular status and footwear.
• X-ray of the foot (weight bearing) shows joint alignment, arthritis, fracture and bone infection. Probe any ulcer to bone and add MRI for suspected osteomyelitis.
• HbA1c, CRP, urate and rheumatoid markers when systemic disease is possible.

• Conservative treatment for flexible disease:
  • Wide, deep toe box shoes with a low heel and enough length (a thumb's width beyond the longest toe).
  • Toe sleeves, gel caps, toe crest pads under the toes, and tip padding. Taping the toe straight, and passive stretching of the distal joint.
  • Corn paring by a podiatrist every 4 to 8 weeks.
  • Paracetamol 1 g orally 6 hourly, or short course ibuprofen 400 mg 8 hourly with food.
• Surgery for pain or tip ulcer after 3 to 6 months of failed care:
  • Flexible deformity: percutaneous flexor digitorum longus tenotomy at the distal phalanx or at the base of the toe, under local anaesthesia (lidocaine 1% 1 to 2 mL digital block, plain, no adrenaline), 10 minutes in the clinic, with about 90% success and a stiff soled shoe for 2 to 3 weeks.
  • Rigid deformity: distal interphalangeal joint arthroplasty (resection of the condyles of the middle phalanx) or fusion with a pin or screw, with 2 to 6 weeks of protection.
  • Recurrent corns may be treated by exostectomy.
  • Complications: recurrent deformity, floppy toe, stiffness, infection and numbness.
• Infection or ulcer: debridement and offloading, flucloxacillin 500 mg orally 6 hourly for 5 to 7 days (clindamycin 300 to 450 mg 8 hourly in penicillin allergy), and for diabetes and ischaemic limbs, wider cover and urgent foot clinic review.
• Special groups:
  • Diabetes and neuropathy: daily foot checks, therapeutic shoes, podiatry every 4 to 8 weeks, and early treatment of any tip skin break.
  • Peripheral arterial disease: assess perfusion before any procedure.
  • Anticoagulation: tenotomy is possible with local pressure, but plan with the prescriber.
  • Children: unusual, so exclude a neurological cause.
• Follow up: review at 2 to 3 weeks after surgery and at 6 to 8 weeks for conservative care. Refer to podiatry or foot and ankle surgery for rigid deformity, ulcer, recurrent corns or inflammatory arthritis.