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ICD-9-CM Codes

  • 755.66 Other congenital anomalies of toes

  • 735.4 Other hammer toe (acquired)

ICD-10-CM Codes

  • M20.40 Other hammer toe(s) (acquired), unspecified foot

  • Q66.89 Other specified congenital deformities of feet

Preferred Practice Pattern

Key Features


  • Toe bent into claw-like position

    • Distinguished from claw toe, which includes extension of metatarsophalangeal (MTP) joint

    • Distinguished from mallet toe, which includes flexion of only the distal interphalangeal joint (DIP)

  • Shortened flexor muscles, fascia, tendons

  • Flexion of proximal interphalangeal (PIP) and DIP joints

  • Most commonly affects 2nd toe, though may also affect 3rd or 4th

  • May alter mechanics during push-off phase of gait

Essentials of Diagnosis

  • Diagnosis usually made by clinical examination or x-ray

  • May be independent diagnosis, not associated with disease process

General Considerations

  • Swelling

  • Inflammation around joint

  • Altered joint position

  • Evaluation of footwear


  • Infants, congenital

  • Children who wear shoes they have outgrown and are too small

  • Adults

    • Poor footwear: improper fit, pointed toe, narrow forefoot, high heels

    • Dancers at higher risk

Clinical Findings

Signs and Symptoms

  • Pain in metatarsal with walking

  • Corn on top of toe

  • Decreased extension or dorsiflexion of toe

  • Pain, redness around joint

  • Callus under metatarsal head

  • Difficulty finding shoes with proper fit

  • Limited motion of MTP joint

Functional Implications

  • Pain with standing

  • Pain in affected toe with ambulation

  • Inability to wear stiff shoes

  • Need to wear shoes with large toe box to accommodate bunion, corn, flexion, and hypomobile PIP

  • Altered gait pattern and mechanical issues of the forefoot

Possible Contributing Causes

  • Improper footwear

  • Commonly in conjunction with bunions

  • Joint arthritis/injury

  • Muscle atrophy

  • Nerve damage

  • Friedrich's ataxia

  • Osteoarthritis

  • Rheumatoid arthritis

  • Stroke

  • Charcot-Marie-Tooth disease

Differential Diagnosis

  • Mallet toe: flexion of only the DIP

  • Claw toe

  • Hallux valgus

  • Gout

  • Osteochondrotic lesion of first metatarsal head

  • Sesamoiditis, turf toe

  • Osteochondritis dissecans

  • Metatarsalgia

  • Metatarsal stress fracture

Means of Confirmation or Diagnosis


  • X-ray

Findings and Interpretation

  • Location and size of bone spur



  • NSAIDs

Medical Procedure

  • Surgery to straighten toe, involves cutting or lengthening tendons and ligaments, possible fusion of the joint


  • To hospital for imaging, x-ray

  • To physician for medication, anti-inflammatory, corticosteroid injection

  • To surgeon for surgical consult



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