Hammer toe is a Z-shaped deformity caused by dorsal subluxation at the metatarsophalangeal joint. Diagnosis is clinical. Treatment is modification of footwear and/or orthotics.
The usual cause is misalignment of the joint surfaces due to a genetic predisposition toward aberrant foot biomechanics and tendon contractures. RA and neurologic disorders such as Charcot-Marie-Tooth disease are other causes. The 2nd toe is the most common digit to develop a hammer toe deformity (see Fig. 2: Foot and Ankle Disorders: Hammer toe.). Second toe hammer toes commonly result from an elongated 2nd metatarsal and from pressure due to an excessively abducted great toe (hallux valgus deformity) causing a bunion (see Foot and Ankle Disorders: Bunion). Unusually long toes often develop hammer toe deformities. Painful corns (see Cornification Disorders: Calluses and Corns) often develop in hammer toe deformity, particularly of the 5th toe. Reactive adventitial bursas often develop beneath corns, which may become inflamed.
Symptoms include pain while wearing shoes, especially shoes with low and narrow toe boxes, and sometimes metatarsalgia. Diagnosis is clinical. Joints are examined for coexistent arthritis (eg, RA).
Shoes should have a wide toe box. Toe pads sold in pharmacies also help by shielding the affected toes from the overlying shoe. If conservative measures are ineffective, surgical correction of the deformity often relieves symptoms. If there is accompanying metatarsalgia, OTC or prescription orthotic devices with metatarsal pads and cushioning may help alleviate the pain.
Last full review/revision December 2012 by Kendrick Alan Whitney, DPM