Hammer toe deformity consists in the flexion contracture of the proxmal interphalangeal joint (PIP).
Depending on severity, the contracture may be:
- correctable, when passive correction of deformity (that is the possibility of toe extension using the examiner’s hand) is possible,
- permanent, when the toe is permanently flexed without the potential for extension.
Hammer toe deformity – symptoms
Secondary to this deformity, metatarsophalangeal joint hypertrophy occurs and in most cases, also the flexion in the distal interphalangeal joint (DIP). Hammer toe deformity is often concomitant with hallux valgus.
The chief patient complaint is a callus on the dorsal surface of the proximal interphalangeal joint (PIP), which makes it impossible for the patient to wear closed toe shoes. In more advanced cases, a wound may develop in the involved area. Initially metatarsalgia develops, that is a painful sensation under the metatarsal head of the deformed toe. Later, if a patient is untreated, a painful subluxation followed by dislocation of the metatarsophalangeal joint occurs, which significantly impedes walking. It occurs particularly in patients with concomitant hallux valgus, and usually the second metatarsophalangeal (MTP) joint is involved.
Hammer toe – treatment
At early stages wearing flat shoes with a high and wide toe box may help. In order to protect the dorsal surface of the PIP joint, special orthoses or soft protective shields may also be used. Then, in order to off-load the metatarsal head, it is advised to purchase the orthopaedic shoe insole with a metatarsal pad, or only a metatarsal pad inserted to each shoe. At early stages of the deformity, exercises are recommended to improve the motion range of the contracted toes and reducing the contracture of the flexor and extensor muscles of the involved toe. Unfortunately, in many cases, the deformity progresses rapidly and surgery becomes essential. In less advanced cases, relatively small procedures may be performed, limited to soft tissues only (tendons, joint capsule). If the deformity is permanent, more extensive surgery is required to set the patient free from pain. This involves the resection of articular surface, which results in joint stiffness.
In most cases, if the hammer toes are concomitant with hallux valgus both deformities need a repair during one procedure, in order to bring out the therapeutic effect. Only such treatment offers both the possibility to set the patient free from pain and only a minimum chance for the recurrence.