A Case Of Hammar -Toe Deformity

A 47-year-old woman presented with pain in the ball of her feet on weight-bearing. She works as a nurse and walks most of her 12-hour shift. Few months ago she noticed deformity of the digits in her feet. On examination it was noticed that her deformed digits are contracted with a nonreducible proximal interphalangeal joint and reducible metatarsophalangeal (MTP) joint. The picture is shown above. She was referred to a podiatrist who diagnosed hammer-toe deformity.

Case Discussion:
Hammar-Toe Deformity:

Hammer-toe deformity is a flexion contracture in the PIP joint of a pedal digit, resulting in plantar flexion of the middle phalanx at the PIP joint with dorsal angulation of the proximal phalanx at the MTP joint. Hammer toes are associated with imbalance of soft-tissue structures around the joints in the digits and are often progressive.

Etiology: A hammer toe is caused by multiple factors:
• Genetic and hereditary factors
• Abnormal biomechanics (cavus or high-arch foot, flatfoot deformity, loss of intrinsic muscle function, and hypermobile first ray).
• Long metatarsal and/or digit.
• Systemic arthritidis.
• Neuromuscular diseases such as Charcot-Marie-Tooth disease
• Ill-fitting shoes.
• Trauma.
• Iatrogenic causes.

Risk Factors: for Hammar toe deformity include:
• High-arch foot type (cavus foot).
• Flatfeet.
• Bunion deformity

Clinical Features: The clinical signs and symptoms include:
• Pain and deformity in 1 or more of the lesser toes.
• Dorsiflexed proximal phalanx at the MTP joint and plantarflexed middle phalanx at the PIP joint of a lesser digit.
• Callus formation at the dorsal aspect of the PIP joint and/or distal aspect of the digit.
• Edema and tenderness on the plantar aspect of the lesser MTP joint(s).
• Associated signs—Cavus foot deformity, flatfoot deformity, bunion deformity, transverse deformity of the digits, decreased ankle dorsiflexion, and bowstringing of the extensor and/or flexor tendons.
• Evaluation of the digit in weight-bearing and non–weight-bearing conditions helps assess reducibility and rigidity of the deformity. In the case of predislocation syndrome (acute rupture or tear of the MTP joint capsule or plantar plate), the deformity may not be appreciated unless the foot is evaluated in the weight-bearing position

Diagnosis: The diagnosis of hammer-toe deformity is made clinically and radiographically.

Management: Conservative measures and surgical treatment may be used to correct this condition. Note that a neglected hammer-toe deformity could result in ulceration in a patient with diabetes.

Conservative Measures:
• Change shoes.
• Pad shoes to limit shearing force. A crest pad can be used to prevent painful callus formation at the distal tip of the digit
• Splinting can be used in an early flexible hammer toe.
• Custom-made orthoses are helpful to slow down progression of the deformity if it is caused by biomechanical factors.
• Rest, NSAIDs, and ice help an inflamed joint and/or shoe irritation.

Surgical treatment:
• Consider surgical referral to a foot specialist to correct the deformity.
• Percutaneous tenotomy and/or capsulotomy are used for mild, flexible deformities.
• Resectional arthroplasty at the PIP joint may be beneficial for a more rigid deformity.
• Shortening osteotomy of the metatarsal is indicated in the deformities resulting from the long metatarsal.