The hammer toe deformity is one of the most common deformity of lesser toes of the foot. It’s used to describe an abnormal flexion posture of the proximal interphalangeal joint of one of the lesser four toes.
The distal joint usually stays supple, but it also may develop a flexion or an extension deformity.
The flexion deformity may be fixed (not passively correctable to the neutral position) or flexible (passively correctable).
It’s more common in women than in men, and the 2nd toe is more commonly involved.
See Also: Adult Hallux Valgus
Hammer toe Causes
Causes of hammer toe deformity include:
- Synovitis (the most common cause).
- The long-term use of poorly fitting shoes
- Foot trauma.
- Untreated compartment syndrome in deep posterior compartment of the leg or foot that causes Complex regional pain syndrome (Sudeck atrophy).
- It can be associated with cavus deformity, neuromuscular disease or inflammatory arthropathies.
See Also: Ankle and Foot Anatomy
Lesser toe deformities include the following:
|Hammer Toe||Mallet Toe||Claw Toe|
|MTP||normal (slight extension)||Normal||Hyperextension|
Three areas may be painful in this deformity:
- The most common area is the dorsum of the proximal interphalangeal joint, where a hard corn caused by pressure from the toe box or vamp of the shoe develops.
- When a flexion posture or end-bearing posture of the distal interphalangeal joint is present, a painful callus develops just plantar to the nail end. This is called an end corn.
- Finally, a painful callus may develop beneath the metatarsal head if the proximal phalanx subluxates dorsally.
Hammer toe treatment is dependent upon the flexibility of the deformity.
- Nonoperative: protective padding, tall toe-box shoes, corrective hammer-toe splints are effective.
- Operative: flexor tenotomy or flexor to extensor tendon transfer.
- Nonoperative: accommodative shoes and protective padding can minimize callous formation. A corrective splint should NOT be used.
- Operative: PIP arthroplasty (resection of distal neck and head of proximal phalanx) or PIP arthrodesis