A hammertoe deformity is a flexion deformity of the foot where there is an abnormal flexion posture of the proximal interphalangeal (PIP) joint of one or more of the lesser toes. The PIP joint flexion deformity may be fixed or supple. With a severe hammertoe deformity, there is a compensatory hyperextension of the metatarsophalangeal (MTP) and distal interphalangeal (DIP) joints.
- 1. Felix S. Chew. Skeletal Radiology. ISBN: 9781608317066