Disorders of the Lesser Metatarsophalangeal Joints.

Pain in the region of the lesser metatarsophalangeal joints (often termed metatarsalgia) is a common complaint. It can be due to a variety of causes, and accurate diagnosis is essential for effective treatment. Understanding the anatomy and functions of the extrinsic and intrinsic musculature and the plantar plate, ligaments, and fat pad is important in evaluating metatarsophalangeal joint disorders. Claw toe is a hyperextension deformity of the metatarsophalangeal joint in combination with a hammer toe. Pathologic changes involving an isolated metatarsophalangeal joint may be due to monarticular synovitis. Systemic inflammatory disorders can cause variable degrees of instability, resulting in sub-luxation or dislocation. Other specific disorders at the lesser metatarsophalangeal joints include discrete and diffuse intractable plantar keratoses, Freiberg's infraction, and cock-up fifth toe. Once the specific pathologic entity has been determined, the appropriate course of nonsurgical or, if necessary, operative treatment can be instituted.