Disorders of the First Metatarsophalangeal Joint.

The two most common disorders of the first metatarsophalangeal (MTP) joint are hallux valgus and hallux rigidus. The hallux valgus deformity has been the subject of numerous clinical studies in the past decade. This information has enabled the creation of an algorithm to assist the clinician in evaluating the patient with hallux valgus and selecting the appropriate surgical procedure. The technical aspects of various operative procedures and the most common complications are reviewed. The other major disorder of the first MTP joint is arthrosis, which results in hallux rigidus. As the arthrosis progresses, there is often proliferation of bone on the dorsal aspect of the metatarsal head, which results in impingement of the proximal phalanx during dorsiflexion. The impingement causes jamming, instead of gliding, of the proximal phalanx on the metatarsal head, which results in pain. The treatment for this condition consists of debridement of the MTP joint to relieve the dorsal impingement and, in most cases, the pain. If the arthrosis is advanced in an active individual, arthrodesis is indicated.