title: Freiberg's infraction in identical twins: a case report.
abstract: Freiberg's infraction is an ostechondrosis of a lesser metatarsal head resulting in degeneration of the metatarsophalangeal joint. Several mechanisms have been suggested in its pathenogenesis. Freiberg first described the entity and believed single impact trauma was the underlying cause. Repetitive biomechanical microtrauma is the most widely accepted etiologic theory. Other factors contributing to its development include aseptic necrosis, ischemia, and a congenital predisposition. We present a case report of Freiberg's infraction occurring in identical twins involving multiple metatarsals in various stages of degeneration. One of the twins was affected unilaterally whereas the other twin was affected bilaterally. Both twins had involvement of the second metatarsal on the same side extremity. The occurrence of Freiberg's infraction in identical twins suggests that an underlying congenital predisposition to the condition may play more of a role than previously considered.
authors.affiliation: Department of Orthopedic Surgery, Kaiser Permanente, Santa Rosa, CA, USA. nealblitz@yahoo.com
authors.forename: Neal M
authors.initials: NM
authors.lastname: Blitz
authors.forename: Jonathan H
authors.initials: JH
authors.lastname: Yu
mesh_terms: D000328:Adult; D004200:Diseases in Twins; D005260:Female; D006801:Humans; D008682:Metatarsal Bones / Q000000981:diagnostic imaging; D010007:Osteochondritis / Q000000981:diagnostic imaging* / Q000235:genetics; D011859:Radiography; D014430:Twins, Monozygotic