A malunited fracture is one that has healed with the fragments in a nonanatomic position. Whether the deformity is unsightly or not it can impair function in several ways: (1) an abnormal joint surface can cause irregular weight transfer and arthritis of the joint, especially in the lower extremities; (2) rotation or angulation of the fragments can interfere with proper balance or gait in the lower extremities or positioning of the upper extremities; (3) overriding of fragments or bone loss can result in perceptible shortening; and (4) the movements of neighboring joints can be blocked. Malunions, by strict definition, commonly are the rule in the closed treatment of fractures; however, they frequently are compatible with function. A malunited fracture becomes surgically significant only when it impairs function.
