MALUNION AND NONUNION OF THE METACARPALS AND PHALANGES

Abstract

The management of nonunion and malunion in the metacarpals and phalanges is influenced by the multiple gliding structures and the propensity for stiffness, the ability of adjacent digits to substitute functionally for compromised digits, the small size of the bones, and associated complications. Amputation and arthrodesis are useful treatment options for nonunions in the hand because they are nearly always atrophic, are frequently associated with joint stiffness and tendon adhesions, and often occur in digits with poor nerve function, vascularity, or skin cover. Surgical fixation with autogenous bone grafts and stable internal fixation has a high union rate with resultant restoration of alignment and stability, but achieves modest improvements in motion. Slightly larger implants than one would use for a fracture at the same size and structural (corticocancellous) bone grafts are useful for obtaining adequate stability to initiate immediate exercises in order to limit the potential for stiffness. Malunion is treated only when doing so offers useful functional advantages. The optimal timing and site of intervention are debatable; however, it is usually easiest to restore alignment when operating at the site of the original fracture and prior to complete consolidation of the fracture. This is particularly true for articular fractures. Once these fractures are mature, it may be preferable to perform an extra-articular osteotomy. If a late intra-articular osteotomy is performed, it should be done in such a way as to create large fragments that are easier to repair and more likely to retain their blood supply.