The unique anatomy of the scaphoid leads to a predisposition for significant functional sequelae of malunited fractures while increasing the risks for fracture nonunion and avascular necrosis. First, the scaphoid is positioned anatomically as a link between the proximal and distal carpal rows. Fracture leads to uncoupling of the distal and proximal fragments, resulting in altered load distribution and abnormal wrist kinematics. The distal fragment flexes and the proximal fragment extends leading to the commonly described "humpback" deformity. The resultant scaphoid shortening and/or angular malunion or nonunion often progresses to carpal collapse resulting in significant functional disability and wrist degeneration.3
Second, the scaphoid has a precarious vascular supply. Branches from the radial artery enter the dorsal ridge of the scaphoid either at or distal to the anatomic waist of the bone. These dorsal branches provide 70% to 80% of the entire intraosseous blood supply and 100% of the vascularity to the proximal pole.4 This retrograde blood supply accounts for the direct correlation between proximal fractures and the increasing risk of delayed healing, nonunion, and avascular necrosis. Thus, successful management of scaphoid fractures demands restoring precise anatomy and choosing appropriate treatments based on fracture location and configuration.
Scaphoid fractures account for 60% to 70% of all carpal fractures.1,2 Athletes are at increased risk due to the extremes of wrist positions and forces at injury. The annual incidence of scaphoid fractures in collegiate football players is estimated to be as high as 1%.5 The mechanism of injury is most often a fall on the outstretched hand, placing the wrist in extreme dorsi-flexion and radial deviation.6
Athletes present with pain localized to the radial side of the wrist either following an acute trauma or, not uncommonly, at the conclusion of the athletic season. Often, the athlete provides a history of recurrent, nagging "wrist sprains." Clinical and radiographic evaluation must be systematically performed to identify the presence of a scaphoid fracture and define the parameters known to guide appropriate treatment and affect long-term outcomes. Paramount to this endeavor is a high index of suspicion for scaphoid fracture in any athlete presenting with radial-side wrist pain. History centers on (1) the acute event, with emphasis placed on the timing and energy of injury and (2) history of upper extremity trauma or wrist pain/swelling. Time from injury to presentation has significant implications with regard to success of treatment and length of time to fracture union. Several studies have documented substantially increased risk of delayed healing and nonunion in fractures where treatment is initiated later than 4 weeks after injury.1,2,6,7 Defining the energy of injury, documenting previous wrist pain/swelling, and correlating these with radiographic findings allow the differentiation of an acute fracture versus an exacerbation of a
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