Abstract and Introduction
Fractures of the carpus can be debilitating injuries and often lead to chronic pain and dysfunction when not properly treated. Although scaphoid fractures are more common, fractures of the other carpal bones account for nearly half of all injuries of the carpus. Often missed on initial presentation, a focused physical examination with imaging tailored to the suspected injury is needed to identify these fractures. In addition to plain radiographs, advanced imaging such as CT and MRI are helpful in diagnosis and management. Treatment of carpal fractures is based on the degree of displacement, stability of the fracture, and associated injuries. Those that require surgical fixation often affect the congruency of the articular surfaces, are unstable, are at risk for symptomatic nonunion, are associated with notable ligamentous injury, or are causing nerve or tendon entrapment. Surgical strategies involve percutaneous Kirschner wires, external fixation, screws and/or plates, excision, or fusion for salvage. Owing to the intimate articulations in the hand, small size of the carpal bones, and complex vascular supply, carpal fracture complications include symptomatic nonunion, osteonecrosis, and posttraumatic arthritis.
The carpus is a complicated mosaic of polyarticular bones that allows for the impressive range of motion of the human wrist. Scaphoid fractures are the most common, representing 60% of carpal fractures, and deservedly receive the most attention. However, the neglected neighbors of the scaphoid still represent 40% of carpal fractures, which accounts for 1.1% of all fractures. Carpal fractures from most to least common are scaphoid (68%), triquetrum (18%), trapezium (4%), lunate (4%), capitate (2%), hamate (2%), pisiform (1%), and trapezoid (0.5%)[1–3] (Figure 1). These injuries most often occur in young adults after a fall on to an outstretched hand and are frequently missed on initial presentation.[4,5] This is partly because of their small and densely packed arrangement that makes imaging difficult and limits physical examination specificity. Trained orthopaedic surgeons have a 30% to 88% precision in palpating the various bony landmarks of the carpal bones, with emergency medicine-trained physicians having a third to a fifth of this precision. This underscores the difficulty of diagnosing carpal fractures on initial presentation and the high index of suspicion that must be maintained during this evaluation. All suspected fractures should be evaluated with a general hand and wrist examination as well as basic PA and lateral hand and wrist radiographs. Additional examination maneuvers and imaging can then be tailored to the suspected injury.
J Am Acad Orthop Surg. 2020;28(15):e651-e661. © 2020 American Academy of Orthopaedic Surgeons