This carpal bone has the lowest incidence of injury which can be attributed to the protected location of the bone within the distal carpal arch. The trapezoid is wedge-shaped, widest at the distal end, and fits into the distal carpal row as a keystone in an arch between the capitate and trapezium.
Standard hand radiographs are sufficient to diagnosed fracture-dislocation injuries. Nondisplaced fractures may be difficult to identify on plain radiographs, given the osseous overlap in which case CT is helpful in establishing the diagnosis.
Injuries about the trapezoid are most often due to an axial load through the second metacarpal, which creates a coronal fracture pattern with displacement (Figure 11). Nondisplaced fractures can be managed with short arm-thumb spica casting for 4 to 6 weeks. Displaced fractures are best managed with open reduction and internal fixation with K-wires and compression screw fixation through a dorsal approach.
Imaging of a trapezoid fracture treated with open reduction and internal fixation (B). Preoperative radiograph demonstrates fracture displacement with intra-articular extension (A). Fixation included pinning of the first and second metacarpals to maintain length (B). (Reproduced with permission from Kain N, Heras-Palou C: Trapezoid fractures: report of 11 cases. J Hand Surg Am 2012;37: 1159–1162.)
The literature would suggest that isolated trapezoid fractures have good outcomes with limited complications. Case reports and limited case series indicate that reduced fractures heal without complication. Displaced fractures, even when presenting in a delayed fashion, do well with surgery without reported complication. The lack of negative outcomes in this case may be a misleading artifact, given the low incidence of cases.
J Am Acad Orthop Surg. 2020;28(15):e651-e661. © 2020 American Academy of Orthopaedic Surgeons