A Rare Case of Complex Carpal Injury: Divergent Trapezium-Trapezoid Fracture Dislocation.

Divergent trapezium-trapezoid fracture dislocation is a rare and complex injury. The authors present an unusual case of dislocation of the trapezium-trapezoid complex with scaphoid fracture. A 25-year-old man suffered a road traffic accident leading to complex carpal injury due to axial and rotation forces (steer wheel injury) on the left wrist. X-rays and computed tomographic (CT) scan were done showing trapezium-trapezoid dissociation with fracture of distal pole of scaphoid and ulna styloid. The second metacarpal base was fractured with many ligamentous injuries in the wrist. Volar flexor carpi radialis (FCR) approach was used to reduce and fix scaphoid fracture with 2.7-mm cannulated screw. Dorsal approach was used to fix fracture of second metacarpal base and perform reduction in trapezium-trapezoid complex with help of 0.8-mm K-wires, and suspension wiring of first to second and second to third metacarpal was done using 1.5-mm K-wires. The transverse flexor retinaculum (TFR) in this case was avulsed. The divergent trapezium-trapezoid joint with scaphoid fracture is not described in the literature yet. The authors implicate steering wheel injury pattern for such complex carpal fracture dislocations. CT scan is imperative to diagnose and plan treatment of such fracture morphology. Early fracture reduction and stabilization of carpal dislocations are essential for proper functioning of wrist.