A metacarpal neck fracture often develops an apex dorsal angulation deformity because the thin volar cortex is frequently comminuted, which leads to flexion of the metacarpal head. The flexion is maintained by the intrinsic muscles that cross volar to the axis of the metacarpophalangeal joint (MCPJ).
The Jahss maneuver shown here is an effective technique for closed reduction of metacarpal neck fractures:
- After suitable anesthesia, the metacarpophalangeal joint (MCPJ) and distal interphalangeal joint (DIPJ) are flexed to 90 degrees
- Force is exerted upwards through the flexed proximal phalanx and downwards on the metacarpal shaft to correct the flexion deformity at the metacarpal neck
- The proximal interphalangeal joint (PIPJ) is extended and a splint is applied to maintain the wrist in extension, the MCPJ in maximal flexion, and the PIPJ in extension. An adjacent stable finger should be included in the splint.
