Mechanism of angulation of proximal phalangeal shaft fractures

The deforming forces on a proximal phalanx fracture are the intrinsic tendons and the extrinsic extensor tendons. A proximal phalanx fracture will typically develop an apex volar angulation. The reduction of a proximal phalangeal fracture requires metacarpophalangeal joint (MCPJ) flexion and wrist extension along with axial traction.