[Palmar angular stable plate fixation of nonunions and comminuted fractures of the scaphoid].

OBJECTIVE: Stabilization of comminuted fractures and nonunions of the scaphoid with an angular stable low-profile scaphoid plate. INDICATIONS: Scaphoid nonunions with a large palmar defect, second and third surgical procedure after previous stabilization by headless compression screw (HCS). Comminuted fractures of the scaphoid that cannot be sufficiently stabilized by screws. CONTRAINDICATIONS: Radio- and midcarpal osteoarthritis, small proximal pole fragments, fragmentation of the proximal pole. SURGICAL TECHNIQUE: The scaphoid is accessed by a palmar approach. After correcting the DISI (dorsal intercalated segment instability) deformity of the lunate and humpback deformity of the scaphoid, the reduction is secured by temporary Kirschner wires. The nonunion is debrided and the bone defect filled with cancellous bone graft. Subsequently the scaphoid plate and the angular stable screw are positioned in the order to place three screws in the proximal and distal fragment of the scaphoid. Comminuted fractures of the scaphoid are fixated by temporary Kirschner wires, then the plate is positioned in the same way as nonunions. POSTOPERATIVE MANAGEMENT: Comminuted fractures and nonunions of the scaphoid are immobilized by a below-elbow cast or thermoplastic splint with inclusion of the thumb for 8 weeks. No heavy work, high-risk or contact sport activities for 12 weeks. Plate removal is recommended after 6 months or after bony healing.
RESULTS: By stabilizing scaphoid nonunions with a plate, high union rates with good clinical outcome can be achieved if the indication is correct.