[Free microvascular transfer of segmental corticocancellous femur for the treatment of scaphoid nonunion]

Abstract

Objective: Reconstruction of the scaphoid in length and form. Revitalization of the proximal fragment in case of avascular necrosis.

Indications: Nonunion of the scaphoid, especially with avascular necrosis of the proximal pole. Persisting nonunion of the scaphoid after operative treatment.

Contraindications: Pattern of advanced carpal collapse (SNAC > 1). Malformation, disease or previous injury of the vascular system. Low compliance. Reduced general health.

Surgical technique: Reconstruction of the scaphoid in correct dimension and angulation with use of a vascularized microvascular corticocancellous bone graft from the medial distal femur. Anastomoses to the radial artery or its palmar branch. Fixation by a cannulated scaphoid screw or Kirschner wires.

Postoperative management: Postoperative immobilization in a short cast with thumb support for 6 weeks followed by a removable splint for another 6 weeks. Physiotherapy after cast removal.

Results: 15 patients with avascular necrosis of the scaphoid were treated with this technique after a mean of 128 weeks following trauma. In five patients, one to three previous operations had already been performed. 6 months after surgery, osseous healing of the nonunion was registered in all patients. The carpal height ratio according to Nattrass was increased by 0.07. The scapholunate angle had decreased by 10.7 degrees on average. 14 patients had a mean improvement of the Mayo Wrist Score of 13.3 points.