Abstract
This study reviews the results of the treatment of non-union of fractures of the scaphoid by the use of micro-surgical, vascular pedicle grafts (VPG). The indications for VPG included long-standing non-union of a fracture of the scaphoid, avascular necrosis of the proximal pole and failed conventional grafting. The contraindications were periscaphoid degenerative changes (scaphoid non-union advanced collapse) and vascular damage from previous surgery. The technique in each involved harvesting a vascularised bone graft from the distal radius based on a vascular pedicle with retrograde flow from one of a number of described vessels that constitute the vascular plexus over the carpus. The scaphoid was prepared to receive an inlay graft and then the graft was positioned and its stability was determined. Some were secured with a single 0.7mm diameter Kirschner wire. The wrist was then immobilised in a plaster cast until either the fracture had healed or it was evident that the procedure had failed to result in union.
Fourteen patients have undergone VPG over 30 months. Of these eight have healed (four fractures of the waist and four of the proximal poles), four have failed (one waist and three proximal poles) and two are still in plaster casts. The mean time to healing was 20.6 weeks (range: 12.7–28.7 weeks). Of the eight that healed, seven were aged between 21 and 27 years. The four failures were aged between 34 and 44 years. The mean time since the fracture in the healed group was 2.9 years (range: 1.2 years to five years) and in the failed group it was 6.5 years (range: two years to 20 years). The first failure was related to deep infection and a subsequent Matte-Russe procedure has also failed. In the second failure the graft healed to the distal pole but the very small proximal pole collapsed resulting in a wrist arthrodesis. The graft in the third failure healed to the distal pole but failed to unite with the small proximal pole. No further treatment has been planned. The fourth failure was a non-union of the waist of 20 years standing. The graft became dislodged from the scaphoid but no further surgery has been carried out. One of the successful unions had a poor result because of degeneration in the scaphoid-trapezoid-trapezium (STT) joint secondary to damage done at the time of previous surgery (Herbert screw). A successful STT arthrodesis was done subsequently.
VPG is technically challenging. Careful patient selection is vital as is preoperative planning and vessel selection. VPG can be used successfully to salvage obstinate non-unions of fractures of the scaphoid.
Correspondence should be addressed to the editorial secretary: Associate Professor Jean-Claude Theis, Department of Orthopaedic Surgery, Dunedin Hospital, Private Bag 1921, Dunedin, New Zealand.
