SUCCESSFUL TREATMENT OF COMPLICATED NONUNIONS OF THE SCAPHOID WITH A VASCULARISED BONE GRAFT: SURGERY FOR PROXIMAL POLE NONUNIONS AND REVISION AFTER FAILED INITIAL SURGERY.

Abstract

To determine union rate in complicated nonunions of the scaphoid treated with a vascularised bone graft.

Vascularised bone grafting for scaphoid nonunions (1–2 ICSRA, Zaidemberg technique) has shown initial enthusiasm. Its usefulness has been challenged in cases where the proximal pole of the scaphoid is avascular. Complicated nonunions where the proximal pole is highly likely to be avascular occur in revision surgery and proximal pole nonunions.

Fourteen patients were retrospectively followed up. Eight had nonunion following previous scaphoid surgery (two previous ORIF, two previous nonvascular grafting, and four with two previous surgeries). Six patients had no previous surgery for a proximal pole nonunion of 12.5 months’ duration. All patients were male with an average age of twenty-four. Delay from fracture to vascularised bone grafting was twenty months. Graft harvesting was done according to the Zaidemberg technique by two orthopaedic surgeons. CT-scan was used to confirm union in all patients except two who were lost of the follow-up. Twelve patients were followed up by an independent surgeon at a postoperative minimal period of four months. Functional status was assessed with the DASH questionnaire and follow x-rays were performed to determine the presence of degenerative changes.

Union was confirmed by CT-scan in eleven of twelve followed patients (92%) at an average time of six months following vascularised graft. Radio-scaphoid osteoarthritis was seen in the one patient that didn’t achieve union.

This series suggests that the Zaidemberg graft is useful and may be proposed in situations of revision surgery and proximal pole non-unions. We achieved a high union rate in these complicated nonunions even though there was high likelihood that the proximal pole was avascular. This study stresses the importance of protective immobilization until documented union by CT-scan in this difficult subset of patients.