Free-vascularized medial femoral condyle bone transfer in the treatment of scaphoid nonunions

Background: Scaphoid nonunions with associated avascular necrosis and carpal collapse have proven difficult to treat reliably. This study outlines the rationale and approach to the use of a free-vascularized medial femoral condyle bone graft and the authors' experience with it in the treatment of scaphoid nonunions. Methods: A retrospective review was conducted to identify all patients with scaphoid nonunions with avascular necrosis and carpal collapse treated with a medial femoral condyle bone graft. Between July of 2004 and August of 2007, 12 such patients (12 men and no women), with a mean age of 25.3 years (range, 18 to 40 years), were identified. Nine of the twelve had failed prior operative treatment. Mean duration of nonunion was 20 months (range, 4 to 36 months). Carpal indices, time to union, early functional outcomes, and complications were recorded. Results: All 12 nonunions healed at a mean of 13 weeks (range, 6 to 26 weeks). Radiographic evaluation demonstrated significant improvement from preoperative to postoperative mean lateral intrascaphoid angle (66 and 28 degrees, respectively; p = 0.00005), scaphoid height-to-length ratio (0.78 and 0.65 respectively; p = 0.006), scapholunate angle (63 and 49 degrees, respectively; p = 0.001), and radiolunate angle (15 and 6 degrees, respectively; p = 0.0005). Five patients underwent subsequent procedures (one radial styloidectomy and four Kirschner wire removals, with one concurrent donor-site stitch abscess débridement). Conclusions: Free-vascularized medial femoral condyle grafts provide both blood supply and structural support to restore scaphoid vascularity and architecture, thereby promoting union. These results suggest that this graft is a promising alternative in the treatment of scaphoid nonunions associated with avascular necrosis and carpal collapse.