Novel complex scaphoid nonunion surgery uses free vascularized bone graft
A 17-year-old male presented with pain upon wrist extension and radial deviation, one year after injuring his wrist in a football game. Initial diagnosis elsewhere identified wrist sprain. A subsequent evaluation diagnosed scaphoid fracture nonunion with carpal collapse and proximal pole avascular necrosis.
Scaphoid nonunion surgery can be quite challenging due to the following factors:
- Significant bone loss
- Carpal collapse
- Avascular necrosis
- Arthritic changes
- Previous surgeries with continued nonunion
While use of vascularized bone grafts is not new, recent advances have improved the outcomes as they address both avascularity and carpal collapse. These improvements have resulted in good to excellent success rates for these difficult nonunions.
In particular, free vascularized bone graft taken from the medial femoral condyle demonstrates significant promise in addressing complex scaphoid nonunions. This type of free vascularized bone graft has been used in other difficult nonunions. But its use as an interposition vascularized bone graft for scaphoid nonunions with carpal collapse and avascular necrosis was pioneered by orthopedic surgeons at Mayo Clinic in Rochester, Minn.
Radiographs at 16 weeks and clinical evaluation show the patient's nonunion resolved and pain-free function recovered. To date, Mayo Clinic orthopedic hand specialists have performed nearly 70 free medial femoral condyle vascularized bone grafts for difficult scaphoid nonunions with avascular necrosis. Results show only five confirmed failures, for a 93 percent union rate.
"The procedure is a complex microvascular surgical technique that utilizes two microvascular-trained hand surgeons, with an average surgical time of 2.5 hours," explains Mayo hand and microvascular surgeon, Alexander Y. Shin, M.D. "One team harvests the medial femoral condyle graft, while the other prepares the scaphoid and the recipient vessels, and in this way a promising new technique can effectively manage a complex and difficult problem."
Feb. 11, 2014