橈骨舟状骨偽関節に対する関節鏡視下骨移植術

Scaphoid non-union continues to be a big challenge in scaphoid fracture management. The drawbacks of conventional open techniques are damage to local vascularity and supporting ligamentous structures. The advancement of wrist arthroscopy prompted the development of arthroscopic bone grafting on scaphoid nonunion and has become the treatment of choice in many international centers nowadays.

From 1997 to 2016, 111 symptomatic scaphoid nonunion and 14 delayed union cases were being operated.

Nonunion site was debrided through Midcarpal Radial (MCR) portal until healthy cancellous bone was uncovered. Scaphoid fragments were fixed with three Kirschner wires (K-wires) or cannulated screw percutaneously after correction of humpback and dorsal intercalated segment instability deformity. The bone defect was fully packed with autologous bone graft delivered through MCR portal. Early mobilization was initiated as early as 5 to 7 days after the operation. K-wires were removed under local anesthesia after clinical and radiological union was confirmed.

Bone union was achieved in 14 weeks (range 6-80) and overall union rate was 90.3%. Fourteen cases failed to achieve bone union after arterial blood gas test. Poor bleeding from the proximal scaphoid fragment resulted in a less favorable union rate of 78.8% and was the only statistically significant factor that affected the bone union.

Arthroscopic bone grafting was a breakthrough in managing difficult scaphoid delayed and nonunion. It provides a more favorable biological environment for the nonunion to heal. This is evidenced by the high union rate and satisfactory clinical outcome.