Arthroscopic bone grafting in scaphoid fracture nonunion: Is it a universal solution?

Since 1997, arthroscopic bone grafting has offered hand surgeons a solution to the riddle of scaphoid fracture nonunion. The intended merit of an arthroscopic approach for scaphoid fracture nonunion management lies in its minimal invasiveness, which preserves the tenuous vascularity of the scaphoid, poses minimal disturbance to carpal ligaments, and allows comprehensive evaluation in diagnostic uncertainty. What does the evidence tell us about its outcomes and limitations compared to open techniques? Level III evidence suggests that arthroscopic bone graft yields similar union rates and potentially earlier time to union compared to open bone graft, at an average union rate of 96 % and union time of 13.5 weeks. It offers a universal solution to scaphoid fracture nonunion, with similar union rate and time achieved regardless of smoking, chronicity, proximal fracture or avascular necrosis. Radiological correction of humpback deformity and dorsal intercalated segment instability (DISI) may be inferior compared to an open technique, but correction to within normal range is still possible. Hence, it's long term clinical implication remains unclear. Perhaps the only true contraindications to arthroscopic bone grafting are proximal pole fragmentation due to unsalvageable necrosis, or advanced scaphoid nonunion advanced collapse (SNAC). While it is easy to get lost in the debate of biology and the necessity of vascularized bone graft, ultimately, fracture healing is multifactorial and surgeons must not neglect the mechanical importance of well placed instrumentation.