How Long Should We Immobilize the Wrist after Vascularized Bone Grafting for the Treatment of Scaphoid Nonunion?

Abstract

Background: Although vascularized bone grafting can effectively treat scaphoid nonunion, the optimal duration of the immobilization period after bone grafting is unclear. Therefore, we aimed to examine the difference in the union rate and range of motion between short and long immobilization periods and infer the optimal post-immobilization period after pedicled vascularized bone grafting for scaphoid nonunion treatment. Methods: A total of 23 wrists (21 men and 1 woman) with scaphoid nonunion treated using an intercompartmental supraretinacular artery pedicled vascularized bone graft were analyzed. We examined the difference in the union rate and range of motion between patients immobilized for less than 49 days (short immobilization group) and those immobilized for more than 49 days (long immobilization group). The range of motion of the wrist joint was measured before and after surgery. Patient outcomes were also assessed. Results: The overall union rate was 95.6%. A significant difference was found in postoperative extension and flexion between the two groups, but not in terms of the functional outcome. If the intraoperative fixation is solid, intraoperative proximal pole bleeding is confirmed, and the follow-up radiograph shows a normal healing process, we propose immobilization of the wrist for ≤ 7 weeks. Conclusions: The immobilization duration should depend on the solidity of intraoperative fixation and a satisfactory appearance on follow-up radiography: absence of a gap at the graft interface, surrounding lucency, or movement of the implant and displacement of the graft. If there are no signs of graft failure and fixation is solid, immobilization of the wrist for 7 weeks or less is recommended.