[Therapy of Scaphoid Nonunion: Treatment Algorithm and Union Rate Analysis after Autologous Reconstruction]

Scaphoid nonunion develops in approximately 15% of patients following scaphoid fractures. To prevent carpal collapse, targeted diagnosis and early initiation of treatment are crucial.This paper describes the algorithm for scaphoid nonunion treatment established at the Department of Plastic and Hand Surgery at the Medical Center - University of Freiburg. We carried out a monocentric, retrospective analysis of scaphoid reconstructions for scaphoid nonunion performed at our clinic between January 2012 and December 2022. We selected among four treatment options based on the vascularity of the proximal pole and the size of the substance defect, and / or the presence of a humpback deformity. In cases of a vital proximal scaphoid pole, reconstruction was performed using avascular autologous bone grafts: radius cancellous bone if there was no substance defect, or iliac crest bone if there was a relevant substance defect or a humpback deformity. In cases of an avital proximal pole without a relevant substance defect or humpback deformity, reconstruction was performed using a pedicled bone graft from the radius. In the presence of a substance defect or humpback deformity, a medial femoral condyle free flap was used. We analysed the union rate and epidemiological data of the patient cohort.A total of 123 scaphoid reconstructions were included. The median follow-up was 422 days. According to the established algorithm, 13 reconstructions were performed with cancellous bone grafts from the radius, 82 with iliac crest bone grafts, 13 with pedicled bone grafting from the radius, and 15 with medial femoral condyle free flaps. Union rates were 84.6% for reconstructions using cancellous bone grafts from the radius, 79.3% for iliac crest bone grafts, 69.2% for pedicled bone grafts from the radius, and 86.7% for medial femoral condyle free flaps. We identified nicotine abuse as an independent risk factor for scaphoid nonunion in patients undergoing reconstruction with iliac crest bone grafts.In line with current literature, we confirmed the importance of nicotine abstinence in scaphoid reconstructions. Since the treatment algorithm in our analysis was predetermined due to the retrospective design, no conclusions can be drawn regarding the superiority of any method. Prospective, randomised trials are needed to demonstrate the superiority of a treatment method.