Graft choice for managing scaphoid non-union: umbrella review

Introduction: Since the introduction of the non-vascularized bone graft by Matti and Russe, followed by vascularized grafts and more recently by free vascularized bone grafts, the choice of technique in scaphoid non-union has been controversial. The purpose of the present study was to address the following questions in an umbrella review: Do union rates differ between techniques? Is there any evidence that one technique is superior to another? Methods: An umbrella review conducted during September 2023 month included systematic reviews and meta-analyses. The primary criterion was mean union rate according to technique. The secondary criterion was indication according to type of non-union. The PubMed, Cochrane, and MEDLINE databases were searched using a predefined methodology according to the criteria of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA version 2020). The quality of the systematic reviews included was evaluated by the "Assessing the Methodological Quality of Systematic Reviews"instrument (AMSTAR 2). Results: Nine studies (systematic reviews or meta-analyses) were included. Quality ranged between low and high. A Table was constructed to summarize the qualitative findings of each article. There was no significant difference in union rates between vascularized and non-vascularized bone grafts in 8 of the 9 studies: vascularized bone graft, 84-92%; non-vascularized bone graft, 80-88%. One study found higher union rates with vascularized bone graft (RR 1.1; 95% CI 1.0-1.2; P = 0.02), but no significant difference in functional results. However, vascularized bone graft was more effective in case of avascular necrosis of the proximal pole (74-88% union for vascularized bone graft vs. 47-62% for non-vascularized bone graft) and in revision cases, while non-vascularized bone graft showed fewer failures in case of humpback deformity and/or dorsal intercalated segment instability (IRR 0.7 +/- 0.09; P = 0.01). Conclusions: This umbrella review provides an overview for management of scaphoid non-union. There were no significant global differences between techniques. Thus, various factors need to be considered when selecting the appropriate technique.