Microsurgical Bone Transplants: Is It Necessary to Perform Venous Anastomosis in the Bone-Only Graft? A Systematic Review and Metanalysis

BACKGROUND Non-unions are one of the major challenges that orthopaedic surgeons must face. Vascularized bone transplants are widely used to treat these bony defects. OBJECTIVES The aim of this systematic review and meta-analysis was to investigate whether venous anastomosis in the bone-only graft increases the survival rate of the flap. METHODS We conducted this review in accordance with the PRISMA guidelines. PubMed, Embase, and the Cochrane Library were systematically searched from the inception through January 2025. Studies reporting results about bone graft performed with microsurgical anastomosis of both vein and artery and studies reporting the results of bone graft with only arterial anastomosis were selected and compared. Data quality was assessed using the Newcastle-Ottawa Scale (NOS). RESULTS The literature search yielded 1.140 papers, but only 26 papers were included in the systematic review. Heterogeneity was high, so a subgroup analysis was performed. Twenty papers dealt with only arterial anastomosis with a pooled failure rate at 4.5%. On the other side, six papers reported both vein and artery anastomosis with a pooled failure rate at 1.6%. The subgroup analysis of the papers in which venous anastomosis was made, however, did not allow to demonstrate that the venous anastomosis is truly protective (p = 0.3133). CONCLUSION Bone vascularized grafts are an indispensable therapeutic technique. The results of this review are not definitive about the role of the venous anastomosis, but it is not possible to exclude its protective role on the transplant survival. More targeted studies are essential to confirm it.