The Cutoff Graft Diameter Of Small Hamstring Autografts And Clinical Outcomes Of Allograft Augmentation In Single-bundle ACL Reconstruction

Objective:To analyze graft failure of hamstring tendon(HT) autograftswith cutoff graft diameter of 8 mm or 7 mm,and compare clinical outcomes between augmented small HT with an allograft and non-augmented relative largeHT in single-bundle anterior cruciate ligament reconstruction(ACLR).Methods:A literature search of PubMed,EMBASE,and the Cochrane Library was performed based on the PRISMA(Preferred Reporting Items for Systematic Reviews and Meta-analysis) guidelines.Studies to assess graft failure of autologous HT ACLR were reviewed,and graft failure rate with the cutoff graft diameter of 8 mm or 7 mm was further extracted.Clinical comparative studies of ACLR between augmented small HT with an allograft and non-augmented relative large HT autografts were also included.Results are presented as risk ratio(RR) for binary data and weighted mean difference(WMD) for continuous data with 95%confidence intervals(CI).Results:Nine studies with 2243knees were included.Four studies were about effect of HT autografts diameter on graft failure;and 5 studies were for clinical outcomes of allograft augmentation to small HT autografts.No significant difference was noted in graft failure with the cutoff diameter of 8mm.No significant difference was found between the diameter of>7 and?7mm,but significant between the diameter of?7 and<7 mm(RR=0.49;95%CI,0.26 to 0.92;I~2=0%,P=0.03).A trend towards increased risk of graft failure was noted for allograft-augmented HT compared with non-augmented HT autografts(RR=0.43;95%CI,0.18 to 1.02;I~2=0%,P=0.06),but no significant differences were noted in IKDC,Lysholm,and Tegner scores between these two groups.Conclusion:The present study may support the utilization of 7 mm as a reference for cutoff diameter of small HT autografts,but not the augmentation to small HT autografts with an allograft.