Hamstring autograft versus patellar tendon autograft for anterior cruciate ligament reconstruction, which graft has a higher contralateral anterior cruciate ligament injury rate?: A meta-analysis of 5561 patients following the PRISMA guidelines

BACKGROUND: Contralateral anterior cruciate ligament (CACL) injury is one of the devastating complications after anterior cruciate ligament (ACL) reconstruction. Whether the risk of CACL tear is related to graft selection remains controversial due to contradictory results in studies. There are no meta-analyses to compare which graft has a higher CACL injury rate. Hence, this meta-analysis was conducted to compare the incidence of the CACL injury after ACL reconstruction with bone-patellar tendon-bone (BPTB) autografts compared with hamstring (HT) autografts. METHODS: A comprehensive search of literature published between 1980 and January 2020 was performed using MEDLINE, EMBASE, Web of Science, and the Cochrane Library databases. RevMan 5.3 software was used for meta-analysis. The overall risk ratio (RR) was calculated using a fixed- or random-effects. The heterogeneity among the included results was analyzed by chi-square test with significance set at P < .10, and the heterogeneity was quantitatively detected by I-square tests. RESULTS: Fifteen prospective comparative studies met inclusion criteria. In the BPTB group, the CACL rupture rate ranged from 1.8% to 30%, with a pooled percentage of 8.5%. In the HT group, the CACL rupture rate ranged from 0% to 14.4%, with a pooled percentage of 3.3%. The overall CACL rupture rate was 3.1% and ranged from 1.1% to 27.1%, with a pooled percentage of 4.9%. The pooled results indicate that there was a statistical significant difference in CACL rupture risk rate between BPTB and HT autograft. (RR, 1.53; 95% CL, 1.21–1.91; P = .0004). CONCLUSION: This review showed that patients undergoing primary ACL reconstruction with BPTB autograft were more likely to have CACL rupture than patients treated with HT autograft.