Cortical Button Versus Cross-pin Femoral Fixation for Hamstring Anterior Cruciate Ligament Reconstruction: A Meta-analysis of Randomized Controlled Trials

Background: Incidences of graft rupture are associated with postoperative knee laxity after anterior cruciate ligament (ACL) reconstruction. Reports of postoperative knee laxity after ACL reconstruction using different femoral fixation techniques in several studies are controversial. Purpose: To compare, via meta-analysis of randomized controlled trials (RCTs), the clinical outcomes and postoperative knee laxity of autogenous hamstring ACL reconstruction using cortical button versus cross-pin femoral fixation. Study Design: Meta-analysis. Methods: This study followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The online PubMed, EMBASE, and Cochrane Central Register of Controlled Trials databases were searched from inception to April 1, 2017. The study included only level 1 or 2 RCTs that compared cortical button and cross-pin femoral fixation for ACL reconstruction with hamstring autografts and that reported clinical outcomes or postoperative knee laxity. The Cochrane Collaboration’s risk of bias tool was used to assess the risk of bias for all included studies. For the meta-analysis, the investigators extracted data on clinical outcomes measured by postoperative International Knee Documentation Committee (IKDC) score or Lysholm score and postoperative knee laxity defined as >5 mm side-to-side difference by the arthrometric measurement, Lachman test ≥2+, and pivot-shift test ≥2+. The risk ratio (RR) and its corresponding 95% confidence interval (CI) were computed for dichotomous data. Heterogeneity was assessed by I 2 tests. Results: A total of 6 RCTs with 445 patients were included. Statistical analysis of pooled data showed no significant difference between the cortical button and cross-pin groups on postoperative IKDC score (RR, 0.94; 95% CI, 0.88-1.02; P = .13; I 2 = 4%) and Lysholm score (RR, 0.97; 95% CI, 0.91-1.04; P = .45; I 2 = 0%). Postoperative knee laxity was reported in 5 studies, and no significant difference was found between the 2 groups (RR, 1.49; 95% CI, 0.83-2.68; P = .18; I 2 = 37%). Conclusion: Cortical button femoral fixation for autogenous hamstring ACL reconstruction had no significant difference in terms of clinical outcomes and postoperative knee laxity compared with cross-pin femoral fixation.