Can the ideal femoral tunnel position be achieved by modified transtibial technique of anterior cruciate ligament reconstruction using bone patellar bone graft? – A prospective study

In the transition from isometric to anatomical anterior cruciate ligament (ACL) reconstruction, the transportal technique of ACL reconstruction has become the widely used method. However, with the difficulty in bone patellar bone (BTB) graft passage and technical demand, transtibial is gaining popularity over the transportal technique. For achieving a femoral tunnel to be centered in the ACL attachment site using the traditional transtibial approach of ACL reconstruction, a shorter tibial tunnel becomes inevitable. By adopting a modified transtibial approach for ACL reconstruction with a BTB graft, the study intends to analyze the accuracy of the femoral tunnel. Thirty four patients who underwent single-bundle ACL reconstruction with BTB graft using the modified transtibial technique in a single center were included in the study. The femoral tunnel position was determined with a computed tomography scan using the quadrant method. The results were compared with that of cadaveric study and transportal technique. The tibial tunnel angulation in the coronal plane and intraarticular aperture location was measured for standardization of the technique. The mean distance of the femoral tunnel from the posterior condylar surface (t) was 33 +/- 6.8, and from the notch (h) was 21 +/- 5.2. On comparing the horizontal distance (t) obtained with that of the transportal technique (P = 0.001; 95% confidence interval (CI); difference -10) and cadaveric study (P = 0.016; 95% CI; difference -5) by the analysis of variance (ANOVA) post hoc test, p-value was found to be significant. Similarly, on comparing the vertical distance (h) with that of the transportal technique (P = 0.9; 95% CI; difference 2), P value was found to be not significant. The drawback of the conventional transtibial approach is thus addressed by our modified transtibial technique of ACL repair with BTB graft, which makes the femoral tunnel nearly anatomical and comparable to the tunnel location achieved by the transportal technique.