Effect of the TT and AM approaches in anterior cruciate ligament reconstruction on femoral tunnel and efficacy analysis

Abstract

AbstractObjectiveTo compare the clinical efficacy, location and length of the femoral tunnel, graft angle, and radiographic findings between the transtibial tunnel (TT) approach and the anteromedial (AM) approach in the setting of anterior cruciate ligament (ACL) reconstructionMethodsFrom September 2020 to December 2021, prospectively, 86 consecutive patients who met the criteria for ACL reconstruction were prospectively included in this study. The patients were randomly divided into two groups, TT group and am group, according to the computer-generated sequence. Finally, a total of 45 patients were included in the TT group and 41 patients in the AM group. All patients were assessed for knee clinical function using the Lysholm score, International Knee Documentation Committee (IKDC) score preoperatively, 6 months postoperatively, and at last follow-up. Anteroposterior and rotational stability of the knee were assessed by the Lachman test, axial shift test, and rotarod. The location of the femoral tunnel was evaluated within 1 week postoperatively using CT three-dimensional reconstruction combined with the Bernard quadrant method. Magnetic resonance imaging (MRI) MRI of the knee was performed 1 year after surgery to assess graft tone, morphology, and signal and was graded. The angle between the graft and the joint line was measured.ResultsFollow up ranged from 15 to 36 months with a mean (SD) of 23.76 ± 5.63. Both procedures resulted in satisfactory clinical outcomes after ACL reconstruction, and no patients in either group developed intra-articular infection, graft fracture, and joint stiffness during follow-up. At the last follow-up, the Lysholm, IKDC, Lachman and pivot shift tests were significantly improved (P < 0.05) compared to their preoperative values in both groups, and there was no significant difference between them (P > 0.05). The JGS and JGC angles in the TT group were significantly larger than those in the AM group (P < 0.05). CT three-dimensional reconstruction showed that the femoral tunnel center position of the AM approach was lower and deeper than that of the TT approach, and the difference was statistically significant (P < 0.05). Graft MRI grade after TT approach was superior to am approach (P < 0.05).ConclusionThere were no significant differences between the AM approach and the TT approach in terms of knee clinical function and stability, but the femoral tunnels of the AM approach were located deeper and lower, and closer to the femoral anatomic foot print area of the anterior cruciate ligament. The TT approach was superior to the AM approach in postoperative radiographic grading of grafts.