The attic of the femoral tunnel in anterior cruciate ligament reconstruction: A comparison of outcomes of two suspensory femoral fixation systems

摘要

Purpose: This study aimed to find answers to the following questions: (1) Is it possible to determine and measure the space between the top of the graft and entrance of implant tunnel by magnetic resonance imaging (MRI)? (2) Is there any correlation between the hole above the graft in femoral tunnel and the femoral tunnel widening? (3) Does the tunnel widening affect clinical outcomes? (4) Are clinical and radiological outcomes of Toggle Loc with Zip Loop implant-loop design better than Endobutton CL? Methods: The operative data of two surgeons were analysed. One surgeon used Endobutton CL femoral fixation (E-CL group, n = 46); the other used Toggle Loc with Zip Loop femoral fixation (TL-ZL group, n = 32). At the last follow-up, clinical evaluation was performed with International Knee Documentation Committee Subjective Knee Form (IKDC), Tegner activity scale, Lysholm score, active and passive ROM, Lachman and pivot shift tests, and KT-1000 arthrometer. Radiological evaluation including measurement of tunnel widening on X-ray and MRI and the height of attic of femoral tunnel (space above the graft in femoral tunnel) on MRI was performed. Results: No difference was found in patient demographics, concomitant meniscal surgery and clinical outcomes. The femoral tunnel widening was evaluated significantly low in TL-ZL group on the PA X-ray and MRI. No difference was observed in the tibial tunnel widening on X-ray and MRI. A correlation between the height of attic of femoral tunnel and the femoral tunnel widening was determined. Thus, the greater the height of attic of femoral tunnel, the greater the femoral tunnel widening. No correlation was established between the tunnel widening and IKDC and Lysholm scores. Conclusions: The results of this study demonstrate that a positive correlation exists between the height of the attic of the femoral tunnel and femoral tunnel widening. Therefore, increasing the height of the attic of the femoral tunnel may contribute to graft motion, which would then enhance femoral tunnel widening. Level of evidence: III.