Comparison of Bioabsorbable Interference Screw and Attachable Button System for Tibial Fixation in Anterior Cruciate Ligament Reconstruction: A Prospective Study with Magnetic Resonance Imaging-based Graft Ligamentization Assessment

Abstract Background: The optimal tibial fixation technique in anterior cruciate ligament (ACL) reconstruction remains debated. This study compares bioabsorbable interference screws and attachable button system (ABS) suspensory fixation concerning functional outcomes, knee stability, and graft ligamentization. Materials and Methods: In this prospective two-arm comparative study, 144 patients underwent arthroscopic ACL reconstruction using quadrupled hamstring autografts. Femoral fixation was standardized with TightRope devices, while tibial fixation (interference screw or attachable button system) was selected intraoperatively. Clinical evaluation included the Tegner–Lysholm score and knee stability tests (Lachman, anterior drawer, and pivot shift). Graft ligamentization was assessed through magnetic resonance imaging (MRI) at 12 months using signal intensity and Figueroa scoring. Results: Both the groups demonstrated significant functional improvement at 24 months (mean Lysholm scores: Interference screw, 99.39 ± 0.69; ABS button, 99.47 ± 0.72; P < 0.001). Knee stability was satisfactory in 82.7% of patients, with mild residual laxity in 7.3%, evenly distributed between the groups ( P = 0.880). MRI revealed low signal intensity in 65.97% and intermediate in 34.03%, with 100% achieving Figueroa scores of 3–5. No fixation failures or major complications were observed. Conclusion: Bioabsorbable interference screws and ABS button suspensory devices provide comparable functional and radiological outcomes in ACL reconstruction. Both the techniques are safe and effective, allowing for intraoperative selection based on graft length and tunnel visibility.