Rectangular-Tunnel Anterior Cruciate Ligament Reconstruction Using Quadriceps Tendon-Patellar Bone Autograft Can Reduce Early Donor Site Morbidity While Maintaining Comparable Short-term Clinical Outcomes

Background: Rectangular tunnel and graft have been recently designed to closely resemble the native anatomy in anterior cruciate ligament reconstruction (ACLR). This study was performed to compare the short-term clinical outcomes between rectangular and round femoral tunnels in ACLR using quadriceps tendon-patellar bone (QTPB) autografts. Methods: A total of 78 patients who underwent primary ACLR with QTPB autografts performed by three senior surgeons and had at least 1 year of postoperative follow-up were retrospectively reviewed. Patients who underwent rectangular tunnel ACLR (n = 40) were compared to those treated with the conventional round tunnel ACLR (n = 38). Outcomes including knee stability, clinical scores, quadriceps strength, associated complications, postoperative knee range of motion, and cross-sectional area of the graft were assessed. Results: Significant improvements in knee stability and clinical scores were observed after surgery in both groups (all p < 0.001). The postoperative measurements of knee stability and clinical scores were not significantly different between the two groups. Knee extension strength deficit at 60°/sec was significantly less in the rectangular tunnel group than in the round tunnel group at postoperative 6 months (41.7% vs. 48.9%, p = 0.032). The cross-sectional area of the partial-thickness QTPB graft was approximately 60% of the full-thickness QTPB graft. Conclusions: In the short-term, rectangular tunnel ACLR was comparable to round tunnel ACLR with QTPB autograft despite the smaller cross-sectional area. Additionally, the rectangular tunnel ACLR allowed partial-thickness grafting technique, which could subsequently reduce early donor site morbidity.