BackgroundGraft choice is very controversial. This study compared the second-look evaluation and clinical outcomes of anatomic ACL-R using a thin autograft versus a thick hybrid graft.Material/MethodsSixty-eight patients who had received ACL-R with hamstring autograft or autograft-allograft hybrid graft accepted second-look arthroscopy were grouped (autograft: n=31, age: 32.8±8.9, Male/Female: 16/15, and hybrid graft: n=37, age: 33.9±8.4, Male/Female: 27/10). Patients were evaluated with the functional score and KT-1000 test before reconstruction. The re-examination and second-look evaluation were performed at 2-year follow-up. Results were compared and further comparisons were made for grafts size >8.5 mm.ResultsThe hybrid group showed thicker graft size and bigger graft occupancy (9.0±0.5 mm vs. 8.5±0.7 mm, P=.003; 80.1±7.0% vs. 69.9±6.9%, P<.001). KT-1000 test, subjective evaluation, and activity level scores increased significantly between pre- and post-reconstruction for both groups (P<.001). There was no significant difference of the second-look evaluation (Graft continuity, Tension and Synovial coverage) between groups. However, from those 2 groups, only grafts size >8.5 mm were selected and compared (autograft, n=16; hybrid, n=29). Graft tension and Synovial coverage showed a significant difference (P=.036 and P=.029). The Lysholm, IKDC, and KT-1000 test were significantly superior for the autograft than the hybrid graft (P=.036, P=.004, and P=.003, respectively).ConclusionsA pure autograft is superior to a hybrid graft with same diameter in ACL-R because the augmenting allografts may be null and void. Therefore, a homogenous graft is recommended.