Clinical outcomes and second-look arthroscopic findings of anterior cruciate ligament reconstruction with autograft, hybrid graft, and allograft

BACKGROUND: There is no consensus as to the choice of grafts for primary anterior cruciate ligament (ACL) reconstruction. The purpose of this study was to compare the clinical and second-look arthroscopic outcomes after ACL reconstruction by use of autograft, hybrid graft, and γ-irradiated allograft. METHODS: Ninety-seven patients who underwent second-look arthroscopy after ACL reconstruction with autografts (28 patients, hamstring autograft), hybrid grafts (32 patients, hamstring autograft augmented with γ-irradiated tibialis anterior tendon allograft), or γ-irradiated allografts (37 patients, tibialis anterior tendons) were included in this study. The clinical outcomes were compared by using Lysholm score, International Knee Documentation Committee (IKDC) score, and Tegner activity score, and the side-to-side differences of KT-1000 measurement. Second-look arthroscopic findings were compared in terms of synovial coverage and graft tension. RESULTS: There were no statistical significances among the three groups in Lysholm score, IKDC score, or Tegner activity score (P > 0.05). The KT-1000 examination showed more anterior laxity in the γ-irradiated allograft group than in the autograft or hybrid graft groups (P = 0.006, and P = 0.013, respectively). Two patients in the autograft group, 2 patients in the hybrid graft group and 4 patients in the allograft group were evaluated as graft failure on second-look arthroscopy. The synovial coverage was superior in the autograft group than that in the hybrid graft group or the allograft group (P = 0.013 and P = 0.010, respectively), and was comparable between the hybrid graft group and allograft group (P = 0.876). With regard to graft tension, the autograft group and hybrid group were comparable (P = 0.883) but showed better results than the allograft group (P = 0.011 and P = 0.007, respectively). CONCLUSION: The hamstring autografts and hybrid grafts used for ACL reconstruction produced equal efficacy but provided better knee stability than allografts. In addition, the hamstring autografts showed better synovial coverage than the other two graft types.