Purpose: To prospectively compare outcomes of primary anterior cruciate ligament (ACL) reconstruction with either Achilles tendon allograft with soft-tissue fixation or standard bone-patellar tendon-bone autograft with interference screw fixation.
Type of study: Prospective comparative case series.
Methods: A group of 41 patients who underwent soft-tissue allograft reconstruction and a group of 118 patients who underwent autograft bone-patellar tendon-bone reconstruction were included in the final results. Patients were evaluated preoperatively and postoperatively at 1 to 2 weeks, 6 weeks, 3 months, 6 months, and then annually for 5 years. Objective measures of outcome included KT-1000 measurements, range of motion, ligamentous integrity, thigh atrophy, and International Knee Documentation Committee score. Subjective evaluations included patient completion of 5 questionnaires documenting functional status, pain, and health-related quality of life: (1) the short-form McGill Pain Questionnaire, (2) a patient subjective assessment of knee function and symptoms, (3) a patient subjective assessment follow-up, (4) a knee pain scale, and (5) the RAND 36-Item Health Survey. Mixed models analysis of variance was used to compare the outcomes of the treatment groups using baseline values of the study variables as a covariate.
Results: Autograft patients reported significantly more pain on the bodily pain subscale of the RAND-36 than the allograft group at 1 week (P = .0006), 6 weeks (P = .0007), and 3 months (P = .0270). Autograft patients reported more pain than allograft patients on the McGill Pain Scale visual analog scale at 1 to 2 weeks (P < .0001) and 6 weeks (P = .0147). Patient assessment of function and symptoms showed that a higher proportion of patients reported normal or nearly normal knee function in the allograft group than in the autograft group at 3 months (33% v 14%, P = .0558, respectively). Fewer activity limitations were reported by allograft patients than autograft patients at 6 weeks (P = .0501), 3 months (P = .0431), and 6 months (P = .0014). After reconstruction, the allograft group displayed significantly more laxity in KT-1000 measurements at all time points than the autograft group (P = .0520). These measurements decreased over time for both groups (P < .0001).
Conclusions: Five-year follow-up of patients undergoing ACL reconstruction with allograft versus autograft were compared objectively and subjectively. Both groups of patients achieved similar long-term outcomes. Overall, the allograft patients reported less pain at 1 and 6 weeks after surgery, better function at 1 week, 3 months, and 1 year, and fewer activity limitations throughout the follow-up period.
Level of evidence: Level II, prospective cohort study.