112 patients scheduled for unilateral anterior cruciate ligament reconstruction were randomized to have the procedure completed using either a gamma-irradiated hamstring allograft or a non-irradiated hamstring allograft. Patients were assessed over a 5-year follow-up after surgery. Findings demonstrated significantly poorer results for instrumented knee laxity and subjective knee stability tests at 5 years in the irradiated allograft group compared to the non-irradiated allograft group. However, there were no differences in functional and activity outcomes.