Inclusion Criteria:  - Males and females, aged 18 - 30 years Isolated, traumatic primary anterior cruciate ligament rupture requiring surgical reconstruction Surgical reconstruction performed using a single-bundle technique utilizing an autograft No history of ipsilateral traumatic knee injury or fracture No evidence of PCL injury or more than grade 1 injury to the MCL or LCL  Exclusion Criteria:  - BMI < 18.5 or >35 kg/m2 Injury occurred longer than 4 weeks before enrollment Intra-articular steroid injection within 3 months of injury Chondral defects greater than 3 cm2 or Outerbridge grade II or higher lesions