The purpose of this double-blind, randomized clinical trial to compare outcomes of
single-bundle (SB) to anatomic double-bundle (DB) ACL reconstruction. We hypothesize that
anatomically reconstructing both bundles of the ACL will lead to better restoration of
healthy knee mechanics and clinical outcomes. In addition to standard clinical outcome
measures, we will utilize a unique combination of high-speed biplane radiography (for highly
accurate assessment of knee kinematics) and 3D imaging (MRI and CT, to define joint and
cartilage morphology) to characterize joint kinematics and cartilage surface interactions
during functional tasks.
The specific aims of this study are to:
Specific Aim 1: Determine if anatomic double-bundle ACL reconstruction restores normal
dynamic knee function better than single-bundle ACL reconstruction.
Hypothesis 1.1 Knee kinematics after anatomic double-bundle ACL reconstruction are more
similar to the uninjured contra-lateral limb than after single-bundle ACL reconstruction, as
measured with dynamic stereoradiography 6 and 24 months after surgery.
Hypothesis 1.2 Graft elongation from 6 to 24 months after surgery is reduced with anatomic
double-bundle ACL reconstruction in comparison to single-bundle ACL reconstruction, as
measured with dynamic stereoradiography.
Specific Aim 2: Determine if anatomic double-bundle ACL reconstruction results in better
clinical outcomes than single-bundle ACL reconstruction.
Hypothesis 2.1 Anatomic double-bundle ACL reconstruction will result in more symmetrical
laxity and better range of motion and hop test scores in comparison to single-bundle ACL
Hypothesis 2.2 In comparison to single-bundle ACL reconstruction, anatomic double-bundle ACL
reconstruction will result in better patient-oriented outcomes, indicating fewer symptoms, a
higher level of activity and more complete return to sport.
Successful completion of these aims will provide quantitative evidence of the efficacy of
anatomic double-bundle ACL reconstruction for restoring normal knee mechanics. Should the
results show a clear benefit for this procedure, it would provide support for wider
adaptation of anatomic DB reconstruction. By completing the proposed aims, we will also
establish a sound basis for additional studies with longer follow-up (including the subjects
in this cohort), to assess the benefits of anatomic DB ACL reconstruction for improving
long-term clinical outcomes and maintaining joint and cartilage health.