Single- vs. Double-Bundle ACL Reconstruction
Condition: Anterior Cruciate Ligament Injury
MeSH terms: Anterior Cruciate Ligament Injuries
Study type: Interventional
Phase: Phase 2

Summary: 
      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
      reconstruction.

      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.
    

Detailed description: 
      Anterior cruciate ligament (ACL) reconstruction is the 6th most common orthopaedic procedure.
      Disruption of the ACL leads to altered knee function and significantly increases the risk for
      osteoarthritis (OA). Current methods to reconstruct the ACL are generally perceived to be
      successful; however, several recent meta-analyses have indicated that normal structure and
      function of the knee is restored only 60% to 70% of the time and 60 to 90% have radiographic
      evidence of knee OA within 10 to 20 years. Though the causes of post-traumatic OA are almost
      certainly multifactorial, a significant factor contributing to the increased risk for OA
      following ACL injury and surgery may be failure to restore normal anatomy and kinematics of
      the knee.

      We have previously shown that conventional single-bundle (SB) ACL reconstruction fails to
      restore normal knee kinematics, leading to altered patterns of joint loading. There is
      growing support for the theory that cartilage adapts to its local loading environment and
      abnormal joint loading may play an important role in the development and progression of OA.
      Our understanding of ACL anatomy has also improved over the last few years, revealing the
      shortcomings of current surgical techniques to restore anatomy of the ACL. We have developed
      double-bundle (DB) surgical procedures to restore normal anatomy of the anteromedial (AM) and
      posterolateral (PL) bundles of the ACL. The underlying principle for this approach is that
      more anatomical graft placement will lead to better knee mechanics, which are necessary for
      improved long-term outcome.

      To determine if anatomic DB ACL reconstruction can effectively restore normal dynamic knee
      function, we will conduct a double-blind randomized clinical trial to compare SB vs. anatomic
      DB ACL reconstruction. The specific aims of this study are to determine if DB is better than
      SB ACL reconstruction in terms of 1) dynamic knee function and 2) clinical outcomes. We will
      randomly assign 160 subjects with an isolated ACL injury to SB or DB ACL reconstruction and
      will follow the subjects for 2 years. We will utilize a unique combination of high-speed
      biplane radiography (for 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. Clinical outcomes will include laxity, range of
      motion, functional strength and patient-reported symptoms, function and activity. Successful
      completion of this study will provide evidence of the efficacy of anatomic DB ACL
      reconstruction for restoring normal knee mechanics and improving clinical outcomes. If the
      results show a clear benefit of this procedure, then a sound basis will have been established
      for future studies to assess the benefits of anatomic DB ACL reconstruction on long-term
      clinical outcomes and joint health.
    

Intervention name(s): Anatomic Double-Bundle ACL Reconstruction; Anatomic Single-Bundle ACL Reconstruction
Intervention type(s): Procedure; Procedure
Intervention description(s): Surgical reconstruction of the posterolateral (PL) and anteromedial (AM) bundles of the ACL using an autograft quadriceps tendon with a bone block that is split into 2 free arms to recreate the AM and PL bundles. The bone block is placed in a single femoral tunnel located in the center of the femoral ACL insertion site. The free ends of the graft are be placed in 2 separate tunnels located in the centers of the tibial insertions for the PL and AM bundles. The PL bundle is fixed with the knee in full extension and the AM bundle is fixed with the knee at 45 degrees of flexion.; Surgical reconstruction of the ACL using a single autograft quadriceps tendon with a bone block. The free end of the graft is not split. The bone block is placed in a single femoral tunnel located in the center of the femoral ACL insertion site. The single free end of the graft is placed in a single tibial tunnel located in the center of the tibial ACL insertion site. The graft is fixed with the knee in 10 to 20 degrees of flexion.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Anterior cruciate ligament surgery; Anterior cruciate ligament reconstruction; Single bundle anterior cruciate ligament reconstruction; Double bundle anterior cruciate ligament reconstruction; Randomized clinical trial