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Early Weight-Bearing Rehabilitation Protocol After Anterior Cruciate Ligament Reconstruction
Published on: March 1, 2024
Simulated pivot-shift testing with single and double-bundle anterior cruciate ligament reconstructions
Keith L Markolf1, Samuel Park, Steven R Jackson
1Biomechanics Research Section, Department of Orthopaedic Surgery, University of California at Los Angeles Rehabilitation Center, 1000 Veteran Avenue, Room 21-67, Los Angeles, CA 90095-1759, USA. kmarkolf@mednet.ucla.edu
The Journal of Bone and Joint Surgery. American Volume
|August 5, 2008
Summary
A single-bundle anterior cruciate ligament reconstruction effectively restored knee function in a simulated pivot-shift test. Some double-bundle techniques overcorrected, reducing motion below intact levels, which may have unknown clinical effects.
Area of Science:
- Orthopedic Surgery
- Biomechanics
- Sports Medicine
Background:
- The anterior cruciate ligament (ACL) is crucial for knee stability.
- ACL reconstruction aims to restore normal knee function and stability.
- Double-bundle ACL reconstruction is hypothesized to be superior to single-bundle in restoring the pivot-shift sign.
Purpose of the Study:
- To compare the ability of single-bundle and double-bundle ACL reconstructions to restore normal knee kinematics.
- To evaluate graft forces during a simulated pivot-shift test for both reconstruction types.
- To assess the impact of different graft tensioning protocols on knee stability.
Main Methods:
- Simulated pivot-shift test performed on knees with intact ACL, and after single-bundle and four double-bundle (DB1-DB4) reconstructions.
- Knee kinematics (displacements and rotations) and graft forces were measured.
- Double-bundle graft tensioning involved specific protocols for anteromedial and posterolateral bundles.
Main Results:
- Single-bundle reconstruction successfully restored knee kinematics to intact levels during the pivot shift.
- Double-bundle reconstructions (DB2, DB3, DB4) resulted in less tibial rotation and lateral displacement than intact knees and single-bundle reconstructions.
- Graft forces were higher than intact levels post-reconstruction, with DB3 and DB4 showing higher forces than single-bundle.
Conclusions:
- Single-bundle ACL reconstruction adequately restored knee kinematics in the simulated pivot-shift model.
- Certain double-bundle tensioning protocols led to overcorrection, reducing motion below intact levels.
- While potentially reducing pivot-shift, overcorrection in double-bundle techniques may have unpredictable clinical implications.