Biomechanical Comparison: Single-Bundle versus Double-Bundle Posterior Cruciate Ligament Reconstruction Techniques

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Sports Medicine

Background:

• Debate exists on double-bundle (DB) versus single-bundle (SB) posterior cruciate ligament (PCL) reconstruction techniques.
• Understanding the biomechanical differences is crucial for optimizing clinical outcomes.

Purpose of the Study:

• To compare the immediate postimplantation biomechanics of SB versus DB PCL reconstructions.
• To assess the importance of restoring both PCL bundles versus total graft volume.

Main Methods:

• Twenty knees underwent PCL reconstruction using five techniques (3 SB, 2 DB) by experienced surgeons.
• Biomechanical testing involved posterior-directed force at various flexion angles (10-90 degrees) under intact, deficient, and reconstructed conditions.
• Measurements included load to displacement, maximum displacement, and stiffness, with data normalized and analyzed via ANOVA.

Main Results:

• DB reconstructions were stiffer and exhibited less laxity than SB reconstructions across most tested angles.
• Neither SB nor DB reconstructions fully replicated the biomechanics of an intact PCL.
• Graft volume showed minimal correlation with biomechanical outcomes.

Conclusions:

• Double-bundle PCL reconstruction offers superior immediate biomechanical performance over single-bundle techniques.
• DB reconstruction may be advantageous when immediate graft strength and stability are paramount.
• Graft size is not a primary determinant of biomechanical success in PCL reconstruction.