Movement Patterns of the Knee During Gait Following ACL Reconstruction: A Systematic Review and Meta-Analysis

Area of Science:

• Biomechanics
• Orthopedics
• Sports Medicine

Background:

• Altered gait patterns post-anterior cruciate ligament reconstruction (ACLR) may lead to long-term impairments and post-traumatic osteoarthritis.
• Understanding these gait alterations is crucial for optimizing patient outcomes and preventing secondary complications.

Purpose of the Study:

• To systematically review and meta-analyze lower limb kinematics and kinetics after ACLR.
• To compare the ACL-reconstructed knee with the contralateral limb and healthy controls during walking, stair climbing, and running.
• To describe the temporal changes in biomechanical variables following ACLR.

Main Methods:

• Systematic literature search from inception to August 2015.
• Inclusion of studies reporting peak knee angles and moments during gait activities.
• Risk of bias assessment using a modified Downs and Black quality index.
• Meta-analysis and qualitative assessment of gait variable recovery over time.

Main Results:

• No significant difference in peak knee flexion angles during walking and stair ascent between ACLR and control groups.
• Lower peak knee flexion moments in ACLR participants during walking and stair activities.
• Lower peak knee adduction moments in ACLR limbs compared to contralateral limbs during walking and stair descent.
• Qualitative analysis suggests restoration of peak knee flexion angle over time, but peak knee adduction moments were higher than controls 5 years post-surgery.

Conclusions:

• Joint kinematics generally restore around 6 years post-ACLR.
• Knee external flexion moments remain lower than controls long-term.
• Knee adduction moments show altered patterns, being lower early post-surgery but higher than controls at 5 years.
• Findings suggest incomplete functional recovery post-ACLR, highlighting the potential need for long-term maintenance programs.