Gait Characteristics of People with Lateral Knee Osteoarthritis after ACL Reconstruction

HARVI F. HART, NATALIE J. COLLINS, DAVID C. ACKLAND, SALLIE M. COWAN, KAY M. CROSSLEY

Lateral knee osteoarthritis (OA) is common following anterior cruciate ligament reconstruction (ACLR), yet gait characteristics associated with lateral knee OA after ACLR are not well understood. This cross-sectional study aimed to compare knee, trunk, pelvis, hip and ankle kinematics and moments between people with predominant lateral knee OA after ACLR and healthy controls. Nineteen post-ACLR people with lateral knee OA and twenty-five healthy controls were recruited. Quantitative gait analysis was conducted during walking, and knee pain, confidence, and kinesiophobia assessed. Between-group differences in peak kinematics and moments were evaluated, and Pearson correlations evaluated relationships between biomechanical and patient-reported measures (p<0.05). Participants with lateral knee OA after ACLR had greater peak knee flexion (mean difference: 3.5°, 95% confidence interval: 0.9 to 6.1) and lower knee internal rotation angles (-3.3°, -6.2 to -0.5) than the controls. Those with lateral knee OA also had greater peak pelvic anterior tilt (3.1°, 0.4 to 5.9), and hip flexion angles (5.1°, 1.9 to 8.3), and a greater peak ankle dorsiflexion moment (0.1Nm/kg, 0.0 to 0.2). In the lateral knee OA group, worse knee confidence and kinesiophobia were significantly correlated with greater peak trunk flexion angle (r=0.654; r=0.535, respectively), and greater knee pain was significantly correlated with greater peak knee flexion angle (r=0.535). Gait characteristics associated with lateral knee OA after ACLR differ from healthy individuals, predominantly in the sagittal plane. Increased sagittal plane knee and trunk kinematics appear to be related to worse knee pain, confidence and kinesiophobia. These findings will assist development of compartment-specific interventions for individuals with post-traumatic lateral knee OA.