Abstract
Objectives:
To systematically review the effects of meniscal tears on in vivo knee biomechanics, with a focus on kinematic and kinetic outcome measures.
Methods:
Databases were queried for level I-IV studies that met the following criteria: in vivo studies of gait or motion analysis, cohorts with isolated meniscal pathology, and kinematics and/or kinetics outcome measures. Demographic data, methods of motion analysis, tasks performed, and kinematics and kinetics outcomes were extracted. Standardized mean differences with a random-effects model were calculated to compare cohorts with meniscal tears and healthy controls when outcomes were homogeneous.
Results:
Thirteen studies were eligible, with a pooled sample of 176 medial meniscal and 74 lateral meniscal tears. Eleven studies assessed gait biomechanics. There was considerable variability in reported outcomes and motion capture methods. Meta-analysis revealed statistically significant decreases in peak knee flexion angle, range of adduction-abduction, and internal-external rotation (p < 0.05) for the pooled sample of lateral meniscus tears. In terms of kinetics, although qualitative evidence in individual studies suggested alterations (e.g., decreased total support moment of the injured limb), quantitative analysis failed to demonstrate significant differences in peak knee flexion moment and peak knee adduction moment (p ≥ 0.05).
Conclusion:
Lateral meniscus tears significantly impact in vivo knee kinematics across all three planes of motion. No significant differences were observed in the kinetics of medial meniscus tears, and the evidence for their impact on kinematics remains conflicting. Our findings suggest that analyzing more demanding functional tasks may be necessary to detect the biomechanical changes caused by meniscal tears.