Correlation of Knee Joint Stabilization Force with Anterior and Mediolateral Rotational Laxity Using the Arthrometer

Knee joint laxity is commonly evaluated using instrumented arthrometers; however, the relationship between externally applied stabilization force and measured anterior and rotational laxity remains insufficiently explored. This study aimed to examine the correlation between knee joint stabilization force and both anterior and mediolateral rotational knee laxity in healthy adults. Methods: A cross-sectional study was conducted on 100 healthy participants (50 males and 50 females; aged 18–29 years). One randomly selected knee per participant was assessed using the DYNEELAX arthrometer. Anterior knee laxity was measured at loading forces of 134 N, 150 N, and 200 N. Mediolateral rotational laxity was assessed during medial and lateral rotation at torques of 3 Nm and 5 Nm. Stabilization force was recorded during standardized limb fixation. Associations were analysed using Spearman’s correlation coefficient rₛ. No meaningful correlations were observed between stabilization force and anterior knee laxity at any loading condition (rₛ = -0.055 to -0.061). In contrast, moderate, statistically significant negative correlations were identified between stabilization force and mediolateral rotational laxity across all tested conditions (medial 3 Nm: rₛ = -0.455; medial 5 Nm: rₛ = -0.554; lateral 3 Nm: rₛ = -0.554; lateral 5 Nm: rₛ = -0.553; all p < 0.001). Conclusion: Stabilization force shows no meaningful correlation with anterior knee laxity but demonstrates a moderate inverse correlation with mediolateral rotational laxity. These findings indicate that rotational laxity is more sensitive to testing conditions, emphasizing the importance of standardized stabilization procedures in instrumented knee joint assessment.