A Review of Rodent Behavior, Mobility, and Pain Modifications in Response to Destabilization of the Medial Meniscus...

Increasing emphasis is being placed on evaluating pain and mobility outcomes of osteoarthritis (OA) in both clinical and preclinical studies. In rodent models of post-traumatic OA (PTOA), particularly those utilizing destabilization of the medial meniscus (DMM), behavioral assays are becoming more prominent as researchers seek to bridge the translational gap between structural joint pathology and human disability. However, substantial variability exists in how behavior, mobility, and pain are assessed, potentially limiting reproducibility and cross-study comparisons. This review evaluates the current literature on behavioral and pain-related outcomes in rodent DMM models, with the aim of cataloging observed phenotypes, identifying methodological inconsistencies, and proposing recommendations for standardization. We compiled data on a range of behavioral assays, including mechanical and thermal sensitivity, cage monitoring, gait analysis, weight distribution, balance, and joint compression, to construct a temporal framework of post-injury changes in behavior. Across studies, behavioral changes were observed as early as one day post-injury and persisted up to 30 weeks, with notable variability depending on age, sex, and testing protocols. Young male mice (≤12 weeks old) were the most extensively studied. The findings highlight clear trends in pain sensitivity and functional decline but also underscore the need for harmonized methodologies and reporting standards. By providing a comprehensive synthesis of behavioral outcomes post-DMM, this review aims to support more informed study design and interpretation, offering a foundation for greater consistency and translational relevance in future rodent DMM research.