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Updated: Mar 13, 2026

Standardized Histomorphometric Evaluation of Osteoarthritis in a Surgical Mouse Model
Published on: May 6, 2020
The common and specific osteoarthritis gait characteristics: A quantitative grading system for OA associated gait
Yajun Liu1, Ashley Knebel1, Jing Ding1
1Laboratory of Molecular Biology and Nanomedicine, Department of Orthopaedics, Warren Alpert Medical School of Brown University, Rhode Island Hospital, Brown University Health, Providence, RI 02912 USA.
Objective:
Osteoarthritis (OA) severity in animal models has been quantified primarily through grading systems reflecting the changes of joint morphology. There is a lack of a uniform grading system to quantify the changes in motion. Here, we develop a quantitative, easy-to-use grading system for OA-associated gait changes in mice.
Design:
We characterized the mouse gait changes in a surgery induced post-traumatic OA (PTOA) model and aging-associated OA (aging-OA) models using DigiGait. This treadmill system captured running motions for video analysis. We developed and validated the OA Gait grading system with a quantitative formula indicating the extent of OA-related movement changes.
Results:
We found gait changes in both aging-OA and PTOA mouse models, consistent with OA cartilage degeneration and increasing OARSI (Osteoarthritis Research Society International) scores. The female aging-OA and male PTOA mice share common gait alterations including a significant decrease in stride time and stride length and a significant increase in stride frequency. These three gait changes compose the "Common OA Gait" in mice. In addition, aging-OA alters gait symmetry between forelimbs and hindlimbs while PTOA alters ataxia coefficient between left and right limbs. These "Specific OA Gait" may indicate the involvement of aging and/or injury in OA pathogenesis.
Conclusions:
The OA Gait grading system correlated with OA pathogenesis. In some instances of aging-OA, it preceded the histopathological changes indicated by the OARSI grading system. Thus, the OA Gait grading system may be widely used for detecting alteration of functional movement outcomes in a sensitive, quantitative, and mechanistic manner.

