Osteoarthritis Progression Induced by Meniscectomy In Rats: Correlation Between Histological Changes and Pain-Related Behavior
A.R. Zorzi, G.G. Marques, J.P.H. Pfeifer, W.E. De Brito, J.T.C. Napimoga, M.H. NapimogaObjective:
To evaluate the correlation between histological joint changes and pain-related behavior in rats subjected to anterior root medial meniscectomy as a mechanical model of osteoarthritis.
Methods:
Sixty male Wistar rats were allocated into six groups (n = 10): meniscectomy, negative control, and sham surgery, with euthanasia at 14 or 28 days. Histological assessment was performed using the OARSI and modified Mankin scoring systems. Pain was evaluated using the facial grimace scale and Von Frey algometry (mechanical threshold and paw withdrawal time). Statistical analyses included nonparametric tests, generalized linear models, and Spearman and Pearson correlations.
Results:
At 14 days, OARSI (median 2; p = 0.048) and Mankin (median 6; p = 0.005) scores were significantly higher in the meniscectomy group compared with sham animals. At 28 days, meniscectomized rats showed higher OARSI (median 10; p = 0.014) and Mankin (median 8; p = 0.014) scores than both sham and control groups. Facial grimace scores increased significantly on the third postoperative day in the meniscectomy group (p = 0.029). Von Frey algometry demonstrated a sustained reduction in mechanical threshold and withdrawal time in meniscectomized animals at both 14 days (p < 0.001) and 28 days (weight: p = 0.001; time: p = 0.013). Histological scores correlated significantly with pain-related parameters.
Conclusion:
Anterior root medial meniscectomy induces progressive osteoarthritis and objective pain-related behavioral changes, supporting its translational value for preclinical osteoarthritis research.