Weight-bearing asymmetry and vertical activity differences in a rat model of post-traumatic knee osteoarthritis. Issue 7 (July 2015)

• Record Type: Journal Article
• Authors: Hamilton, C.B.; Pest, M.A.; Pitelka, V.; Ratneswaran, A.; Beier, F.; Chesworth, B.M.
• Is Part Of: Osteoarthritis and cartilage. Volume 23:Issue 7(2015)
• Page Start: 1178
• Page End: 1185
• Publication Date: 2015-07
• Subjects: Anterior cruciate ligament -- Animal models -- Osteoarthritis -- Pain -- Behaviour; Osteoarthritis -- Periodicals; Cartilage -- Periodicals; Osteoarthritis -- Periodicals; Cartilage -- Periodicals; Arthrose -- Périodiques; Articulations -- Maladies -- Périodiques; 616.7223005
• DOI: 10.1016/j.joca.2015.03.001
• Languages: English
• ISSNs: 1063-4584

Abstract

Summary: Objective: This study used a rat model of post-traumatic knee osteoarthritis (OA) created by anterior cruciate ligament transection with partial medial meniscectomy (ACLT + pMMx). In this model, mild to moderate structural changes that are typical of knee OA have been observed within 2 and 8 weeks post-surgery. We aimed to determine whether pain-related behaviours can distinguish between an ACLT + pMMx and a sham surgery group. Design: Three-month old male Sprague–Dawley rats underwent ACLT + pMMx on their right hindlimb within two groups of n = 6 each, and sham surgery within two groups of n = 5 each. Assessments evaluated percent ipsilateral weight-bearing for static weight-bearing and 18 different variables of exploratory motor behaviour at multiple time points between 1 and 8 weeks post-surgery. Histology was performed on the right hindlimbs at 4 and 8 weeks post-surgery. Results: Histology confirmed mild to moderate knee OA changes in the ACLT + pMMx group and the absence of knee OA changes in the sham group. Compared to the sham group, the ACLT + pMMx group had significantly lower percent ipsilateral weight-bearing from 1 through 8 weeks post-surgery. Compared to the sham group, the ACLT + pMMx group had significantly lower vertical activity (episode count, time, and count) values. Conclusions: These findings suggest that ipsilateral weight-bearing deficit and vertical activity limitations resulted from the presence of knee OA-like changes in this model. When using the ACLT + pMMx-induced rat model of knee OA, percent ipsilateral weight-bearing and vertical activity distinguished between rats with and without knee OA changes. These variables may be useful outcome measures in preclinical research performed with this experimental post-traumatic knee OA model.