Concordance of Radiological and Histopathological Features in a Monosodium Iodoacetate–Induced Osteoarthritis

Osteoarthritis (OA) is a common degenerative joint disease characterized by progressive impairment of joint function involving cartilage and synovium. Although histopathological examination remains the gold standard for confirming OA, radiological assessment in small-animal models is less frequently reported. In this study, we evaluated the concordance between radiological and histopathological OA features in a rat model induced by intra-articular injection of monosodium iodoacetate (MIA). Twenty male Wistar rats were divided evenly into four groups (Control, P1, P2, P3), with the latter three groups receiving 2 mg/kg of MIA in the right knee. Radiological (Kellgren–Lawrence) and histopathological (OARSI) scores were assessed at days 7 (P1), 14 (P2), and 21 (P3). Compared to the control, both K&L and OARSI scores were significantly elevated on days 14 and 21 (p < 0.001). Radiological and histological features showed good concordance over time, revealing clear, progressive OA-like changes by day 21. Our study revealed that the histopathology of features in experimental OA by using MIA has significant concordance with the radiographic manifestation.