Characterization of pathological and biochemical changes in rat destabilization of medial meniscus models of osteoarthritis

Destabilization of medial meniscus (DMM) surgical instability models of osteoarthritis (OA) have been underutilized despite having many inherent advantages. At present, there is a lack of studies clarifying cartilage degenerative changes induced by DMM in rats, which would further verify a greater use of this model. Therefore, the present study compared biochemical and histological characteristics in rat models using DMM against the anterior cruciate ligament transection (ACLT). OA was surgically induced in male SD rats by transection of the medial meniscotibial ligament (MMTL) or anterior cruciate ligament in the right femorotibial joint. Histopathological and biochemical (glycosaminoglycans (GAG) content) evaluations were performed at the end of the 2nd, 4th, and 6th week after OA induction. The ACLT model gave severe OA and, in some cases, severe subchondral erosion of the tibial plateau. Surgical DMM was less invasive than the ACLT procedure. Lesions progressed from mild-to-moderate OA at 4 weeks to moderate-to-severe OA at 6 weeks post-surgery. Destruction of the subchondral bone was not observed in the early DMM model, while detectable reduction in GAG content in the DMM group was observed (DMM: 4 +/- 0.62; normal: 7 +/- 0.51) as early as 4 weeks post-surgery. In conclusion, the DMM model produced more moderate degenerative changes than ACLT, with the advantages of being minimally invasive and reproducible. Therefore, more extensive application of DMM in rats as an animal OA model should be promoted.