Combined Effect of Bilateral Ovariectomy and Anterior Cruciate Ligament Transection With Medial Meniscectomy on the Development of Osteoarthritis Model

To investigate the combined effect of bilateral ovariectomy (OVX) and anterior cruciate ligament transection (ACLT) with medial meniscectomy (MM) on the development of osteoarthritis (OA). Twenty female 15-week-old Sprague-Dawley rats were used. Five rats in each group underwent bilateral OVX (OVX group), bilateral ACLT with MM (ACLT with MM group), bilateral OVX plus ACLT with MM (OVX plus ACLT with MM group), and sham surgery (SHAM group). All the rats were subjected to treadmill running for 4 weeks. The behavioral evaluation for induction of OA used the number of rears method, and this was conducted at 1, 2, and 4 weeks post-surgery. Bone mineral density (BMD) was calculated with micro-computerized tomography images and the modified Mankin's scoring was used for the histological changes. The number of rears in the OVX plus ACLT with MM group decreased gradually and more rapidly in the ACLT with MM group. Histologically, the OVX plus ACLT with MM group had a significantly higher modified Mankin's score than the OVX group (p=0.008) and the SHAM group (p=0.008). BMDs of the OVX plus ACLT with MM group were significantly lower than the SHAM group (p=0.002), and the ACLT with MM group (p=0.003). We found that bilateral OVX plus ACLT with MM induced definite OA change in terms of histology and BMD compared to bilateral OVX and ACLT with MM alone. Therefore, OVX and ACLT with MM was an appropriate degenerative OA rat model.