No Effect of Long-Term Risedronate Use on Cartilage and Subchondral Bone in an Experimental Rabbit Model of Osteoarthritis

Abstract

Osteoarthritis (OA) is the most prevalent degenerative joint disease in animals and humans. It is characterized by pain, articular cartilage damage and joint stiffness. It has been suggested that the status of the subchondral bone compartment plays an important role in the initiation and progression of OA. Bisphosphonates have been proposed as a potential disease-modifying treatment for OA, however their effectiveness is not yet clear. Twenty-four male adult New Zealand rabbits were used to evaluate the effects of risedronate on the subchondral bone quality and cartilage degradation in a long-term model of experimentally induced OA. Animals underwent an anterior cruciate ligament transection and partial medial meniscectomy or sham operation in only one knee, which was randomly chosen, using the contralateral as healthy control. Animals were divided into three groups (n = 8): untreated control group and sham surgery control group; both groups received only vehicle; and risedronate group, treated with 2.5 mg orally weekly for 24 weeks. Stifle joints were harvested and scanned using a high-resolution micro-CT to evaluate the subchondral plate and trabecular bone changes. The macroscopic evaluation and histological analysis were determined using an adapted Osteoarthritis Research Society International scoring scheme to assess the cartilage degeneration. The lateral and medial femoral condyle and tibial plateau were evaluated. Additionally, the histological synovial membrane assessment was carried out. Sample analysis showed that the experimental model induced osteoarthritic changes in the operated joints, whereas in sham-operated rabbits, almost no histological changes were observed on articular cartilage surfaces. In terms of macroscopic and histological analyses, risedronate-treated animals did not show improved cartilage health compared with untreated operated rabbits, but a slightly anti-inflammatory activity was observed in the synovial membrane. Risedronate administration showed a slight tendency to increase subchondral bone plate thickness in lateral compartments but, it did not show conservation of periarticular bone and was not be able to suppress the osteophyte formation. In conclusion, long-term risedronate use did not demonstrate a positive effect Fernández-Martín et al. Long-Term Risedronate Use in Osteoarthritis on reducing the cartilage damage, and failed to prevent the subchondral bone changes and osteophytogenesis in an experimental rabbit model of OA.

Histomorphometric Quantitative Evaluation of Long-Term Risedronate Use in a Knee Osteoarthritis Rabbit Model

“…In conclusion, it is important to note that the scientist community is currently involved in carrying out the 3R principles of replacement, reduction and refinement. Given that we adhered to a policy of reducing animal numbers, we considered to be appropriate to continue the research with the same experimental animals ( 45 ) and consequently, complete the characterization of the risedronate effect at all levels. The results of this study may improve our knowledge about osteoarthritis anatomic location and disease evolution, more specifically allowing an appropriate tissue selection in the OA preclinical studies.…”

“…The anesthetic protocol and the postoperative treatment was thoroughly described in a recent publication of our research group ( 45 ). Osteoarthritis was surgically induced by ACLT and partial medial meniscectomy achieving the instability of the knee joint.…”

“…The animals were euthanised at 27 weeks post-surgery by a sodium pentobarbital injection in the lateral auricular vein (100 mg/kg IV, Dolethal, Vétoquinol, Madrid, Spain), after sedation with ketamine (25 mg/kg IM, Imalgène 1000, Merial, Toulouse, France) and medetomidine (50 μg/kg IM, Domtor, Esteve, Barcelona, Spain). As mentioned in a previous publication ( 45 ), the risedronate dosage used in the study corresponds to the human clinical doses recalculated according to the mean weight of the animals.…”

“…In order to measure the 3D structural parameters of the trabecular bone, the distal part of the femur and proximal part of the tibia were scanned with a high-resolution micro-CT (Skyscan 1172, Bruker microCT NV, Kontich, Belgium) using parameters according to our previous study ( 45 ). In order to evaluate the specific regional changes and based on the method described by Batiste et al ( 40 ), the knee was examined at the lateral and medial sides of femoral condyles and tibial plateaus and three cylindrical volumes of interest (VOIs), of ×2.5 mm of diameter and 2.5 mm depth for femoral compartments and 2.5 × 1.5 mm for tibial compartments, were placed in separate anatomical regions: anterior, central and posterior ( Figure 4 ).…”

“…This manuscript focused on the histological modifying-effects of risedronate on hyaline cartilage and subchondral bone, after 24 weeks of treatment, considering its possible positive impact by reducing the periarticular bone turnover ( 11 , 16 , 17 , 23 , 44 ). In this line of research, the long-term risedronate effect on the synovial structures has recently been evaluated by macroscopically and decalcified histology assessments as well as micro-CT general analysis ( 45 ). However, on this occasion, a thorough 2D undecalcified histomorphometric protocol was used for the study of the quantitative cartilage and bone changes.…”