Pathomorphologic evaluation of intra-articular injections of soluble platelet‑rich plasma for treatment of experimental osteoarthritis

Introduction Non-surgical treatment of osteoarthritis is aimed at managing joint degeneration and inflammation to prolong the life of the original joint and delay total joint replacement. The objective was to pathomorphologically substantiate preclinical effectiveness of PRP in OA using comparative analysis of depleted plasma and serum. Material and methods The experiment was performed in 120 Wistar rats, divided into 4 groups. Osteoarthritis was simulated using an original method. Knee joint injection given to the animals after skin dissection under inhalation anesthesia and visual control two weeks later contained 0.05 ml PRP in group 1, 0.05 ml plasma in groups 2 and 0.05 ml blood serum in groups 3. The same volume of physiological saline solution was used for the injections produced for control animals. Injections were administered three times at 2-week intervals. Animals were sacrificed in groups of 10 at 2 weeks of each injection. Results The median MANKIN value scored 2.0 (1.0; 2.0) in group 1, 6.0 (5.0; 7.0) in group 2 and 7.0 (6.0; 7.0) in group 3 at 6 weeks. The median MANKIN value scored 7.5 (7.0, 8.0) in the control group. Statistically significant differences were determined between the groups at p < 0.001. Discussion Literature data on preclinical evaluation of the effectiveness of PRP therapy in biological models of OA are controversial. An original, low-traumatic functional method was used for simulating knee OA to reproduce major pathogenetic mechanisms in rats. Conclusion The findings suggested a pronounced therapeutic effect with improved morphofunctional features of the hyaline cartilage and MANKIN score of 2 at 6 days of intra-articular administration of modified PRP as compared with plasma and serum