Dose-dependent effect of betamethasone on the articular cartilage (experimental study)

Abstract

Introduction Glucocorticosteroid injections have been widely used in clinical practice. Betamethasone is one of the agents of this group of drugs. Its efficacy and therapeutic effect with intra-articular administration are undeniable. There are special instructions on the dosage and frequency of use of the drug but unfortunately there are cases of its wrong administration. There is also an evidence of an adverse effect on cartilage both of the drug itself and its combination with local anesthetics. Aim Evaluation of the results of different weekly intra-articular protocols of betamethasone administration on histological preparations of rabbit knee joints. Methods Histological preparations of the right knee joints of three groups of rabbits were studied: after one, three, and six administrations of betamethason per week and the control intact left knee joints. Results Histological preparations of the control group and the group with a single weekly administration of the drug did not have any changes in the structure of diarthrosis. Dystrophic and necrotic changes affecting all morphological components were observed in the joints of animals that received intra-articular injections of betamethason three times a week (compared to a single injection, the area of dystrophy and necrosis of the cartilage was greater by 10.05 ± 0.75 % (p < 0.05), of subchondral bone by 8.11 ± 0.5 % (p < 0.001), and of synovium by 6.25 ± 0.32 % (p < 0.05). The group with six injections of the drug per week had the most pronounced changes. The area of necrotic changes of the cartilage was greater by 6.39 ± 0.75 % than in the group with three injections per week (p < 0.001), of subchondral bone by 11.18 ± 0.5 % (p < 0.001), of synovium by 6.12 ± 0.32 % (p < 0.001). Discussion Inflammatory cell infiltration of joint structures was absent in all cases. It indicates an aseptic nature of tissue necrosis. Evidence has been obtained between the increase in the frequency of intra-articular injections of betamethasone and the severity of dystrophic and necrotic changes in all morphological components of the joint.

Keywords

• glucocorticosteroids
• betamethasone
• intra-articular injection