Abstract:

BACKGROUND: Ultrasound therapy can relieve pain and improve the movement function in patients with knee osteoarthritis, but there lacks of consistency in the literatures of ultrasound therapy.
OBJECTIVE: To further identify the effectiveness of ultrasound therapy in the treatment of knee osteoarthritis.
METHODS: Twenty-four rabbits were randomly divided into three groups: normal group, model group and ultrasound group. The rabbit in the normal group received no intervention; rabbits in the model group received anterior cruciate ligament transaction to establish the knee osteoarthritis model without any treatment; the rabbit in the ultrasound group received ultrasound therapy after modeling for 10 minutes once time, once per day,    0.3 W/cm2, 1 MHz and treated for 10 times. Hematoxylin-eosin staining was conducted for histological observation of rabbit articular cartilage; western blot and reverse transcription PCR assessment were used to assess the expressions of caspases-3 and caspases-8 in rabbit articular cartilage, while Terminal deoxynucleotidyl transferase dUTP nick end labeling was used to assess the ratio of chondrocytes apoptosis of rabbit knee articular cartilage.
RESULTS AND CONCLUSION: The normal rabbit cartilage tissues and chondrocytes were neatly arranged in column; the middle cartilage layer of the model was thin; the chondrocytes were arranged disorderly and became less. After ultrasound therapy, the chondrocytes were rearranged neatly, and the number was increased. Compared with the normal group, the Mankin scores in the model group and ultrasound group were higher; the apoptotic rate of chondrocytes was higher in the model group and ultrasound group than in the normal group, and was also higher in the model group than in the ultrasound group. Compared with the normal group, the expressions of caspases-3 and caspases-8 were higher in the model group and the ultrasound group, while decreased after ultrasound therapy. The results indicate that ultrasound can improve the structure of cartilage tissues, decrease the expressions of caspases-3 and caspases-8 and reduce the apoptosis rate of chondrocytes. It is effective for the treatment of knee osteoarthritis with ultrasound therapy.

Key words: osteoarthritis, chondrocytes, ultrasonic therapy, apoptosis, caspases