VI Connective and Cartilaginous Tissue Effects of Altered Load on Canine Articular Cartilage In Vivo and In Vitro

The role of exercise and physical modalities in the treatment of osteoarthritis

Physical rehabilitation is a valuable and often underutilized part of the overall management of small animals with OA. A team consisting of the veterinarian, physical therapist, veterinary technician, and owner is vital to determine and carry out an appropriate therapeutic regimen. To maintain enthusiasm for the program, measurements should be regularly obtained to document progress. In addition, controlled studies should be performed to determine the degree of improvement that may be expected with physical rehabilitation programs.

Decrease of proteoglycan granule number but increase of their size in articular cartilage of young rabbits after physical exercise and immobilization by splinting

The effects of physical exercise (running) and immobilization by splinting on the number and size of proteoglycan (PG) granules and the diameter of collagen fibers of the articular cartilage were studied with the transmission electron microscope with a stereological method. The lateral tibial condyles of 24 young rabbits were examined. The analysis was carried out in the superficial, middle, and deep zones of uncalcified articular cartilage and also in the pericellular, territorial, and interterritorial regions of each zone. PGs were demonstrated in situ by using en bloc staining with the cationic dye ruthenium red, which binds to negative groups of glycosaminoglycans. Results of the control group showed that there was a large pericellular number of PG granules, and the number of granules tended to increase through cartilage depth. The mean diameter of PG granules was highest in the superficial zone and decreased through cartilage depth. The collagen fibers were thicker in the interterritorial than in the territorial region and their diameters increased from superficial toward the deep zone of uncalcified cartilage. Results of the experimental groups showed that the number of ruthenium-red-positive PG granules decreased by 3-46% in all zones and regions after both physical exercise and joint immobilization. On the other hand, the diameter of PG granules increased by 4-42% in all zones and regions in all groups. Collagen fibers in the territorial region of the middle zone were thinner in the exercised and in the splinted knee, while thicker in the contralateral knee to the splinted limb, as compared with the controls.(ABSTRACT TRUNCATED AT 250 WORDS)