MORPHOLOGICAL AND MECHANICAL STUDY ON THE EFFECTS OF EXPERIMENTALLY-INDUCED INFLAMMATORY KNEE ARTHRITIS IN RABBIT LONG BONES

Inflammatory knee arthritis was induced by intraarticular injection of carrageenan twice a week for a total of 6 weeks in New Zealand White rabbits and the effects of the arthritis on the morphological and mech anical properties of the adjacent femur and tibia were evaluated 8 wee ks after the first injection. Carrageenan-induced knee arthritis resul ted in severe osteopenic changes and a dramatic decrease in bone stren gth of the entire ipsilateral femur and tibia, including the femoral h ead and distal tibia, but not the contralateral femur and tibia and th e remote humerus. The osteoporotic changes of the adjacent bones of th e inflammatory arthritic knee are the basis for the reduced mechanical strength of these bones. These findings may have clinical significanc e with regard to the mechanisms and consequences of osteoporotic chang es in patients with rheumatoid arthritis.