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Effects of mechanical loading on the tissues of the rabbit knee
Author(s) -
Radin Eric L.,
Martin R. Bruce,
Burr David B.,
Caterson Bruce,
Boyd Robert D.,
Goodwin Claudia
Publication year - 1984
Publication title -
journal of orthopaedic research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.041
H-Index - 155
eISSN - 1554-527X
pISSN - 0736-0266
DOI - 10.1002/jor.1100020303
Subject(s) - cartilage , anatomy , chondrocyte , ankle , osteoarthritis , chondrogenesis , chemistry , medicine , pathology , alternative medicine
We studied changes in subchondral bone and articular cartilage in an animal model of osteoarthrosis. In this model we applied repetitive impulsive loads to rabbits' knees. Their legs were held in short leg splints so the rabbits were unable to dampen the peak applied load with ankle flexion. After sacrifice, at 1 day to 6 weeks, we studied proximal tibial load‐bearing cartilage histologically, biochemically, and with radioactive sulfate uptake. We also studied the subchondral bone under that cartilage histologically, histomorphometrically, with bone scan ( 99m Tc pyrophosphate), and by tetracycline labeling. An increase in 99m Tc labeling of the subchondral bone was the first reliable change observed. This was followed by an increase in tetracycline labeling, bone formation, and a decrease in porosity, which has been associated with relative stiffening of bone. Horizontal splitting and deep fibrillation of the overlying articular cartilage followed the early bone changes. All of these changes preceded changes in content and characterization of cartilage proteoglycans or increased chondrocyte activity as manifested by incorporation of radioactive sulfate. In this model the early bone changes preceded changes in the articular cartilage. The deep splitting of articular cartilage occurred prior to metabolic alteration of that tissue.