Metabolic responses of cartilage in experimentally induced osteoarthritis

Serial metabolic responses in developing osteoarthritis induced in the right knees of a rabbit model of partial meniscectomy (PM) were studied. Controls were sham-operated (SH) right knees, left knees of all operated animals, nd right and left knees of a nonoperated series. Glycosaminoglycan and protein synthesis and cell replication were separately analysed utilising 35 SO4, 14C-Glycine, and 3H-thymidine, respectively. Pitting, ulceration, and osteophytes, seen only in the PM knees, increased over the 12-week period of study. 3H-thymidine and 14C-glycine incorporations by PM cartilage were increased at 3 weeks, less than nonoperated control animals at 9 weeks, and approximated to those of controls at 12 weeks. 35 SO4 incorporation by tibial osteophytes was decreased at 9 and 12 weeks. Similar isotope incorporations seen after partial meniscectomy and sham surgery represented a nonspecific response to arthrotomy. Cartilage synthetic activity did not increase in parallel with degenerative change.