Partial patellectomy induces a decrease in the proteoglycan content in theremaining patellar articular cartilage. An experimental study in rabbits

We studied the alterations and distribution of the proteoglycan (PG) conten t of the remaining patellar articular cartilage after unilateral partial pa tellectomy in 13 rabbits. Sagittal sections of the patella were prepared an d stained with Safranin O for quantification of changes in the PC content o f the patellar articular cartilage using a commercially available imaging a nalysis system. Our findings suggest that partial patellectomy results in a decreased PC content in the remaining patellar articular cartilage. In add ition, the postoperative development of metaplasia in the scar tissue next to the healing interface may represent a compensatory response, which could prevent a further reduction in the PG content and hence the development of osteoarthritis in the remaining patellar articular cartilage.