Background: Knee osteoarthritis is a chronic joint illness distinguished by the gradual cartilage loss of extracellular matrix and subsequent disturbance in chondrocyte biology. Decorin is a small leucin-rich proteoglycan that provides physical linkage among both molecules of aggrecan and collagen II fibrils. It is an important structural component of matrix integrity and cartilage biomechanical function. Its level helps to determine OA grading and subsequently management.
Objective: to measure the serum decorin levels in knee OA patients and to explore their association with clinical manifestations and disease severity.
Methodology: In this case-control study, 50 patients with varying grades of knee OA were compared to 50 age-and sex-matched seemingly healthy people as controls. The serum decorin level in both groups has been measured using the enzyme linked immunosorbent assay (ELISA) technique.
Results: There had been a highly statistically significant elevation in serum decorin in the OA patient group, with a median of 52.4 (9.8-66.8)compared to 8.6 (6.6-9.13)in the control group, and there was a significant positive correlation (p < 0.05) between decorin level and Western Ontario and McMaster Universities (WOMAC).

Conclusion: Serum decorin has been significantly elevated in the patient group and its level correlates positively with WOMAC