Clinical, enzymatic and histological study of synovium in coxarthrosis

A comparison was made between the specific activity of cathepsin D and a histologic score for inflammation on synovial tissue obtained from 36 patients undergoing total hip replacement and an excellent correlation was found between these parameters (correlation coefficient 0.82). In addition it was found that 5 patients with the clinical diagnosis of rheumatoid arthritis had high cathepsin-specific activity (0.92±0.07) and high histologic scores (27.0±7.0). Patients with other diagnoses (failed prosthesis, idiopathic avascular necrosis, former resected hip) had low enzyme levels (0.44±0.23) as well as low histologic scores for inflammation (11.4±5.5). In cases with degenerative hip disease two groups could be definitively separated. Group 1 (20%) was characterized by high enzyme levels (0.89±0.19) and high histological scores (20.6±5.4). Group II (80%) was characterized by low enzyme levels (0.31±0.15) and low histologic scores (8.6±4.7) (Table 1).