Biochemical aspects of the etiology of articular cartilage degeneration in osteonecrosis of the femoral head have not been investigated extensively. We analyzed biochemical conditions in the hip joint cavity, regarding articular cartilage turnover in osteonecrosis of the femoral head (ONFH).
Cartilage metabolism markers in synovial fluid were measured. Synovial fluid (SF) samples were collected from 19 ONFH cases and 17 control hips with osteoarthrosis (OA). Concentrations of carboxy-terminal type II procollagen peptide (pCOL-II-C), matrix metalloproteinase-3 (MMP-3), and tissue inhibitor of metalloproteinase-1 (TIMP-1) were measured. In addition, concentrations of unsaturated disaccharides of hyaluronic acid (delta di-HA), chondroitin 4-sulfate (delta di-4S), and chondroitin 6-sulfate (delta di-6S) in SF were measured by high performance liquid chromatography.
The mean SF concentration of pCOL-II-C was higher on ONFH than in OA. The mean SF MMP-3 level was higher in ONFH than in OA, while the mean SF TIMP-1 level was the same in the 2 groups. The SF concentration of delta di-HA and the delta di-6S/delta di-4S ratio were higher in ONFH than in OA.
Higher concentrations of cartilage metabolism markers in ONFH compared with OA SF suggest elevated cartilage turnover in the former disease.