Plasma C-terminal cross-linking telopeptide of type II collagen as a biomarker in advanced stages of femoral head osteonecrosis

Aim: The aim of this study is to investigate the potential role of C-terminal cross-linking telopeptide of type II collagen (CTX-II) in the development of femoral head osteonecrosis (FHN).Materials and methodsOne hundred and thirty-two patients diagnosed with FHN and 66 age- and sex-matched healthy subjects were included in this cross-sectional case-control study between May 2016 and November 2016. Bone histomorphology, cartilaginous immunohistochemistry, Western blotting, and level of plasma CTX-II, as well as the receiver operating characteristic (ROC) curve, were evaluated. ResultsImmunohistochemistry and Western blotting showed that CTX-II was abundantly detected in the cartilage of FHN samples in stages III & IV. Plasma CTX-II levels were significantly higher in FHN patients in the advanced stages (III & IV) than was the level in the control group (164.81% and 198.15% higher in stages III & IV, respectively). However, the levels of CTX-II did not differ significantly among the FHN patients with different etiology or other clinical data. ConclusionOur result suggests that the degeneration of cartilage has already begun in stage III, even though a relatively normal articular gap can be found in the X-ray. Plasma CTX-II level may be a biomarker of the development of FHN.