The mechanical and structural changes of rat cartilages under mechanical loading: an in vitro wear test of whole rat joints

Abstract

respectively. Ten of 18 subjects (56%) were classified as the vitamin D deficiency group, while remaining 8 subjects (44%) were classified as the vitamin D insufficiency or sufficiency group. Mean serum calcium (adjusted for the serum albumin level, if it was 4.0 g/dl or less), phosphorus and bone alkaline phosphatase (BAP) levels of the subjects were within the reference range. No one was diagnosed with osteomalacia. No significant difference of total osteophyte length was observed between vitamin D deficiency and vitamin D insufficiency or sufficiency groups. However, cartilage OS of the vitamin D deficiency group (1.8 mm) was significantly longer than that of the vitamin D insufficiency or sufficiency group (1.0 mm, p¼0.001). s25(OH)D level was correlated with JKOM (r¼-0.55, p¼0.029), LDFA (r¼-0.49, p¼0.037), bone OP length (r¼0.48, p¼0.047) and cartilage OP length (r¼-0.62, p¼0.006). A linear regression analysis indicated that the cartilage OP length was mostly associated with s25(OH)D levels [b¼-8.39, p¼0.015]. Conclusions: The lower s25(OH)D levels, the longer cartilage OP length in patients with knee OA, suggesting the association between vitamin D status and osteophyte mineralization.