After detailed history and clinical evaluation, synovial fluid was taken for the estimation of MMP-13 and serum for the estimation of MMP-13 and vitamin D. There was significant difference between grade 3 and grade 4 osteoarthritis and control for all the parameters (Table 2) such as synovial MMP-13, serum MMP-13, and serum vitamin D. Here, MMP13 is linked to osteoarthritis.