| Abstract: | Purpose: To quantify the expression changes of gelatinase-A & B (matrix metalloproteinase-2 & 9, MMP-2 & 9) in a series of chondral, meniscal, and synovial cultures of knee osteoarthritis (OA) for investigation of the possible roles of the cartilage, menisci and synovia and the efficacy of arthroscopic dbridement. Type of Study: Case series. Methods: In consecutive 43 patients with knee OA to receive arthroscopic dbridement, we examined the amount of MMP-2 & 9 in a series of chondral, meniscal and synovial cultures. We also compared the gene expressions of MMP-2 & 9 and membrane-type 1 MMP (MT1-MMP) in the chondral, meniscal, and synovial cultures using reverse transcription polymerase chain reaction (RT-PCR). Results: Latent & activated forms of MMP-2 were produced in all series of chondral, meniscal, and synovial cultures and their activities in lesional cultures were significantly higher than that in paralesional ones (P < .001). Moreover, the latent form of MMP-9 (proMMP-9) appeared in 29 of 37 series of synovial cultures and in 13 of 40 series of meniscal cultures. In meniscal cultures after 24 hours incubation and synovial cultures after 3 and 24 hours incubation, the activity of proMMP-9 in lesional cultures was significantly higher than that in paralesional ones (P < .001). The activated form of MMP-9 appeared in 10 of 37 series of synovial cultures and its activity in lesional cultures was significantly higher than that in paralesional ones (P < .05). Furthermore, MMP-2, -9 and MT1-MMP mRNA levels of lesional areas also showed the increased expression in RT-PCR. Conclusions: Our data confirm that tissue repair of OA is ascribable to enzymic digestion of the ECM ex vivo. When technically appropriate, arthroscopic debridement for the pathologic lesions of OA, such as meniscal tears, chondral lesions, and hypertrophic villi, may be beneficial to the process of early cases. Still, it should be carefully studied for its overall effect and mechanism in vivo. |
