[P3-0781] Influence of knee joint stability and instability in anterior cruciate ligament injury
Keywords:Anterior cruciate ligament, joint stability, gene expression
【Purpose】
Anterior cruciate ligament（ACL）tear is a common cause of knee instability, and several studies have reported that an ACL tear does not spontaneously heal after complete rupture. However, our laboratory has reported that joint stability is effective in healing ligament. The aim of this study was to elucidate the influence of joint stability and instability after ACL injury using biochemical analysis.
【Methods】
Forty Wistar rats were randomized into three groups：Joint Laxity（JL）（ACL transection）, Joint Stability（JS）（ACL transection and surgery of joint stability）, and Control（opposite side ligament）. Intra-articular tissue（ACL, medial collateral ligament, medial meniscus）samples were collected on the 1st, 3rd, 5th, 14th, and 28th postoperative day. We quantified gene expression for collagen type 1A1（COL1A1）, collagen type 3A1（COL3A1）, transforming growth factor-β（TGF-β）, matrix metallopeptidase 13（MMP-13）and tissue inhibitor of metalloproteinase-1（TIMP-1）using real-time polymerase chain reaction.
【Results】
The expression of COL1A1, COL3A1, and TGF-β in the ACL tissue sample was higher in the JS group than that in the JL group（p＜0.05）. The mRNA expression level of MMP-13 in the JS group was lower than that in the JL group on the 14th and 28th day（p＜0.05）.
【Discussion】
In this study, joint stability promoted collagen synthesis at the mRNA level. In contrast, the gene expression of proteases, such as MMP-13, was limited. Previous report had indicated that joint instability causes a negative effect on the intra-articular tissues and articular cartilage of the knee. We observed that joint reaction caused by instability may inhibit healing of tissues such as ligaments. In this study, there have shown a possibility of promoting the healing of tissue by intra-articular stabilization of the joint. Protein analysis such as Western blot and ELISA are currently in progress.
Anterior cruciate ligament（ACL）tear is a common cause of knee instability, and several studies have reported that an ACL tear does not spontaneously heal after complete rupture. However, our laboratory has reported that joint stability is effective in healing ligament. The aim of this study was to elucidate the influence of joint stability and instability after ACL injury using biochemical analysis.
【Methods】
Forty Wistar rats were randomized into three groups：Joint Laxity（JL）（ACL transection）, Joint Stability（JS）（ACL transection and surgery of joint stability）, and Control（opposite side ligament）. Intra-articular tissue（ACL, medial collateral ligament, medial meniscus）samples were collected on the 1st, 3rd, 5th, 14th, and 28th postoperative day. We quantified gene expression for collagen type 1A1（COL1A1）, collagen type 3A1（COL3A1）, transforming growth factor-β（TGF-β）, matrix metallopeptidase 13（MMP-13）and tissue inhibitor of metalloproteinase-1（TIMP-1）using real-time polymerase chain reaction.
【Results】
The expression of COL1A1, COL3A1, and TGF-β in the ACL tissue sample was higher in the JS group than that in the JL group（p＜0.05）. The mRNA expression level of MMP-13 in the JS group was lower than that in the JL group on the 14th and 28th day（p＜0.05）.
【Discussion】
In this study, joint stability promoted collagen synthesis at the mRNA level. In contrast, the gene expression of proteases, such as MMP-13, was limited. Previous report had indicated that joint instability causes a negative effect on the intra-articular tissues and articular cartilage of the knee. We observed that joint reaction caused by instability may inhibit healing of tissues such as ligaments. In this study, there have shown a possibility of promoting the healing of tissue by intra-articular stabilization of the joint. Protein analysis such as Western blot and ELISA are currently in progress.