A Possible Cause of Articular Cartilage Degeneration in the Acute Phase after Anterior Cruciate Ligament Reconstruction

Abstract

Abstract Backgroud: To evaluate the influence of intra-articular hemarthrosis on activities of a disintegrin and metalloprotease with thrombospondin motifs (ADAMTS) family and matrix metalloproteases (MMPs) in the acute phase after anterior cruciate ligament reconstruction (ACLR). Methods: Intra-articular hemarthrosis was collected from 17 patients who underwent primary ACLR on postoperative day POD1, POD4 and POD7. As control samples, synovial fluid without intra-articular hemarthrosis was obtained from ipsilateral knees prior to ACLR. ADAMTS-4, -5, and -9 and MMP-2 and -9 were measured by enzyme-linked immunosorbent assay (ELISA). Results: Expression levels of ADAMTS-4 were significantly higher in POD4 and POD7 samples than in control (Pc-4<0.0001, Pc-7<0.0001). Expression levels of ADAMTS-5 were significantly higher in POD1 samples than in control samples (Pc-1=0.0007). MMP-2 expression levels in POD4 and POD7 samples were significantly increased compared to control samples (Pc-4=0.0017, Pc-7=0.0013). Expression levels of MMP-9 were increased in POD1, POD4 and POD7 samples, significantly higher than in control (Pc-1<0.0001, Pc-4<0.0001, Pc-7=0.0004). Conclusion: These findings indicate that intra-articular hemarthrosis induces expression of ADAMTS-4, -5, MMP-2 and -9 in the acute phase, and especially increasing ADAMTS-4, -5 after ACLR may lead to cartilage degeneration. So intra-articular hemarthrosis may be suggested to remove as soon as possible after knee injury or surgery.