MRI findings of joint infection and adhesion after anterior cruciate ligament reconstruction / 中国医学影像技术

ABSTRACT

Objective To analyze the joint lesions of synovial thickening after anterior cruciate ligament (ACL) reconstruction,and to explore the differences of MRI findings between joint infection and adhesion.Methods Clinical and MRI data of 25 patients with synovial thickening (11 with infections and 14 with adhesion) confirmed by arthroscopy were retrospectively analyzed.The time interval from first ACL reconstruction to the arthroscopy after ACL was 0.3-2.5 (mean[1.1±0.6]) months and 6.0-19.0 (mean[11.0±4.9]) months,respectively.Results The lesions caused synovial thickening on MRI included joint infection and joint adhesion.MRI findings of joint infection included synovial thickening,moderate to massive joint effusion,different degrees of soft tissue swelling,bone marrow edema of distal femur and proximal tibia,ACL graft continuous fiber (high signals in 5 patients) and bone tunnel pseudo widened in 5 patients,while of joint adhesion included synovial thickening,striped short T2 signals in part of the thickened synovium on suprapatellar bursa,medial and lateral recess,the infrapatellar fat pad and the intercondylar fossa,without or only a small amount of joint effusion,ACL graft continuous,as well as high signals and rough edge in 3 patients,while bone tunnel was not significantly widened.Statistical differences of joint effusion,soft tissue swelling,edema of bone marrow and bone tunnel pseudo widened were found between joint infection and joint adhesion (all P＜0.05).Conclusion MRI findings of joint infection mainly included synovial thickening,joint effusion and high signal of joint cavity,while of joint adhesion were synovial thickening,equal or slightly high signal of joint cavity.Joint infections mainly occurred in the early stage after operation,while joint adhesions mainly occurred in the middle and late stage after operation.