A new method for diagnosis of anterior cruciate ligament tear: MRI with maximum flexion of knee in the prone position: A case control study

Background: The diagnosis of anterior cruciate ligament tear can be made by physical examination and magnetic resonance imaging (MRI) in the supine position. In cases where the tear is partially evaluated on MRI, the choice of treatment may vary. The purpose of the study was to investigate the efficiency of MRI at maximum knee flexion in the prone position and to compare the images with findings of the ACL detected during surgery. Materials and methods: Sixty-one patients with partial ACL tears with meniscal and cartilage lesions requiring arthroscopic knee surgery were included in the study between 2017 and 2019. MRI of these patients was prescribed at maximum knee flexion in the prone position. Then, an arthroscopic operation was performed on 61 patients and the findings (intact, partial or total tear of ACL) were recorded. The ACL was evaluated as being intact and partial or total tear. The statistical significance of the efficacy of MRI in the supine position with the knee at maximum flexion in the prone position was compared. Results: It was found that, of 61 patients with suspected partial ACL tears, 25 patients had intact ACLs, 22 patients had partial tears and 14 patients had total ACL tears, through the interpretation of MRIs of the prone position by the radiologist. In the arthroscopic surgery of 61 patients, 20 patients had intact ACLs, 27 patients had a partial tear and 14 patients had a total tear. The MRI results with maximum knee flexion in the prone position were more compatible with the findings of the arthroscopic surgery. Conclusions: It could be considered that MRI with maximum knee flexion in the prone position may also be guiding in the diagnosis and treatment of patients with partial anterior cruciate ligament rupture