Introduction】In determining the treatment strategy of lumbar spondylolysis, staging is essential. It has been performed mainly based on the classification by CT images. However, CT should be avoided as much as possible in terms of radiation exposure, especially in younger patients. Recently, a new MR imaging technique called FRACTURE began to be used. FRACTURE stands for Fast Field Echo Resembling CT Using restricted echo-spacing. It produces CT-like bone images. Last year, we applied it to the diagnosis of lumbar spondylolysis with CT, and reported its effectiveness. In this study, we reviewed the results of patients with lumbar spondylolysis who were treated with staging performed only by MRI, including FRACTURE, to determine whether CT may be unnecessary in the future.
【Methods】The subjects were 54 young patients diagnosed as spondylolysis only by MRI including FRACTURE imaging without CT at our hospital from July 2022 to August 2023. The average age was 15 years (9 -18), male was 45 and female was 9 cases. We treated them only with staging by FRACTURE images (very-early, early, progressive, terminal), which was based on CT classification. Philips 1.5T model was used. In CT, we have used sagittal images and oblique axial images which was parallel to lamina, but in FRACTURE we had to use axial images perpendicular to the body axis, due to image quality. Based on this staging, bracing and exercise therapy were performed for bone fusion, and the rate of bone union was investigated.
【Results】Of the 54 cases, 31 were unilateral, and 24 cases were bilateral. The stages were; very early stage 12, early stage 23, progressive stage 17, and terminal stage 2. The fusion rate is 100% in very early stage, 95.6% in early stage, and 58.8% in progressive stage. There was no significant difference compared to treatment with CT classification. There was no difference in the rate of return to the original sport.
【Discussion】FRACTURE is a high-resolution imaging technique that can delineate bones, ligaments, tendons, and calcifications. In this study we showed that it was possible to diagnose and treat spondylolysis without CT. Since FRACTURE would greatly help reduce radiation exposure, we believed that it would be essential in the future for the treatment of lumbar spondylolysis.