After brace removal, a CT was performed to determine bone healing. When bone marrow edema improved on both sides, patients could remove the brace and return to playing sports. Since the disappearance of bone marrow edema on MRI has been reported to indicate the loss of a fracture healing mechanism, an MRI was performed every 1–2 months until the bone marrow edema around the pedicle resolved on short tau inversion recovery images. Our conservative treatment protocol for lumbar spondylolysis, other than terminal-stage, was for patients to wear a semi-rigid lumbosacral back brace to limit trunk extension, refrain from participating in sports, and undergo physiotherapy. An MRI showing the absence of bone marrow edema with CT indicating bone defect was classified as the terminal-stage. Alternatively, an MRI showing bone marrow edema and CT indicating clear bone gap was classified as a progressive-stage. An MRI showing bone marrow edema with CT indicating visible hairline fracture was classified as an early-stage. Stages were classified according to previous reports using both MRI and CT at the first consultation. The study was performed in accordance with the Declaration of Helsinki and approved by the Institutional Review Board of Mito Kyodo General Hospital (approval no., 19–44). Informed consent was obtained from all participants in this study. No patient had any history of medical or spinal disorders. The most popular sport activity was soccer, with 13 patients (27%), followed by baseball with 11 patients (23%). All patients were students who were active in both sports and club activities. The mean age of the patients was 13.5 years (range, 8–17 years). We constructed a cohort of 48 patients (38 boys and 10 girls) who were seen at our facility between April 2015 and March 2019. Patients with pseudoarthrosis on both sides at the first consultation were excluded. Using both MRI and computed tomography (CT), we identified students diagnosed for the first time with bilateral L5 spondylolysis. There have been some reports that the pathological stage on the contralateral side can affect bone healing, but no reports have exclusively examined L5 spondylolysis.įor this study, we aimed to evaluate bone healing rates in L5 spondylolysis comparing the fracture stages present. There is a possibility that this process progresses to lumbar spondylolisthesis, where a vertebra slips from its location to rest on the lower bone. When spondylolysis progresses to terminal-stage, inflammation may first occur at the site of pseudoarthrosis and then spread to the adjoining facet joints and synovitis, causing low back pain. Patients diagnosed with terminal spondylolysis at first consultation cannot achieve successful bone healing. Sometimes, bone healing is not achieved even with early diagnosis and conservative treatment. Current treatment strategies suggest that early diagnosis, coupled with conservative treatment for lumbar spondylolysis, is a way to achieve successful bone healing. Recent diagnostic advances in magnetic resonance imaging (MRI) have resulted in early diagnosis of spondylolysis. The L5 pars interarticularis is the spinal level most affected and susceptible to mechanical stress. reported that 33% of young patients that complained of sports-related low back pain lasting more than 7 days had lumbar stress injuries. Lumbar spondylolysis is a stress fracture of the pars interarticularis and that typically occurs in adolescent athletes.

Bilateral l5 spondylolysis