L4 Spondylolysis in a Young Adult: Selective Imaging and Conservative Management

Spondylolysis, a defect of the pars interarticularis, is a frequent cause of low back pain in young adults. A 19-year-old male presented with a year of chronic pain that recently worsened, limiting ambulation. He denied trauma, fever, neurological symptoms, or bowel/bladder dysfunction. Examination revealed an antalgic gait without focal tenderness or deficits. Given the underlying chronicity and functional limitation in a young patient, lumbar radiographs were obtained, which demonstrated a pars defect at L4. Spondylolysis most commonly involves L5, may progress to spondylolisthesis, and is strongly associated with repetitive lumbar stress, particularly in athletes. Current imaging guidelines discourage routine radiography for uncomplicated low back pain without red flags; however, selective imaging may be warranted when clinical features increase the pre-test probability of structural pathology. Management is typically conservative with activity modification, physical therapy, and selective bracing, with surgery reserved for refractory cases. This case underscores individualized imaging decisions in young patients with disabling symptoms and highlights an uncommon L4 presentation.