A remarkable case of hypertrophic pseudoarthrosis of the pars interarticularis in a young American football professional player.

Lumbar spondylolysis is a defect of the pars interarticularis regarded as a stress fracture. The bone stump around the pars defect usually appears atrophic and is fibrously united or filled with fibro cartilaginous mass, similar to long bone pseudoarthrosis. Lumbar spondylolysis sometimes causes bone growth resembling that of an osteophyte in osteoarthritis, and in elderly patients, the ragged edges result in radiculopathy around the defect. However, lumbar spondylolysis is rarely reported to cause hypertrophic changes resulting in spinal canal stenosis in young patients. In this report, we present an unprecedented radiological finding of distinctive hypertrophic change around the pars defect, which occurred in a young professional football player.