Introduction
-The pars interarticularis is an area of force concentration and is subject to failure with repetitive stress.
-Spondylolysis is a bilateral defect in the pars interarticularis.
-Such a defect diminishes the stabilizing ability of the posterior elements in the spinal motion segment and may lead to isthmic spondylolisthesis.
Case report
In November 1993, a 32 year-old man who was working as a aircraft engineer, clinically asymptomatic, attended the annuall medical assessment of his department, were radiographs (standing anteroposterior and lateral views of the lumbar spine) revealed bilateral spondylolysis in L4-L5 level, without spondylolysthesis (Figure 1A and 1B).
