Fig. 2From: Factors associated with non-fusion after direct pars repair of lumbar spondylolysis with pedicle screw and lamina hook: a clinical and CT-assessed studyRepresentative CT images of different stages of pars defects (orange arrows). Stage I: Early stage, the gap is narrow, similar to hairline (A). Stage II: Progressive stage, the bone gap is clear and small fragments are present (B). Stage III: Terminal stage, characterized by a wide gap, atrophy, and sclerosis edge of the bony defect (C)Back to article page