Lumbar Spondylolysis in the Pediatric Population: A Retrospective CT Review with Radiology Rereview

INTRODUCTION: Spondylolysis, a defect in the pars interarticularis, can be symptomatic or asymptomatic with an estimated prevalence of 4% by age 6 years and 6% by adulthood. This study's goal was to determine the prevalence of lumbar spondylolysis found on CT scans in children and to characterize patient-specific risk factors.

METHODS: Abdominopelvic CT scans done (2017 to 2020) in patients up to age 18 years were reviewed. The radiology report was retrospectively reviewed for a spondylolysis, and a radiologist rereviewed the CT scan. Patient demographics and indications for CT scan were included. Firth bias-reduced logistic regression was used to model spondylolysis with each demographic variable as a predictor.

RESULTS: One thousand nine hundred thirty-one CT reports and imaging were reviewed; abdominal pain (41.91%) and trauma (29.46%) were the most common reasons for CT scan. Spondylolysis was found in 42 patients (2.18%) per the radiology report and in 71 patients (3.68%) on radiologist overread. Median age was 13 years (interquartile range, 10 to 16 years). Age groups had the following prevalence: 0 to 6 years (0.41%); 7 to 10 years (1.58%); 11 to 13 years (3.59%); 14 to 18 years (5.1%). Increased prevalence was found in ages 14 to 18 years that was statistically significant (odds ratio 1; P = 0.0004). L5 was the most common level; most defects were bilateral. White patients had a higher rate of spondylolysis (5.06%) than Black patients (2.05%). Black patients were less likely to have a spondylolysis with an OR of 0.4 (0.22 to 0.69; P = 0.0007).

DISCUSSION: This study demonstrated a lower prevalence of lumbar spondylolysis (3.68%) in children compared with the previous literature. Increasing prevalence with age suggests that spondylolysis develops over time, likely because of repetitive stress. Future studies should characterize these age-related and race-related differences for better understanding.

LEVEL OF EVIDENCE: Level IV, retrospective.