Prevalence, MRI Characteristics, and Sports-Related Associations of Baastrup's Disease in Pediatric Athletes With Low Back Pain: A STIR-MRI-Based Study.

BACKGROUND: Baastrup's disease is characterized by close approximation and inflammation of adjacent lumbar spinous processes. Although Baastrup's disease is traditionally considered an age-related degenerative disorder, recent reports have described its occurrence in younger people; however, its prevalence and sports-related factors in pediatric athletes remain unclear. HYPOTHESIS: Baastrup's disease is prevalent among pediatric athletes with low back pain (LBP) and is associated with specific physical characteristics, sports-related factors, and lumbar magnetic resonance imaging (MRI) findings. STUDY DESIGN: Cross-sectional study. LEVEL OF EVIDENCE: Level 3. METHODS: A retrospective analysis was performed on 177 pediatric athletes (mean age, 14.1 years; range, 9-18 years) who presented with LBP. The presence of Baastrup's disease was evaluated using short tau inversion recovery MRI (STIR-MRI), and its associations with physical characteristics, sports-related factors, and other MRI abnormalities were analyzed. Statistical analyses included t tests, chi-square tests, and multivariate logistic regression. RESULTS: Baastrup's disease was identified in 50 of 177 athletes (28.2%). Affected athletes were older, had longer sports participation, and participated more frequently in basketball and speed skating. The prevalence of lumbar spondylolysis was significantly lower in athletes with Baastrup's disease, and its absence was associated independently with the condition (adjusted odds ratio, 0.30; 95% CI, 0.12-0.75). CONCLUSION: The prevalence of Baastrup's disease in pediatric athletes with LBP was substantially higher than reported previously, suggesting that this condition may be under-recognized in young patients. The use of STIR-MRI may improve diagnostic accuracy. Notably, associations were observed with basketball and speed skating, sports in which excessive lumbar extension is not required frequently. Both flexion and extension may contribute to the development of Baastrup's disease in young athletes. CLINICAL RELEVANCE: Baastrup's disease is a common and clinically relevant STIR-MRI finding in pediatric athletes with LBP and may help differentiate causes of sport-related LBP.