Conservative treatment for lumbar spondylolysis in children of elementary school age

Purpose Lumbar spondylolysis in children of elementary school age has different characteristics from those of junior or senior high school patients. The purpose of the present study was to investigate the outcomes of conservative treatment for lumbar spondylolysis in patients of elementary school age. Methods We included 46 lesions in 32 consecutive patients of elementary school age with fresh cases of lumbar spondylolysis (5 girls and 27 boys; mean age, 11.3 years). We examined the relationship between bone union after conservative treatment and factors such as the CT axial staging, whether the lesion was unilateral or bilateral, whether the contralateral lesion was terminal stage, and the presence of spina bifida occulta. Results Bone union was achieved in 33 lesions (72%) in 23 patients, whereas 13 lesions (28%) in 9 patients could not obtain bone union. The proportion of unilateral lesions with bone union was 13 of 13 (100%), significantly higher than that for bilateral lesions (20/33 lesions, 61%, p = 0.009). Of the 33 bilateral lesions, bone union was attained in 20 of 28 (71%) lesions without contralateral terminal stage, whereas bone union was not attained in any of 5 (0%) lesions with contralateral terminal stage, showing a significant difference between those with or without contralateral terminal stage (p = 0.005). Conclusion Bilateral lesions and contralateral terminal stage are possible unfavorable factors to bone union in conservative treatment for patients of elementary school age with lumbar spondylolysis. Early diagnosis and treatment before the lesions become bilateral or progressive stage are important.