Radiographic Outcomes of Immobilization using Boston Brace for Pediatric Spondylolysis

: E. Virkki, M. Holstila, K. Mattila, O. Pajulo, I. Helenius

Publisher: SAGE PUBLICATIONS LTD

: 2020

: Scandinavian Journal of Surgery

: SCANDINAVIAN JOURNAL OF SURGERY

: SCAND J SURG

: ARTN 1457496919896998

: 5

: 1457-4969

: 1799-7267

DOI: https://doi.org/10.1177/1457496919896998

: https://journals.sagepub.com/doi/10.1177/1457496919896998

Background and Aims: Spondylolysis is a common cause of lower back pain during youth.The aim of this study is to report the bony union rate and risk factors for non-union ofthe lumbar spondylolysis of pediatric patients treated with a rigid thoracolumbosacralorthosis (Boston brace).
Materials and Methods: A retrospective review of 68 children (mean age = 13.9years)treated for spondylolysis with a thoracolumbosacral orthosis. Patient charts and imagingstudies were evaluated to identify the bony union rate of the spondylolysis after a minimumof 3months of immobilization (mean = 4.2months). Laterality, grade, level, and presence ofhigh signal intensity in the magnetic resonance imaging were evaluated as prognostic factors.Results: Sixty-eight patients presented with 110 defects. Of them, 46 (42%) wereincomplete fractures, 38 (35%) complete fractures, and 26 (24%) pseudoarthrosis. Of thesedefects, 38 (82.6%), 11 (28.9%), and 0 (0.0%) had bony union at the end of the treatment(p<0.001). Unilateral defects healed significantly better than bilateral ones (relative risk= 1.71, 95% confidence interval = 1.16–2.54, 17/26 (65%) vs 32/84 (38%), p=0.014). Highsignal intensity in the magnetic resonance images before the treatment predicted healing(relative risk = 13.24, 95% confidence interval = 1.93–91.01, 48/87 (55%) vs 1/24 (4.3%),p<0.001). The level of the spondylolysis (L5 vs above L5) did not affect the healing rate.
Conclusion: The union rates of spondylolysis with a thoracolumbosacral orthosis weresimilar as compared to earlier studies done with a low thoracolumbosacral orthosis.The grade of the defect, laterality, and presence of high signal intensity increased theprobability of bony union. A high thoracolumbosacral orthosis (underarm) does not seemto improve the healing rate of pediatric spondylolysis defects.