Radiographic Outcomes of Immobilization using Boston Brace for Pediatric Spondylolysis.

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 of the lumbar spondylolysis of pediatric patients treated with a rigid thoracolumbosacral orthosis (Boston brace). MATERIALS AND METHODS: A retrospective review of 68 children (mean age = 13.9 years) treated for spondylolysis with a thoracolumbosacral orthosis. Patient charts and imaging studies were evaluated to identify the bony union rate of the spondylolysis after a minimum of 3 months of immobilization (mean = 4.2 months). Laterality, grade, level, and presence of high signal intensity in the magnetic resonance imaging were evaluated as prognostic factors. RESULTS: Sixty-eight patients presented with 110 defects. Of them, 46 (42%) were incomplete fractures, 38 (35%) complete fractures, and 26 (24%) pseudoarthrosis. Of these defects, 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). High signal 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 were similar as compared to earlier studies done with a low thoracolumbosacral orthosis. The grade of the defect, laterality, and presence of high signal intensity increased the probability of bony union. A high thoracolumbosacral orthosis (underarm) does not seem to improve the healing rate of pediatric spondylolysis defects.

Brown adipose tissue triglyceride content is associated with decreased insulin sensitivity, independently of age and obesity.

The aim of the present study was to determine whether single-voxel proton magnetic resonance spectroscopy ((1)H-MRS) can non-invasively assess triglyceride content in both supraclavicular fat depots and subcutaneous white adipose tissue (WAT) to determine whether these measurements correlate to metabolic variables. A total of 25 healthy volunteers were studied using (18)F-fluorodeoxyglucose positron emission tomography (PET) and (15)O-H2O PET perfusion during cold exposure, and (1)H-MRS at ambient temperature. Image-guided biopsies were collected from nine volunteers. The supraclavicular triglyceride content determined by (1)H-MRS varied between 60 and 91% [mean ± standard deviation (s.d.) 77 ± 10%]. It correlated positively with body mass index, waist circumference, subcutaneous and visceral fat masses and 8-year diabetes risk based on the Framingham risk score and inversely with HDL cholesterol and insulin sensitivity (M-value; euglycaemic-hyperinsulinaemic clamp). Subcutaneous WAT had a significantly higher triglyceride content, 76-95% (mean ± s.d. 87 ± 5%; p = 0.0002). In conclusion, the triglyceride content in supraclavicular fat deposits measured by (1)H-MRS may be an independent marker of whole-body insulin sensitivity, independent of brown adipose tissue metabolic activation.