Correlation of spine deformity, lung function, and seat pressure in spina bifida.
BACKGROUND
Spinal deformity, a common problem in children with myelodysplasia, is associated with alterations in pulmonary function and sitting balance. Sitting imbalance causes areas of high pressure in patients already at high risk for developing pressure ulcers due to insensate skin.


OBJECTIVE
We asked: Does spinal deformity affect pulmonary function tests in children with myelodysplasia? Does the magnitude of spinal curvatures and pelvic obliquity affect seating pressures? Does spinal deformity and seated pressures correlate with a history of pressure ulcers?


METHODS
We retrospectively reviewed 32 patients with myelodysplasia and scoliosis (mean age, 14 years). The mean thoracic scoliosis was 64° with a mean pelvic obliquity of 15°. The mean forced vital capacity was 59% of predicted. The mean of the average and peak seated pressures were 24 and 137 mm Hg, respectively. We examined spinal radiographs, pulmonary function tests, and seated pressure maps and evaluated correlations of spinal deformity measures, pulmonary function, and seated pressures.


RESULTS
The thoracic scoliosis inversely correlated with lung volume and weakly related with only the forced midexpiratory volume parameter (R(2) = 31%). The curve magnitude was associated with % seated area with pressures of 38 to 70 mm Hg while lesser degrees of pelvic obliquity were associated with % seating area with pressures of less than 38 mm Hg (R(2) = 25% and 24%, respectively). A history of pressure ulcers did not correlate with any spinal deformity or seated pressure measures.


CONCLUSIONS
All patients displayed a reduced forced vital capacity, but this reduction was not related to increasing scoliosis. The smaller scoliosis curves and lesser degrees of pelvic obliquity were associated with larger areas of low seated pressures.
Department of Orthopaedic Surgery, University of Kentucky, Lexington, KY, USA.
Jayesh
J
Patel
Janet L
JL
Walker
Vishwas R
VR
Talwalkar
Henry J
HJ
Iwinski
Todd A
TA
Milbrandt
D000293:Adolescent; D000704:Analysis of Variance; D002081:Buttocks / Q000503:physiopathology*; D005541:Forced Expiratory Volume; D006801:Humans; D007629:Kentucky; D008168:Lung / Q000503:physiopathology*; D008176:Lung Volume Measurements; D008450:Maximal Midexpiratory Flow Rate; D008591:Meningomyelocele / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology; D010366:Peak Expiratory Flow Rate; D011187:Posture; D011312:Pressure; D003668:Pressure Ulcer / Q000209:etiology* / Q000503:physiopathology; D011859:Radiography; D012044:Regression Analysis; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012600:Scoliosis / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D012720:Severity of Illness Index; D016135:Spinal Dysraphism / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology; D013131:Spine / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000503:physiopathology; D013147:Spirometry; D014797:Vital Capacity