Prevalence of sacral spina bifida occulta and its relationship to age, sex, race, and the sacral table angle: an anatomic, osteologic study of three thousand one hundred specimens.
METHODS
An anatomic, osteologic study of spina bifida occulta (SBO).


OBJECTIVE
To determine the prevalence and patterns of SBO in a large population and examine its relationship to age, sex, and race; then to evaluate SBOs relationship to the sacral table angle (STA) when compared with an age-matched control group.


BACKGROUND
SBO has a reported prevalence of 1.2% to 50% and has been implicated in various pathologic problems. SBO is often associated with spondylolysis or spondylolithesis. The STA has been implicated as an etiologic or predictive factor in the presence of pars defects.


METHODS
Three thousand one hundred osteologic specimens were evaluated for the presence of SBO. SBO was graded on a scale from 0 to III. Information on the age, sex, race, and STA of each specimen was recorded and measured, respectively. Prevalence and patterns of SBO were enumerated. The STAs of an age-matched control group of 355 specimens were examined. The SBO group and control groups were compared in regards to STA, controlling for age, sex, and race.


RESULTS
Overall, 355 specimens displayed SBO, for an overall prevalence of 12.4%. Of the SBO specimens, 68.7% were white, 88.2% were men, 53% were grade I, 37% II, and 10% III. All 3 grades of SBO were more common in men than women (88.2% vs. 11.8%) and more prevalent in whites than blacks (68.7% vs. 31.3%) (P = 0.01). SBO decreased in prevalence with increasing age. The average STA in SBO specimens was 95.9 degrees . This differed from an age-matched control group, 92.1 degrees (P < 0.0001). Every 1 degrees increase in STA resulted in a 6% increased likelihood of SBO. In SBO specimens, the STA decreased with increasing age, contrary to age-matched controls.


CONCLUSIONS
SBO has an overall prevalence of 12.4% in a large, diverse population. SBO is more common in men and whites and decreases in prevalence with increasing age. The STA is greater in SBO when compared with controls and an increased STA predicts SBO. In SBO, the STA decreases with increasing age.
Eubanks
Jason David
JD
Department of Orthopaedics, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA. Jdeubanks2002@yahoo.com
Cheruvu
Vinay K
VK
D000328:Adult; D017677:Age Distribution; D000368:Aged; D000886:Anthropometry / Q000379:methods; D044383:Black People; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D044469:Racial Groups; D012447:Sacrum / Q000002:abnormalities* / Q000473:pathology / Q000503:physiopathology; D012720:Severity of Illness Index; D017678:Sex Distribution; D012863:Skeleton; D016136:Spina Bifida Occulta / Q000453:epidemiology* / Q000473:pathology / Q000503:physiopathology; D013131:Spine / Q000002:abnormalities* / Q000473:pathology / Q000503:physiopathology; D044465:White People