Reliability of radiographic parameters in neuromuscular scoliosis.
METHODS
Retrospective review of radiographic data.


OBJECTIVE
This study sought to define interobserver and intraobserver variability to further delineate reliable means by which radiographs of patients with neuromuscular scoliosis can be examined.


BACKGROUND
Previous studies analyzed the use of Cobb angles in the measurement of idiopathic and congenital scoliosis, but no study until now describes a critical analysis of measurement in evaluating neuromuscular scoliosis.


METHODS
Forty-eight patients with neuromuscular scoliosis radiographs were reviewed. These were evaluated for Cobb angle, end vertebrae selection, Ferguson angle, apex of the curve, C7 balance, pelvic obliquity, Risser sign, status of the triradiate cartilage, kyphosis Cobb angle, endplate selection for kyphosis, and kyphotic index. Interclass and intraclass variability was examined with statistical analysis.


RESULTS
Cobb angle had an intraobserver variability was 5.7 degrees and the interobserver variability was 14.8 degrees . The intraobserver and interobserver variability for Ferguson angle was 6.8 degrees and 20.6 degrees, respectively. The kyphotic Cobb angle intraobserver variability was found to be 17.4 degrees, and the interobserver variability was 24.01 degrees .


CONCLUSIONS
Neuromuscular scoliosis radiographs can be reliably analyzed with the use of Cobb angle. Other forms of analysis, such as Ferguson angle, are not as reliable. Pelvic obliquity should be measured from the horizontal, as other methods are not as reliable. Kyphosis is best evaluated with the use of the kyphotic Cobb angle. Finally, it is felt that a separate anteroposterior pelvis radiograph should be used to assess skeletal maturity, as scoliosis films often truncate the vital anatomy necessary to determine skeletal maturity.
Gupta
Munish C
MC
University of California, Davis, Department of Orthopaedic Surgery, Sacramento, CA 95817, USA. munish.gupta@ucdmc.ucdavis.edu
Wijesekera
Shirvinda
S
Sossan
Allen
A
Martin
Linda
L
Vogel
Lawrence C
LC
Boakes
Jennette L
JL
Lerman
Joel A
JA
McDonald
Craig M
CM
Betz
Randall R
RR
D001837:Body Weights and Measures / Q000379:methods*; D006801:Humans; D007738:Kyphosis / Q000175:diagnosis / Q000000981:diagnostic imaging*; D008499:Medical Records; D009468:Neuromuscular Diseases / Q000175:diagnosis / Q000000981:diagnostic imaging*; D015588:Observer Variation; D017410:Practice Guidelines as Topic; D011859:Radiography; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012600:Scoliosis / Q000175:diagnosis / Q000000981:diagnostic imaging*; D013131:Spine / Q000000981:diagnostic imaging*