Intraobserver and interobserver reliabilty of measures of kyphosis in thoracolumbar fractures.
BACKGROUND
Consensus documents have recently been developed enumerating the radiographic parameters thought to be most valid in the clinical evaluation of patients with thoracolumbar fractures.


OBJECTIVE
The objective of this study was to assess the measurement reliability of plain X-rays, computed tomography (CT), and magnetic resonance imaging (MRI) and their inter-modality agreement, as the three imaging modalities are often clinically interchangeable. This process is an essential reliability evaluation of the measurement parameters being proposed.


METHODS
This study evaluated the interobserver and intraobserver reliability of plain radiographs, CT, and MRI measurements of sagittal kyphosis in thoracolumbar fractures.


METHODS
Suitable plain X-ray, CT, and MRI radiographic imaging of ten cases of thoracolumbar fracture were examined.


METHODS
Suitable plain X-ray, CT, and MRI radiographic imaging of ten cases of thoracolumbar fracture were examined by ten independent spine surgery fellowship-trained observers.


METHODS
Cobb angle measurement, Gardner segmental deformity angle, and anterior body compression percentage were measured.


RESULTS
Regardless of the imaging modality or the parameter being measured, the intraobserver reliability is always better than the interobserver. Plain radiography has better overall, interobserver and intraobserver reliability, followed by CT and then MRI. Reliability is very high in general, with the highest reliability for intraobserver reliability of the linear measures on plain radiographs. The inter-modality agreement is highest for plain X-ray and CT.


CONCLUSIONS
This study demonstrates that Cobb angle measurement, Gardner segmental deformity angle, and anterior body compression percentage are reliable measures of thoracolumbar fracture kyphosis with very high interobserver and intraobserver reliability and very high inter-modality agreement of plain X-ray with CT.
Combined Neurosurgical and Orthopedic Spine Program, Vancouver Hospitals and Health Sciences Center, 2733 Heather Street, Vancouver, British Columbia V5Z 3J5, Canada. john.street@vch.ca
John
J
Street
Brian
B
Lenehan
John
J
Albietz
Paul
P
Bishop
Marcel
M
Dvorak
Charles
C
Fisher
D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000592:standards / Q000706:statistics & numerical data; D007738:Kyphosis / Q000000981:diagnostic imaging* / Q000473:pathology; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000293:injuries / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000592:standards* / Q000706:statistics & numerical data*; D015588:Observer Variation; D015203:Reproducibility of Results; D012984:Software; D016103:Spinal Fractures / Q000000981:diagnostic imaging* / Q000473:pathology; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging / Q000293:injuries / Q000473:pathology; D014057:Tomography, X-Ray Computed / Q000592:standards* / Q000706:statistics & numerical data*