Impact of patient position on coronal Cobb angle measurement in non-ambulatory myelodysplastic patients

  • Norman RamirezEmail author
  • Jorge Padilla
  • Sigfredo Villarin
  • Francisco Irizarry
  • Ivan Iriarte
  • Jeffrey Sawyer
Original Article • SPINE - IMAGING



The purpose of this study was to assess the impact of patient position on the magnitude of the coronal Cobb angle measurements in relation to the change of position using plain radiograph on non-ambulatory children with myelodysplasia.

Summary of background data

Whole-spine radiographs with the patient sitting generally are preferred for the diagnosis and monitoring of progression of scoliosis in neuromuscular patients. Supine, supine traction, and sitting push-up positions have been used as substitutes, although there is no general consensus validating if these positions correlate with the sitting position. The magnitude of the Cobb angles in neuromuscular scoliosis may vary greatly depending on the position of the patient.


Radiographs of 39 myelodysplastic, non-ambulatory children were evaluated to assess the impact of change in positions (unsupported sitting, sitting push-up, supine, and supine traction) on coronal Cobb angle measurement using plain whole-spine radiographs.


The mean difference in thoracic Cobb angle measurements between sitting and all other positions ranged from 6° to 12°. At the lumbar level, the Cobb angles ranged from 12° to 16°.


Statistically significant differences in the Cobb angle measurements were identified between plain radiographs of the whole spine with the patient in the unsupported sitting position compared to sitting push-up, supine, and supine traction positions. The data support that the magnitude of the Cobb angles in neuromuscular scoliosis varies greatly depending on the position of the patient.

Level of evidence



Neuromuscular scoliosis Coronal Cobb angle Myelodysplasia Spine radiograph 



The authors thank the Children’s Spine Foundation for the grant awarded to perform the study. We also give recognition to John M Flynn MD (deceased) who gave the initial support.


Funding was provided by Children Spine Foundation Grant #18.

Compliance with ethical standards

Conflict of interest

The authors declared that they have no conflict of interest.


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Copyright information

© Springer-Verlag France SAS, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Pediatric Orthopedic SurgeonHospital De La Concepcion - San German, Puerto RicoMayaguezUSA
  2. 2.Ponce Health Sciences UniversityPonceUSA
  3. 3.University of Tennessee-Campbell ClinicMemphisUSA

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