Comparison Between Two Methods of Measuring Pelvic Obliquity in Cerebral Palsy and Myelomeningocele

Abstract

Objective: To evaluate the intra- and inter-observer reproducibility of the evaluation of the pelvic obliquity (PO) in patients with neuro-muscular deformities via the method that uses the iliac crests and the method that uses the upper endplate of S1 and to determine whe ther there is a relationship between the methods. Methods: The digitized panoramic radiographies of thirty patients with cerebral paralysis or myelomeningocelein outpatient monitoring were evaluated by four examiners: two experienced spinal surgeons and two fellows. Two radiographs were excluded because analysis was impossible. All exams were obtained in accordance with the periodic monitoring protocol in the sitting position, using digitized film and a film-focus distance of 110 cm Results: High intra- and inter-observer agreement was observed both for method that uses the iliac crests and the method that evaluates the S1 endplate. However, no significant relationship between the two methods was observed. Conclusions: The methods evaluated had good reproducibility and agreement among the observers. It was confirmed that, on account of the existent linear relation, it is possible to estimate the value of the iliac crest method knowing the value obtained by the S1 plateau multiplied by 0.76. There was no agreement between the iliac crest and S1 plateau PO evaluation methods. Level of evidence IV; Retrospective cross-sectional study.