Dados do Trabalho

Título

The Effect of Patient Position on Psoas Morphology and in Lumbar Lordosis

Objetivo

The current study aimed to analyze patient positioning on the lumbar lordosis and the psoas muscle’s morphology.

Metodologia

Patient Positioning. The patients were positioned in the MRI
following a protocol. For the prone position, the patients were
positioned with one bolster on the hips and one bolster in the
chest. In the lateral position, the patient was positioned in a right
lateral decubitus with slightly flexed hips and legs. As for the
dorsal frame, the patient was positioned in a traditional lumbar
MRI position. performed the measures using RadiAnt DICOM Viewer software
(Pozàn, Poland). The observers were blind to the patient’s position. To improve the homogeneity, the observers received a draft containing the intended measurements. The analyses of psoas related, such as plexus distance and psoas cross-sectional area measures, were all performed in the left psoas muscle. The data analysis and the summary statistics were performed in the software R

Resultados

The prone position yielded a significant increase in the lumbar lordosis, both in L1-S1 (57 vs.
46.5) and proximal lordosis (40.4 vs. 36.9) compared with the lateral position. Regarding the
morphologic aspects, patients in the prone position presented lesser psoas muscles forward shift, but no
the difference was noted in the plexus position neither for L3-L4 nor L4-L5.

Conclusões

The prone position resulted in a significantly increased lumbar lordosis, both distal and proximal,
which may enable the spine surgeon to achieve significant sagittal restoration just by positioning. The prone position also produced a posterior retraction of the psoas muscle. However, it did not significantly affect the position of the plexus concerning the vertebral body.