Study Objective: The objective of this study was to investigate whether the area of the intervertebral space changes with body position.
Design: Case study.
Setting: Operating room.
Patients: Healthy adult male.
Interventions: A C-arm X-ray fluoroscopy system captured bone condition images of Th9/10, Th10/11, L3/4, and L4/5 of a healthy male volunteer. A three-dimensional (3D) model of the spine was created.
Measurements: We compared the areas of the intervertebral spaces in the supine and flexed body positions at Th9/10, Th10/11, L3/4, and L4/5 in the 3D model. The areas were compared and viewed caudally.
Main Results: In the anteversion position, the areas of the intervertebral spaces were larger by 60% in the thoracic spine and by 100% in the lumbar spine of L4/5.
Conclusions: The intervertebral spaces in the lower thoracic and lumbar spines were larger in the anteversion position. Hence, the anteversion position may be the preferred body position for spinal or epidural anaesthesia.

Keywords: 3D image; Body position; Intervertebral space; Spinal anaesthesia; Spine