Ultrasound as a Screening Tool for Proceeding With Caudal Epidural Injections Carl P. Chen, MD, PhD, Alice M. Wong, MD, Chih-Chin Hsu, MD, PhD, Wen-Chung Tsai, MD, PhD, Chen-Nen Chang, MD, Shih-Cherng Lin, MS, Yin-Cheng Huang, MD, PhD, Chih-Hsiang Chang, MD, Simon F. Tang, MD Archives of Physical Medicine and Rehabilitation Volume 91, Issue 3, Pages 358-363 (March 2010) DOI: 10.1016/j.apmr.2009.11.019 Copyright © 2010 American Congress of Rehabilitation Medicine Terms and Conditions
Fig 1 (A) Transverse plane placement of the ultrasound transducer. (B) Transverse plane ultrasound image of the sacral hiatus. Between the 2 cornua, there are 2 hyperechoic band-like structures. The band-like structure on top is the apex of the sacral hiatus. The band-like structure at the bottom is the dorsal bony surface of the sacrum or the posterior wall of the sacral hiatus. The sacral hiatus is the hypoechoic region observed between these 2 hyperechoic band-like structures. The distance between bilateral cornua was measured from the apex of one sacral cornu to the other. Archives of Physical Medicine and Rehabilitation 2010 91, 358-363DOI: (10.1016/j.apmr.2009.11.019) Copyright © 2010 American Congress of Rehabilitation Medicine Terms and Conditions
Fig 2 (A) Longitudinal plane ultrasound image of the sacral hiatus. (B) Schematic illustration of figure 2A. The apex of sacral hiatus, sacral canal, sacrococcygeal ligament, posterior wall of the sacral hiatus, and how the diameter of the sacral canal is measured at the apex of the sacral hiatus are clearly shown. Archives of Physical Medicine and Rehabilitation 2010 91, 358-363DOI: (10.1016/j.apmr.2009.11.019) Copyright © 2010 American Congress of Rehabilitation Medicine Terms and Conditions
Fig 3 Sonographic images on the anatomical variations of sacral hiatus that caused failure in caudal epidural injections. (A) Small sacral hiatus was observed under transverse view. The diameter of the sacral hiatus was measured to be about 1.2mm. (B) Small sacral canal at the apex of the sacral hiatus under sonographic longitudinal view. The entire sacrococcygeal ligament lies directly on top of the base of the sacrum. Archives of Physical Medicine and Rehabilitation 2010 91, 358-363DOI: (10.1016/j.apmr.2009.11.019) Copyright © 2010 American Congress of Rehabilitation Medicine Terms and Conditions
Fig 4 Roentgenogram and sonographic images showing closed sacral hiatus. (A) Lateral roentgenogram of the sacrococcygeal bone. Enlarged image of the sacral bone confirmed a closed sacral hiatus. (B, C) Both sonographic transverse and longitudinal views showing nonexistent sacral hiatus. Archives of Physical Medicine and Rehabilitation 2010 91, 358-363DOI: (10.1016/j.apmr.2009.11.019) Copyright © 2010 American Congress of Rehabilitation Medicine Terms and Conditions