Article

OBJECTIVE: To study the anatomical structure of the sacral hiatus using
ultrasound. Based on the sonographic images of the sacral hiatus, the feasibility
of caudal epidural injection can then be assessed. DESIGN: Case-controlled study.
SETTING: Rehabilitation outpatient clinic in a tertiary medical center.
PARTICIPANTS: Patients (N=47; 20 women, 27 men) with low back pain and sciatica
who were to receive caudal epidural injection treatments were recruited into this
study. INTERVENTIONS: Sonographic images of the sacral hiatus were obtained from
all the patients. An ultrasound machine capable of examining musculoskeletal
tissues with real-time linear-array ultrasound transducer was used to measure the
distance between the anterior wall and posterior wall of the sacral hiatus
(diameter of the sacral hiatus) and the distance between bilateral cornua. MAIN
OUTCOME MEASURES: Diameter of the sacral canal and distance between bilateral
cornua measured in millimeters. RESULTS: The mean diameter of the sacral canal
was measured to be 5.3+/-2.0 mm in our recruited patients. The mean distance
between bilateral cornua was measured to be 9.7+/-1.9 mm. Caudal epidural
injections failed in 7 patients. In these 7 patients, 4 had very small diameter
of the sacral canal (1.6, 1.2, 1.4, and 1.5 mm). In 1 man, sonographic images
revealed a closed sacral hiatus (no sacral canal diameter can be measured). Two
patients revealed flow of fresh blood into the syringe while checking for the
escape of cerebrospinal fluid after the needles were inserted into the sacral
canal. For safety reasons, steroid injections were not performed in these 2
patients. CONCLUSIONS: Ultrasound may be used as an effective screening tool for
caudal epidural injections. Anatomic variations of the sacral hiatus can be
clearly observed using ultrasound. Sonographic images indicating a closed sacral
canal and sacral diameters ranging from 1.2 to 1.6mm may suggest a higher failure
rate in caudal epidural injection.
CI - Copyright 2010 American Congress of Rehabilitation Medicine. Published by
Elsevier Inc. All rights reserved.

Langue : ANGLAIS