Study Design. Pain pattern mapping of the sacroiliac joint in asymptom
atic volunteers was investigated. Prospective evaluation of 10 volunte
ers who received sacroiliac joint injections was performed. The inject
ions consisted of contrast material followed by Xylocaine. Objectives.
To determine the pain referral pattern of the sacroiliac joint in asy
mptomatic individuals Summary of Background Data. All 10 individuals e
xperienced discomfort upon initial injection, with the most significan
t sensation felt directly around the injection site. Subsequent sensor
y examination revealed an area of hypesthesia running caudally from th
e posterior superior iliac spine. Methods. Volunteers were asked to de
scribe the nature and location of the sensation upon sacroiliac inject
ion. Sensory examination immediately followed the injection to determi
ne referral patterns. Results. Sensory examination immediately after s
acroiliac injection revealed an area of buttock hypesthesia extending
approximately 10 cm caudally and 3 cm laterally from the posterior sup
erior iliac spine. This area of hypesthesia corresponded to the area o
f maximal pain noted upon injection. Conclusion. A pain referral map w
as successfully generated using provocative injections into the right
sacroiliac joint in asymptomatic volunteers.