Sacroiliac joint: pain referral maps upon applying a new injection/arthrography technique. Part I: Asymptomatic volunteers.

STUDY
DESIGN: Pain pattern mapping of the sacroiliac joint in asymptomatic volunteers was investigated. Prospective evaluation of 10 volunteers who received sacroiliac joint injections was performed. The injections consisted of contrast material followed by Xylocaine.
OBJECTIVES: To determine the pain referral pattern of the sacroiliac joint in asymptomatic individuals. SUMMARY OF BACKGROUND DATA: All 10 individuals experienced discomfort upon initial injection, with the most significant sensation felt directly around the injection site. Subsequent sensory examination revealed an area of hypesthesia running caudally from the posterior superior iliac spine.
METHODS: Volunteers were asked to describe the nature and location of the sensation upon sacroiliac injection. Sensory examination immediately followed the injection to determine referral patterns.
RESULTS: Sensory examination immediately after sacroiliac injection revealed an area of buttock hypesthesia extending approximately 10 cm caudally and 3 cm laterally from the posterior superior iliac spine. This area of hypesthesia corresponded to the area of maximal pain noted upon injection.
CONCLUSION: A pain referral map was successfully generated using provocative injections into the right sacroiliac joint in asymptomatic volunteers.