The value of radionuclide imaging in the diagnosis of sacroiliac joint syndrome.

STUDY DESIGN: A prospective study was done to assess the diagnostic value of radionuclide imaging (bone scan) in the evaluation of sacroiliac joint syndrome

OBJECTIVES: To determine the sensitivity and specificity of radionuclide imaging in establishing a diagnosis of sacroiliac joint syndrome in patients with low back pain.

SUMMARY OF BACKGROUND DATA: There is no pathognomonic symptom or sign to establish the diagnosis of sacroiliac joint syndrome. It has been accepted that confirmation of sacroiliac joint syndrome requires relief of pain, a positive response to a sacroiliac joint block. Bone scanning has been proposed as a useful imaging technique to evaluate for sacroiliac joint syndrome. The authors explored the use of nuclear imaging as a cost-effective and noninvasive technique in the diagnostic algorithm of sacroiliac joint syndrome.

METHODS: Patients presenting to the author's Spine Center with complaints of low back pain including the region of the sacral sulcus were screened for inclusion into this study. Positive response to three provocative Sacroiliac joint maneuvers was requisite, two of which had to be Patrick's test and pain with palpation over the sacral sulcus. Patients who met these criteria were entered into a physical therapy program comprised of lumbar spine stabilization techniques and excluded any interventions considered specific for sacroiliac joint syndrome. Those whose symptoms failed to improve with this program underwent bone scan and fluoroscopically guided sacroiliac joint block. Response to sacroiliac joint block was assessed with pre- and post-block visual analog scale scores completed by the patient. A reduction of the VAS rating by at least 80% was considered a positive response to sacroiliac joint block.

RESULTS: Fifty consecutive patients met the author's criteria and underwent bone scan and sacroiliac joint block. Thirty-one patients who had positive responses to sacroiliac joint block comprised the positive sacroiliac joint block group. Nineteen patients had less than 80% pain reduction with sacroiliac joint block and were labeled the negative sacroiliac-joint block group. Four patients had positive bone scans, all of whom were in the positive sacroiliac joint group.

CONCLUSIONS: The results demonstrated very low sensitivity and high specificity of nuclear imaging in the evaluation of sacroiliac joint syndrome. The authors do not recommend bone scan in the diagnostic algorithm for sacroiliac joint syndrome.