THE VALUE OF RADIONUCLIDE IMAGING IN THE DIAGNOSIS OF SACROILIAC JOINT SYNDROME

Study Design. A prospective study was done to assess the diagnostic va lue of radionuclide imaging (bone scan) in the evaluation of sacroilia c joint syndrome. Objectives. To determine the sensitivity and specifi city 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 diagn osis of sacroiliac joint syndrome. It has been accepted that confirmat ion of sacroiliac joint syndrome requires relief of pain, a positive r esponse to a sacroiliac joint block. Bone scanning has been proposed a s 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 jo int syndrome. Methods. Patients presenting to the author's Spine Cente r 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 s yndrome. Those whose symptoms failed to improve with this program unde rwent bone scan and fluoroscopically guided sacroiliac joint block. Re sponse to sacroiliac joint block was assessed with pre- and post-block visual analog scale scores completed by the patient. A reduction of t he VAS rating by at least 80% was considered a positive response to sa croiliac joint block. Results. Fifty consecutive patients met the auth or's criteria and underwent bone scan and sacroiliac joint block Thirt y-one patients who had positive responses to sacroiliac joint block co mprised the positive sacroiliac joint block group. Nineteen patients h ad less than 80% pain reduction with sacroiliac joint block and were l abeled the negative sacroiliac joint block group. Four patients had po sitive bone scans, all of whom were in the positive sacroiliac joint g roup. Conclusions. The results demonstrated very low sensitivity and h igh specificity of nuclear imaging in the evaluation of sacroiliac joi nt syndrome. The authors do not recommend bone scan in the diagnostic algorithm for sacroiliac joint syndrome.