Effect of periarticular and intraarticular lidocaine injections for sacroiliac joint pain: prospective comparative study

Background The sacroiliac joint (SIJ) can be a source of low back pain. Previous studies indicated that SIJ pain could originate from both the joint capsule and the posterior ligamentous tissues. It has not been clarified as to whether an intraarticular or periarticular injection procedure is more effective for this type of pain. The purpose of this study was to evaluate the effect of two injection procedures prospectively. Methods After a pain provocation test, an intraarticular injection of local anesthetic (2% lidocaine) was performed on the first 25 consecutive patients with SIJ pain and a periarticular injection on another 25. The periarticular injections were given to one or more sections of the posterior periarticular area of the SIJ and to another section in the extracranial portion. The effect of these injections was assessed using the "restriction of activities of daily life" scoring system from the Japanese Orthopaedic Association. Results The periarticular injection was effective in all patients, but the intraarticular one was effective in only 9 of 25 patients. An additional periarticular injection was performed in 16 patients who experienced no effect from the initial intraarticular injection and was considered effective in all of them. The injection into the middle of the periarticular area was more effective for SIJ pain. The improvement rate after the periarticular injection was 96%, which was significantly higher than that after the intraarticular injection, which was 62%. Conclusions For patients with SIJ pain, periarticular injection is more effective and easier to perform than the intraarticular injection and should be tried initially.