Minimally invasive implant procedure shown to be highly effective in treatment of sacroiliac joint dysfunction


A clinical trial featured in the November issue of Neurosurgery has shown that minimally invasive sacroiliac joint fusion using triangular titanium implants is highly effective in reducing pain and disability for patients with sacroiliac joint (SIJ) dysfunction.

The randomised controlled trial shows superior outcomes in patients treated by this method, as opposed to nonsurgical management.

The study, which was overseen by Daniel J. Cher of SI-Bone, San Jose, USA and sponsored by SI-Bone, included 148 patients treated at 19 US spine surgery clinics for low back pain caused by confirmed SIJ dysfunction.

Trial subjects had severe SIJ pain, with an average pain score of 82 on a 0-to-100-point scale. Average pain duration was longer than six years, and about two-thirds of subjects were taking opioid (narcotic) medications. Many had previously received many non-surgical SIJ treatments, and many had a history of prior spinal surgery.

Two-thirds of subjects were randomly assigned to undergo minimally invasive SIJ fusion. Procedures were unilateral in most cases, but some subjects underwent bilateral treatment. The remaining subjects received nonsurgical treatments, such as physical therapy, steroid injections and/or radiofrequency ablation of sacral nerve root lateral branches.

Pain and other outcomes were compared at baseline and at one, three, six and 12 months. At six months, subjects in the nonsurgical group had the option to swap to the implant procedure.

Based on reduction in pain and absence of complications at 6 months, treatment was rated successful in 81% of subjects assigned to the SIJ implant procedure, compared to 26% with nonsurgical treatment. Average pain score decreased to 30 in the surgical group versus 72 in the nonsurgical group. Seventy-three per cent of subjects undergoing the implant procedure had “clinically significant” reduction in disability scores, compared to just 14% in the nonsurgical group.

After one year, subjects assigned to SIJ fusion still had significant reductions in pain and disability, as well as improved quality of life. Thirty-five subjects from the nonsurgical group opted to undergo the implant procedure, with similarly good results. There were only a few complications related to the SIJ implant procedure.

The minimally invasive SIJ implant approach evaluated in this trial has been cleared by the US Food and Drug Administration. The study is the first randomised controlled trial to directly compare the results of surgical and nonsurgical treatment for SIJ dysfunction.

According to Cher and colleagues, “profound differences” were found between the surgical and nonsurgical groups. The implant procedure is minimally invasive, has few complications, and produces significant and lasting improvements in pain, disability, and quality of life.

The authors note some important limitations of the trial, including the lack of long-term outcomes in the nonsurgical group due to the high crossover rate. They plan further analyses, including two-year follow-up CT scans and a cost-effectiveness comparison of SIJ fusion vs. nonsurgical treatment.