A minimally invasive implant procedure is highly effective in reducing pain and disability for patients with sacroiliac joint dysfunction (SIJ), according to a study published in the November issue of Neurosurgery. The randomized controlled trial showed superior outcomes in patients undergoing minimally invasive sacroiliac joint fusion using triangular titanium implants, compared with nonsurgical management, according to lead author David W. Polly, MD, a professor in the Departments of Orthopedic Surgery and Neurosurgery at the University of Minnesota in Minneapolis.
David W. Polly, MD
This study included 148 patients with low back pain caused by confirmed SIJ dysfunction, treated at 19 spine surgery clinics in the United States. SIJ disruption, also known as osteoarthritis, is estimated to cause 15% to 23% of cases of chronic low back pain.
Study participants had severe SIJ pain, with an average pain score of 82 on a 0-to-100-point scale. Average pain duration was longer than 6 years, and about two-thirds of subjects were taking opioid medications. Many study participants had previously received nonsurgical SIJ treatments and many had a history of prior spinal surgery.
Two-thirds of subjects were randomly assigned to undergo minimally invasive SIJ fusion. In this procedure, triangular titanium implants were placed through a small incision to stabilize and fuse the SIJ. 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 1, 3, 6, and 12 months. At 6 months, subjects in the nonsurgical group had the option to “cross over” 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 with 26% of people with nonsurgical treatment. The average pain score decreased to 30 in the surgical group compared with 72 in the nonsurgical group. A total of 73% of subjects undergoing the implant procedure had “clinically significant” reduction in disability scores, compared with 14% in the nonsurgical group.
After 1 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.
The minimally invasive SIJ implant approach that was evaluated in this trial has been cleared by the FDA. The study is the first randomized controlled trial to directly compare the results of surgical and nonsurgical treatment for SIJ dysfunction.
The results show “clinically and statistically important” improvements in clinical outcomes for patients undergoing the SIJ implant procedure, according to Dr. Polly and colleagues, with “profound differences” 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 study authors noted some important limitations of their trial, including the lack of long-term outcomes in the nonsurgical group due to the high crossover rate.
Investigators plan further analyses, including 2-year follow-up CT scans and a cost-effectiveness comparison of SIJ fusion versus nonsurgical treatment.