General Session: MIS - Hall F
Presented by: A. Araghi
A. Araghi(1), R. Woodruff(2), K. Colle(3), C. Boone(4), A. Tohmeh(5)
(1) The CORE Institute, Phoenix, AZ, United States
(2) Black Hills Orthopedic and Spine Center, Rapid City, SD, United States
(3) Regional Brain and Spine, Cape Girardeau, MO, United States
(4) Bellevue Bone and Joint Physicians, Bellevue, WA, United States
(5) Northwest Orthopaedic Specialists, Spokane, WA, United States
Background: The sacroiliac (SI) joint affects 15-30% of chronic low back pain sufferers1. After conservative therapy no longer provides lasting relief, those with SI joint pain may be left with SI joint fusion surgery as an option. SI joint fixation has demonstrated superior pain relief to conservative therapies2. Although numerous fixation devices are available for this surgery, they don't all share the same biomechanical properties. Joint decortication and bone grafting is not available with most techniques. The purpose of this trial is to quantify radiological evidence of arthrodesis and pain relief following minimally invasive SI joint fusion surgery including decortication of the joint, bone grafting, and fixation with threaded implants.
Methods: This is a prospective, multi-center trial which will include up to 250 subjects at 40 centers. Adult patients with at least six months of non-operative therapy, three positive provocative maneuvers, and positive diagnostic injection who are scheduled for SI joint fusion surgery are included; worker's compensation excluded. The primary endpoint of pain reduction is quantified by use of a visual analog scale, 0-100, at six months post-surgery. The primary endpoint of fusion is assessed by thin-slice computerized tomography (CT) at 12 and 24 months and evaluated by an independent radiologist group. Fusion is defined as presence of a contiguous segment of solid bridging bone extending from the sacrum to the ilium.
Results: This analysis includes 50 patients at 13 institutions followed through 6 months to assess the primary endpoint of pain relief. The mean age was 61.5 years and 58% of subjects were women. Low back pain decreased 41 points from 76.2 pre-operatively to 35.1 at six months, representing a statistically significant reduction in pain (54%, p < 0.0001). The proportion of patients achieving the minimal clinically important difference of at least 20 points was 72%; these patients had an average reduction in pain of 74%. Results of the Oswestry Disability Index (ODI) also demonstrated a statistically significant and clinically substantial improvement in disability after SI joint fusion surgery (55.5 to 35.3, p < 0.001). A substantial decline in opioid use was reported. Pre-operatively, 66% of patients were taking opioids for SI joint pain compared to 30% at 6 months (55% decrease). One (2%) revision surgery occurred due to nerve impingement. Enrollment and data collection are ongoing. Results from the first 100 patients will be available early 2018 and the results will be updated for presentation. The primary endpoint of SI joint fusion will be assessed after completion of 12 month visits.
Conclusions: Minimally invasive SI joint fusion surgery with decortication, bone graft and threaded implants results in pain and disability improvement through 6 months. This interim analysis demonstrates an average reduction in pain of 54%, significantly improved disability, and a substantial reduction in the use of opioids. While pain and disability improvement is comparable to similar studies, the reduction in opioid use (55%) was much greater than previously reported in other studies. Additional pain and fusion data from more patients and longer follow-up will continue to further delineate clinical and radiographic outcomes.