Long-term prospective outcomes after minimally invasive trans-iliac sacroiliac joint fusion using triangular titanium implants

Emily Darr,1 S Craig Meyer,2 Peter G Whang,3 Don Kovalsky,4 Clay Frank,5 Harry Lockstadt,6 Robert Limoni,7 Andy Redmond,8 Philip Ploska,9 Michael Y Oh,10 Daniel Cher,11 Abhineet Chowdhary12 1Orthopaedics and Physical Medicine, Medical University of South Carolina, Charleston, SC, USA; 2Columbia Orthopaedic Medical Group, Columbia, MO, USA; 3Department of Orthopedics, Yale University, New Haven, CT, USA; 4Orthopaedic Center of Southern Illinois, Mt. Vernon, IL, USA; 5Integrated Spine Care, Wauwatosa, WI, USA; 6Bluegrass Orthopedics, Lexington, KY, USA; 7Orthopedics & Sports Medicine, BayCare Clinic, Green Bay, WI, USA; 8Precision Spine Care, Tyler, TX, USA; 9OrthoSpine Solutions, Stockbridge, GA, USA; 10Allegheny General Hospital, Pittsburgh, PA, USA; 11SI-BONE, Inc., San Jose, CA, USA; 12Overlake Medical Center, Bellevue, WA, USA Background: Minimally invasive sacroiliac joint fusion (SIJF) has become an increasingly accepted surgical option for chronic sacroiliac (SI) joint dysfunction, a prevalent cause of unremitting low back/buttock pain. Objective: The objective of this study was to report clinical and functional outcomes of SIJF using triangular titanium implants (TTI) in the treatment of chronic SI joint dysfunction due to degenerative sacroiliitis or sacroiliac joint (SIJ) disruption at 3 years postoperatively. Methods: A total of 103 subjects with SIJ dysfunction at 12 centers were treated with TTI in two prospective clinical trials (NCT01640353 and NCT01681004) and enrolled in this long-term follow-up study (NCT02270203). Subjects were evaluated in study clinics at study start and again at 3, 4, and 5 years. Results: Mean (SD) preoperative SIJ pain score was 81.5, and mean preoperative Oswestry Disability Index (ODI) was 56.3. At 3 years, mean pain SIJ pain score decreased to 26.2 (a 55-point improvement from baseline, p<0.0001). At 3 years, mean ODI was 28.2 (a 28-point improvement from baseline, p<0.0001). In all, 82% of subjects were very satisfied with the procedure at 3 years. EuroQol-5D (EQ-5D) time trade-off index improved by 0.30 points (p<0.0001). No adverse events definitely related to the study device or procedure were reported; one subject underwent revision surgery at year 3.7. SIJ pain contralateral to the originally treated side occurred in 15 subjects of whom four underwent contralateral SIJF. The proportion of subjects who were employed outside the home full- or part-time at 3 years decreased somewhat from baseline (p=0.1814), and the proportion of subjects who would have the procedure again was lower at 3 years compared to earlier time points. Conclusion: In long-term (3-year) follow-up, minimally invasive trans-iliac SIJF with TTI was associated with improved pain, disability, and quality of life with relatively high satisfaction rates. Level of evidence: Level II. Clinical relevance: SIJF with TTI. Keywords: sacroiliac joint fusion, chronic low back pain, multicenter stud