Neurosurgery Resident Inova Neuroscience and Spine Institute Fairfax, VA, US
Disclosure(s):
Luke Mugge, MD: No financial relationships to disclose
Introduction: Multipoint pelvic fixation (PF) is increasingly being utilized in an effort to reduce rates of distal failure. There is a paucity of literature examining clinical and radiographic outcomes with this fixation strategy.
Methods: A single-center, consecutive series of ASD patients treated with multipoint PF was retrospectively reviewed. Multipoint PF was defined as ≥2 fixation points on each side of the pelvis. A minimum of 1 year of follow-up was required for inclusion. Fusion was assessed at 1-year with CT.
Results: 45 patients met inclusion criteria between from 2019-23. Of these, 18 had radiographic and clinical follow-up at 1 year. The mean follow-up was 13.8 (±3.9) months. M:F ratio was 8:10 with a mean age of 63.6 years. Mean construct length and number of rods used was 9.9 and 3.6, respectively. Four different pelvic construct configurations were identified (Figure 1). PF included sacroiliac fusion implants in 12 patients. At 1 year, there was significant improvement in PROMs as assessed by SRS-22r and ODI (p < 0.05 and p< 0.001, respectively). All patients had either partial or complete fusion of L5-S1 at 1 year based on CT, with no cases of L5-S1 pseudarthrosis. Pseudarthrosis of the SI joint was identified in 4/12 (33%) patients with lucency around the SI fusion device. 3 of 4 of the SI joint pseudarthroses were with triangular SI fusion devices. One patient underwent revision surgery at 4 months for a delayed sacropelvic fracture.
Conclusion : ASD patients treated with multipoint PF have significant improvement in PROMs and high rates of lumbosacral fusion at 1 year postoperatively. For patients with attempted SI fusion, triangular implants exhibited a higher rate of pseudarthrosis than screw-based implants in this cohort. Longer term follow-up is needed to better understand the durability of these constructs.