107 - Improvement in Sacroiliac Joint Pain 2 Years after Fusion with the Dis...

General Session: Innovative Technologies

Presented by: T. Freeman - View Audio/Video Presentation (Members Only)


K. Duncan(1), B. Manchec(1), C. Borlongan(2), D.L. Scott(3), F. Bernardo(1), W. Monahan(1), T. Freeman(4)

(1) University of South Florida, Morsani College of Medicine, Tampa, FL, United States
(2) University of South Florida, Center of Excellence for Aging and Brain Repair, Tampa, FL, United States
(3) University of South Florida, Neurosurgery & Brain Repair, Tampa, FL, United States
(4) University of South Florida, Neurosurgery, Tampa, FL, United States


Introduction: The sacroiliac joint (SIJ) is a common generator of low back pain that is under-diagnosed and under-treated. Here, we evaluate the safety and efficacy of SIJ arthrodesis using the novel Signus DIANA™ Sacroiliac Joint interpositional device two years post-operatively.

Methods: In this retrospective study, 38 consecutive patients with severe SIJ pain underwent arthrodesis using the distraction-interference DIANA™ cage. All patients failed conservative therapy. No subjects were excluded including patients with worker's compensation cases, litigation and narcotic addiction. Smoking cessation was attempted in all patients before surgery. Surgeries were performed by a single surgeon with no intellectual property interests. Records were evaluated at baseline and 2 years postoperatively for change in SIJ pain, self-reported pain scores related to the SIJ, and the Oswestry disability index, among others. Our primary endpoint was improvement in SIJ pain as assessed using a 10-point VAS in all patients without osteoporosis (n=35). Secondary endpoints included improvement in SIJ pain scores for patients with osteoporosis, and patients with isolated SIJ pain vs. those with other concomitant surgical issues in the lumbosacral spine. A Bonferroni correction for subgroups was utilized.

Results: Severe adverse events included four failed fusions, three of which have since been successfully fused. There were no neurovascular or device-related adverse events. SIJ pain scores in patients without osteoporosis (n=35) improved from an average of 9.43 preoperatively to 2.64 2 years post-operatively (p< 0.0001, 72% improvement). Similar improvement was noted in all patient subgroups without osteoporosis, including those who had: 1) isolated SIJ pain (9.54-2.82; n=13; p< 0.0001) 2) previous or concomitant laminectomy (9.38-2.50; n=8; p=0.0036) 3) previous or concomitant short segment fusion (9.27-2.91; n=11; p=0.0008) and 4) previous long segment fusion (9.67-1.33; n=3; p=0.20). Nearly all improvements in SIJ pain scores were achieved within the first 6 weeks post-operatively. Patients with osteoporosis experienced less but still meaningful improvement in SIJ pain, (8.67-4.33; n=3; p=0.0495; 50% improvement). Patient-reported global improvement averaged 79% (n=29). Ninety percent (26/29) said they would have the surgery again and recommend it to others. Patients also demonstrated meaningful improvement in Oswestry scores (62.20-38.46) and sitting tolerance, as well as pain scores in the ipsilateral leg, contralateral SIJ, and bilateral inguinal regions.

Conclusions: This study suggests that SIJ arthrodesis using the DIANA™ device is safe, effective, and provides meaningful and sustained alleviation of SIJ pain. This study is limited due to subgroup sample size, retrospective design, and inclusion of a challenging patient cohort. Long term consequences such as adjacent segment failure cannot be ascertained with only 2 year follow up. Results may be used to power a prospective trial.