Cost-Utility Analysis of Sacroiliac Joint Fusion in High-Risk Patients Undergoing Multi-Level Lumbar Fusion to the Sacrum

Abstract

Multi-level lumbar fusion to the sacrum (MLF) can lead to increased stress and angular motion across the sacroiliac joint (SIJ), with an incidence of post-operative SIJ pain estimated at 26-32%. SIJ fusion (SIJF) can help obviate the need for revisions by reducing range of motion and screw stresses. We aimed to evaluate the cost-utility of MLF + SIJF compared to MLF alone among high-risk patients from a payer perspective, where high risk is defined as high body mass index and high pelvic incidence. Methods: A Markov process decision-analysis model was developed to evaluate cumulative 5-year costs, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratio (ICER) of MLF + SIJF compared to MLF alone using published data; costs from Medicare claims data analyses and health state utility values (derived from EQ-5D) informed by three prospective, multicenter, clinical trials. The base case assumed a reduction in post-operative SIJ pain from 30% to 10% (relative risk reduction [RRR] of 67%). Costs and utilities were discounted 3% annually. The ICER is reported in 2020 US dollars. One-way, multi-way, and probabilistic sensitivity analyses were performed. Results: With an assumed 30% incidence of SIJ pain after MLF alone, stabilizing with SIJF was associated with an additional 5-year cost of $2421 and a gain of 0.14 QALYs, resulting in an ICER of $17,293 per QALY gained (similar to total knee arthroplasty and more favorable than open discectomy). ICERs were most sensitive to the RRR of post-operative SIJ pain conferred by SIJF, time horizon, and probability of successful treatment with MLF alone. At a willingness-to-pay threshold of $50,000/QALY gained, MLF + SIJF has a 97.7% probability of being cost-effective in the target patient population. Conclusion: Fusing the SIJ in high-risk patients undergoing MLF was cost-effective when the incidence of post-operative SIJ pain after MLF alone exceeds approximately 25%, providing value-based healthcare from a payer perspective.

A New Approach to the Treatment of Sacroiliac Joint Pain and First Patient-Reported Outcomes Using a Novel Arthrodesis Technique for Sacroiliac Joint Fusion

“…From an economic point of view SIJF and multilevel lumbar fusion with SPF appear to be cost-effective in this patient population and cost saving in the long term. 30 , 31 …”

“…29 From an economic point of view SIJF and multilevel lumbar fusion with SPF appear to be cost-effective in this patient population and cost saving in the long term. 30,31 Open arthrodesis, as described by Smith-Petersen in 1921, with maximum cartilage removal from the joint surfaces and bone grafting, is only possible in combination with extensive soft tissue damage. 2,32 More recently, minimally invasive SIJF has been shown to reduce morbidity and recovery time compared to the traditional open approach.…”

Bilateral sacroiliac joint fusion in long constructs using self-harvesting porous S2–alar iliac screws with an integrated tulip: technical considerations and early clinical and radiographic experience

“…18 This phenomenon may be a source of significant disability to the patient and cost burden for the healthcare system. 19 To avoid subsequent patient dissatisfaction, disability, and SIJ fusion surgery, some authors have advocated for concomitant SIJ fusion at the time of index surgery. 18,19 There is biomechanical evidence to support that the addition of a triangular titanium implant across the SIJ has benefits.…”

Estimating the Cost of Spinopelvic Complications After Adult Spinal Deformity Surgery

“…SI joint pain can be treated both non-surgically and surgically. According to Ackerman et al, 15 5-year treatment costs of non-surgical treatment for SI joint pain in the Medicare population averaged $18,527. Mean costs were substantially higher in those who had undergone prior lumbar fusion.…”