Minimally Invasive Sacroiliac Joint Fusion with Triangular Titanium Implants: Cost-Utility Analysis from NHS Perspective

Objective The aim was to identify the cost-effectiveness of minimally invasive sacroiliac joint fusion (MI SIJF) surgery with titanium triangular implants for patients with sacroiliac joint (SIJ) pain who have failed conservative management, compared to non-surgical management (NSM) from a National Health Service (NHS) England perspective. Methods Over a time horizon of 5 years, a cohort state transition model compared the costs and outcomes of treating patients with MI SIJF to those of traditional NSM treatment pathways. The NSM arm included two treatments: grouped physical therapy and corticosteroid injections (PTSI) or radiofrequency ablation (RFA). Three different strategies were considered: (1) a stepped pathway, (2) patients split between PTSI and RFA, and (3) RFA only. The outcome measure was incremental cost-effectiveness ratio (ICER), reported in 2018 British pounds per quality-adjusted life year (QALY) gained. One-way and probabilistic sensitivity analyses were used to test the robustness of the model results. Results Patients undergoing MI SIJF accrued total procedure-related and pain-management costs of £8358, while NSM treatment strategy 1 had total costs of £6880. The MI SIJF cohort had 2.98 QALYs compared to strategy 1 with 2.30 QALYs. This resulted in an ICER for MI SIJF versus strategy 1 of £2164/QALY gained. Strategy 2 of the NSM arm had lower costs than strategy 1 (£6564) and 2.26 QALYs, and this resulted in an ICER of £2468/QALY gained for MI SIJF. Strategy 3 of the NSM arm had lower costs than strategy 1 (£6580), and this resulted in 2.28 QALYs and an ICER of £2518/QALY gained for MI SIJF. Probabilistic sensitivity analysis shows that at a threshold of £20,000/QALY gained, MI SIJF has a probability of being cost-effective versus NSM strategies of 96%, 97%, and 91% for strategies 1, 2, and 3, respectively. Conclusion MI SIJF appears to be cost-effective over a 5-year time horizon when compared to traditional NSM pathways in an NHS context.