Cost-effectiveness of minimally invasive surgery for grade 1 lumbar spondylolisthesis: a 5-year Quality Outcomes...

Minimally invasive surgery (MIS) is a reasonable treatment option for lumbar spondylolisthesis, but its long-term cost-effectiveness is not well established. Herein, the authors describe the 5-year cost-effectiveness of posterior MIS using prospective data from the multicenter Quality Outcomes Database (QOD).

Patients from the Spine COReTM study group's multicenter, prospectively collected QOD grade 1 lumbar spondylolisthesis dataset who had undergone single-stage posterior surgery were included. Gains in quality-adjusted life years (QALYs) were quantified using EQ-5D scores across 60 months. Costs from index surgeries and related reoperations were estimated using Medicare rates for inpatient care and Current Procedural Terminology rates for outpatient care. Validation was achieved via price transparency diagnosis-related group (DRG) charges and charge/cost ratios (CCRs). The cost per QALY gained was ultimately calculated.

Of the 608 patients identified as having undergone single- or multiple-stage surgery, 559 underwent single-stage posterior surgery, 242 via MIS (mean age 64.3 ± 11.7 years, 71.1% arthrodesis rate) and 317 via open surgical approaches (mean age 61.3 ± 12.2 years, 78.5% arthrodesis rate). Length of stay (LOS) was 2.3 ± 1.9 days for patients in the MIS group and 3.1 ± 1.7 days for those in the open surgery group (p < 0.0001). Operative duration was similar between the groups (171.7 ± 93.3 vs 174.2 ± 72.3 minutes, p = 0.739), whereas estimated blood loss was 108.3 ± 102.2 mL for the MIS group and 251.9 ± 230.6 mL for the open surgery group (p < 0.0001). Moreover, 6.2% of patients in the MIS group and 7.9% in the open surgery group underwent related reoperations; 5.0% and 7.6% of patients, respectively, had complications. Thirty-day readmission was required in 1.2% of patients in the MIS group and 2.5% in the open surgery group. DRG costs were stable between our model and the CCR-based model, providing external validation. The mean QALY gain was 1.06 (95% CI 0.92-1.20) for MIS and 0.94 (95% CI 0.83-1.05) for open surgery (p = 0.191); the mean QALY gain was 1.09 (95% CI 0.92-1.25) versus 0.95 (95% CI 0.82-1.08), respectively, among those who underwent arthrodesis (p = 0.193) and 0.99 (95% CI 0.71-1.28) versus 0.90 (95% CI 0.64-1.16) among those who underwent decompression only (p = 0.628). The mean cost of MIS was significantly lower ($31,822) than that of open surgery ($39,151; p = 0.001). Among those who underwent arthrodesis, the mean cost was $41,916 for MIS versus $46,626 for open surgery (p = 0.031). Among patients who underwent decompression only, the mean respective cost was $7021 versus $11,780 (p = 0.004). The mean cost per QALY gained was $29,995 for MIS and $41,635 for open surgery (p = 0.0017), $38,501 versus $48,998 among those who underwent arthrodesis (p = 0.0193), and $7073 versus $13,100 among those who underwent decompression only (p = 0.0123).

MIS for grade 1 lumbar spondylolisthesis demonstrated a 60-month cost per QALY gained of $29,995, which was significantly lower than open surgery's $41,635. Differences were driven by LOS, complications, and reoperations, and MIS remained more cost-effective even after stratification for arthrodesis. However, both surgical approaches remained below the $100,000 willingness-to-pay threshold, highlighting overall long-term cost-effectiveness.