Cost minimization in treatment of adult degenerative scoliosis

Abstract

OBJECT Back pain is an increasing concern for the aging population. This study aims to evaluate if minimally invasive surgery presents cost-minimization benefits compared with open surgery in treating adult degenerative scoliosis. METHODS Seventy-one patients with adult degenerative scoliosis received 2-stage, multilevel surgical correction through either a minimally invasive spine surgery (MIS) approach with posterior instrumentation (n = 38) or an open midline (Open) approach (n = 33). Costs were derived from hospital and rehabilitation charges. Length of stay, blood loss, and radiographic outcomes were obtained from electronic medical records. Functional outcomes were measured with Oswestry Disability Index (ODI) and visual analog scale (VAS) surveys. RESULTS Patients in both cohorts were similar in age (AgeMIS = 65.68 yrs, AgeOpen = 63.58 yrs, p = 0.28). The mean follow-up was 18.16 months and 21.82 months for the MIS and Open cohorts, respectively (p = 0.34). MIS and Open cohorts had an average of 4.37 and 7.61 levels of fusion, respectively (p < 0.01). Total inpatient charges were lower for the MIS cohort ($269,807 vs $391,889, p < 0.01), and outpatient rehabilitation charges were similar ($41,072 vs $49,272, p = 0.48). MIS patients experienced reduced length of hospital stay (7.03 days vs 14.88 days, p < 0.01) and estimated blood loss (EBL) (EBLMIS = 470.26 ml, EBLOpen= 2872.73 ml, p < 0.01). Baseline ODI scores were lower in the MIS cohort (40.03 vs 48.04, p = 0.03), and the cohorts experienced similar 1-year improvement (ΔODIMIS = −15.98, ΔODIOpen = −21.96, p = 0.25). Baseline VAS scores were similar (VASMIS = 6.56, VASOpen= 7.10, p = 0.32), but MIS patients experienced less reduction after 1 year (ΔVASMIS = −3.36, ΔVASOpen = −4.73, p = 0.04). Preoperative sagittal vertical axis (SVA) were comparable (preoperative SVAMIS = 63.47 mm, preoperative SVAOpen = 71.3 mm, p = 0.60), but MIS patients had larger postoperative SVA (postoperative SVAMIS = 51.17 mm, postoperative SVAOpen = 28.17 mm, p = 0.03). CONCLUSIONS Minimally invasive surgery demonstrated reduced costs, blood loss, and hospital stays, whereas open surgery exhibited greater improvement in VAS scores, deformity correction, and sagittal balance. Additional studies with more patients and longer follow-up will determine if MIS provides cost-minimization opportunities for treatment of adult degenerative scoliosis.