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 (Age(MIS) = 65.68 yrs, Age(Open) = 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) (EBL(MIS) = 470.26 ml, EBL(Open)= 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 (ΔODI(MIS) = -15.98, ΔODI(Open) = -21.96, p = 0.25). Baseline VAS scores were similar (VAS(MIS) = 6.56, VAS(Open)= 7.10, p = 0.32), but MIS patients experienced less reduction after 1 year (ΔVAS(MIS) = -3.36, ΔVAS(Open) = -4.73, p = 0.04). Preoperative sagittal vertical axis (SVA) were comparable (preoperative SVA(MIS) = 63.47 mm, preoperative SVA(Open) = 71.3 mm, p = 0.60), but MIS patients had larger postoperative SVA (postoperative SVA(MIS) = 51.17 mm, postoperative SVA(Open) = 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.
Keywords: ASD = adult spinal deformity; BMI = body mass index; DVT = deep vein thrombosis; EBL = estimated blood loss; ISSG = International Spine Study Group; LLIF = lateral lumbar interbody fusion; MIS = minimally invasive spine surgery; ODI = Oswestry Disability Index; PI-LL = pelvic incidence-lumbar lordosis; PJK = proximal junctional kyphosis; SVA = sagittal vertical axis; TLIF = transforaminal lumbar interbody fusion; VAS = visual analog scale; adult degenerative scoliosis; adult spinal deformity; cost benefit; cost effectiveness; minimally invasive spine surgery.