1118 Is There a Gender Disparity for Outcomes Following Minimally Invasive Surgery for Adult Spinal Deformity?

INTRODUCTION: Gender disparities have been observed during traditional-open adult spinal deformity (ASD) surgery but are unknown in minimally invasive spine surgery (MIS). METHODS: The prospective, multicenter ISSG MIS database was retrospectively reviewed. We compared baseline and intraoperative characteristics, 1-year PROs (NRS back/leg pain, ODI, SRS-22r, Upper and Lower Extremity Motor Score), 1-year radiographic parameters (sagittal vertical axis (SVA), pelvic incidence minus lumbar lordosis (PI-LL), pelvic tilt (PT), T1 pelvic angle (T1PA), coronal vertical axis (CVA), max coronal Cobb angle), and 2-year complications between genders. RESULTS: Of 217 patients total, 39.6% were male. No significant differences existed for age (67.3+10.1 years), BMI, osteoporosis prevalence, NRS-BP, NRS-LP, UEMS, LEMS, CVA, and PI-LL(p>0.05). More males underwent prior spine surgery (62.8% vs 41.2%, p=0.002) and received more primary lateral MIS procedures (12.8% vs 3.1%, p=0.0056). Males had lower mean PT (21.5+7.9 vs 24.0+9.8 degrees, p=0.048) and higher SVA (70.52+53.2 vs 48.7+54.7 mm, p=0.006). Males experienced no difference in remaining surgical approaches(ALIF/PLIF/TLIF) or levels fused. Mean EBL, intraoperative complications, and length of stay was similar. In multivariable analysis controlling for preoperative gender differences, male gender corresponded to lesser odds of achieving MCID at 1-year for SRS-activity (OR:0.42, 95%[0.19, 0.92], p=0.029). No differences existed for remaining PROs (NRS-BP and LP, ODI, SRS-22r total score), radiographic parameters (SVA, PI-LL, PT, T1PA, CVA, max coronal Cobb angle), and radiographic complications (proximal junctional kyphosis, adjacent segment disease). CONCLUSIONS: Gender was associated with different baseline and surgical characteristics for ASD patients receiving MIS spine surgery. Males received more revision spine surgery and primary lateral approaches, had more severe global sagittal malalignment, and lower PT. Male gender was independently associated with decreased odds of reaching MCID for SRS activity. Otherwise, both genders fared similarly for other PROs, radiographic parameters, and complications.