Pedicle Subtraction Osteotomy in the Revision Versus Primary Adult Spinal Deformity Patient

Abstract

Multicenter, prospective study of consecutive adult spinal deformity (ASD) patients.To compare alignment correction and perioperative complications after pedicle subtraction osteotomies (PSO) in the primary versus revision surgery setting for ASD.PSO are performed to correct sagittal plane deformity; however, these are difficult procedures that have potential for large blood loss and risk for intraoperative and postoperative complications.Inclusion criteria were age at least 18 years, lumbar PSO, and available data on perioperative (up to 6 weeks after surgery) complication data. Patients were classified according to SRS-Schwab sagittal modifiers: PT (pelvic tilt), SVA (sagittal vertical axis), and lumbo-pelvic mismatch (pelvic incidence-lumbar lordosis). Patients were divided into primary (P; no previous spine fusion surgery) or revision (R; previous fusion). Baseline and 1-year demographic, radiographic parameters, complications and revision rates were analyzed.A total of 421 patients were included. P (n = 70) and R (n = 351) were similar for age, body mass index, sex, mean total Posterior Spinal Fusion (PSF) levels (P = 10.0; R = 10.5), PSO angle (P = 27°; R = 25°), estimated blood loss (P = 2.76L; R = 2.92L), and operative time (P = 437 min; R = 434 min). The most common osteotomy site was L3 for both primary (31.8%) and revision groups (43.6%). Both groups demonstrated improvement in sagittal spinopelvic parameters from baseline to 1 year, with similar changes in sagittal modifiers except for the pelvic mismatch that improved to a grade 0 (i.e., less than 10°) more often for primary PSO group (83%) than revision PSO group (57%; P = 0.004). Complication rates were similar (P > 0.05) for the following: new motor deficit (P = 4.2%, R = 9.4%), bowel/bladder deficit (P = 1.4%, R = 2.8%), 1-year revision rate (P = 4.3%, R = 7.4%), and pseudarthrosis rate (P = 1.4%; R = 2.5%; P < 0.05).PSO may be performed in primary or revision ASD patient with similar sagittal deformity correction and similar complication rates; however, primary PSO patients were more likely to achieve better lumbo-pelvic mismatch correction.3.