Pedicle Subtraction Osteotomy in the Revision Versus Primary Adult Spinal Deformity Patient: Is There a Difference in Correction and Complications?

STUDY DESIGN: Multicenter, prospective study of consecutive adult spinal deformity (ASD) patients. OBJECTIVE: To compare alignment correction and perioperative complications after pedicle subtraction osteotomies (PSO) in the primary versus revision surgery setting for ASD. SUMMARY OF BACKGROUND DATA: 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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. LEVEL OF EVIDENCE: 3.

Duke Scholars

Author Christopher Ignatius Shaffrey Orthopaedic Surgery