Results of revision surgery after pedicle subtraction osteotomy for fixed sagittal imbalance with pseudarthrosis at the prior osteotomy site or elsewhere: minimum 5 years post-revision.

Abstract

Retrospective review of pedicle subtraction osteotomy (PSO) cases. To report our results, radiographic and clinical outcomes at a minimum 5 years following revision surgery for pseudarthrosis after a PSO. To our knowledge, there is no report on the results of revision surgery for pseudarthrosis after a PSO. Eighteen consecutive patients with pseudarthrosis after PSO (16 females/2 males; average age at surgery, 49.8 yr) treated with revision surgery at one institution were analyzed (average follow-up, 6.5 yr; range, 5-12 yr). Radiographic and clinical outcomes analysis was performed. Sagittal vertical axis (SVA) and lumbar lordosis (LL) improved significantly after revision surgery (SVA, P = 0.000; LL, P = 0.024) and were maintained until ultimate post-revision follow-up (SVA, P = 0.170; LL, P = 0.729). Proximal junctional angle (P = 0.828), thoracic kyphosis (P = 0.828), and PSO angle (P = 0.717) achieved by the primary surgery were also maintained until ultimate post-revision. We increased the number of rods and/or changed them to 6.35-mm diameter in all patients. There were significant improvements post-revision in Oswestry Disability Index (45 vs. 37.9, P = 0.041) and Scoliosis Research Society pain subscale (2.6 vs. 3.1, P = 0.047) but not in Scoliosis Research Society total score or other subscales. Pelvic incidence greater than 60° demonstrated a trend toward poorer Oswestry Disability Index and Scoliosis Research Society scores (P > 0.05), but there were no significant differences between SVA greater or less than 11 cm. Revision surgery for pseudarthrosis after PSO can provide acceptable radiographic and clinical outcomes at a minimum 5 years post-revision. Successful surgical outcomes may be achieved by using an increased number or size of implants and ample bone graft for complete fusion after revision surgery. 4.