Spine - 2026-03-20 - Journal Article
Iatrogenic Anteverted Pelvis After Adult Spinal Deformity Surgery: Is It a Risk Factor for Postoperative Mechanical Complications in a Young Adult Population or a Physiological Variant?
Roscop C, Bourghli A, Baroncini A, Alanay A, Pellise F, Kleinstueck F, Pizones J, Charles YP, Larrieu D, Boissière L, Obeid I, European Spine Study Group (ESSG)
Topics
Key Takeaway
Iatrogenic postoperative pelvic anteversion after ASD surgery was not associated with significantly increased mechanical complications at 2 years (10.5% vs 23.9%, P=0.154), suggesting it may represent a physiological adaptation rather than a pathological outcome.
Summary Depth
Choose how much analysis to show on this article page.
Summary
This study asked whether iatrogenic postoperative pelvic anteversion in patients with preoperative normo- or retroverted pelvis increases mechanical or clinical complication risk after ASD surgery. From a 2,043-patient multicenter database, 84 patients with postoperative anteversion were stratified by preoperative pelvic version and analyzed at 2-year follow-up. Mechanical complication rates did not differ significantly between groups (10.5% vs 23.9%, P=0.154), and both groups achieved significant ODI and SRS-22 improvement, with NRP-converted patients showing greater spinopelvic parameter changes but no worse outcomes.
Key Limitation
The sample of 84 patients drawn from 2,043 is too small to reliably detect a statistically significant difference in mechanical complication rates between groups, making the primary negative finding inconclusive rather than reassuring.
Original Abstract
STUDY DESIGN
Retrospective cohort study based on a multicenter prospectively collected database.
OBJECTIVE
To determine whether postoperative anteverted pelvis (AP) in patients with preoperative normo- or retroverted pelvis (NRP) is associated with increased risk of mechanical or clinical complications after adult spinal deformity (ASD) surgery.
SUMMARY OF BACKGROUND DATA
Pelvic anteversion is a rare spinopelvic morphology, typically considered physiological in young patients with low pelvic incidence. However, its occurrence after ASD correction-especially in patients with initially normo- or retroverted pelvic orientation-raises concerns about its potential impact on postoperative outcomes.
METHODS
From a database of 2043 surgically treated ASD patients, 84 patients with postoperative AP were identified. Based on preoperative pelvic version, patients were categorized into two groups: preoperative AP (n=38) and preoperative NRP converted to postoperative AP (n=46). Demographic, surgical, radiographic, and health-related quality of life (HRQoL) parameters were analyzed at baseline and at 2-year follow-up.
RESULTS
There were no significant differences in age, BMI, or baseline HRQoL between groups. Both groups underwent similar surgical procedures, although the NRP group required more frequent decompression and pelvic fixation. At 2 years, both groups showed significant improvement in ODI and SRS-22 scores. Mechanical complication rates were not significantly different (10.5% in AP vs. 23.9% in NRP, P=0.154). Radiographic analysis showed that postoperative AP patients maintained a lumbar lordosis >60°, despite low or normal pelvic incidence. NRP patients exhibited greater changes in spinopelvic parameters postoperatively.
CONCLUSIONS
Postoperative AP does not appear to be associated with increased mechanical complications, even in patients who were normo- or retroverted preoperatively. These findings suggest that iatrogenic AP may represent a physiological adaptation rather than a pathologic outcome, particularly in younger patients without hip or neuromuscular comorbidities. Pelvic fixation is not necessary in cases of isolated AP when global sagittal balance is restored.