Reverse pedicle subtraction osteotomy for iatrogenic hyperlordosis in a scoliosis patient: illustrative case

Abstract

BACKGROUND Overcorrection of lumbar lordosis (LL) during deformity surgery can create iatrogenic hyperlordosis with negative sagittal balance, a rare but disabling complication with no standard treatment. OBSERVATIONS A 21-year-old woman with adolescent idiopathic scoliosis had undergone T3–L5 fusion, revision L4–5 transforaminal lumbar interbody fusion (TLIF) with carbon fiber instrumentation due to a nickel allergy, and L4–S1 anterior lumbar interbody fusion with L3–pelvis fusion for pseudarthrosis. She developed severe low back and bilateral groin pain that worsened with standing. Imaging demonstrated exaggerated LL (L1–S1 82° vs pelvic incidence 52°), a negative sagittal vertical axis (–96 mm), and a PI-LL mismatch of –30°, consistent with global sagittal imbalance and hip impingement. She underwent revision L1–S1 fusion with bilateral iliac fixation, reverse pedicle subtraction osteotomy (PSO) at L4, and L3–4 TLIF. Postoperatively, LL decreased to 60° with more physiological segmental distribution and sagittal parameters improved toward neutral, with resolution of her symptoms. LESSONS Iatrogenic lumbar hyperlordosis with negative sagittal balance can cause debilitating spinopelvic mismatch. Careful attention to patient-specific spinopelvic targets is essential during deformity correction, and reverse PSO is a useful strategy to reduce fixed hyperlordosis, restore alignment, and alleviate symptoms. https://thejns.org/doi/10.3171/CASE25944