Transpedicular Lumbar Wedge Resection Osteotomy for Fixed Sagittal Imbalance

STUDY DESIGN: A retrospective consecutive case series, radiographic analysis, outcomes analysis, and report on complications. OBJECTIVES: To evaluate the radiographic and functional outcomes of a reconstructive realignment procedure for fixed sagittal imbalance and discuss the complications. SUMMARY OF BACKGROUND DATA: We describe a modification of an existing technique permitting greater single-level correction for which no reports exist in the peer-reviewed literature. METHODS: Twenty-four patients were eligible for 2-year minimum follow-up (average, 4.0 years). Etiologies included iatrogenic (n = 17), post-traumatic (n = 3), ankylosing spondylitis (n = 2), degenerative (n = 1), and congenital (n = 1). Patients were evaluated by standardized upright radiographs, chart review, and National Spine Network questionnaire. RESULTS: Seventeen patients had undergone 17 previous procedures. Seven of 24 patients required augmentation with anterior structural grafting. The majority of osteotomies were performed at L3 (15); others included L2 (6), L4 (2), and L5 (1). Lumbar lordosis before surgery averaged 13 degrees (range, 55 degrees to -65 degrees) and improved to 53 degrees (range, 20 degrees to 99 degrees), an average correction of 40%. The sagittal vertical axis measured from C7-S1 demonstrated a preoperative sagittal decompensation averaging 11.4 cm (range, 5.5-23 cm) with correction to 2.4 cm (-9.0 cm or 79% average correction). Coronal balance did not change significantly. There were 17 complications in 14 patients. Nine patients required additional surgery at latest follow-up. CONCLUSIONS: Transpedicular wedge resection osteotomy procedure is a very effective technique to correct fixed sagittal imbalance and provide biomechanical stability. The high complication rate mandates a careful assessment of the risk/benefit ratio before undertaking what is a major reconstructive procedure. Most patients are satisfied, particularly when sagittal balance is achieved.