Transpedicular lumbar wedge resection osteotomy for fixed sagittal imbalance - Surgical technique and early results

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 singlelevel 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.