The relationship between the spinopelvic balance and the incidence of adjacent vertebral fractures following percutaneous vertebroplasty.

Abstract

We evaluated the relationship between sagittal spinopelvic parameters and the occurrence of adjacent vertebral fractures (AVF) and determined the possible risk factor. The most important factors for AVFs are the degree of osteoporosis and altered biomechanics due to the spinopelvic imbalance in the fractured area of the spine. We intend to evaluate the relationship between sagittal spinopelvic parameters and the occurrence of adjacent vertebral fractures following the initial compression fracture and to determine the possible dominant risk factor associated with new compression fractures. From March 2010 to May 2012, 240 consecutive patients with painful vertebral compression fractures (VCFs) were enrolled in a retrospective study. Ninety-one patients with VCFs underwent percutaneous vertebroplasty (VP) at 112 levels. The sagittal vertical axis (SVA), thoracic kyphosis (TK), lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), and segmental kyphotic angle on sagittal standing radiographs were used to evaluate radiologic outcomes. In 2 years, 15 out of 134 patients (11.1%) treated with conservative treatment, and 12 out of 91 patients (13.1%) treated with VP sustained adjacent level fracture. More patients with the BMD higher or equal to 3.0 experienced a new fracture than those with a BMD less than 3.0 (p = 0.019), and the risk for adjacent level fractures decreased significantly when segmental kyphotic angle was less than 11° (p = 0.001), SVA was less than 6 cm (p = 0.001), SS was higher or equal to 25° (p = 0.004), and LL was higher or equal to 25° (p = 0.020). The most important factors for new VCFs after the initial compression fractures are the degree of osteoporosis and altered biomechanics due to the spinopelvic imbalance in the fractured area of the spine. Regarding the spinopelvic alignment to investigate the relationship with a subsequent AVF, segmental kyphotic angle, SS, LL, and SVA may be a potential predictor.