The aim of this retrospective study was to evaluate the effect of shape and severity of osteoporotic vertebral fractures on the clinical and surgical outcomes of kyphoplasty. Ninety-four patients with single level vertebral fractures were enrolled. Fractures were divided into two types according to the shape of the fractured vertebrae: wedge type (n = 54) or biconcave type (n = 40). All fractures were further classified into 3 grades (grade 1-3) according to their severity. The Visual Analog Score for back pain improved significantly in the "wedge" and in the "biconcave" group: there was no significant difference between groups. Wedge type fractures had a significantly greater correction of anterior vertebral height and kyphotic angle than biconcave type fractures (p < 0.01). Biconcave type fractures had a significantly greater correction of the middle vertebral height (p < 0.01), but had a higher risk of intradiscal cement leakage (p = 0.03). Rates of cement leakage in grade 1, grade 2, and grade 3 fractures were 12.8%, 25.8%, and 50.0%, respectively : there was a gradually higher risk of cement leakage as the severity of compression increased (p < 0.01).
Conclusion: assessing the shape and severity of fractured osteoporotic vertebrae gives an idea of the potential correction of body height and kyphosis, and of the risk of cement leakage.