Outcome and efficacy of height gain and sagittal alignment after kyphoplasty of osteoporotic vertebral compression fractures

Objective : Although a significant correction of local kyphosis has been reported previously, only a few studies have investigated whether this correction leads to an improved overall sagittal alignment. The study objective was to determine whether an improvement in the local kyphotic angle improves the overall sagittal alignment. We examined and compared the effects of thoracic and lumbar level kyphoplasty procedures on local versus overall sagittal alignment of the spine. Methods : Thirty-eight patients with osteoporotic vertebral compression fractures who showed poor response to conventional, palliative medical therapy underwent single-level kyphoplasty. The pertinent clinical data of these patients, from June 2006 to November 2006, were reviewed retrospectively. We measured preoperative and postoperative vertebral body heights, which were classified as anterior, middle, or posterior fractured vertebral body heights. Furthermore, the local and overall sagittal angles after polymethylmethacrylate deposition were measured. Results : More height was gained at the thoracic level, and the middle vertebral height regained the most. A significant local kylphosis correction was observed at the fractured level, and the correction at larger spanning segments decreased with the distance from the fractured level. Conclusion : The inflatable balloon kyphoplasty procedure was the most effective in regaining the height of the thoracic fractured vertebra in the middle vertebral body. The kyphosis correction by kyphoplasty was mainly achieved in the fractured vertebral body. Sagittal angular correction decreased with an increase in the distance from the fractured vertebra. No significant improvement was observed in the overall sagittal alignment after kyphoplasty. Further studies in a larger population are required to clarify this issue.