Abstract

Introduction: Kyphoplasty is an increasingly popular treatment for osteoporotic vertebral fractures (OVF), based on an easy-to-learn technique and few perioperative complications. Good reimbursement and intense advertisement by the industry also play a role. PMMA-cement does not integrate into bone and there is no secondary stabilization around the cement tamp. Therefore, only primarily stable OVF should be treated with this technique. Because of the reduced bone quality in OVF, correct fracture analysis may be difficult, even with computed tomography (CT). Methods: Analysis of 5 cases referred to our departments in 2006 and 2007. All patients had received kyphoplasty of the thoracolumbar junction or of the thoracic spine for OVF. After initial improvement in back pain, all 5 patients experienced renewed pain and immobilization within weeks, one patient suffered neurological deficits. Presented is an analysis of the radiographic features of these fractures, how these relate to the AO fracture classification and what the implications for the primary stability of these fractures are. Based on this analysis, recommendations as to specific pitfalls when indicating OVF for kyphoplasty are made. Results: In all 5 cases, gross instability was found around the cement tamp, in several cases with advanced destruction of neighboring vertebrae. In 1 case, subtotal spinal canal occlusion by the cement tamp had occurred. Exact analysis of the preoperative imaging studies gave either evidence to unstable burst fractures of AO-type 3.2 or 3.1, to pedicle root discontinuity or to disc-with-endplate avulsion. In all cases, this had not been recognized preoperatively. The low contrast of severely osteoporotic vertebrae in CT and inadequate slice thickness of the CT may have been contributing. 4 patients required multisegment posterior instrumentation, 1 patient died from complications of immobilization prior to the scheduled stabilization. Discussion and Conclusion: Performing kyphoplasty in unstable OVF may cause complications that far exceed the original problem. Correct fracture analysis is therefore of paramount importance and a highresolution, thin-slice CT scan is a prerequisite. Despite the availability of kyphoplasty, the non-operative options for treating OVF should not be forgotten.