Delayed neurologic complications of vertebral bone cement injections.

paradigms. In some instances, they have enabled surgeons to perform procedures that would otherwise be impossible. Elsewhere, they have minimized potential morbidity. In the field of neurological surgery, deep brain stimulation would fit in the former category and endovascular treatment of cerebral aneurysms the latter. Reinforcement of pathological fractures of the vertebral axis, usually with polymethyl methacrylate (PMMA) injection, provides instant fixation of unstable and painful fractures and is usually well tolerated by patients. This technique, performed either as vertebroplasty or kyphoplasty, affords both of the aforementioned advantages and has therefore been a welcome addition to the surgical armamentarium. Significant improvement in pain is reported in about 90% of patients after PMMA vertebral body embolization for osteoporotic compression fractures1. Benefit appears to be durable, as evidenced by a study with a mean follow-up of 48 months2. The potential for complications, however, is not negligible. These include pulmonary venous embolism and spinal cord or nerve root compression from aberrant PMMA. The literature suggests that these complications are rare1. Symptomatic pulmonary embolism typically manifests itself rapidly and, similarily, one would expect significant PMMA in the spinal canal to cause symptoms right after the injection. Neurological problems associated with PMMA vertebral injections may, however, manifest themselves at a later date3. It is important that practitioners of this technique recognize when a patient is having an adverse event. We report here two patients with delayed symptomatic lesions that were, eventually, treated surgically and improved clinically.