Image-guided Percutaneous Polymethylmethacrylate-augmented Spondylodesis for Painful Metastasis in the Veteran Population

Abstract

The treatment of painful spinal metastases in patients with limited life-expectancy, significant perioperative risks, and poor bone quality poses a surgical challenge. Recent advances in minimal-access spine surgery allow for the surgical treatment of patients previously considered not to be operative candidates. The addition of fenestrated screws for cement augmentation to existing image-guided percutaneous pedicle screw fixation can enhance efficiency, decrease risk of hardware complications, and improve back pain in this patient population. The patient is a 70-year-old man with severe axial back pain due to metastatic prostate cancer and L5 pathologic fractures not amenable to kyphoplasty. In the setting of a 6-12-month life-expectancy, the primary goal of surgery was relief of back pain associated with instability with minimal operative morbidity and post-operative recovery time. This was achieved with an internal fixation construct including percutaneously placed cement-augmented fenestrated pedicle screws at L4 and S1. The patient was discharged to home on post-operative day 1 with substantial improvement of his low back pain. Image-guided, percutaneous placement of fenestrated, cement-augmented pedicle screws is an emerging treatment for back pain associated with metastasis. Fenestrated screws allow for integrated cement augmentation. The minimal associated blood loss and recovery time make this approach an option even for patients with limited life-expectancy. This is the first report of utilization of this technique for the veteran population.

Keywords: cement-augmentation; minimal access spine surgery; polymethylmethacrylate; spinal metastases; spondylodesis.

Figure 1. Lateral plain films of the lumbar spine, demonstrating a compression fracture of the L5 vertebral body, with approximately 50% loss of height and mild retropulsion into the spinal canal, and disruption of the posterior endplate. There is also radiographic evidence of prior cement augmentation of the L2, L3, and L4 vertebral bodies.

Figure 2. Intraoperative AP (A) and lateral (B) plain films of the lumbosacral spine, demonstrating optimally placed bilateral L4 and S1 PMMA-augmented pedicle screws.

Figure 3. Repeat AP (A) and lateral (B) plain films of the lumbosacral spine two weeks post-operatively, demonstrating intact L4-S1 instrumentation, and early evidence of posterolateral bony fusion mass.