Unilateral pedicle screw fixation as a less invasive surgical procedure: A case series and literature review

Abstract

Introduction: The principle of treatment for degenerative spinal diseases when conservative modality failed is surgery. Unilateral pedicle screw fixation is a less invasive methods with clinical outcomes that were similar to a bilateral fixation, especially for lumbar degenerative disease. Improvement of symptoms, neurological outcome and spinal stability is the utmost priority. This was a case series study with five patients with degenerative spine disease from January 2019-January 2020. The aims are to evaluate unilateral pedicle screw surgery outcomes and elucidate the effectiveness of this method clinically. Case Description: Five patients aged 40-64 years old involved in this series. Four patients presented with lumbar radiculopathy and one patient with cervical radiculopathy. All experienced weakness (MMT score 2-4) and pain along the affected extremities. Three patients diagnosed with concomitant Herniated Nucleus Pulposus (HNP) and Foraminal Stenosis (FS) based on clinical examination and Magnetic Resonance Imaging result. The rest of two patients each diagnosed with FS and HNP. Surgery initiated with a midline incision. Muscle ipsilateral to the symptomatic side was dissected and retracted to expose the facet joint and the vertebral lamina. Screws were inserted into the vertebral body and the rod used to connect the screws was bent following the vertebral curvature. Facetectomy or Hemilaminectomy was done to expose and decompress the ipsilateral side’s nerve root and intervertebral space. The incision site is then irrigated and closed. All operation was done by the same surgeon. Postoperative clinical outcomes were evaluated for six months after surgery. All patients showed a complete motor improvement and fully relieved from pain. Conclusion: Unilateral pedicle screw fixation is considered as a less invasive instrumentation system with clinical outcome comparable to bilateral screw fixation.