الفهرس | Only 14 pages are availabe for public view |
Abstract Pedicle screw insertion is typically used for degenerative, neoplastic, infectious, and deformative pathologies associated with axial instability. The most common technique for the placement of pedicle screws remains the conventional use of dorsal anatomic landmarks with or without fluoroscopic assistance. Pedicle screws proper placement is important not only for the prevention of neurological injury but also for the maintenance of long-term spinal stability. This study aimed to determine the incidence of screw misplacement and complications in a group of 32 patients who underwent lumbosacral transpedicular screw fixation performed using the conventional open fluoroscopic guided technique. This was a prospective evaluation study. Subjects were chosen from 2 hospitals: (1) Menofia University Hospital, Egypt and (2) Al-Helal hospital in Cairo, Egypt. Our study concentrated on degenerative indications (Herniated intervertebral disc: 14 cases; and spondylolisthesis: 18 cases). Instrumentation using transpedicular screw fixation was performed between L3 to S1. The mean age of the patients was 51.8[ranging from 31 to 70 years]. with 13 men and 19 women. Evaluation of screw placement was performed according to the criteria initially described by Gertzbein and Robbins modified to include assessment in the coronal and sagittal reformatted images. Patients who did not have a postoperative CT scan were excluded from the study. A total of 162 pedicle screws were evaluated. All patients were followed clinically and radiologically for at least 6 months after the procedure. After discharge from hospital, clinical and radiological assessment was done at one, three and six months. A correlation between clinical symptoms and radiological violation was reported. In this study, 26.5% of screws breached the pedicle wall. However, the majority (74.4 %, 32/43) of breaches were graded B (<2 mm). None of the patients with screws presenting this grade of violation developed symptoms related to the positioning of the screws, therefore in this study, the overall “clinically acceptable” accuracy rate (<2 mm) was 93.2%. However, these breaches are representative of the real world and may have clinical consequences and therefore were included in the final analysis. In the current study, the neurological injury, defined as the presence of new postoperative radicular pain and/or sensorimotor weakness, 1.2% (2/162) of the screws perforated the pedicle by 4 mm or more. Radicular pain without sensory or motor deficits occurred only in one patient. In 1 patient (3.1% of all patients), a 51-year-old female with spondylolisthesis at L4-L5, there was a 5mm medial breach of the right L5 pedicle. This was associated with a transient right side L5 transient sensory radiculopathy that resolved spontaneously at the follow-up evaluation. None of the patients with pedicle violations of >4 mm had postoperative neurologic symptoms and showed no radiographic signs of instability. No patient developed adjacent segmental instability after surgery. No assembly disengagement or broken screws were noted in any patient during follow-up. The number of clinical symptoms related to screw misplacement in our study appears well within the previously reported incidence. Nevertheless, no early revision was performed for screw misplacement. |