Lumbar Percutaneous Pedicle Screw Breach Rates

Abstract

STUDY DESIGN: Cadaveric study. SUMMARY OF BACKGROUND DATA: Pedicle screw fixation is an established means of stabilizing the thoracic and lumbar spine. However, there are associated complications including pedicle breach which can result in neurological injury, durotomy, vascular injury, and suboptimal fixation. OBJECTIVE: The aim of this study is to determine whether use of a navigated robotic platform results in fewer pedicle breaches and the underlying reasons for any difference in pedicle breach rates. MATERIALS AND METHODS: Ten board-certified neuro- and orthopedic spine surgeons inserted 80 percutaneous lumbar screws in 10 unembalmed human cadavers. Forty screws were inserted using conventional fluoroscopic guidance and 40 were inserted using a navigated robotic platform. None of the participating surgeons had any prior experience with navigated robotic spine surgery. At the end of the study each screw was assessed with a computed tomography scan, plain radiographs and visual inspection to determine the presence or absence of pedicle breaches. RESULTS: Forty percent (40%) of screws inserted using conventional fluoroscopic guidance breached compared with 2.5% of screws inserted with robot assistance (P=0.00005). Lateral breaches accounted for 88.2% (15/17) of all breaches. Detailed analysis revealed that the starting point of screws that breached laterally were significantly more lateral than that of the contralateral accurate screw (P=0.016). Pedicle screw diameter, length, and angulation in the transverse plane did not differ significantly between accurate screws and those that breached (P>0.05). CONCLUSIONS: The use of a navigated robotic platform in the present study resulted in significantly fewer pedicle breaches. This was achieved through correct starting point selection with subsequent safe pedicle screw insertion.