An article published in The Journal of Spinal Disorders and Techniques examines the incidence of pedicle breach after percutaneous screw fixation in the lumbar spine.
The article authors examined 151 patients who were evaluated after receiving single-level or two-level minimally invasive transforaminal lumbar interbody fusion. There were 601 screws placed for percutaneous fixation. The average patient was 56.6 years old. There were 129 single-level procedures and 22 two-level procedures.
Pedicle breach rates have been reported as high as 29 percent for the open technique, and between 5 percent and 23 percent for the computer assisted two-dimensional fluoroscopy.
Here are five findings from the study:
1. There were 37 pedicle breaches — 6.2 percent.
2. There were significant breaches in 22 of the patients, or 3.7 percent of patients.
3. Broken down, the breach pedicle levels were:
• L3: 10.2 percent
• L4: 7 percent
• L5: 9.5 percent
• S1: 3.4 percent
4. The side and location of the screw also made a difference. The breaches by position were:
• Medial: 22 breaches
• Lateral: 12 breaches
• Superior: two breaches
• Inferior: one breach
5. There were two symptomatic breaches that were both associated with a medial breach at the L5 pedicle, and the symptoms for these events were transient. They did not require hardwire repositioning.
"Percutaneous pedicle screw fixation in the lumbar spine continues to be a technique embraced by modern spinal surgeons," reported the study authors. "The use of intraoperative fluoroscopic guidance is both a clinically safe and accurate method for instrumentation and is of comparable accuracy to other techniques. Although trajectory errors may occur, they are of rare clinical significance."