LAS VEGAS — When a variety of settings are used for O-arm imaging in conjunction with pedicle screw placement in pediatric patients with scoliosis, a pediatric-dose setting provides images sufficient for screw placement, according to data presented at the American Academy of Orthopaedic Surgeons Annual Meeting.
Furthermore, the screws placed with the guidance of pediatric-dose scans were not associated with screw or neurologic complications, said T. David Luo, MD, here.
“All of our images were found to be of adequate quality before proceeding with screw implementation,” he said.
Luo and colleagues studied 37 consecutive patients younger than 18 years who had scoliosis (23 patients), congenital spine deformities (6 patients), kyphosis (5 patients) and spondylolisthesis (3 patients). The majority of the scans, which were done between 2011 and 2001, were carried out intraoperatively with a pediatric dose setting.
The other two settings used were Luo’s institution’s “low dose” and the default from the manufacturer of the O-arm, but those settings were associated with higher mean effective dose per O-arm spin of 2.37 mSv and 4.65 mSv, respectively, compared to 0.65 for the pediatric technique spins, according to the study findings.
“For reference, a chest X-ray gives off approximately 0.1 mSv and the annual natural background radiation in the United States is approximately 3 mSv,” Luo said.
Luo said the study’s limitation were the small number of patients included, the lack of postoperative images and the absence of a quantitative assessment of the overall image quality.
“Despite these limitations, we can safely conclude that our pediatric dose settings are feasible with sufficient image quality for clinical use for screw placement and we showed a significant reduction in radiation exposure for our pediatric patients. And, we feel the settings were easy to change,” Luo said. – by Susan M. Rapp
Luo TD, et al. Paper #97. Presented at: American Academy of Orthopaedic Surgeons Annual Meeting; March 24-28, 2015; Las Vegas.
Disclosure: Luo reports no relevant financial disclosures.