sonographic evaluation of magec growing scoliosis rods in pediatric patients cincinnati children’s...
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Sonographic Evaluation of MAGEC Growing Scoliosis Rods
in Pediatric Patients
Cincinnati Children’s Hospital Medical Center
Department of Orthopaedics Department of Radiology
Peter Sturm, MDSara M. O’Hara, MD
Lindsay Schultz, BS,CCRP
Disclosures
• Peter Sturm, MD- Consultant for Medtronic
Consultant for Ellipse• Sara M. O’Hara, MD- Speakers bureau Toshiba
Medical Ultrasound• Lindsay Schultz, BS,CCRP - NONE
Purpose•Adjustable, magnetically controlled “growing” scoliosis rods (MAGEC rods) are increasingly used in pediatric patients, and require periodic adjustments and confirmation of lengthening following this non-invasive procedure.
•Previously, adjustable rods required open surgical procedures for lengthening. The purpose of our study was to determine if these MAGEC rods could be adequately visualized and measured with ultrasound, thereby minimizing radiation exposure from serial spine X-rays.
Motor and housing
Expandable rod housing
Expanded segment
MAGEC ROD
Motor
Rod housingExtended segment of rod
Segment we measure
MAGEC ROD
Materials & Methods• All patients with recently implanted MAGEC rods were examined with
ultrasound before and after their first transcutaneous magnetic rod lengthening procedures. Measurements obtained sonographically were compared with the length programmed into the magnetic motor used to extend the rod. Measurements will also be compared with scoliosis X-rays obtained once or twice each year.
Ortho localizes the motor with magnetic wand (blue)or with ultrasound, and marks site(s),
Sets the motor driver parameters, then activates on patient
Motor is audible, stops automatically, not painful!
Ultrasound can readily identify: Gap between housing and extended rod and tapered end of rod
We measure and report distance between gap and TOP of slope, pre & post lengthening
Results• 12 patients have been studied to this point (3 month period)
• 6 female, and 6 male, between 6 and 10 years of age
• All of the MAGEC rods were well visualized sonographically
before and after lengthening procedure.
• All of the patients showed good correlation between post-op
scoliosis measurements and first, pre-lengthening ultrasound
measurements.
• 4 of the 13 patients rods showed less lengthening than expected
based on the length programmed into the magnetic motor driver.
• All patients will be re-imaged in the next few months to quantify
measurement reliability and compare with
expected extension parameters.
ConclusionMAGEC rods can be reliably imaged with ultrasound before and after transcutaneous lengthening procedures, thereby reducing radiation exposure.
In addition, the ultrasound may offer additional confidence that the rods have in fact extended the length programmed into the magnetic motor.