Penn State Hershey Children’s Hospital Early Adopter of Magnetically Controlled Growing Rod System

Orthopaedic surgeons at Penn State Hershey Children’s Hospital have started to employ a new, innovative technology that uses a magnetically controlled growing rod system, MAGnetic Expansion Control (MAGEC™), to correct early onset scoliosis (EOS). Approved by the Food and Drug Administration in February 2014, MAGEC provides a noninvasive distraction alternative to conventional growing rod systems, reducing the need for frequent surgery and anesthesia. Douglas Armstrong, M.D., chief, pediatric orthopaedics, Penn State Hershey Children’s Hospital, specializes in treating pediatric scoliosis and welcomed the new device, explaining, “We currently have more than 12 patients who have a MAGEC system in place for treatment of EOS. The expansion is performed in the clinic every three months, as an office visit.”

Baseline
Baseline
Postoperative
Postoperative

The MAGEC system is similar to conventional growing rod systems, except that the center of each rod (4.5 mm or 5.5 mm in diameter) contains a magnetically activated expansion device. The rods are implanted using standard fixation components (Figure). To achieve vertebral distraction, the rods are lengthened in the outpatient clinic, without anesthesia, by placing an external remote controller over the patient’s spine at the location of the magnet in the rod. Lengthening and distraction can be confirmed by X-ray or ultrasound. Armstrong notes, “parents are especially happy that their child does not require as many operations and anesthetics as would be typically necessary with traditional growing rod instrumentation.”

Neuromuscular Curve
Six-year-old boy with neuromuscular curve.

Complications with the MAGEC system are less frequent than with conventional growing rods, due to the nonsurgical nature of the repeated distraction procedures. Armstrong adds, “Although the devices have only been used in the U.S. for a little more than one year, it appears that there may be less risk of infection, and in the long run there seem to be fewer device-related complications. With the variety of disease conditions, curve severity and dealing with very young children with small, fragile bone structure, one can expect that some patients will experience difficulties during the course of their treatment. However, MAGEC system expansions are relatively painless.”

Depending on rod size, number and frequency of expansions, the MAGEC rods are expected to last for approximately 24 to 36 months before replacement is necessary. Most patients require a definitive fusion at skeletal maturity.

For scoliosis, seen in patients younger than 8 years old, surgical intervention using growing rods is usually required when the curve is greater than 50 to 60 degrees, to prevent increased curvature, and allow for more normal spinal and thoracic growth as the child matures. A primary concern is to prevent development of pulmonary insufficiency, which is linked to premature death.

To learn more about the MAGEC System or to make a referral, please contact 717-531-7123.


Penn State Hershey Bone and Joint InstituteDouglas G. Armstrong, M.D.
Division Chief, Pediatric Orthopaedics
Edwards P. Schwentker Professor, Orthopaedics
PHONE: 717-531-4826 • E-MAIL: darmstrong@hmc.psu.edu
FELLOWSHIPS: Pediatric orthopaedics, Buffalo Children’s Hospital, Buffalo, New York; Spine surgery, University of Ottawa Civic Hospital, Ottawa, Ontario
RESIDENCY: Orthopaedic surgery, McGill University, Faculty of Medicine, Montreal, Quebec
MEDICAL SCHOOL: University of Ottawa Faculty of Medicine, Ottawa, Ontario

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