Health Technology Brief

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Magnetically Controlled Growing Rods for Treatment of Early-Onset Scoliosis

November 27, 2018

Health Problem: Early-onset scoliosis (EOS) affects skeletally immature patients younger than 10 years of age. Patients with EOS are still undergoing development, which can place them at risk for progression of the deformity. If EOS progresses to a severe state, the spine can crowd the space within the chest cavity, and can cause thoracic insufficiency syndrome (TIS), where the chest cavity (thorax) cannot support normal breathing or lung growth.

Technology Description: Magnetically controlled growing rods (MCGR), such as the Magnetic Expansion Control (MAGEC) System, are a distraction-based system that is designed to avoid the repeated anesthetics and open surgical lengthening that occurs with traditional growing rod (TGR) systems. The titanium MAGEC rod includes an actuator portion that holds a small internal magnet that can be turned noninvasively by an external remote control, allowing for lengthening or shortening of the MAGEC rod.

Controversy: Concerns related to the safety of the MAGEC System are growing due to existing studies reporting implant-related complications, such as rod breakage and distraction failure, that often lead to unplanned revision surgery. A few studies have reported cases of metallosis associated with use of the MACEG System. In addition, as with TGRs, an increase in serum levels of titanium are of potential concern. Such concerns have led to more careful selection and monitoring of patients who are implanted with MAGEC growing rods. Some researchers suggest that more studies of longer duration are needed to fully understand the long-term safety of the MAGEC System, and that surgeons should create a patient registry to better monitor associated safety concerns.

Key Questions:

  • Are MCGRs effective in treating children with EOS (onset at < 10 years)?
  • How do MCGRs compare with spine-based distraction with TGRs?
  • Are MCGRs safe?
  • Have definitive patient selection criteria been identified for MCGRs?