Failure to lengthen consensus for the magnetically controlled growing rod (MCGR)

Area of Science:

• Spinal Surgery
• Pediatric Orthopedics
• Biomedical Engineering

Background:

• Magnetically Controlled Growing Rods (MCGRs) are an innovative treatment for early onset scoliosis (EOS).
• MCGRs offer an alternative to traditional growing instrumentation, requiring one surgery followed by non-invasive outpatient lengthening.
• Failure to lengthen is a significant complication requiring revision surgery, yet no consensus exists on its definition or management.

Purpose of the Study:

• To establish a consensus on defining MCGR lengthening failure.
• To define the necessary steps following a MCGR lengthening failure.
• To identify factors influencing decisions after MCGR failure.

Main Methods:

• A Delphi method involving 3 surveys distributed to 49 early onset scoliosis surgeons.
• 37 surgeons (75%) responded to the first survey, with 100% response rate for subsequent surveys.
• Consensus was defined as at least 70% agreement among respondents.

Main Results:

• Consensus was reached on defining MCGR failure as achieving less than 1 mm of lengthening (97%).
• Agreed-upon steps for failure include re-attempting lengthening in-office (78%) and repositioning the patient (100%).
• A non-operational MCGR was defined as failure to lengthen over 3 consecutive visits (100%), with decisions based on skeletal age, curve progression, and stiffness.

Conclusions:

• Established best clinical practice guidelines for MCGR lengthening failure using a Delphi method.
• Defined failure to lengthen (<1 mm), appropriate responses (re-attempt, reposition), and non-functionality (3 consecutive failures).
• This consensus aims to standardize research and clinical management of MCGR lengthening failures in EOS.