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Growth-Friendly Implant
A 'growth-friendly implant
' is a temporary spinal device used in the management of 'early-onset scoliosis (EOS)
' that permits continued spinal and thoracic growth while controlling deformity. Unlike definitive spinal fusion, these systems aim to stabilize curvature without halting skeletal development.
Key Characteristics
- Designed for
'children with immature spines
' - Allows for
'incremental lengthening
' over time - Intended for use
'prior to final spinal fusion
' - Helps preserve
'lung development and height potential
'
Common Types
- Traditional Growing Rods (TGR)
- Magnetically Controlled Growing Rods (MCGR, e.g., MAGEC)
- Vertical Expandable Prosthetic Titanium Rib (VEPTR)
- Shilla Growth Guidance System
Clinical Goal
To control progressive spinal curvature in EOS while maintaining spine and thoracic growth, delaying or avoiding early definitive fusion.
Comparative cohort studies
In a registry-based comparative cohort study (early-onset scoliosis patients after implant removal) Matan S Malka et al. from the Morgan Stanley Children’s Hospital (Columbia Univ, New York). Arkansas Children’s Hospital; Shriners Philadelphia; Seattle Children’s Hosp. published in Spine Deformity Journal, to evaluate if re-implanting growth-friendly constructs within 12 months after implant removal (ROI) stabilizes deformity compared to observation-only. Early re-implantation (< 12 mo post-ROI) significantly reduces 2‑year coronal Cobb progression compared to no replacement 1).
Critical Review
- Strengths:
Multicenter registry with well-defined exposure groups.
Radiographic outcomes measured at a meaningful 2‑year follow-up.
Statistically robust with p-values: Cobb 81° vs 53° (p=0.003); progression ≥5°: 64% vs 30% (p=0.04)
- Limitations:
Small observation cohort (n=11) limits generalizability.
Indications for ROI and patient selection unclear—could bias results.
Lack of data on functional outcomes or complications post re-implantation.
Does not assess long-term outcomes past 2 years or final fusion timing.
Score (0–10)
5.5
(Moderate quality; clinically relevant, but underpowered and limited in scope)
Takeaway for Practicing Neurosurgeons
Prompt re-implantation after growth‑friendly device removal appears crucial to arrest deteriorating curves in EOS. However, decision-making should be individualized, considering technical feasibility and patient comorbidities.
Bottom Line
Re-inserting a growth-friendly implant within 12 months of removal significantly reduces coronal curve progression over 2 years and should be prioritized when feasible—though data are limited by small control group and absence of long-term outcomes.
Full Citation and Corresponding Author
Published online: July 4, 2025 Corresponding author: msm2244@cumc.columbia.edu.