Journal of Pediatric Orthopaedics - 2026-01-01 - Journal Article; Multicenter Study
Ambulatory Patients With Early Onset Scoliosis Have Similar Complication Profiles Following MCGR Treatment Across All Classification Etiologies.
Krajewski KT, Carry PM, McIntosh AL, Skaggs DL, Garg S
Topics
Key Takeaway
Among ambulatory EOS patients treated with MCGR, UPROR rates were statistically equivalent between idiopathic (12.3%) and non-idiopathic etiologies (13.9%), with a risk difference of +1.5% (95% CI: -6.7% to +9.7%) falling within the pre-specified ±20% equivalence threshold.
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Summary
This multicenter study tested whether UPROR rates following MCGR implantation differ by EOS etiology (idiopathic vs. congenital/syndromic/neuromuscular) when restricted to ambulatory patients, using 1:1 propensity score matching on age, Cobb angle, curve apex, and kyphosis. UPROR was 12.3% in the idiopathic group versus 13.9% in the non-idiopathic group, with the 95% CI of the risk difference (-6.7% to +9.7%) falling entirely within the pre-specified ±20% equivalence margin. The authors conclude that ambulatory status, rather than diagnostic etiology, is the primary driver of UPROR risk in this population.
Key Limitation
Ambulatory status was not standardized across contributing centers, and the absence of a validated functional definition (e.g., GMFCS level, community vs. household ambulation) limits reproducibility and may have introduced selection bias favoring higher-functioning non-IS patients.
Original Abstract
BACKGROUND
Studies evaluating outcomes following the surgical treatment of early onset scoliosis (EOS) often stratify their results within the classification of EOS (C-EOS) categories based on the assumption that the complication risk differs across etiology. Complication risk across C-EOS categories among ambulatory patients has not been thoroughly evaluated. The purpose was to test for differences in the incidence of unplanned return to the operating room (UPROR) following magnetically controlled growing rod (MCGR) implantation among ambulatory patients with idiopathic (IS) EOS relative to ambulatory patients with EOS secondary to congenital, syndromic, or neuromuscular conditions (Non-IS).
METHODS
A multicenter pediatric spine database was queried to identify all ambulatory patients with EOS who underwent an index MCGR surgery from 2011 to 2019 and a 2-year follow-up (n=518). Patients in the IS group were matched to patients in the non-IS group using a nearest neighbor propensity score methodology. Patients were matched at a 1:1 ratio based on age, primary Cobb angle, midpoint of primary curve, and degree of kyphosis. To test our equivalence hypothesis, we evaluated the lower and upper 95% CI relative to our a priori clinically relevant threshold, +/- 20%.
RESULTS
A total of 133 patients with IS were matched to 133 patients with non-IS diagnoses. The risk of UPROR was 12.3% in the IS group compared with 13.9% in the non-IS group. The risk difference and corresponding 95% CI (risk difference: +1.5%, 95% CI: -6.7% to +9.7%) were less than our clinically relevant risk thresholds (95% CI limits within ±20%).
CONCLUSION
Previous studies have demonstrated worse UPROR rates associated with neuromuscular and syndromic EOS etiology, our data demonstrate that among ambulatory patients, UPROR rates do not differ by etiology. This suggests that ambulatory status may be a stronger driver of UPROR than etiology as ambulatory status is likely a surrogate for medical complexity/disease severity.
LEVEL OF EVIDENCE
Level III.