Failure to replace removed growth friendly implants results in deteriorating radiographic outcomes

Management of early onset scoliosis (EOS) patients can require growth-friendly surgery to manage spinal deformity in children too immature for a definitive fusion. There is limited literature on outcomes for patients with failed growing constructs requiring removal of implants (ROI).

We studied EOS patients from an international registry undergoing removal of growth-friendly implants, comparing early re-implantation (within 12 months of ROI) to observation-only. We examined demographic data and radiographic measurements with a significance level of p < 0.05.

Sixty-four patients met the inclusion criteria for radiographic analysis: 53 had early re-implantation and 11 were observed. There were no significant differences between the groups in age at index, ROI, or etiology. Pre-ROI, observation and re-implantation groups had similar coronal Cobb angles (55° vs 47°, p = 0.35) and similar time from index procedure to ROI. However, at two years post-ROI, the observation group had a larger coronal Cobb angle than the re-implantation (81° vs 53°, p = 0.003). In the re-implantation group, 16 (30%) patients progressed ≥ 5° vs 7 (64%) in the observation group (p = 0.04). The re-implantation group had a smaller difference in major Cobb angle between post-ROI and two years post-ROI (-2° vs 12°, p = 0.01). The re-implantation group had no significant progression in the major Cobb angle at two years post-ROI compared to immediate post-ROI (55° vs 53°, p = 0.36), while the observation group increased by about 13° (68° vs 81°, p = 0.03), resulting in a total increase of more than 25° from pre-ROI.

Our interim data strongly suggest that promptly replacing removed implants stabilizes curves in this population of EOS patients. Timely re-implantation should be a priority, when possible, to enhance outcomes, despite technical challenges for some patients.