International Journal of Spine and Neurosurgery

Curve Progression in Children with Spinal Deformity after Removal of Vertical Expandable Prosthetic Titanium Ribs

*Anna-Kathrin Hel
Department Of Trauma, University Medical Center Goettingen, Germany

*Corresponding Author:
Anna-Kathrin Hel
Department Of Trauma, University Medical Center Goettingen, Germany
Email:anna.hell@med.uni-goet-tingen.de

Published on: 2018-09-25

Abstract

Purpose
Vertical expandable prosthetic titanium rib (VEPTR) implants may be used in children with severe spinal deformities during the growth period before definite spinal fusion. The purpose of this study was to evaluate spinal deformities before, during and after VEPTR treatment, with special focus on potential differences between congenital and neuromuscular scoliosis.
Methods
Retrospective cohort study on a population of 15 children with a continuous documentation starting before VEPTR treatment and ending with the removal of hardware prior to spinal fusion. Radiologic measurements of scoliosis and of pelvic obliquity were performed in anteroposterior radiographs, while kyphosis, lordosis and spinal length were evaluated in lateral radiographs. Measurements were conducted before and after initial VEPTR implantation, in two years intervals during VEPTR treatment as well as before and after final VEPTR explanation.
Results
Initial implantation of VEPTR was able to significantly reduce the main curve, which increased again over time. However, scoliosis in children with congenital spinal deformity remained stable after implant removal, whereas neuromuscular scoliosis showed a significant deterioration of the main curve immediately after VEPTR removal. Bending films pre VEPTR and after explanation showed 50% and 24% curve flexibility, respectively. The primary achieved correction of pelvic obliquity remained unchanged after implant removal in patients with congenital scoliosis, but deteriorated in neuromuscular children.
Conclusions
After removal of long-standing VEPTR implants, spinal deformity in children with congenital scoliosis remained unchanged, suggesting an observing approach in the future. Bilateral VEPTR treatment using rib-to-pelvis constructs without touching the spine preserved some spinal flexibility in children with neuromuscular scoliosis.
Level of Evidence
Therapeutic Level IV

Keywords

Vertical Expandable Prosthetic Titanium Rib; Congenital Scoliosis; Neuromuscular Scoliosis; Spinal Flexibility; Veptr Removal

Introduction

Progressive spinal deformity in children often requires early and repetitive surgical treatment. In the last decades, several growth-friendly devices such as vertical expandable prosthetic titanium rib (VEPTR) implants [1, 2], magnetically controlled devices [3, 4], growing rods [5, 6] and other growth-guided implants [7, 8] have been used to achieve this goal. However, the majority of these constructs serve as interim solutions, requiring definitive spinal fusion in puberty [9]. Recently, several problems connected with these pediatric implants have been reported [10–13]. Many of these devices may lead to stiffness of the spine due to auto fusion and ossifications, thus making the definitive spinal fusion more complex [9, 10]. Additionally, this may also lead to a longer fusion area than initially assumed. Another major problem poses the recently identified asymptomatic bacterial colonization of the implant [12, 13]. Routinely, growth-friendly implants are removed at the same surgery as definitive spinal fusion. If bacteria colonizing the growth-friendly implants infect the final spondylodesis devices, severe local infection with multiple surgeries, septicemia and potentially life-threatening events may occur [14]. To avoid the latter complications, juvenile patients had their definitive spinal fusion in average 8 months after explanation of long-standing VEPTR devices allowing analysis of the flexibility of spinal deformity after VEPTR treatment. In this group curve pattern changes were analyzed focusing on the behavior of frontal and sagittal profiles in adolescents with neuromuscular or congenital scoliosis after VEPTR treatment.