PELVIC OBLIQUITY CONTROL IN CHILDREN WITH NEUROMUSCULAR EARLY

PELVIC OBLIQUITY CONTROL IN CHILDREN WITH NEUROMUSCULAR EARLY ONSET SCOLIOSIS TREATED WITH MAGNETICALLY-CONTROLLED GROWING RODS María del Mar Pozo-Balado, Ph. D; David Farrington, MD; Esther Fernández, MD; María Raya, MD

INTRODUCTION q Pelvic Obliquity (PO) • PO is commonly associated with neuromuscular Early-Onset Scoliosis (EOS). • Traditional Growing Rods provides good control of PO. • However, the control of PO provided by magnetically-controlled growing rods (MCGR) along the time is still unknown.

HYPOTHESIS AND OBJECTIVES q Hypothesis • We hypothesized that PO increases over time in neuromuscular EOS patients treated with MCGR. q Objective • Our aim was to evaluate the control of PO in neuromuscular EOS children treated with MCGR along the time.

METHODS q Study design • Retrospective medical record review on all children treated with MCGR at our institution between March 2014 and September 2015. • Preoperative, postoperative and 6, 12 and 18 month radiographs were reviewed. • PO and Cobb angles were obtained. q Statistical Analysis • Willcoxon paired test for longitudinal comparisons between two groups. • Friedman test for multiple longitudinal comparisons. • p<0. 05 was considered statistically significant. PO PO measurement

RESULTS I q Demographic and Clinical Characteristics Characteristic Male Sex (%) 5 (50) Age, mean months [min, max] 105. 8 [66. 0 -128. 0] Etiology (%) SMA type II 6 (60) CP 2 (20) MMC 2 (20)

RESULTS II q Cobb Angle significantly decreases over time

RESULTS III q PO values 18 months after initial surgery were comparable to PO preoperative values (p=0. 080) Proximal anchor migration was observed in all study patients except 3, and interestingly, 2 of them did not experimented loss of control of PO.

CONCLUSIONS MCGR is an effective option in the treatment of scoliosis in neuromuscular EOS patients, since curve progression seems to be stabilized along the time. However, the control of PO provided by MCGR is transitory, returning to preoperative levels 18 months after the implantation.

SIGNIFICANCE Even though our results are preliminary, and should be supported with larger and longer series, we consider loss of PO control with MCGR may be related with proximal anchor migration. This possible relation should be studied furthermore.