Spine to pelvis "T-Construct" using magnetic controlled growing rods in non-walkers neuromuscular early-onset scoliosis: a preliminary study.

Abstract

Backgrounds: Magnetic controlled growing rods (MCGRs) have been proven to be effective in controlling early onset neuromuscular scoliosis but no study has evaluated the combination with a sacro-bi-iliac construct. The aim of our study is to report surgical management of early onset non-walkers neuromuscular scoliosis correction using MCGRs associated with a sacro-bi-iliac "T-construct" and its mid-term outcomes. Our hypothesis was that this set-up provided well correction of the pelvic obliquity and that this correction was maintained over time.

Methods: A retrospective single-center study was conducted including all consecutive neuromuscular early onset scoliosis who underwent spinopelvic fixation using "T-construct" with two MCGRS. Four millimeters lengthening was performed every 4 months during outpatient clinics sessions. All children had a low-dose biplanar stereoradiography in EOS-Chair at pre/postoperative phase, each outpatient clinic appointment and last follow-up.

Results: Eighteen patients were included and 17 analyzed at the last follow-up. The mean age at surgery was 9.5 (range from 5 to 12 years), the mean follow-up was 4,7 years (range from 2.5 to 6.6 years) and 8 patients had a Risser stage above four. The global complication rate was 35% (N = 6/17 patients) including three medical and three mechanical complications related to "T-construct", while the reoperation rate was 18% (N = 2 patients for wound debridement and one for iterative pelvic fixation). Cobb angle and pelvic obliquity were significantly improved by surgery (mean correction was 33.2 ° (55%) and 11 ° (77%) respectively; p < 0.001). At the last follow-up, we noted a loss of frontal Cobb angle correction (p < 0.01) whereas we did not observe any significant loss of pelvic obliquity (p > 0.9).

Conclusions: Although the global complication rate was 35% (half of which are mechanical complications), the treatment combining pelvic T-construct and MCGRs provides satisfactory correction of pelvic obliquity correction, good maintenance in the medium term and may be a procedure to consider for the surgical treatment of early onset neuromuscular scoliosis.

Level of evidence: IV; Retrospective cohort prognostic study.