Severe adolescent idiopathic scoliosis: posterior staged correction using a temporary magnetically-controlled growing...

A two-staged posterior correction, using a temporary magnetically controlled growing rod (MCGR), was employed to gradually and safely correct severe adolescent idiopathic scoliosis (AIS). The aim of the study is illustrating the results of this procedure.

A retrospective review of a consecutive series of 17 severe AIS. The first surgery was a posterior release (multiple Ponte osteotomies) with implant of pedicle screws and MCGR on the concave side of the curve. In post-operative days, a distraction was applied with MCGR, which allowed to obtain a total mean lengthening of 2 cm in about 2 weeks, with no complications arising. In the second posterior surgery, MCGR was removed and the definitive rods were applied for final fusion. The mean pedicle screws density was 93.3% (85-100). The extension of the final posterior fusion-instrumentation was of 13.8 levels (12-15).

At an average follow-up (FU) of 2.9 years, the main scoliosis curves from average pre-operative Cobb angle of 98.2° (91°-138°) bent down to 38.3° (35°-76°) after definitive fusion (p < 0.05); at last FU, the overall correction was 58.7% (50.4-71.2), with an average correction loss of 2.1° (1.5°-3.1°). At last FU, no complications were reported.

Gradual traction with MCGR in severe AIS proved to be a safe method to achieve progressive curve correction before posterior final fusion, with no neurologic complications associated to more aggressive one-stage surgeries. In a staged approach, MCGR appears as an alternative to halo traction, avoiding frequent traction-related complications.