Results of the spine-to-rib-cage distraction in the treatment of early onset scoliosis

Background: Growing rod systems have been used in the last 30 years for the treatment of early onset scoliosis (EOS) with variable success rates. We report the results of treatment of EOS with a newly developed hybrid rod distraction system applied to the rib cage and spine with a nonfusion technique in a prospective multicenter clinical trial.

Materials and methods: A total of 22 patients affected by progressive EOS resistant to cast and/or brace treatment were enrolled from 2004 to 2005 after informed consent into a trial of surgical treatment with a single spine-to-rib growing rod instrumentation growing spine profiler (GSP). Curves >60 degrees Cobb in the frontal plane or bending < 50% were addressed with staged anterior annulotomy and fusion and posterior implantation of a GSP rod. Less severe and rigid curves were treated with posterior implantation of GSP only. The elongation of GSP was planned according to spinal growth. Patients were kept in a brace between elongations.

Results: A total of 20 patients were available to follow-up with complete data. The mean follow up is 4.1 years. Mean age at time of initial surgery was 5 years (3-8). Nine patients had staged antero-posterior surgeries, 11 posterior only surgeries. Mean spinal growth was 1.9 cm (1.5-2.3) or 0.5 cm per year. Mean coronal Cobb's angle correction was from 56 degrees to 45 degrees . Major complications affected 40% of patients and included rod failure in 6/20 and crankshaft in 5/20 (all in the anteroposterior surgery group).

Conclusion: Treatment of EOS with spine-to-rib growing rod in the present form provides similar correction and complication rates to those published in the series considering traditional single or dual growing rod systems. Based on this, the authors recommend revision of the GSP design and a new clinical trial to test safety and efficacy.