Complications incidence in the treatment of early onset scoliosis with growing spinal implants

Early onset scoliosis (EOS) surgery based on growing spinal implants can lead to several complications. Aim of the study was to identify strategies to prevent those complications. A retrospective review was conducted to identify all pediatric patients affected by EOS surgically treated with growing rod or Vertical Expandable Prosthetic Titanium Rib (VEPTR) at our division between 2006 and 2011. Nineteen consecutive patients (8 males, 11 females; mean age 6.8 years) were included. The scoliosis was: idiopathic in 7 cases, congenital in 5, associated with congenital heart disease in 2, with syringomyelia and Arnold Chiari syndrome in 1, with neurofibromatosis type 1 (NF1) in 1, with Prader Willi syndrome in 1, with trisomy 8 in 1, with arthrogryposis in 1. Instrumentation used was: growing rod in 9 patients (dual rod construct in 8 cases, single rod in 1), VEPTR in 10 (always rib to spine construct). At a mean follow-up of 28 months (range, 12 to 55) 12 mechanical complications occurred in 8 of 19 patients treated (42.1%). Among cases treated with growing rod (9) 6 complications occurred in 4 patients (44.4%): revision was performed in 4 cases due to proximal anchors migration, in 2 cases due to a rod breakage. Among cases treated with VEPTR (10) 6 complications occurred in 4 patients (40%): revision was performed in 4 cases due to rib fracture with anchors migration, in 1 case due to vertebral anchor migration and in 1 case due to proximal and distal anchor migration. So, in our series mechanical complications rate was 42.1%. Our strategy to prevent these complications is to use hooks as proximal anchors, to avoid single rod construct and to use a brace as external support until final surgery is performed. If it's possible, is better to substitute VEPTR with a dual Growing Rod implant when patient's age and anatomy permits this.