Intraoperative monitoring of somatosensory (SSEPs) and transcranial electric motor-evoked potentials (tce-MEPs) during surgical correction of neuromuscular scoliosis in patients with central or peripheral nervous system diseases.

PURPOSE: Combined intraoperative monitoring (IOM) of transcranial electric motor-evoked potentials (tce-MEPs) and somatosensory-evoked potentials (SSEPs) is safe and effective for spinal cord monitoring during scoliosis surgery. However, the literature data regarding the reliability of spinal cord monitoring in patients with neuromuscular scoliosis are conflicting and need to be confirmed. METHODS: We reviewed IOM records of 40 consecutive patients with neuromuscular scoliosis related to central nervous system (CNS) (29 pts) or peripheral nervous system (PNS) (11 patients) diseases, who underwent posterior fusion with instrumentation surgery for spinal deformity. Multimodalitary IOM with SSEPs and tce-MEPs was performed. RESULTS: Spinal cord monitoring using at least one modality was attempted in 38/40 (95 %) patients. No false-negative results were present in either group, but a relatively high incidence of false-positive cases (4/29, 13.8 %) was noted in the CNS group. Two patients in the CNS group and one patient in the PNS group presented transient postoperative motor deficits (true positive), related to surgical manoeuvres in two cases and to malposition in the other one. CONCLUSIONS: Multimodalitary IOM is safe and effective to detect impending spinal cord and peripheral nerves dysfunction in neuromuscular scoliosis surgery. However, the interpretation of neurophysiological data may be challenging in such patients, and the rate of false-positive results is high when pre-operatory motor deficits are severe.

Surgical treatment of neuromuscular scoliosis: current techniques.

41 consecutive patients surgically treated at Our Department by posterior only instrumented fusion from January 1995 to January 2009 were reviewed. There were 20 females and 21 males with a mean age of 15.8 years (range, 10 to 38). Diagnosis was: cerebral palsy (13 cases), Duchenne muscular dystrophy (7), spinal amyotrophy (7), myelomeningocele (5), poliomyelitis (3), Friedreich's ataxia (2), Escobar syndrome (2), Steinert's disease (1), Charcot Marie Tooth disease (1). Main scoliosis Cobb angle averaged 94.05° (range, 34° to 165°), the curve was thoracic in 19 cases, thoracolumbar or lumbar in 22 cases. Kyphosis (T5-T12) averaged 42.86° (range, 7° to 90°), lordosis was 33.57°. The fusion was extended to the lumbar tract in 23 patients, to the sacrum in the other 18. Our results showed that, in patients with neuromuscular scoliosis, posterior instrumented fusion is a safe and effective procedure and is the treatment of choice for patients with limited respiratory function, as in Duchenne muscular dystrophy and spinal muscular atrophy. The surgery should be performed as early as possible, and the extension of the fusion to the sacrum should be avoided in patients with residual walking ability.

Surgical treatment for scoliosis associated with rare disease.

This is a retrospective study of 11 patients, 7 females and 4 males, treated at Our Department for an early onset scoliosis (EOS) associated with rare syndromes with growing spinal implants (Growing Rod or VEPTR-like) from 2006 to 2011. Mean follow-up was 24 months (range, 12 to 36). The mean age at surgery was 7. Patients were affected by Escobar's syndrome (1), scoliosis associated to congenital heart disease (1), Arnold Chiari type 1 (1), syringomyelia (1), NF 1 (2), Prader-Willi syndrome (1), trisomy 8 (1), arthrogryposis (2) and spondylo-rib dysplasia (1). Each patient was studied from the genetic point of view, and were performed: brain-spine MRI, pulmonary function tests, Cardio-US and abdominal US, neuropsychiatric and neurological evaluation, C0-C2 CT scan. After first implant and lengthening procedures (11), the correction of the thoracic curve averaged 50%. Unfortunately, a little loss of correction of the lumbar curve occurred during the follow up. There were 8 post-operative complications, that required revision surgery in 2 cases. Our results confirmed the effectiveness and safety of growing spinal implants in the treatment of early-onset scoliosis in rare syndromes.

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.