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.

Less invasive surgery in idiopathic scoliosis: a case report.

BACKGROUND: Minimally invasive spine surgery (MISS) has become popular during the last decade due to continuous evidence in favor of lesser soft tissue damage, faster recovery, higher patient satisfaction and reduced health costs. During the last years, surgical ambition for better results as well as most detailed knowledge of spinal anatomy, have resulted in the continuous and successful expansion of indications of MISS, covering already successfully a wide range of degenerative spinal pathologies as well as adult spinal deformities. AIM: We describe here a case report of a patient with adolescent idiopathic scoliosis (AIS) treated by minimally invasive posterior pedicle screw instrumentation. MATERIALS AND METHODS: We report the case of an 18 years old female patient affected by AIS, Lenke type 1AN, with a 65 degree right thoracic curve and severe rib hump. Posterior pedicle screw instrumentation as well as corrective manoeuvres were performed exclusively by minimally invasive procedure, through three small midline skin incisions. RESULTS: We obtained a good clinical and radiographical correction of scoliosis, which was maintained during the follow-up period. We also observed a limited intra-operative blood loss, a limited operative time, limited pain, earlier mobilization and limited hospital stay. CONCLUSIONS: A minimally invasive technique can be used for the surgical treatment of AIS, showing satisfying deformity correction and multiple perceived advantages, although long-term data are needed before this kind of surgery can be recommended for routine use.

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.

The prevention of neural complications in the surgical treatment of scoliosis: the role of the neurophysiological intraoperative monitoring.

Iatrogenic spinal cord injury is the most feared complication of scoliosis surgery. The importance of combined somatosensory evoked potentials (SEP) and motor evoked potentials (MEP) monitoring during spine surgery is well known. The current authors retrospectively evaluated the results of neurophysiological intraoperative monitoring (IOM) in a large population of patients who underwent surgical treatment for spinal deformity. Intraoperative monitoring of SEPs and transcranial electrical stimulation MEPs (TES-MEP) was performed in 172 successive patients who underwent surgical treatment of idiopathic (128 pts), congenital (15 pts) or syndromic (29 pts) scoliosis. The first 106 patients (Group 1) underwent only SEP monitoring, while the other 66 patients (Group 2) underwent combined SEP and TES-MEP monitoring, when the technique was introduced in the current authors' institution. Halogenate anaesthesia (Sevoflurane, MAC 0.6-1.2) was performed in Group 1 cases, total intravenous anaesthesia (Propofol infusion, 6-10 mg/kg/h) in Group 2 patients. A neurophysiological "alert" was defined as a reduction in amplitude (unilateral or bilateral) of at least 50% for SEPs and of 65% for TES-MEPs compared with baseline. In Group 1, two patients (1.9%) developed postoperative neurologic deficits following surgical correction of spinal deformity, consisting of permanent paraparesis in one case and transient paraparesis secondary to spinal cord ischaemia in the other. Twelve patients presented intraoperative significant changes of neurophysiological parameters that improved following corrective actions by surgeons and anaesthesiologists, and did not show any postoperative neurologic deficits. In ten cases the alert was apparently unrelated to surgical manoeuvres or to pharmacological interventions and no postoperative neurologic deficits were noted. Considering the patients of Group 2, two patients (3.0%) presented transient postoperative neurologic deficits preceded by significant intraoperative changes in SEPs and TES-MEPs. In five cases a transient reduction in the amplitudes of SEPs (1 patient) and/or TES-MEPs (5 patients) was recorded intraoperatively with no postoperative neurologic deficits. In conclusion, in the current series of 172 patients the overall prevalence of postoperative neurologic deficit was 2.3% (4 patients). When combined SEP and TES-MEP monitoring was performed, the sensitivity and specificity of IOM for sensory-motor impairment was 100 and 98%, respectively. Combined SEP and TES-MEP monitoring must be regarded as the neurophysiological standard for intraoperative detection of emerging spinal cord injury during corrective spinal deformity surgery. Early detection affords the surgical team an opportunity to perform rapid intervention to prevent injury progression or possibly to reverse impending neurologic sequelae.

Thoracoplasty in the surgical treatment of adolescent idiopathic scoliosis.

A consecutive series of 40 adolescents surgically treated between 1998-2001, by posterior spinal fusion and thoracoplasty were compared with a similar group of 40 adolescents treated in the same period by posterior only segmental fusion. Clinical and radiographic analysis was performed, including the SRS-30 questionnaire and Pulmonary Function Tests (PFT). Minimum five years follow-up was requested. No statistical differences were found between the two groups in PFT's both pre-operatively and at latest follow up. Our findings suggest that thoracoplasty did not adversely affected long-term PFT's in AIS patients treated by posterior spinal fusion alone.