Aims. Spinal deformity surgery carries the risk of neurological injury. Neurophysiological monitoring allows early identification of intraoperative cord injury which enables early intervention resulting in a better prognosis. Although multimodal monitoring is the ideal, resource constraints make surgeon-directed intraoperative transcranial motor evoked potential (TcMEP) monitoring a useful compromise. Our experience using surgeon-directed TcMEP is presented in terms of viability, safety, and efficacy. Methods. We carried out a retrospective review of a single surgeon’s prospectively maintained database of cases in which TcMEP monitoring had been used between 2010 and 2017. The upper limbs were used as the control. A true alert was recorded when there was a 50% or more loss of amplitude from the lower limbs with maintained upper limb signals. Patients with true alerts were identified and their case history analyzed. Results. Of the 299 cases reviewed, 279 (93.3%) had acceptable traces throughout and awoke with normal clinical neurological function. No patient with normal traces had a postoperative clinical neurological deficit. True alerts occurred in 20 cases (6.7%). The diagnoses of the alert group included nine cases of adolescent idiopathic scoliosis (AIS) (45%) and six of congenital scoliosis (30%). The incidence of deterioration based on diagnosis was 9/153 (6%) for AIS, 6/30 (20%) for congenital scoliosis, and 2/16 (12.5%) for spinal tuberculosis. Deterioration was much more common in congenital scoliosis than in AIS (p = 0.020). Overall, 65% of alerts occurred during rod instrumentation: 15% occurred during decompression of the internal apex in vertebral column resection surgery. Four alert cases (20%) awoke with clinically detectable neurological compromise. Conclusion. Surgeon-directed TcMEP monitoring has a 100% negative predictive value and allows early identification of physiological cord distress, thereby enabling immediate intervention. In resource constrained environments, surgeon-directed TcMEP is a viable and effective method of intraoperative spinal cord monitoring. Level of evidence: III. Cite this article: Bone Joint J 2021;103-B(3):547–552

To establish the current practice of spinal cord monitoring in units carrying out scoliosis surgery in the UK. To illustrate the benefit of routinely monitoring motor evoked potentials (MEPs). Questionaire: Nationwide survey of spinal monitoring modalities used by spinal units carrying out deformity surgery. 10 out of 27 units routinely measure motor evoked potentials (MEPs), the remainder use only sensory potentials (SEPs). There is significant variability in use of monitoring around the UK and we have compared this to the practice elsewhere in the world. We report the case of a thirteen year old girl who underwent posterior instrumentation for correction of an idiopathic scoliosis. Intra-operatively there was a significant reduction in the amplitude of the MEPs without any corresponding change in the SEPs. These changes reversed when the correction was released. The surgery was abandoned and was carried out as a staged procedure, initially anteriorly then posteriorly. There was no loss of motor potentials during either operation and no post operative neurological abnormalities. We propose that the changes noted initially were due to transient ischaemia of the cord which would not have been detected without MEPs and may have led to long term sequelae. This highlights the safety benefit of routinely using MEPs in scoliosis surgery. Nationally there is wide variation in the monitoring of spinal cord function during scoliosis surgery. We feel that monitoring of motor potentials is a vital component in ensuring scoliosis surgery is as safe as possible

Segmental vessel ligation during anterior spinal surgery has been associated with paraplegia. However, the incidence and risk factors for this devastating complication are debated. We reviewed 346 consecutive paediatric and adolescent patients ranging in age from three to 18 years who underwent surgery for anterior spinal deformity through a thoracic or thoracoabdominal approach, during which 2651 segmental vessels were ligated. There were 173 patients with idiopathic scoliosis, 80 with congenital scoliosis or kyphosis, 43 with neuromuscular and 31 with syndromic scoliosis, 12 with a scoliosis associated with intraspinal abnormalities, and seven with a kyphosis. There was only one neurological complication, which occurred in a patient with a 127° congenital thoracic scoliosis due to a unilateral unsegmented bar with contralateral hemivertebrae at the same level associated with a thoracic diastematomyelia and tethered cord. This patient was operated upon early in the series, when intra-operative spinal cord monitoring was not available. Intra-operative spinal cord monitoring with the use of somatosensory evoked potentials alone or with motor evoked potentials was performed in 331 patients. This showed no evidence of signal change after ligation of the segmental vessels. In our experience, unilateral segmental vessel ligation carries no risk of neurological damage to the spinal cord unless performed in patients with complex congenital spinal deformities occurring primarily in the thoracic spine and associated with intraspinal anomalies at the same level, where the vascular supply to the cord may be abnormal

To determine whether neurophysiological electrical pedicle testing (EPT) is a useful aid in the detection of malpostioned pedicle screw tracts. EPT data from 246 screws in 32 spinal operations on 32 patients over a 5 year period (2009–2014) were recorded and analysed. In addition to physical palpation, a ball-tipped electrode delivered stimuli and the output was recorded by evoked electromyogram (EMG). When breach threshold values were recorded, the surgeon rechecked the tract for breaches and responded appropriately. In addition, standard motor evoked potential (MEP) and sensory evoked potential(SEP) spinal cord monitoring was performed. There were 24(9.8%) pedicle breaches by tract testing and 8(3.3%) by screw testing. In 11 instances in 7 patients where the tract testing showed a breach, the tract was redirected and subsequent screw testing showed adequate integrity of the pedicle. The total time for tract and screw testing was 25 seconds. There were no associated changes in MEP or SEP monitoring with any of the recorded pedicle breaches and none of the patients had any post-operative neurological deficit. EPT for the pedicle screw and tract is a safe, simple, practical and reliable technique which improves the accuracy of screw placement. Further studies would be required to confirm (and possibly revise) the threshold levels and to demonstrate whether EPT reduces the risk of misplaced screws or post-operative neurological deficit

Introduction. Changes in the central nervous system (CNS) pathways controlling trunk and leg muscles in patients with low back pain and radiculopathy have been observed and this study investigated whether surgery impacts upon these changes. Methods. Parameters of corticospinal control were examined on 3 occasions in 22 patients prior to, at 6 and 26 weeks following lumbar decompression surgery and in 14 control subjects at the same intervals. Electromyographic activity was recorded from tibialis anterior (TA), soleus (SOL), rectus abdominis (RA), external oblique (EO) and erector spinae (ES) muscles at the T12 & L4 levels in response to transcranial magnetic stimulation of the motor cortex. Results. In the surgical group, asymmetries in the size of motor evoked potentials (MEPs) in TA (P=0.001) and in the cortical silent periods (cSP) were found between the left and right sides in SOL (P=0.005) and ES at L4 (P=0.014) prior to surgery. This was not observed at 6 or 26 weeks. Abdominal responses could be evoked in 12 patients and there was a significant reduction in the cSP contralateral to the pain in EO (P=0.034) and RA (P=0.041) at 6 weeks. These parameters remained stable in controls over time. Discussion. The fact that changes appear to stabilise at 6 weeks is of interest as this parallels clinical outcome studies. Current work is ongoing to examine these excitability changes in both inhibitory and excitatory cortical pathways in these patients, and to what extent they may be related to clinical outcome

Aims

The outcome following the development of neurological complications after corrective surgery for scoliosis varies from full recovery to a permanent deficit. This study aimed to assess the prognosis and recovery of major neurological deficits in these patients, and to determine the risk factors for non-recovery, at a minimum follow-up of two years.

Aims

The aim of this retrospective study was to compare the correction achieved using a convex pedicle screw technique and a low implant density achieved using periapical concave-sided screws and a high implant density. We hypothesized that there would be no difference in outcome between the two techniques.

Aims

High-grade dysplastic spondylolisthesis is a disabling disorder for which many different operative techniques have been described. The aim of this study is to evaluate Scoliosis Research Society 22-item (SRS-22r) scores, global balance, and regional spino-pelvic alignment from two to 25 years after surgery for high-grade dysplastic spondylolisthesis using an all-posterior partial reduction, transfixation technique.

Aims

To report the surgical outcome of patients with severe Scheuermann’s kyphosis treated using a consistent technique and perioperative management.

Aims

The surgical treatment of tuberculosis (TB) of the spine consists of debridement and reconstruction of the anterior column. Loss of correction is the most significant challenge. Our aim was to report the outcome of single-stage posterior surgery using bone allografts in the management of this condition.

Aims

Magnetically controlled growing rod (MCGR) systems use non-invasive spinal lengthening for the surgical treatment of early-onset scoliosis (EOS). The primary aim of this study was to evaluate the performance of these devices in the prevention of progression of the deformity. A secondary aim was to record the rate of complications.

We report the results of vertebral column resection (VCR) for paediatric patients with spinal deformity. A total of 49 VCRs in paediatric patients from four university hospitals between 2005 and 2009 with a minimum two-year follow-up were retrospectively identified. After excluding single hemivertebral resections (n = 25) and VCRs performed for patients with myelomeningocele (n = 6), as well as spondylectomies performed for tumour (n = 4), there were 14 patients who had undergone full VCR at a mean age of 12.3 years (6.5 to 17.9). The aetiology was congenital scoliosis in five, neuromuscular scoliosis in three, congenital kyphosis in two, global kyphosis in two, adolescent idiopathic scoliosis in one and secondary scoliosis in one. A total of seven anteroposterior and seven posterolateral approaches were used.

The mean major curve deformity was 86° (67° to 120°) pre-operatively and 37° (17° to 80°) at the two-year follow-up; correction was a mean of 54% (18% to 86%) in the anteroposterior and 60% (41% to 70%) in the posterolateral group at the two-year follow-up (p = 0.53). The mean Scoliosis Research Society-24 total scores were 100 (92 to 108) for the anteroposterior and 102 (95 to 105) for the posterolateral group. There was one paraparesis in the anteroposterior group necessitating urgent re-decompression, with a full recovery.

Patients undergoing VCR are highly satisfied after a successful procedure.

We reviewed 31 consecutive patients with Friedreich’s ataxia and scoliosis. There were 24 males and seven females with a mean age at presentation of 15.5 years (8.6 to 30.8) and a mean curve of 51° (13° to 140°). A total of 12 patients had thoracic curvatures, 11 had thoracolumbar and eight had double thoracic/lumbar. Two patients had long thoracolumbar collapsing scoliosis with pelvic obliquity and four had hyperkyphosis. Left-sided thoracic curves in nine patients (45%) and increased thoracic kyphosis differentiated these deformities from adolescent idiopathic scoliosis. There were 17 patients who underwent a posterior instrumented spinal fusion at mean age of 13.35 years, which achieved and maintained good correction of the deformity. Post-operative complications included one death due to cardiorespiratory failure, one revision to address nonunion and four patients with proximal junctional kyphosis who did not need extension of the fusion. There were no neurological complications and no wound infections. The rate of progression of the scoliosis in children kept under simple observation and those treated with bracing was less for lumbar curves during bracing and similar for thoracic curves. The scoliosis progressed in seven of nine children initially treated with a brace who later required surgery. Two patients presented after skeletal maturity with balanced curves not requiring correction. Three patients with severe deformities who would benefit from corrective surgery had significant cardiac co-morbidities.