Adolescent idiopathic scoliosis (AIS), defined by an age at presentation of 11 to 18 years, has a prevalence of 0.47% and accounts for approximately 90% of all cases of idiopathic scoliosis. Despite decades of research, the exact aetiology of AIS remains unknown. It is becoming evident that it is the result of a complex interplay of genetic, internal, and environmental factors. It has been hypothesized that genetic variants act as the initial trigger that allow epigenetic factors to propagate AIS, which could also explain the wide phenotypic variation in the presentation of the disorder. A better understanding of the underlying aetiological mechanisms could help to establish the diagnosis earlier and allow a more accurate prediction of deformity progression. This, in turn, would prompt imaging and therapeutic intervention at the appropriate time, thereby achieving the best clinical outcome for this group of patients.

Cite this article: Bone Joint J 2022;104-B(8):915–921.

Aims

To provide normative data that can assess spinal-related disability and the prevalence of back or leg pain among adults with no spinal conditions in the UK using validated questionnaires.

The development of spinal deformity in children with underlying neurodisability can affect their ability to function and impact on their quality of life, as well as compromise provision of nursing care. Patients with neuromuscular spinal deformity are among the most challenging due to the number and complexity of medical comorbidities that increase the risk for severe intraoperative or postoperative complications. A multidisciplinary approach is mandatory at every stage to ensure that all nonoperative measures have been applied, and that the treatment goals have been clearly defined and agreed with the family. This will involve input from multiple specialities, including allied healthcare professionals, such as physiotherapists and wheelchair services. Surgery should be considered when there is significant impact on the patients’ quality of life, which is usually due to poor sitting balance, back or costo-pelvic pain, respiratory complications, or problems with self-care and feeding. Meticulous preoperative assessment is required, along with careful consideration of the nature of the deformity and the problems that it is causing. Surgery can achieve good curve correction and results in high levels of satisfaction from the patients and their caregivers. Modern modular posterior instrumentation systems allow an effective deformity correction. However, the risks of surgery remain high, and involvement of the family at all stages of decision-making is required in order to balance the risks and anticipated gains of the procedure, and to select those patients who can mostly benefit from spinal correction.

Aims

To report the outcome of spinal deformity correction through anterior spinal fusion in wheelchair-bound patients with myelomeningocele.

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

Severe spinal deformity in growing patients often requires surgical management. We describe the incidence of spinal deformity surgery in a National Health Service.

Adolescent idiopathic scoliosis (AIS) is a complex 3D deformity of the spine. Its prevalence is between 2% and 3% in the general population, with almost 10% of patients requiring some form of treatment and up to 0.1% undergoing surgery. The cosmetic aspect of the deformity is the biggest concern to the patient and is often accompanied by psychosocial distress. In addition, severe curves can cause cardiopulmonary distress. With proven benefits from surgery, the aims of treatment are to improve the cosmetic and functional outcomes. Obtaining correction in the coronal plane is not the only important endpoint anymore. With better understanding of spinal biomechanics and the long-term effects of multiplanar imbalance, we now know that sagittal balance is equally, if not more, important. Better correction of deformities has also been facilitated by an improvement in the design of implants and a better understanding of metallurgy. Understanding the unique character of each deformity is important. In addition, using the most appropriate implant and applying all the principles of correction in a bespoke manner is important to achieve optimum correction.

In this article, we review the current concepts in AIS surgery.

Cite this article: Bone Joint J 2018;100-B:415–24.

Aims

We present the results of correcting a double or triple curve adolescent idiopathic scoliosis using a convex segmental pedicle screw technique.

Aims

Clinical and radiological data were reviewed for all patients with mucopolysaccharidoses (MPS) with thoracolumbar kyphosis managed non-operatively or operatively in our institution.

Aims

We reviewed 34 consecutive patients (18 female-16 male) with isthmic spondylolysis and grade I to II lumbosacral spondylolisthesis who underwent in situ posterolateral arthodesis between the L5 transverse processes and the sacral ala with the use of iliac crest autograft. Ten patients had an associated scoliosis which required surgical correction at a later stage only in two patients with idiopathic curves unrelated to the spondylolisthesis.

Acute angulation at the thoracolumbar junction with segmental subluxation of the spine occurring at the level above an anteriorly hypoplastic vertebra in otherwise normal children is a rare condition described as infantile developmental thoracolumbar kyphosis. Three patient series with total of 18 children have been reported in the literature. We report five children who presented with thoracolumbar kyphosis and discuss the treatment algorithm. We reviewed the medical records and spinal imaging at initial clinical presentation and at minimum two-year follow-up. The mean age at presentation was eight months (two to 12). All five children had L2 anterior vertebral body hypoplasia. The kyphosis improved spontaneously in three children kept under monitoring. In contrast, the deformity was progressive in two patients who were treated with bracing. The kyphosis and segmental subluxation corrected at latest follow-up (mean age 52 months; 48 to 60) in all patients with near complete reconstitution of the anomalous vertebra. The deformity and radiological imaging on a young child can cause anxiety to both parents and treating physicians. Diagnostic workup and treatment algorithm in the management of infantile developmental thoracolumbar kyphosis is proposed. Observation is indicated for non-progressive kyphosis and bracing if there is evidence of kyphosis and segmental subluxation deterioration beyond walking age. Surgical stabilisation of the spine can be reserved for severe progressive deformities unresponsive to conservative treatment.

Cite this article: Bone Joint J 2015;97-B:982–7.

Clinical, radiological, and Scoliosis Research Society-22 questionnaire data were reviewed pre-operatively and two years post-operatively for patients with thoracolumbar/lumbar adolescent idiopathic scoliosis treated by posterior spinal fusion using a unilateral convex segmental pedicle screw technique. A total of 72 patients were included (67 female, 5 male; mean age at surgery 16.7 years (13 to 23)) and divided into groups: group 1 included 53 patients who underwent fusion between the vertebrae at the limit of the curve (proximal and distal end vertebrae); group 2 included 19 patients who underwent extension of the fusion distally beyond the caudal end vertebra.

A mean scoliosis correction of 80% (45% to 100%) was achieved. The mean post-operative lowest instrumented vertebra angle, apical vertebra translation and trunk shift were less than in previous studies. A total of five pre-operative radiological parameters differed significantly between the groups and correlated with the extension of the fusion distally: the size of the thoracolumbar/lumbar curve, the lowest instrumented vertebra angle, apical vertebra translation, the Cobb angle on lumbar convex bending and the size of the compensatory thoracic curve. Regression analysis allowed an equation incorporating these parameters to be developed which had a positive predictive value of 81% in determining whether the lowest instrumented vertebra should be at the caudal end vertebra or one or two levels more distal. There were no differences in the Scoliosis Research Society-22 outcome scores between the two groups (p = 0.17).

In conclusion, thoracolumbar/lumbar curves in patients with adolescent idiopathic scoliosis may be effectively treated by posterior spinal fusion using a unilateral segmental pedicle screw technique. Five radiological parameters correlate with the need for distal extension of the fusion, and an equation incorporating these parameters reliably informs selection of the lowest instrumented vertebra.

Cite this article: Bone Joint J 2014;96-B:1082–9.

We report the incidence of and risk factors for complications after scoliosis surgery in patients with Duchenne muscular dystrophy (DMD) and compare them with those of other neuromuscular conditions.

We identified 110 (64 males, 46 females) consecutive patients with a neuromuscular disorder who underwent correction of the scoliosis at a mean age of 14 years (7 to 19) and had a minimum two-year follow-up. We recorded demographic and peri-operative data, including complications and re-operations.

There were 60 patients with cerebral palsy (54.5%) and 26 with DMD (23.6%). The overall complication rate was 22% (24 patients), the most common of which were deep wound infection (9, 8.1%), gastrointestinal complications (5, 4.5%) and hepatotoxicity (4, 3.6%). The complication rate was higher in patients with DMD (10/26, 38.5%) than in those with other neuromuscular conditions (14/84, 16.7% (p = 0.019). All hepatotoxicity occurred in patients with DMD (p = 0.003), who also had an increased rate of deep wound infection (19% vs 5%) (p = 0.033). In the DMD group, no peri-operative factors were significantly associated with the rate of overall complications or deep wound infection. Increased intra-operative blood loss was associated with hepatotoxicity (p = 0.036).

In our series, correction of a neuromuscular scoliosis had an acceptable rate of complications: patients with DMD had an increased overall rate compared with those with other neuromuscular conditions. These included deep wound infection and hepatotoxicity. Hepatotoxicity was unique to DMD patients, and we recommend peri-operative vigilance after correction of a scoliosis in this group.

Cite this article: Bone Joint J 2014; 96-B:943–9.

We describe 13 patients with cerebral palsy and lordoscoliosis/hyperlordosis of the lumbar spine who underwent a posterior spinal fusion at a mean age of 14.5 years (10.8 to 17.4) to improve sitting posture and relieve pain. The mean follow-up was 3.3 years (2.2 to 6.2).

The mean pre-operative lumbar lordosis was 108^° (80 to 150^°) and was corrected to 62^° (43^° to 85^°); the mean thoracic kyphosis from 17^° (-23^° to 35^°) to 47^° (25^° to 65^°); the mean scoliosis from 82^° (0^° to 125^°) to 22^° (0^° to 40^°); the mean pelvic obliquity from 21^° (0^° to 38^°) to 3^° (0^° to 15^°); the mean sacral slope from 79^° (54^° to 90^°) to 50^° (31^° to 66^°). The mean pre-operative coronal imbalance was 5 cm (0 cm to 8.9 cm) and was corrected to 0.6 cm (0 to 3.2). The mean sagittal imbalance of -8 cm (-16 cm to 7.8 cm) was corrected to -1.6 cm (-4 cm to 2.5 cm). The mean operating time was 250 minutes (180 to 360 minutes) and intra-operative blood loss 0.8 of estimated blood volume (0.3 to 2 estimated blood volume). The mean intensive care and hospital stay were 3.5 days (2 to 8) and 14.5 days (10 to 27), respectively. Three patients lost a significant amount of blood intra-operatively and subsequently developed chest or urinary infections and superior mesenteric artery syndrome.

An increased pre-operative lumbar lordosis and sacral slope were associated with increased peri-operative morbidity: scoliosis and pelvic obliquity were not. A reduced lumbar lordosis and increased thoracic kyphosis correlated with better global sagittal balance at follow-up. All patients and their parents reported excellent surgical outcomes.

Lordoscoliosis and hyperlordosis are associated with significant morbidity in quadriplegic patients. They are rare deformities and their treatment is challenging. Sagittal imbalance is the major component: it can be corrected by posterior fusion of the spine with excellent functional results.

Cite this article: Bone Joint J 2014;96-B:800–6.

We reviewed 212 consecutive patients with adolescent idiopathic scoliosis who underwent posterior spinal arthrodesis using all pedicle screw instrumentation in terms of clinical, radiological and Scoliosis Research Society (SRS)-22 outcomes. In Group 1 (51 patients), the correction was performed over two rods using bilateral segmental pedicle screws. In Group 2 (161 patients), the correction was performed over one rod using unilateral segmental pedicle screws with the second ^{rod providing stability of the construct through two-level screw fixation at proximal and distal ends. The mean age at surgery was 14.8 years in both groups. Comparison between groups showed no significant differences with regard to age and Risser grade at surgery, pre- and post-operative scoliosis angle, coronal Cobb correction, length of hospital stay and SRS scores. Correction of upper thoracic curves was significantly better in Group 1 (p = 0.02). Increased surgical time and intra-operative blood loss was recorded in Group 1 (p < 0.001 and p = 0.04, respectively). The implant cost was reduced by mean 35% in Group 2 due to the lesser number of pedicle screws.}

Unilateral and bilateral pedicle screw techniques have both achieved excellent deformity correction in adolescent patients with idiopathic scoliosis, which was maintained at two-year follow-up. This has been associated with high patient satisfaction and low complication rates.

An eight-week-old boy developed severe thoracic spondylodiscitis following pneumonia and septicaemia. A delay in diagnosis resulted in complete destruction of the T4 and T5 vertebral bodies and adjacent discs, with a paraspinal abscess extending into the mediastinum and epidural space. Antibiotic treatment controlled the infection and the abscess was aspirated. At the age of six months, he underwent posterior spinal fusion in situ to stabilise the spine and prevent progressive kyphosis. At the age of 13 months, repeat imaging showed lack of anterior vertebral body re-growth and he underwent anterior spinal fusion from T3 to T6 and augmentation of the posterior fusion. At the age of five years, he had no symptoms and radiographs showed bony fusion across the affected levels.

Spondylodiscitis should be included in the differential diagnosis of infants who present with severe illness and atypical symptoms. Delayed diagnosis can result in major spinal complications with a potentially fatal outcome.

Purpose of the study

Two patients with very severe thoracolumbar Scheuermann's kyphosis who developed spontaneous bony fusion across the apex of the deformity are presented and their treatment, as well as surgical outcome is discussed.

Purpose of the study

We report septic shock as postoperative complication following an instrumented posterior spinal arthrodesis on a patient with multiple body piercings. The management of this potentially catastrophic complication and outcome of treatment is been discussed.

Purpose of the study

To investigate the efficacy of pedicle screw instrumentation in correcting spinal deformity in patients with quadriplegic cerebral palsy. Also to assess quality of life and functional improvement after deformity correction as perceived by the parents of our patients.

Purpose of the study

To investigate the efficacy of pedicle screw instrumentation in correcting thoracolumbar/lumbar idiopathic scoliosis in adolescent patients.

Purpose of the study

To compare the effectiveness of unilateral and bilateral pedicle screw techniques in correcting adolescent idiopathic scoliosis.

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.

This review of the literature presents the current understanding of Scheuermann’s kyphosis and investigates the controversies concerning conservative and surgical treatment. There is considerable debate regarding the pathogenesis, natural history and treatment of this condition. A benign prognosis with settling of symptoms and stabilisation of the deformity at skeletal maturity is expected in most patients. Observation and programmes of exercise are appropriate for mild, flexible, non-progressive deformities. Bracing is indicated for a moderate deformity which spans several levels and retains flexibility in motivated patients who have significant remaining spinal growth.

The loss of some correction after the completion of bracing with recurrent anterior vertebral wedging has been reported in approximately one-third of patients. Surgical correction with instrumented spinal fusion is indicated for a severe kyphosis which carries a risk of progression beyond the end of growth causing cosmetic deformity, back pain and neurological complications. There is no consensus on the effectiveness of different techniques and types of instrumentation. Techniques include posterior-only and combined anteroposterior spinal fusion with or without posterior osteotomies across the apex of the deformity. Current instrumented techniques include hybrid and all-pedicle screw constructs.

A review of the current literature shows that there is a lack of consensus regarding the treatment of spondylolysis and spondylolisthesis in children and adolescents. Most of the views and recommendations provided in various reports are weakly supported by evidence. There is a limited amount of information about the natural history of the condition, making it difficult to compare the effectiveness of various conservative and operative treatments. This systematic review summarises the current knowledge on spondylolysis and spondylolisthesis and attempts to present a rational approach to the evaluation and management of this condition in children and adolescents.

We report five children who presented at the mean age of 1.5 years (1.1 to 1.9) with a progressive thoracolumbar kyphosis associated with segmental instability and subluxation of the spine at the level above an anteriorly-wedged hypoplastic vertebra at L1 or L2. The spinal deformity appeared to be developmental and not congenital in origin. The anterior wedging of the vertebra may have been secondary to localised segmental instability and subsequent kyphotic deformity.

We suggest the term ‘infantile developmental thoracolumbar kyphosis with segmental subluxation of the spine’ to differentiate this type of deformity from congenital displacement of the spine in which the congenital vertebral anomaly does not resolve. Infantile developmental kyphosis with segmental subluxation of the spine, if progressive, may carry the risk of neurological compromise. In all of our patients the kyphotic deformity progressed over a period of three months and all were treated by localised posterior spinal fusion. At a mean follow-up of 6.6 years (5.0 to 9.0), gradual correction of the kyphosis was seen on serial radiographs as well as reconstitution of the hypoplastic wedged vertebra to normality. Exploration of the arthrodesis was necessary at nine months in one patient who developed a pseudarthrosis.

Summary of background data. The development of a spinal deformity, usually affecting the coronal and occasionally the sagittal balance of the spine is a recognised complication of paralysis following a spinal cord injury (SCI) occurring in childhood.

Purpose of the study. The aim of the present study was to report our experience on the surgical treatment of patients who developed a paralytic spinal deformity secondary to SCIs occurring in childhood.

Material-Methods. Our study cohort comprised 18 consecutive patients with a paralytic spinal deformity as a consequence of a SCI. The cause of paralysis in this group of patients included a traumatic incident in 10 patients, spinal cord tumour in 6 patients, vascular injury to the neural cord during cardiac surgery in one patient, and meningitis in one patient. Twelve patients presented with high- or mid-thoracic paraparesis, which was complete in all but two patients. Six patients developed tetraparesis, which was incomplete in 3 of these patients.

Results. Fourteen patients underwent surgical correction of their spinal deformities; 11 patients had a scoliosis, 2 had a lordoscoliosis, and one had a kyphosis. The mean age at spinal arthrodesis was 13.4 years. Eleven patients underwent a posterior spinal fusion alone and 3 patients underwent a combined anterior and posterior spinal arthrodesis. Posterior spinal instrumentation with bilateral Luque rods and segmental fixation with sublaminar wires was used in all but one patient who was stabilised with the use of third generation spinal instrumentation. The spinal fusion extended to the sacrum in 10 of the 14 patients (71.4%) using the Galveston technique of intra-iliac pelvic fixation.

None of the patients developed postoperative wound infections, either early or late. There were no major medical complications following surgery in this group of patients that would result in prolonged intensive care unit or hospital stay. Four of the 14 patients (28.6%) who had initially undergone a posterior spinal arthrodesis alone developed an asymptomatic pseudarthrosis with failure of the instrumentation. The non-union was treated successfully in 2 of these 4 patients with a combined anterior and posterior spinal fusion. The repair of the pseudarthrosis was performed through a repeat posterior spinal fusion in the remaining 2 patients and one of these patients necessitated a second revision procedure to address recurrence of the non-union.

Conclusions. The high rate of pseudarthrosis (28.6%) recorded in the present series suggests that a combined anterior and posterior spinal arthrodesis could be considered as the initial treatment of choice for patients who are at a good general medical condition to tolerate anterior surgery and who have severe deformities. If pseudarthrosis develops following an isolated posterior spinal fusion, this can be treated more effectively by a combined anterior and posterior revision procedure with the use of instrumentation, which can increase the chances for a successful outcome.

Summary of Background Data. Obstruction of the third part of the duodenum by the superior mesenteric artery (SMA) is associated with spinal manipulation in the surgical or conservative management of scoliosis.

Purpose of the study. The aim of the present study was to investigate the prevalence of SMA syndrome in a cohort of 165 consecutive pediatric patients who underwent spine deformity surgery and had minimum 2-year follow-up.

Material-Methods. The study group comprised 85 patients with idiopathic scoliosis, 20 patients with neuromuscular and 18 patients with miscellaneous or syndromic scoliosis, and 42 patients with congenital spinal deformities. Posterior spinal arthrodesis was performed in 94 patients, combined anterior/posterior in 60 patients, and anterior spinal fusion in 11 patients.

Results. We identified 4 patients who developed SMA syndrome postoperatively. These were all markedly underweight, adolescent females; 2 patients had adolescent idiopathic scoliosis, one had neuromuscular, and one congenital scoliosis. Third generation instrumentation systems with derotational effect were used in 3 patients. The spinal arthrodesis in the patient with neuromuscular scoliosis was performed using bone graft followed by application of a spinal jacket. The symptoms developed at a mean of 3.7 days post-surgery and included nausea, vomiting, increased nasogastric aspirates, abdominal pain and distension. Conservative management with prolonged nasojejunal feedings achieved resolution of the symptoms in all but one patient, who required derotation of the duodenum and jejunum. There was no evidence of recurrence of the condition in any patient at the latest follow-up.

Conclusions. The prevalence of SMA syndrome in our series was 2.4%. This draws attention to the significance of prevention of the condition by recognizing patients who are at a higher risk. An early diagnosis of the syndrome will allow for application of conservative methods and will increase the chances for a successful outcome.

Summary of Background Data: The craniofacial malformations described by Goldenhar can be associated with congenital anomalies of the vertebrae. This non-random association of abnormalities represents unilateral errors in the morphogenesis of the spine, as well as the first and second branchial arches.

Purpose of the study: The aim of the present study was to determine the prevalence of Goldenhar related conditions in patients with congenital deformities of the spine and to describe the types of vertebral abnormalities and the necessity for treatment.

Material-Methods: We performed a retrospective study of 668 consecutive patients with congenital deformities of the spine. The medical records and spinal radiographs were reviewed and patients with a Goldenhar associated condition were identified. The vertebral anomalies causing the spine deformity were detected on antero-posterior and lateral spine radiographs. The type and site of the craniofacial abnormalities, as well as other musculoskeletal deformities and systemic anomalies were recorded.

Results: Fourteen patients had Goldenhar associated conditions (7 males and 7 females). A thoracic scoliosis was the most common type of deformity occurring in ten patients (71.5%). Eight of these patients had an isolated hemivertebra and the remaining two had a unilateral unsegmented bar with contralateral hemivertebra at the same level. There was only one patient with a lumbar scoliosis and this was due to a hemivertebra. The side of the vertebral anomaly correlated with that of the hemifacial microsomia in five of the eleven patients who had a scoliosis or kyphoscoliosis. A thoracolumbar kyphosis occurred in four patients; two had posterior hemivertebrae, one had wedge vertebrae, and the remaining patient had an anterior unsegmented bar. A thoracolum-bar kyphoscoliosis occurred in only one patient and was due to a posterolateral quadrant vertebra. Klippel-Feil syndrome occurred in six patients (42.8%).

Eight patients (57%) underwent surgical treatment at a mean age of 9.8 years (range: 2.9–19). Four patients had a combined anterior-posterior spine arthrodesis. The remaining four patients had a posterior spinal arthrodesis.

Conclusions. The prevalence of Goldenhar associated conditions in patients with congenital deformities of the spine was 2%. Failures of vertebral segmentation were the most frequent abnormality in the cervical spine, whereas failures of vertebral formation most commonly occurred in the thoracic or thoracolumbar spine.

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.