Abstract

Children undergoing posterior spinal fusion (PSF) for neuromuscular and syndromic scoliosis were admitted to the paediatric intensive care (PIC) until about 6 years ago, at which time we created a new unit, a hospital floor-based spinal high-dependency unit-plus (SHDU-plus), in response to frequent bed-shortage cancellations. This study compares postoperative management on PIC with HDU-plus for these non-hospital floor suitable children with syndromic and neuromuscular scoliosis undergoing PSF.

Retrospective review of 100 consecutive children with syndromic and neuromuscular scoliosis undergoing PSF between June 2016 and January 2022. Inclusion criteria were: 1) diagnosis of syndromic or neuromuscular scoliosis, 2) underwent PSF, 3) not suitable for immediate postoperative hospital floor-based care. Exclusion criteria were children with significant cardio-respiratory co-morbidity requiring PIC postoperatively.

55 patients were managed postoperatively on PIC and 45 on SHDU-plus. No significant difference between groups was found with respect to age, weight, ASA grade, preoperative Cobb angles, operative duration, number of levels fused and estimated blood loss. 4 patients in the PIC group and 1 in the SHDU-plus group were readmitted back to PIC or HDU following step-down to the hospital floor. Average length of stay was 2 days on PIC and 1 day on SHDU-plus. Average total length of hospital stay was 16.5 days in the PIC group and 10.5 days in the HDU-plus group. 19 (35%) patients developed complications in the PIC group, compared to 18 (40%) in SHDU-plus. Mean specialist unit charge per day was less on SHDU-plus compared with PIC. There were no bed-shortage cancellations in the SHDU-plus group, compared to 11 in the PIC group.

For children with neuromuscular or syndromic scoliosis undergoing PSF and deemed not suitable for post-operative care on the hospital floor, creation of a SHDU-plus was associated with fewer readmissions back to PIC or HDU, shorter hospital stays, an equivalent complication rate, significant cost-saving and fewer cancellations. Level of Evidence: Therapeutic Level III.

The lordosis distribution index (LDI) describes distribution of lumbar lordosis, measured as the % of lower lumbar lordosis (L4-S1) compared to global lordosis (L1-S1) with normal value 50–50%. Maldistributed LDI is associated with higher revision in short lumbar fusions, 4 vertebrae1. We hypothesise maldistributed LDI is also associated with mechanical failure in longer fusions.

Retrospective review of 29 consecutive ASD patients, aged 55+, undergoing long lumbar fusion, 4 levels, with >3-years follow-up. LDI, pelvic incidence (PI) and sagittal vertical axis (SVA) were measured on pre- and post-op whole spine standing X-rays (Fig A and B). Patients were categorized according to their pelvic incidence (PI) and postoperative LDI: Normal (LDI 50 80), Hypolordotic (LDI < 50), or Hyperlordotic (LDI > 80) and assessed for failure rate compared to normal LDI and PI <60.

Mean follow-up 4.5 years. 19 patients had mechanical failures including junctional failure and metalware fracture. PI >60o was associated with higher mechanical failure rates (Chi^2 p<0.05). Hypolordotic LDI was associated with 82% mechanical failure (Chi^2 p<0.001), Hyperlordotic 88% mechanical failure (Chi^2 p<0.001) and Normal 8% mechanical failure (Table 1).

Maldistributed LDI, whether Hyperlordotic or Hypolordotic, correlated with 10× greater mechanical failure rate compared to Normal LDI in long fusions. LDI is a useful measurement that should be considered, especially in high PI patients.

Neural axis anomalies in idiopathic scoliosis (AIS) are well documented, with prevalence of 7% in adolescents; 20% in early-onset and up to 40% in congenital, the case for pre-operative MRI of brainstem to sacrum is well made in these groups. SK is rarer than AIS and the prevalence of anomalies is not defined. The case for routine MRI scan is unclear. A recent report concluded that routine MRI was not indicated, although this was based on only 23 MRI scans in 85 patients. At our institution all patients are undergo whole spine MRI following a diagnosis of SK. We aimed to assess the incidence of significant neural anomalies in Scheuermann's Kyphosis.

Using a keyword search for “Scheuermann”, we reviewed all SK patients' MRI reports over the past 6 years.

117 MRI scans were identified. 13 patients did not fulfil the radiological criteria for SK and thus 104 (73M: 31F) scans were reviewed. 14 (13%) of 104 scans showed unexpected Significant abnormal findings. There were 8 (8%) with neural axis anomalies: 4 syrinxes; 1 cord anomaly; 2 cerebellar descents and 1 cerebellar tumour. All these patients had normal neurological examination except one with examination consistent with a known diagnosis of Parkinson's. A further 6 patients had non-neural anomalies.

The presence of neural axis anomalies may influence the management of a patient with SK. Neurological compromise during correction is higher in patients with neural axis anomalies and this risk can often be partially mitigated by a preceding neurosurgical procedure (such as foramen magnum decompression or shunt). Furthermore it is well described that these anomalies often occur in patients who demonstrate a normal neurological examination. This study confirms this. Given that MRI is widely available and considering the devastating life implications of neurological injury, we advise pre-operative MRI scan in all SK patents.

We describe the prevalence of spondylolisthesis in Scheuermann's Kyphosis (SK) from retrospective review of 104 SK patients over 6 years.

All patients referred to our institution for symptomatic SK undergo MRI scan from hindbrain to sacrum. Our MRI database was reviewed for all SK patients. All scans with spondylolisthesis were re-analysed.

117 scans were identified, 13 patients did not fulfil the MRI criteria for SK and thus 104 (74M: 31F) scans of SK are reported. There were 5 spondylolisthesis (1 cervical and 4 lumbosacral). Of the 4 lumbosacral there were 2 Meyerding grade-1; 1 grade-2 and 1 grade-5 spondyloptosis). An overall rate of 5% for listhesis was therefore found.

The prevalence of spondylolisthesis is around 3% in the general population based on a CT study of 510 patients (Belfi 2006) and Fredrickson's (1984 and 2003) prospective study of 500 children. We describe the prevalence in SK patients being higher at 5%. This may be related to the adaptive change of increased lumbar lordosis in SK, certainly it supports the previous description higher rates of spondylolysis in SK.

Introduction

Monitoring of scoliosis is traditionally done with radiographs, which can be associated with an increased risk of cancer secondary to multiple exposures over many years. This study investigated whether the findings from surface topography can be used to monitor scoliosis curves and how much this method affects outcome scores in patients with scoliosis. This study therefore had two subsets: (1) to investigate whether lateral asymmetry (LA) from ISIS2 surface topography can predict radiographic Cobb angle, providing an alternative non-invasive means of monitoring patients with scoliosis (LA and Cobb subset); and (2) to establish the relationships between the magnitude of the deformity in scoliosis, measured by Cobb angle on radiograph and volumetric asymmetry (VA) with the ISIS2 surface topography, and the patient perception of self-image and mental health, measured with SRS-22 scores (Cobb, VA, and SRS subset).

Purpose of the study

To establish the relation between the magnitude of the deformity in scoliosis, measured by cobb angle on radiograph & Volumetric asymmetry with the ISIS2 surface topography, and the patient perception of self image and mental health, measured with SRS-22 scores.

Purpose of the study

Monitoring of scoliosis is traditionally done with radiographs which can be associated with an increased risk of cancer secondary to multiple exposures over many years. This study investigates whether lateral asymmetry (LA) from ISIS2 surface topography can predict radiographic cobb angle, to provide an alternative non- invasive means of monitoring scoliosis patients.

Reviewing our experience of scoliosis in children with a Cavopulmonary Shunt or Fontan circulation and the cardiovascular challenges that this presents.

A notes and x ray review was performed. Special attention was paid to the changes in cardiovascular status whilst prone. The review was from first presentation to latest follow up.

There were 6 patients who underwent 7 major procedures between 2001 and 2009. All had cardiac procedures in early life. Both definitive fusion and growing instrumentation was used. All procedures were successful. Growing instrumentation allowed earlier primary surgery before completion of the Fontan circulation. All have been subsequently lengthened in a lateral position. The mean follow up is 56 months. There was one death 40 months following last surgery, cause unrelated to spinal surgery.

In the older patients with a completed Fontan significant blood loss was seen, due to the raised venous pressure required to run the Fontan, and occult hypotension seen as a climbing difference between Pulmonary Artery Wedge Pressure and Central Venous Pressure were common when prone.

We recommend early intervention, using instrumentation without fusion to correct the deformity over time and allow intervention prior to completing the Fontan circulation. As haemodynamic instability increases with increasing time in the prone position, surgery should be expedited rapidly.

Spinal Deformity Service, Royal Orthopaedic Hospital, Birmingham, UK

To describe the technique of nonfusion annulotomy and nuclectomy with posterior growing rod instrumentation for the treatment of non-congenital early onset scoliosis

To present our results of the application of this technique in a consecutive series of nine patients with mean follow up of 76 months (range 16 to 123 months)

We undertook retrospective observational casenote and radiograph study of patients with noncongenital early onset scoliosis having annulotomy and nuclectomy at the apex of their respective curves with standard posterior growing rod instrumentation between 1998 and 2009.

10 patients were identified with one excluded due to short follow up period. Of the nine patients included mean follow up was 76 months. Mean age at primary surgery was 71.7 months (range 29- 97 months)

We measured pre and post operative Cobb angle, T1-S1 height change and change in height over the apical segments.

Mean pre op cobb angle was 74° (range 62- 81°). Mean post op cobb angle was 38°. Three patients have completed their treatment programme with a mean number of 9 lengthenings achieved. Six patients are still undergoing lengthenings. CT demonstrates that the annulotmized segment does not fuse at a mean 3.5 years postoperatively. All patients demonstrated growth over total spinal height and also over apical segments which had undergone annultomy/ nuclectomy. We also report complications.

We have demonstrated that anterior annulotomy and nuclectomy with posterior growing rod construct does allow for spinal growth over released segments without autofusion.

Background: Anterior scoliosis surgery is associated with potentially significant intra-operative blood loss, requiring homologous transfusion either intra- or postoperatively. Blood loss in this type of surgery correlates with surgical & anaesthetic techniques. In our centre the development of specific anaesthetic techniques as well as the routine use of Cell Salvage has dramatically reduced the rates of homologous blood transfusion. Currently, specific indications for the use of the Cell Saver in Anterior Scoliosis Surgery have not been proven. Previous studies have commented on the beneficial aspects of autologous transfusion for Orthopaedic patients in general; However, others have shown a negligible advantage specifically in anterior thoracolumbar fusion surgery. The aim of our study was to assess and quantify the use of homologous blood, as well as the effects on haematological indices.

Methods: We carried out a retrospective study of 144 consecutive patients, all of whom underwent instrumented anterior scoliosis correction between April 2001 and October 2004. A cell saver was used in all the cases, and hospital data (including haematological indices and number of levels fused) was collected.

Results: The median age of the study cohort was 15.0 years (range 8 – 46), and there were 31 males and 113 females. The mean preoperative haemoglobin in patients was 13.5g/dl and the mean postoperative haemoglobin was 10.6g/dl. Haematocrit values followed a similar pattern, the mean pre-op value being 0.41, mean post-op value was 0.29. The range of volume of intra-operatively salvaged cells was 200 to 1100mls. 25 of 144 patients required transfusion. In these patients, the average number of units given was 2.3, although the total homologous transfusion rate was 0.4 units per patient. Results show that homologous transfusion was not required in 82.6% of patients. This is better than previously published rates of transfusion in this procedure. There was no correlation between the number of levels instrumented and the number of units transfused (Pearson Correlation Coefficient 0.19), and no correlation between the number of levels instrumented and postoperative haematocrit values (Pearson Correlation Coefficient 0.16). None of the patients required intra-operative homologous transfusion.

Conclusion: Our experience shows that along with meticulous surgical haemostasis, and hypotensive anaesthesia the use of Salvaged Autologous Blood Transfusion in anterior scoliosis surgery has an important role in reducing the incidence of postoperative anaemia and homologous transfusion requirements.

Background: To present the experience of three centres in the surgical management of scoliosis in patients with Prader-Willi syndrome¹, and to describe the associated complications. A retrospective case series reviewing treatment type, surgical outcomes and complications with a review of the literature

Methods: There were 15 patients treated surgically in the three centres over an eleven year period. The average age at initial surgery was 9.6 (5 to 16+8) yrs. Minimum follow-up from index procedure was 28 months. 5 underwent posterior spinal fusion, 2 had anterior fusion alone and 2 had combined anterior/ posterior fusions as their index procedure. 6 patients were initially managed with growing rod constructs. Outcome measures included fusion rate, curve progression and complication rate.

Results: 11 patients achieved a solid fusion. 2 patients were still undergoing the lengthening process and were thus unfused. 1 patient had broken instrumentation with pseudarthrosis, and one patient not fit for final fusion remained without implants. No curve progression was seen in the 11 fused spines. Progressive kyphosis and scoliosis were noted in the two ongoing lengthening patients. There were 17 revision procedures not including planned lengthenings, with a total of 59 surgical procedures. 5 rod breakages occurred in the growing-rod patients. There were 11 infections (4 deep) in 7 patients. There were 6 respiratory complications, 3 requiring ventilatory support. One patient had post-operative neurological deterioration requiring re-exploration and who had grade 3 paraparesis at final follow-up. In total there were 36 complications (240%)

Conclusion: The outcome of surgical management of scoliosis in Prader-Willi syndrome is adversely affected by the obesity and respiratory difficulties of the patients and complications abound². The use of growing constructs, whilst enabling the management of the growing child, greatly increases the risk of implant failures. Their use in Prader-Willi requires careful consideration.

Background: Paediatric spinal systems made from stainless steel are effective at correcting early onset scoliosis in a non-fusion technique. The use of similar systems manufactured from titanium is an attractive alternative as it would allow Magnetic Resonance Imaging of the patient with its recognised imaging advantages.

Objective: We performed a prospective in vitro study to compare the mechanical performance of a current clinically used stainless steel construct with an identical proposed titanium alternative.

Methods: Twelve spinal constructs of each material were constructed in a typical in vivo configuration using a corpectomy model in accordance with ASTM F1798 standard. Five samples for each metal were subjected to axial compressive static loading at a rate of 1mm/s until plastically deformed. Seven samples for each metal were then subject to varying compressive cyclic loads until a 5 million cycle run out was observed. From this data a fatigue S-N curve was generated.

Results: The stiffness of each construct was then calculated and the results were statistically analysed. For steel and titanium we calculated 95% confidence intervals of 23.9 to 35.7 and 18.8 to 23.7 respectfully. Significance P(< 0.05). The fatigue strength to 5 million cycles was 179N and 150N for steel and titanium respectfully. Failure occured most commonly in the rods close to the transverse rod connector or the pedicle screw / polyethylene block interface.

Conclusions: We conclude that with identical dimensions, the stainless steel constructs had a significantly higher Modulus of Elasticity than titanium. The fatigue strength for steel was also higher than titanium. The potential use of titanium as an alternative to stainless steel in paediatric spinal systems is still an attractive alternative. Given the results, we would suggest that further re-designing and testing be carried out before clinical release and then initially be reserved for selected patients with lower body weight or physical demands.

Anterior scoliosis surgery is associated with potentially significant intra-operative blood loss, requiring homologous transfusion either intra- or post-operatively.

Blood loss in this type of surgery correlates with surgical & anaesthetic techniques. In our centre the development of specific anaesthetic techniques as well as the routine use of Cell Salvage has dramatically reduced the rates of homologous blood transfusion.

Currently specific indications for the use of the Cell Saver in Anterior Scoliosis have not been proven. Previous studies have commented on the beneficial aspects of recovered autologous transfusion for Orthopaedic patients in general, whilst others have shown a negligible advantage specifically in anterior thoracolumbar fusion surgery.

In order to assess the cost-effectiveness of the techniques used in Anterior Scoliosis Surgery we carried out a retrospective study of 180 consecutive patients, all of whom underwent instrumented anterior scoliosis correction between July 2000 and September 2004. A cell saver was used in all the cases, and hospital data (including haematological indices and number of levels fused) was collected. The median age of the study cohort was 11.2 years (range 7 – 64), and the male:female ratio was 1:8.4.

The average preoperative haemoglobin in all patients was 12.7g/dl and the average postoperative haemoglobin was 9.8g/dl. In total the rate of homologous transfusion requirement was 1 unit per 9.1 patients.

Results show that homologous transfusion was required in less than 11% of all patients. This is better than previously published rates of transfusion in similar procedures. The range of volume of intra-operatively salvaged cells was 200 to 770mls.

There was no correlation between the number of levels fused (extent of scoliosis corrective surgery) and units transfused.

Our experience shows that the use of Salvaged Autologous Blood Transfusion in anterior scoliosis surgery has an important role in reducing the incidence of postoperative anaemia and homologous transfusion requirements.

Study Design: A retrospective review of case notes and histology reports.

Summary of Background Data: Up to 8% of cancer patients develop second malignancies. The vertebral column is frequently involved in metastatic disease and may represent the first manifestation of malignancy in up to 40% of patients. The rate of vertebral metastasis from a second tumour in patients with a known primary is not well known.

Objective: We sought to identify the incidence of a second primary in patients referred to our unit with spinal malignancy and a previously diagnosed primary tumour.

Subjects: 222 patients underwent definitive surgery for spinal metastatic disease of whom 135 had a prior history of malignancy.

Outcome measures: Histological tissue of origin of spinal metastasis in light of previous known malignancy.

Results: In 16 patients (11.9%) the vertebral histology differed from the initial primary. The period between first and second malignancies varied widely (19 months – 22 years). Thirteen patients (9.6%) had identifiable tissue origins for the metastasis that was not in keeping with the previous malignancy. Three further patients showed sufficient histological and imunohistochemical differences such that a further tumour of unknown origin and not de-differentiation of the previous tumour was suspected. Three previously unrecognised tumours were diagnosed on biopsy and eight on tissue obtained at definitive surgery.

Conclusion: The incidence of second primaries, in particular myeloma, presenting with vertebral metastases is significant and should always be borne in mind when assessing patients and planning treatment. Biopsy should be performed when possible. Comparison needs to be made between the histological features of the previous primary and metastasis.

Aims: The validation of two previously published prognostic scoring systems in relation to survival following surgery for metastatic disease of the spine. Methods: 169 patients operated upon for metastatic disease of the spine were retrospectively reviewed and prognostic scores calculated according to the systems of Tokuhashi and Tomita. Surgical approach and strategy, complications and reoperations were also recorded. Patient survival was compared by prognostic group and surgical strategy within and between the two systems. Results: 126 patients were conþrmed dead at a mean of 8.3 months and 43 alive at a mean 31.2 months. Patients with Tokuhashi scores of 9–12 had 50% survivial of 23 months compared to 5 months and 2 months for scores of 5–8 and 1–4 respectively (p< 0.05). Tomita scoring showed a similar trend with 50% survivals of 15 and 5 months for predicted long and medium term groups (p< 0.05). Each prognostic parameter was signiþcantly related to survival for both systems. There was no difference in survival within the better prognostic groups in relation to surgical stratergy. Tomitañs system was less sensitive to early mortality. Conclusions: Both systems are potentially useful in deciding the suitability for surgery in patients with metastatic spinal disease. There use in the emergency, unstaged patient has not been validated here. They may help in comparing patient status in future studies allowing more meaningful analysis of data.

Objective To assess the validity of Somatosensory Evoked Potential (SSEP) monitoring in identifying potential spinal cord vascular damage resulting from segmental artery ligation in anterior spinal deformity correction.

Design SSEP monitoring was undertaken in patients deemed at risk of spinal cord vascular injury during corrective surgery. The segmental vessels of the vertebral bodies to be instrumented were identified. Baseline SSEPs were obtained prior to application of non-crushing microvascular clamps. After ten minutes of occlusion, further SSEP recordings were made. Surgery proceeded with either, vessel ligation and division allowing anterior instrumentation, or vessel sparing anterior release.

Subjects 22 patients were included; 7 had Scheuermann’s hyperkyphosis and 15 had scoliosis (11 idiopathic, 3 syndromic, 1 neuromuscular). Perceived risk was defined by the presence of hyperkyphosis, abnormal neurological examination or radiologically identified spinal cord anomaly.

Outcome Measures A drop of 30% from baseline reading was taken as significant. Post-operative neurological outcome was correlated with intra-operative signal change and alteration in planned surgery.

Results There was no significant drop in post-clamping SSEPs in the hyperkyphotic patients. In 3 scoliosis patients anterior instrumentation was abandoned and a release was performed. Staged posterior instrumentation followed. In a further 2, anterior instrumentation proceeded but in a modified fashion. The remaining 10 patients had no significant drop and underwent the surgery as planned. No patient sustained a neurological injury.

Conclusions SSEP monitoring is safe in assessing the apparent contribution of segmental vessel blood supply to the spinal cord in spinal deformity surgery. It has allowed timely alteration of planned surgical procedures that potentially may have caused vascular spinal cord injury.

Introduction: Percutaneous or semi-open needle biopsy is recommended to obtain histological or bacteriological diagnosis prior to definitive treatment of destructive vertebral lesions. The clinical efficacy of repeating biopsies when initial samples have been inconclusive has not been established. We have examined the accuracy of repeat biopsy in these cases.

Materials and Methods: 103 patients with destructive vertebral lesions underwent percutaneous trans-pedicular or open vertebral biopsy. Eighty-two were available for analysis, and in 33 (39%) the initial biopsy failed to establish a histological or microbiological diagnosis. Thirteen patients underwent a repeat biopsy. The remaining 20 patients underwent a definitive surgical procedure or were treated empirically.

Results: Repeat biopsy was inconclusive in six patients, two were confirmed as infection (one TB and one Staph Aureus) and five malignancy (four lymphoma and one chordoma).

There was no significant association between the type of biopsy (open or percutaneous), the vertebral level of the lesion or the use of adjuvant therapy in the malignant cases. As has already been shown from this unit, the commencement of ‘blind’ antibiotic therapy reduces the success of bacteriological culture but does not affect the histological appearance.

Conclusion: Repeat vertebral biopsy is indicated if the initial biopsy is inconclusive, especially if antibiotics have not been commenced or a diagnosis of lymphoma is suspected. It should be performed promptly so as not to compromise the definitive treatment.

Introduction: The long term integrity of the intervertebral disc following repair of pars interarticularis defects in the lumbar spine is uncertain. This study was undertaken to clarify this issue.

Materials and Methods: 26 patients with symptomatic lumbar spondylolyis underwent a modified Scott repair of the defects, between 1979 and 1993. The early results of these patients were presented to the British Scoliosis Society in 1998. Ten patients have been recalled and reviewed clinically and by MRI investigation at a mean follow-up of 10 years.

Results: Eight of the 10 patients are completely asymptomatic and the MRI appearances are normal. The remaining two patients are symptomatic; one has MRI evidence of disc degeneration and the other has normal MRI appearances.

Conclusion: Repair of the pars interarticularis defect in symptomatic spondylolysis gives excellent symptomatic relief following surgery. This long term review indicates that it protects the integrity of the adjacent intervertebral disc.

We report 33 cases of femoral supracondylar fracture in elderly or debilitated patients treated by Zickel supracondylar nails. Most of the patients were female and their mean age was 79 years. All had concurrent medical problems and only nine could walk unaided. The operating time averaged one hour and mean blood loss was 100 ml. Postoperative management was by mobilisation in a cast brace or plaster. Six patients died before fracture union; all the others achieved union at an average of 12 weeks. The results were excellent in terms of pain relief, movement and function; there were no infections or nonunions. The locking screws backed out or broke in 26% but this did not prejudice the outcome. Use of the Zickel system is recommended for this group of frail patients.