The relationship of degeneration to symptoms has been questioned. MRI detects apparently similar disc degeneration and degenerative changes in subjects both with and without back pain. We aimed to overcome these problems by re-annotating MRIs from asymptomatic and symptomatic groups onto the same grading system.

We analysed disc degeneration in pre-existing large MRI datasets. Their MRIs were all originally annotated on different scales. We re-annotated all MRIs independent of their initial grading system, using a verified, rapid automated MRI annotation system (SpineNet) which reported degeneration on the Pfirrmann (1-5) scale, and other degenerative features (herniation, endplate defects, marrow signs, spinal stenosis) as binary present/absent. We compared prevalence of degenerative features between symptomatics and asymptomatics.

Pfirrmann degeneration grades in relation to age and spinal level were very similar for the two independent groups of symptomatics over all ages and spinal levels. Severe degenerative changes were significantly more prevalent in discs of symptomatics than asymptomatics in the caudal but not the rostral lumbar discs in subjects < 60 years. We found high co-existence of degenerative features in both populations. Degeneration was minimal in around 30% of symptomatics < 50 years.

We confirmed age and disc level are significant in determining imaging differences between asymptomatic and symptomatic populations and should not be ignored. Automated analysis, by rapidly combining and comparing data from existing groups with MRIs and information on LBP, provides a way in which epidemiological and ‘big data’ analysis could be advanced without the expense of collecting new groups.

Purpose and background

To evaluate the clinical and cost-effectiveness of a physical and psychological group intervention (BOOST programme) compared to physiotherapy assessment and advice (best practice advice [BPA]) for older adults with neurogenic claudication (NC) which is a debilitating spinal condition.

Aims

The primary aim of this study was to evaluate the performance and safety of magnetically controlled growth rods in the treatment of early onset scoliosis. Secondary aims were to evaluate the clinical outcome, the rate of further surgery, the rate of complications, and the durability of correction.

Background

Combined physical and psychological (CPP) programmes are widely recommended for Chronic Low Back Pain (CLBP) patients, but not often implemented. Patients with longstanding CLBP participating in a two-week CPP programme improve in functional status and quality of life and this is maintained at two-year follow up. One-year follow-up data is available of 955 participants.

STUDY DESIGN

Retrospective study of 8 children treated with vertical expandable prosthetic titanium rib (VEPTR) for correction of early onset spinal scoliotic deformities.

STUDY DESIGN

Retrospective review of outcome of submuscular rod placement without apical fusion for the treatment of scoliotic deformities in children with severe co morbidities (ASA IV).

Introduction

Elastic fibres are constructed of a central core of elastin surrounded by microfibrils that are composed mainly of fibrillin-1 and fibrillin-2. Patients with mutations in the gene encoding fibrillin-1 or fibrillin-2 develop Marfan syndrome or Beals syndrome (congenital contractural arachnodactyly), respectively. Scoliosis is one of the clinical manifestations in these patients, but how a defect in the elastic proteins could lead to a spinal deformity is not clear. On the one hand, the mutations could induce scoliosis via mechanical means as they could lead to alterations in the biomechanics of the elastic fibre system. On the other hand, elastic fibres also bind growth factors such as transforming growth factor β (TGFβ) and bone morphogenic proteins (BMPs), and the mutations could hence change patterns of spinal growth.

Introduction

A common question posed by adolescents undergoing corrective scoliosis surgery is, “How much taller will I be after my operation?” This study aims to help answer this question, and quantify the gain in height that might be expected.

To determine extent of correction in spinal osteotomy for fixed sagittal plane deformity

Radiographic retrospective cohort analysis using standardised standing whole spine radiographs. Level III evidence

24 patients (14 females/10 males, av. 53.6 yrs) with sagittal plane deformity due to either ankylosing spondylitis (4), idiopathic (12), congenital (1), tumour (2), infectious (1), or posttraumatic (4) aetiologies. Max. 4 yrs follow up

Sagittal balance, lumbar lordosis correction, osteotomy angle, pelvic indices

Chevron (3), pedicle subtraction (17), and vertebral column resection (4) osteotomies were performed with the majority at L3 (9) and L2 (8). The C7-S1 sagittal vertical axis demonstrated a preoperative decompensation averaging 12.0 cm (range -7 to 37) with 55% of patients achieving normal sagittal balance postoperatively. Lumbar lordosis increased from 28.9° (range -28 to 63) to 48.9° (range 12 to 69) (22.3° av. correction). L3 osteotomy angle was largest, average 31° (range, 16 to 47). There were 11 complications comprising; major (1) and minor (1) neurological, junctional kyphosis (3), metalwork problems (2), dural tear (2) and infection (2). Four patients required additional surgery at latest follow-up. Technical outcome was good 11(50%), fair 8(36%), poor 3(14%).

Spinal osteotomy is a very effective technique to correct fixed sagittal imbalance and provide biomechanical stability. The high complication rate mandates a careful assessment of the risk/benefit ratio before undertaking what is a major reconstructive procedure. Most patients are satisfied, particularly when sagittal balance is achieved.

To compare the effect of intraoperative red cell salvage on blood transfusion and cost in patients undergoing idiopathic scoliosis surgery.

Retrospective

37 patients (36 females, 1 male) underwent scoliosis surgery from February 2007 to October 2008. Intraoperative red cell salvage (Group 1) was used. They were compared with 28 patients (23 females, 5 males) operated from January 2005 to December 2006 without the use of cell salvage (Group 2). 36 patients in group 1 had posterior surgery and 1 had anterior surgery. In Group 2, 20 patients had posterior surgery, 7 anterior and 1 patient had anterior and posterior surgery. Both groups were comparable for age, number of levels fused, preoperative haemoglobin and haematocrit values.

Amount of perioperative blood transfusion, costs

14 patients (50%) in group 2 had blood transfusion whereas only 6 (16%) were transfused blood in group 1. Average blood loss in group 1 was 1076 mls (range 315-3000) and 1626mls (419-4275) in group 2. An average of 2 units of packed red blood cells per patient was processed by the cell salvage system. Postoperative haemoglobin, haematocrit and hospital stay were comparable in both groups. Cost analysis shows the use of cell salvage is cost beneficial by £116.60 per case.

The use of red blood cell salvage reduces the amount of blood transfusion and is cost beneficial.

A literature review of bone graft substitutes for spinal fusion was undertaken from peer reviewed journals to form a basis for guidelines on their clinical use.

A PubMed search of peer reviewed journals between Jan 1960 and Dec 2009 for clinical trials of bone graft substitutes in spinal fusion was performed. Emphasis was placed on RCTs. Small and duplicated RCTs were excluded. If no RCTs were available the next best clinical evidence was assessed. Data were extracted for fusion rates and complications.

Of 929 potential spinal fusion studies, 7 RCTs met the inclusion criteria for BMP-2, 3 for BMP-7, 2 for Tricalcium Phosphate and 1 for Tricalcium Phosphate/Hydroxyapatite (TCP/HA). No clinical RCTs were found for Demineralised Bone Matrix (DBM), Calcium Sulphate or Calcium Silicate. There is strong evidence that BMP-2 with TCP/HA achieves similar or higher spinal fusion rates than autograft alone. BMP-7 achieved similar results to autograft. 3 RCTs support the use of TCP or TCP/HA and autograft as a graft extender with similar results to autograft alone. The best clinical evidence to support the use of DBMs are case control studies. The osteoinductive potential of DBM appears to be very low however. There are no clinical studies to support the use of Calcium Silicate.

The current literature supports the use of BMP-2 with HA/TCP as a graft substitute. TCP or HA/TCP with Autograft is supported as a graft extender. There is not enough clinical evidence to support other bone graft substitutes.

This study did not require ethics approval and no financial support was received.

Plain radiography has traditionally been used to investigate and monitor patients with adolescent idiopathic scoliosis. The X-ray allows a calculation of the Cobb angle which measures the degree of lateral curvature in the coronal plane. ISIS2 is a surface topography system which has evolved from ISIS, but with much higher precision and speed. It measures the three dimensional shape of the back using structured light and digital photography. This system has the benefit of not requiring any radiation. Lateral asymmetry is the ISIS clinical parameter estimating the curve of the spine in the coronal plane. The aim of this study was to compare this parameter to the Cobb angle measured on plain X-ray.

Twelve patients with idiopathic adolescent scoliosis underwent both a standing AP spine X-ray and an ISIS2 scan on multiple occasions. Both scan and X-ray were done within one month of each other. No patient underwent surgery during the study period. The Cobb angle and the degree of lateral asymmetry were calculated.

Twelve patients mean age 12.5 years (range 10-16) were investigated using both ISIS2 and X-ray. They had a mean 2.3 (1-5) combined investigations allowing for 30 comparisons. The correlation between the two measurements was r =0.63 (p=0.0002). The Cobb angle measured on ISIS2 was less than that measured by radiograph in 27 out of 30 comparisons. The mean difference between the measurements was mean 6.4° with a standard deviation of 8.2° and 95% confidence interval of 3.3° to 9.4°.

In adolescent idiopathic scoliosis, curve severity and rib hump severity are related but measure different aspects of spinal deformity. As expected, these relate closely but not precisely. ISIS2 offers the promise of monitoring scoliosis precisely, without adverse effects from radiation. The small numbers in this series focus on the group of patients with mild to moderate curves at risk of progression. In this group, ISIS2 was able to identify curve stability or progression, without exposing the subjects to radiation.

To establish the incidence of litigation in Cauda Equina Syndrome (CES) and the causes of litigation.

Review of 10 years of abbreviated records of the National Health Service litigation authority (NHSLA) (1997-2007) and eight years of medical negligence cases (MNC) reported on by the two senior authors (2000-2008).

Patients who experienced CES and litigated. There were 117 patients in the NHSLA records and 23 patients in the MNC group.

Review of timing of onset, delay in diagnosis, responsible specialist, place, and resulting symptoms

NHSLA cases. 62/117 cases were closed. The responsible specialists were as follows

The commonest failure was delay in diagnosis, and the commonest complications were “neurological”, bladder and bowel.

MNC cases. F:M;17/6. L4/5 13 cases, L5/S1 9 cases. The responsible specialist was orthopaedic (7), other (7) and in 8 cases the opinion was that there was no case to answer. Delay to treatment averaged 6.14 days. 18/23 patients described bowel and bladder symptoms, the information was not available in the remainder.

Litigation is major problem in CES. In most cases orthopaedic surgeons are litigated against, and bowel and bladder symptoms remain the most disturbing cause of litigation. These surgeons are mostly not spinal specialists. In most successful cases of litigation there is considerable delay in diagnosis and management. Where there is incomplete Cauda Equina Syndrome urgent or emergency investigation and treatment is mandatory.

Aim

We report our ten year experience of primary haematogenous non-tuberculous spinal infection.

Background: Scoliotic deformity has been traditionally measured by Cobb angle using radiography. This parameter gives a measure of the lateral curve in the spine in the coronal plane. However, patients are often more concerned about their rib humps or other volumetric asymmetries in the surface of their backs. There is often little relation between Cobb angle and the magnitude of the asymmetry. A method of quantifying volumetric deformity, especially if it requires no radiation, would therefore be useful for spinal surgeons and patients alike.

Methods: The three dimensional shape of the back is measured using structured light and digital photography with ISIS2, a non-commercial surface topography system. Markers are placed on bony landmarks so that the surface can be related to body axes. A zero plane is defined through the sacrum and the vertebra prominens, parallel to the line between the markers on the dimples of Venus. A curve is fitted through the markers on the spinous processes on the measured surface and is used as the line of symmetry. The difference in the areas between the surface and the zero plane on each side of the symmetry line is then calculated for each horizontal (transverse) section. The left and right volumetric asymmetry parameters are then calculated by summing the area differences on each side and normalising for back length. These parameters range from zero for a perfect straight back with no transverse asymmetry to over 70 for extreme transverse asymmetry. The variability in these parameters was investigated using pairs of photographs of 59 patients. Two photographs were taken with the patient walking around the room between them. Left and right volumetric asymmetry was then calculated for each measurement and Bland-Altman analysis was carried out.

Results: The mean difference between pairs of measurements was −0.10, the standard deviation was 2.03 and the 95% tolerance limits covering 95% of the population were −4.8 to 4.6 for left volumetric asymmetry; the mean difference was 0.46, standard deviation was 3.13 and the 95% tolerance limits covering 95% of the population were −6.8 to 7.7 for right volumetric asymmetry. There was no evidence of bias from the Bland-Altman plots.

Conclusions: The variability in the volumetric asymmetry was low in comparison to the levels found for subjectively classified ‘moderate’ deformity. Change in degree of volumetric deformity can be monitored by ISIS2 volumetric asymmetry.

Aim: To report our ten year experience of primary haematogenous spinal infection.

Method: Retrospective case note review of 42 patients presented to our unit with primary spinal infection between 1995–2005 was carried out. Demographic data, timing and modes of presentation, investigations, and methods of treatment were analysed. Information with regard to Mobility, Domestic circumstances, Oswestry disability index(ODI), Hospital Anxiety and depression score(HAD), Visual Analogue Score (VAS) for pain and coping were obtained. The cost benefit of Home Intravenous Antibiotics Service (HIAS) was also investigated.

Results: Mean age was 59.9 years (1–85) with almost equal gender distribution (M 20: F 22). Axial pain was universal. Pyrexia was seen in 62%. Time from presentation to diagnosis averaged 19days (range 0–172). Sensitivity for MRI and plain x-ray was 100% and 46% respectively. Treatment ranged from intravenous antibiotics alone to combined anterior and posterior surgery depending on the presence or absence of significant collection, neurological deficit and structural threat. Mean duration of intravenous antibiotics was 54 days (range 13–240). At mean follow up of 5.4 years (0.6–10.5) there was no mortality directly related to the infection. Recurrence rate was 14%. Significant past medical history(P=0.001), constitutional symptoms(p=0.001) and pyrexia at presentation(0.001) were positively associated with recurrence.

Mobility score dropped in 34% patients whilst domestic circumstances’ score dropped only in 34%. ODI averaged 18% (range 0–53%). Mean HAD for anxiety and depression was normal for 86% and 93% of patients respectively. VAS for pain averaged 1.3 (range 0–9) and that for distress was 1.8 (range 0–9).

Overall it was calculated that HIAS had saved a total of 940 in-patient days.

Conclusion: Primary spinal infection is a treatable condition. Disease and patient characteristics dictate the management strategy. Although most patients can regain their pre infection mobility and go back to their pre morbid domestic circumstances with little or no pain and psychological sequel, a proportion of patients end up with moderate to severe disability, pain and psychological problems despite successful treatment of the primary infection. Finally, HIAS was cost effective.

Aim: In this study we present our ten year experience of primary spinal infection.

Method: Retrospective case note review of 42 patients who presented to our institution with primary spinal infection between 1995–2005 was carried out. Demographic data and information with regard to timing and modes of presentation, results of radiological and laboratory investigations, and methods of treatment were collected. The financial impact of Home Intravenous Antibiotics Service (HIAS) was also investigated.

Results: Axial pain was the most consistent symptom seen in 100% of the patients. Only 62% had pyrexia at presentation. Major neurological deficit was seen in 10.2%.

Mean duration of symptoms was 25 days (range 1–202). Mean time from presentation to diagnosis was 19 days (range 0–172). Staphylococcus Aureus was the most common organism. Mean duration of Intravenous antibiotics was 60 days (range 13–240) followed by oral antibiotics for mean duration of 65 days (range 0–161). CRP was more reliable in monitoring the disease over time. At mean follow up of 5.4 years (0.6–10.5) there has been no mortality directly related to the infection. With our management there has been 14% recurrence rate. All re- presenting within the first year after initial presentation (Mean 5.5 Months, range 1–11).

HIAS saved a total of 940 in-patient days with a total cost saving of approximately £350,000.00.

Conclusion: In the majority of patients spinal infection can be successfully treated. Disease severity dictates the duration of antibiotic treatment and whether surgery is required. Recurrent infection occurred in a number of patients with more significant past medical history and pre-existing risk factors. Finally, HIAS is extremely cost effective in this group of patients.

Introduction: Loads acting on scoliotic spines are thought to be asymmetrical and involved in progression of the scoliotic deformity. Abnormal loading patterns could lead to changes in bone and disc cell and activity and hence to vertebral body and disc wedging. At present however there are no direct measurements of intradiscal stresses or pressures in scoliotic spines.

Methods: Stress profilometry was used to measure horizontal and vertical stresses at 5mm intervals across 25 intervertebral discs of 7 scoliotic patients during anterior reconstructive surgery. Identical horizontal and vertical stresses for at least two consecutive readings defined a region of hydrostatic pressure. Results were compared with similar stress profiles measured during surgery across 10 discs of 4 spines with no lateral curvature and with data from the literature.

Results: Profiles across scoliotic discs were very different from those measured across normal discs of a similar age. Hydrostatic pressure regions were only seen in 16/25 discs, extended only over a short distance and were displaced towards the convexity. Mean pressures were significantly greater (0.24MPa) than those measured in other anaesthetised patients (< 0.06 MPa). A stress peak in the concave annulus was a common feature (13/25) in scoliotic discs. In 21/25 discs, stresses in the concave annulus were greater than in the convex annulus, indicating asymmetric loading in these anaesthetised, recumbent patients.

Conclusions: Intradiscal pressures and stresses in scoliotic discs are abnormal even in the absence of significant applied load. Disc cells respond to changes in pressure, hydration and deformation by altering matrix synthesis and turnover in vivo and in vitro. Hence, whatever the cause of the abnormal pressures and stresses in the scoliotic discs, if present during daily life, these could lead to disc matrix changes and especially if asymmetrical, to disc wedging and progression of the scoliotic deformity.

Work supported by Fondation Cotrel

Our knowledge of the incidence of scoliosis and scoliosis surgery is based on a few small scale studies. The National Health Service (NHS) in the United Kingdom has long collected data on hospital based activity. We have used a five year English database (1998–2002) of hospital admission statistics to study age-adjusted admission rates for scoliosis (code M41 in the International Classification of Diseases, 10th revision) and for two scoliosis surgery codes (V41 ‘instrumental correction of deformity of spine’ and V42 ‘other correction of deformity of spine’ (the latter includes ‘anterolateral release of spine for correction of deformity’).

Results: Three thousand, seven hundred and eighty three patients (2533 females and 1240 males) aged 5–29 years had diagnosis M41 recorded over the five year sample period. Most of the patients were teenagers. 971 (males and females) of these had operation V41 and 1212 had V42, it is likely that the vast majority of these cases had idiopathic scoliosis. We made regional maps based on age-adjusted admission rates/100000 population. Admission rates varied from 5.75/100000 (95% confidence intervals x to y) in London to 2.8/100000 (x to y) in the Yorkshire-Humberside region.

Interpretation: There was wide geographical variation in admission rates. We considered 5 hypotheses:

Social deprivation – we were able to study this, and admission rates appeared independent of social deprivation.

Conclusion: There is wide variation in recorded rates of diagnosis and surgical treatment without obvious explanation. It might be possible to study clinical case notes, identified from the statistical database, to check whether variation is simply attributable to unreliability of coding. To determine whether there may be a genetic explanation for the geographical variation found by us, the possibility could be explored of comparing the scoliosis maps with other maps of genetic profiles of the English population.

ISIS2 is a surface topography system measuring the three-dimensional shape of the back in scoliosis patients using digital photography with structured light. Lateral asymmetry is the ISIS clinical parameter estimating the curve of the spine in the coronal plane [1]. The shape of the back changes with patient stance, breathing and muscle tension. Although ISIS2 uses bony landmark markers to minimise the effect of stance, there will still be variations from measurement to measurement. The aim of this work is to quantify the variability in lateral asymmetry measurements. The patients were asked to stand in the patient stand in a relaxed normal pose; the feet were placed just outside the blocks on the footplate, the abdomen rested lightly against the crossbar of the stand, and the arms were supported away from the sides of the body by the arm rests. Two photographs were taken with the patient walking around the room between them. The mean difference between pairs of measurements on 62 patients was 0.12°, the standard deviation was 1.64° and the 95% limits of agreement were −3.10° to 3.34°. A plot of difference against mean showed no significant evidence of a relationship between them (r = −0.10). The standard deviation for intraob-server measurement of Cobb angle has been reported as ranging from 1.4° to 3.3° [2,3,4] and clinically significant change is generally regarded as greater than 5°. This experiment shows that intraobserver variability in lateral asymmetry is thus sufficiently low to detect clinically significant changes in the curve of the spine.

An automated system has been developed to measure three-dimensional back shape in scoliosis patients using structured light. The low-cost system uses a digital camera to acquire a photograph of a patient with coloured markers on palpated bony landmarks, illuminated by a pattern of horizontal lines. A user-friendly operator interface controls the lighting and camera and leads the operator through the analysis. The system presents clinical information about the shape of the patient’s deformity on screen and as a printed report. All patient data (both photographs and clinical results) are stored in an integral database. The database can be interrogated to allow successive measurements to be plotted for monitoring the deformity.

The system is non-invasive, requiring only a digital photograph to be taken of the patient’s back. Identification of the bony landmarks allows all clinical data to be related to body axes. This reduces the effects of variability in patient stance. Measurement of a patient, including undressing, landmark marking and dressing, can be carried out in approximately 10 minutes. The clinical results presented are based on the old ISIS report. This includes:

transverse sections at 19 levels from vertebra prominens to sacrum.

Additionally, a three-dimensional wire-frame plot, a coloured contour plot and a pair of bilateral asymmetry plots give visual impressions of any deformity in the measured back.

Aim: To assess the functional outcome following spinal infection.

Method: 42 patients who had been treated in our unit for primary spinal infection between 1995–2005 were identified. 33 who were still alive at the time of study, were sent postal questionnaires. Average length of follow up was 5.4 years (rang 0.6–10.5). The non-respondents were contacted by phone two weeks later. Overall 29 (88%) were traced.

Results: Mobility score dropped in 10 (34%) patients whilst domestic circumstances’ score dropped only in 1 (3.4%). Oswestry disability score averaged 18% (range 0–53%). 16 (62%) had mild or no disability, 7(27%) had moderate and 3 (12%) had severe disability. Neck disability index in all those with cervical spine infection was between 10–20% indicating mild disability. Hospital anxiety and depression score for anxiety was normal for 25 (86%) and that for depression was normal for 27(93%) patients. Ten point Visual Analogue Score (VAS) for pain intensity when doing the questionnaire averaged 1.3 (range 0–9) with 19 (66%) having no pain, 9 (31%) mild to moderate (1–5 score) and 1 (3%) having severe pain (6–10 score). Mean VAS over one week was 1.8(range 0–9) with 14(48%) having no pain, 13(45%) mild to moderate and 2 (7%) having severe pain. VAS for distress averaged at 1.8 (range 0–9), 22 (76%) patients were coping very well (8–10 score) and poor coping (0–4 score) was seen in 1 (3%).

Conclusion: Most patients after spinal infection return to activities of daily living with little or no pain and psychological sequelae. A proportion of patients however end up with moderate to severe disability, pain and psychological problems despite successful treatment of the primary infection.

Background: The intervertebral disc and spinal ligaments contain extensive and well organised elastic fibre networks which provide these tissues with elasticity. Morphologically elastic fibres are composed of an amorphous central core consisting mainly of elastin surrounded by a microfibrillar mesh. The importance of the microfibrils has been emphasised by the clinical manifestations of Marfan Syndrome (MFS) and congenital contractual arachnodactyly (CCA) which are caused respectively by mutations of Fibrillin-1 and Fibrillin-2, the main protein components of the microfibrillar mesh. Both patients of MFS and CCA can develop a spinal deformity. Recent studies on genetically modified mice suggested that minor components of the microfibrillar mesh can also play an important role in spine development; knockout mice containing no fibulin-5, microfibrillar associated glycoprotein-2 (MAGP-2), or latent TGF-b protein 3 (LTBP-3) can all develop spinal deformity. Our aim in this study was to understand the involvement of elastic fibre system in pathogenesis of scoliosis.

Methods: Tissue from Marfan patients and adolescent idiopathic kyphoscoliotic human intervertebral discs were removed during routine surgery with consent and ethical permission. Here we report on examination of disc tissue from three Marfan’s syndrome and three AIS patients (with ethical approval), age range 13–33 years. Tissues were dissected and then snap frozen within 4 hours after surgical excision and kept in −80 OC till used. Tissue sections of 20 micron were cut with a cryostat microtome and fixed with 10% formalin before immunostaining. Microfibrils and elastin fibre network were studied by immunostaining fibrillin-1 and elastin. The collagen network was examined by using fluores-cent microscopy with a polarised light system. Spines from transgenic mice, producing no elastin or fibulin-5, were paraffin embedded and sections were stained with Haematoxylin & Eosin or Alcien Blue. The morphology of cells, vertebral body and disc matrix were studied at light microscopic level.

Results and Discussion: Our histological studies on IVD tissues from MFS and AIS patients found that the elastic fibre and collagen networks were disorganised compared to that of normal controls. Studies on spines from fibulin-5 null or elastin null mice indicated delayed ossification of the vertebral body, lower expression of proteoglycans and an abnormal growth plate. Our initial results thus indicate that the elastic fibre system has an effect on matrix synthesis in connective tissue and plays a part in regulating bone growth. They are in agreement with reports that kypho-scoliosis occurs in transgenic mice deficient in other matrix components e.g. collagen-II and perlecan. Matrix-generated regulation of spine development and vertebral body growth thus appears to play an important role in the development of scoliosis.

Study Design: Prospective randomized study.

Objectives: To compare the strategy of spinal fusion with that of rehabilitation for patients with chronic low back pain.

Methods: A multicentre trial of 349 candidates for spinal fusion (where both patient and surgeon were uncertain of the outcome) were randomised to either an operation that the surgeon considered was most appropriate for that patient or to an intensive rehabilitation programme. Rehabilitation was based on a 3 week (15 day) model of exercise therapy, spine stabilisation techniques and education using cognitive behavioural principles. Follow-up was at least 2 years from randomisation. The trial was 90% powered to show a 4 point difference between groups at α= 0.05. A full economic analysis is available.

Outcomes Measures: Oswestry Disability Index (ODI); the Shuttle Walking Test (SWT); SF-36 and EuroQol EQ-5D.

Results: 176 patients were randomized to surgery and 173 to rehabilitation. Demographic features including sex, age, diagnosis (spondylolisthesis, post-laminectomy syndrome, others) duration of back pain, smoking history, litigation, employment status, planned numbers of fused levels and baseline ODI were similar for both groups.

Results: For the surgery group the mean ODI improved from 46.6 (SD 14.5) to 34.9 (SD 21) at two years. For the rehabilitation group mean ODI improved from 44.8 (SD 14.8) to 36.2 (SD 20.6) at two years. For the surgery group the mean SWT improved from 254 (SD 209) to 350 (SD 244.8) at two years. For the rehabilitation group mean SWT improved from 247 (SD 185) to 310 (SD 203) at two years. For the surgery group the mean SF-36 Physical component score improved from 22.2 (SD 18) to 43.6 (SD 32.1) at two years. For the rehabilitation group the mean SF-36 Physical component score improved from 24.0 (SD 20.6) to 40.5 (SD 31.1) at two years.

Conclusions: This is a comparison of treatment strategies: There was no clinical or statistical difference in outcome between the strategy of spinal fusion and that of rehabilitation. Patients randomised to surgery (spinal stabilisation) and patients randomised to rehabilitation have indicated a treatment effect, but this may be due to natural history. The surgery results parallel those reported in other trials. At two years the treatment costs of the surgery arm were approximately twice those of the rehabilitation arm. The costs of rehabilitation depend on how many patients opt for surgery (22% in this trial). “Failed” non-operative treatment is commonly listed as an indication for surgery. “Failed” non-operative treatment should include intensive rehabilitation appropriately supported by the treating surgeon.

Study Design: A six-year retrospective analysis of all instrumented spinal fusions performed in the Nuffield Orthopaedic Centre and the John Radcliffe Hospital.

Objective: To assess the incidence of infection following instrumented spinal fusion, the nature of the infecting organisms and their subsequent management.

Subjects: All patients who had undergone removal of spinal metalwork were analysed for evidence of infection. The indications for removal of metalwork included proven deep infection, refractory postoperative pain or planned removal after thoraco-lumbar fracture.

Outcome Measures: Successful treatment of infection was documented when the patient was asymptomatic and inflammatory markers remained within normal limits following cessation of antibiotic therapy. Failure was documented when the patient had recurrent sepsis, refractory pain following removal of metalwork or died.

Results: 80 spinal infections following instrumented fusions were found between 1997 and 2003. 34 of the infecting organisms were propionibacteria, 19 were coagulase negative staphylococcus, 10 were staphylococcus aureus, 8 were methicillin resistant staphylococcus aureus, 3 were coliforms, 2 were proteus, 2 were diphtheroids, 1 was alpha haemolytic streptococcus and 1 was anaerobic streptococcus. 29 of these infections were polymicrobial. Of 55 patients who had metalwork removed secondary to pain, 20 patients had proven infection postoperatively (36.3%). Preoperative inflammatory markers failed to accurately predict the presence of infection for trauma patients. Our management of infection is removal of metalwork with six intraoperative samples sent for culture and histology specimens, followed by administration of at least six weeks of intravenous or oral antibiotic, depending on the organism and its antibiotic sensitivity. Prolonged treatment is used where inflammatory markers remain raised.

Conclusions: Infection of spinal implants presents different management problems to those which follow infected total joint replacement. The lack of specific clinical, laboratory and radiological findings in patients who are subsequently diagnosed as having infections associated with spinal instrumentation presents a challenging clinical problem. We found the most predictive sign of infection following instrumented fusion of scoliotic spines was postoperative pain. CRP and ESR were unreliable as predictors of infection.

Study Design: Prospective cohort study

Objective: To assess the ‘red flag’ symptom of night pain as an indicator for serious disease in patients attending a back pain triage clinic (BPTC).

Summary of Background Data: Although common in patients with known serious pathology, the prevalence of night pain in this population is not known.

Methods: 482 consecutive patients attending BPTC were assessed (including history of frequency and duration of night pain). Clinical examination was performed and demographic data obtained. MRI was performed if indicated according to local guidelines.

Outcome measures: Oswestry (ODI), Visual Analogue Scales (for pain, distress and coping) and Hospital Anxiety Depression (HAD) patient based outcome scores were obtained. Serious pathology was defined as infection or tumour as per AHCPR Guidelines (1994) which state that these symptoms are associated with severe night time pain.

Results: 213 patients had night pain with 90 having pain every night. No serious pathology was identified. Patients with night pain had 4.95 hours continuous sleep (2–7) and were woken 2.5 times/night (0–6). Patients with pain every night exhibited higher ODI and HAD scores than those that did not.

Conclusions: Although it is a significant and disruptive symptom for patients, these results challenge the sensitivity of the presence of night pain per se as a useful diagnostic indicator for serious spinal pathology in a back pain triage clinic.

Introduction and Aims: A multicentre trial of 349 patients of candidates for spinal fusion (where both patient and surgeon were uncertain of the outcome) were randomised to either an operation or to an intensive rehabilitation program. Rehabilitation was based on a three-week (15-day) model of exercise therapy and education using cognitive behavioural principles.

Method: The main outcome measures were the Oswestry Disability Index (ODI); Shuttle Walking Test; SF-36 and EuroQol EQ-5D recorded at baseline and six, 12 and 24 months after randomisation. The trial was 90%-powered to show a four-point ODI difference between groups at a= 0.05. Full economic analysis is available.

Results: Patients in both treatment arms made statistically significant improvements on all outcome measures between baseline and two-year follow-up. There was a small difference between the treatment arms favouring surgery on one of the main outcome measures, the Oswestry Disability Index; there were no statistically significant differences between the two treatment strategies for the rest. The difference in the change of score for the ODI was a decrease of 3.2 (C.I -7.3 – 0.9) in favour of surgery (p< 0.1), an improvement of 30 metres on the shuttle walking test in favour of the surgery group (p< 0.2), a difference of 0.01 on the Euroqol (p< 0.9) and an increase of 2.7 points on the SF-36 (p< 0.4).

The surgery results parallel those reported in other trials. At two years, the treatment costs of the surgery arm were approximately twice those of the rehabilitation arm. The costs of the rehabilitation strategy depend on how many patients opt to have surgery after rehabilitation (22% in this trial). This is a comparison of treatment strategies: there was no clinical or statistical difference in outcome between the strategy of spinal fusion and rehabilitation.

Conclusion: Patients randomised to both surgery (spinal stabilisation) and rehabilitation have indicated a treatment effect, but this may be due to natural history. ‘Failed’ non-operative treatment is commonly listed as an indication for surgery, this should only be considered once an intensive rehabilitation program backed by the treating surgeon has been tried.

Background and Purpose: Intervertebral discs are the largest avascular tissue sources in the human body. The transport of vital nutrients and oxygen into and metabolic waste products out of the disc, relies mainly on the diffusion through the disc matrix. The health or degree of degeneration of the disc is thought to be directly related to the transport properties of the disc. The diffusivity of nutrients and metabolites varies with matrix composition and especially with matrix hydration. The hydration of the disc varies by approximately 25% in the normal 24hour loading cycle of human beings. This work addresses the question of the effect of hydration of the disc tissue on the solute diffusivity.

Methods: Measurements of the diffusion of solutes were performed in ca. 2year bovine caudal discs. Diffusivity of dissolved oxygen and nitrous oxide was monitored electrochemically. Diffusivity of 0.05 to 70kDa solute species was determined by measuring concentration gradients using either fluorescent or radiotracers. Hydration was controlled by either mechanical static load or by osmotic equilibration.

Results: Diffusion rates varied with solute molecular weight (MW), decreasing steeply with an increase in MW. For small solutes, the diffusivity was greater in the nucleus than the outer annulus, but this difference was insignificant for the larger solutes. Diffusivity changed by a significant amount with hydration changes, which were significantly affected by loading. Application of a 0.2MPa mechanical load led to a drop in hydration of the outer annulus and nucleus of 33.3% and 42.1% and corresponding falls in diffusivity of glucose of 34.0% and 81.3% respectively.

Conclusions: The large changes in hydration experienced during normal loading of the spine have a marked effect on nutrient and metabolite diffusivity. This effect has not been considered previously but could significantly influence supply of nutrients to the disc cells.

Objective: To assess whether Webb Morley Instrumentation had satisfactory long term results.

Design: A retrospective review of 52 patients who underwent fusion and instrumentation with Webb Morley Instrumentation between 1991–1997.

Subjects: 52 patients were reviewed, 32 patients with idiopathic scoliosis who underwent isolated anterior fusion, 19 patients with neuromuscular scoliosis who underwent anterior and posterior surgery.

Outcome measures: Preoperative and postoperative radiographs, ISIS scans, and patient review. The in-patient notes were assessed for duration of surgery, blood loss, hospital stay and complications. Correction of Cobb angle and union were assessed.

Results: In the idiopathic group Cobb angle improved by 57%, apical rotation by 36% and tilt angle by 56%. There were no major complications and all united. The implant has a tendency to kyphose the spine, and an average of 7 degrees of kyphosis was seen across the implant. In the neuromuscular group Cobb angle improved by 52%, apical rotation by 21% and tilt angle by 57%. There was one asymptomatic pseudarthrosis, two rod breakages and two posterior rod dissociations. Only one patient complained of significant back pain.

Conclusions: Webb Morley instrumentation offers results as good as most other anterior implant systems. The flexibility of the rods may be a relative advantage, with a high union rate. Although the implant tends to kyphose the spine this has not been a problem clinically at follow-up of 4-11 years. This may help in design of future implants.

Objective: To assess the cardiology of continuous ECG of Spinal Surgeons performing complex spinal deformity surgery.

Design: Spinal surgeons were attached to 24 hour tape ECG monitors while performing spinal deformity surgery. Pre op, intra-op and immediate post op assessment were performed.

Subjects: 4 Consultants 1 Spinal Fellow

Outcome measures: ECG changes, Heart Rate variance and Heart Rate

Results: Variability in Heart rate was related to the experience of the surgeon and the case performed.

Heart rate variance was highest in the Consultant with the most recent appointment. Heart rate variance in the Trainee was the lowest. The highest heart rate was achieved when scrubbed supervising the surgical trainee. The surgeons with the highest deformity work load had the lowest intra-operative heart rate

Conclusions: Spinal deformity surgery is stressful to the Consultant performing the case. Experience and case mix affect these findings. The highest stress rate occurs with supervising trainees.

Background. Neurogenic claudication is a well recognised symptom of spinal stenosis. Pain in the lower limbs and back limit walking speed and distance. Outcome of treatment should be easily measurable, but in practice is not. Walking tests are difficult to perform reliably. It is possible to measure speed and endurance with a treadmill, but this is expensive, of doubtful reliability, and many elderly patients are reasonably worried about falling off. Commonly used back pain outcome questionnaires are probably invalid for this population, and few questionnaires have been designed specifically for this complaint. The purpose of this study was to evaluate 3 questionnaires (Swiss Spinal Stenosis Score (SSS), Oxford Claudication Score (OCS) and Oswestry Disability Index (ODI)) and a Shuttle Walking Test (SWT). The Shuttle Walking Test, developed originally in respiratory medicine, shows promise as both a clinical measure and outcome measure for patients with neurogenic claudication. In an internal study, we have found that none of our patients selected for surgery can manage more than 200 metres. A fit adult can usually manage about 600 metres on this test.

Study Design: Shuttle Walking Test (SWT), Swiss Spinal Stenosis Score (SSS), Oxford Claudication Score (OCS) and Oswestry Disability Index (ODI) were administered to patients with lumbar spinal stenosis (LSS) and neurogenic claudication.

Objective: To determine reliability of SWT, SSS (Q1–12), OCS and ODI in LSS assessment.

Methods: Thirty two clinic patients with LSS were assessed twice with one week between assessments to determine reliability. Retrospective data from 17 patients assessed before and 18 months after surgery for LSS were used to investigate use of reliability in a clinical setting.

Results: Test-retest reliability was 0.92 for SWT, 0.92 for SSS, 0.83 for OCS and 0.89 for ODI (Intraclass correlation coefficient). Mean scores (percent) were SSS 51, OCS 45 and ODI 40. For 95% certainty of change between assessments for a single patient, SSS would need to change by 15, OCS by 20 and ODI by 16. Mean SWT was 150m, with change of 76m required for 95% confidence. Cronbach’s alpha was 0.91 for SSS, 0.90 for OCS and 0.89 for ODI. Change in ODI correlated most strongly with patient satisfaction after surgery (_=0.80, p< 0.001).

Conclusions: Fluctuations in patient’s symptoms result in wide individual confidence intervals. Performance of SSS, OCS and ODI questionnaires are broadly similar. The condition specific SSS is most precise but not much better than the non-specific ODI. SWT gives a snapshot of physical function which is acceptable for group analysis. Use of SWT for individual assessment after surgery is feasible but multiple testing would improve sensitivity for change.

Introduction: Although the cell density of the intervertebral disc is low, cells perform a vital role, being responsible for maintaining and remodelling the extracellular matrix. In animal models of scoliosis, cell viability of epiphyseal chondrocytes was found to be adversely affected. Here we examine cell density and viability of surgical disc specimens.

Method: A total of 41 discs were removed from 13 consenting patients (3M, 9F, 5–40 yrs) during corrective surgery for scoliosis. Control samples were obtained from 3 non-scoliotic discs. These were further dissected to compare the outer annulus of the disc from the more concave and more convex sides of the quadrant removed at surgery. Cell density was measured using a modified Hoechst’s method. Cell viability was determined microscopically in sections using intracellular fluorescent probes.

Results: Cell density was found to be lowest in apical discs, independent of absolute disc level (p< 0.01, Student’s t test). A significantly lower percentage of live cells was found in samples taken from the convex side of the scoliotic curve (p< 0.01, Student’s t test). No significant differences in cell viability were found in either side of control discs.

Discussion: Cell viability was seen to be lower on the convex side of the scoliotic curve, suggesting that it is more difficult for cells to survive under the conditions on the convexity compared with the concavity. This may be due to differences in the mechanical conditions or the diffusion distances across the disc. Cell numbers were lowest in the apical disc, where stresses are thought to be maximal. Fewer viable cells may decrease production of matrix macromolecules, and thus compromise matrix integrity. A delicate balance exists between production and breakdown of matrix macromolecules, and any factor that interrupts this equilibrium state has the potential to affect the structure and function of the intervertebral disc.

Scoliosis is a disease characterised by vertebral rotation, lateral curvature and changes in sagittal profile. The role of mechanical forces in producing this deformity is not clear. It is thought that abnormal loading deforms the disc, which becomes permanently wedged. Modelling and in vitro studies suggest that such deformations should increase intradiscal pressure. Intradiscal pressure has been measured previously in a variety of clinical environments. The aim of this study is to measure pressure profiles across scoliotic discs to provide further information on the role of mechanical forces in scoliosis.

Pressure readings were obtained in consented patients with ethical approval using a needle-mounted sterilised pressure transducer (Gaeltec, Dunvegan, Isle of Skye) calibrated as described previously. The transducer needle was introduced into the disc of an anaesthetised patient during routine anterior scoliosis surgery and pressure profiles measured. Signals were collected, amplified and analysed using Power-lab and a laptop computer.

Pressure profiles across 10 human scoliotic discs from 3 patients have been measured to date. Pressures varied from 0.1 to 1.2 MPa.

Annular pressures showed high pressure, non-isotropic regions on the concave but not convex side of these discs.

Nuclear pressures recorded from the discs of these scoliotic patients were higher than those recorded previously in non-scoliotic recumbent individuals.

Glycosaminoglycans (GAGs) govern the osmotic environment of cartilaginous tissues and hence determine their ability to resist the large compressive forces encountered during normal activity. In degeneration GAGs are lost and there is now much interest in biological repair processes where cells from cartilaginous tissues synthesise replacement GAGs and other matrix components in situ. In addition, cells can be grown in tissue engineered constructs. Unfortunately, GAG synthesis is slow.

The aim of this study was to determine whether GAG accumulation could be hastened by increasing cell density in a construct using articular cartilage and intervertebral disc cells cultured in alginate beads.

Bovine chondrocytes and intervertebral disc cells were placed in alginate bead suspension at varying cell densities. GAG synthesis rates, total GAG accumulation and lactate production rates were determined by standard methods. The cell viability profile across intact beads was determined using fluorescent probes.

Increasing cell density causes a reduction in lactate production and sulphate incorporation per million live cells. At greater than 20 million cells per ml, cell death is increased compared with lower densities. GAG produced per bead is not increased in proportion to increasing cell density.

These results show that there is a limit to the rate at which matrix per volume of tissue can be produced and accumulated. At high cell densities cellular activity is limited by toxicity arising from low pH and hypoxia.

Instability may present at a different level after successful stabilisation of an unstable segment in apparently isolated injuries of the cervical spine. It can give rise to progressive deformity or symptoms which require further treatment. We performed one or more operations for unstable cervical spinal injuries on 121 patients over a period of 90 months. Of these, five were identified as having instability due to an initially unrecognised fracture-subluxation at a different level. We present the details of these five patients and discuss the problems associated with their diagnosis and treatment.

Mechanical abnormalities of the patellofemoral joint are among the many causes that have been suggested for adolescent knee pain. This study seeks to identify these factors. Measurements of joint mobility and lower limb morphology were made on 446 pupils at a comprehensive school, 136 of whom had suffered knee pain in the previous year. The pupils with symptoms enjoyed sporting activities significantly more than their symptom-free contemporaries. Joint mobility, the Q-angle, genu valgum and anteversion of the femoral neck were not significantly different between those pupils with and those without anterior knee pain. Data on lower limb morphology of normal adolescents are presented. Examination of 52 hospital outpatients aged 13 to 36 years with anterior knee pain produced results comparable with those for the pupils. It is concluded that chronic overloading, rather than faulty mechanics, is the dominant factor in the genesis of anterior knee pain in adolescent patients.