Background

FORECAST is a prospective longitudinal cohort study exploring mechanism-based prognostic factors for pain persistence in sciatica. Here, we share an update on this largest deeply-phenotyped primary care sciatica cohort.

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.

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.

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