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.