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The generic approach of the Spine Tango documentation system, which uses web-based technologies, is a necessity for reaching a maximum number of participants. This, in turn, reduces the potential for customising the Tango according to the individual needs of each user. However, a number of possibilities still exist for tailoring the data collection processes to the user's own hospital workflow. One can choose between a purely paper-based set-up (with in-house scanning, data punching or mailing of forms to the data centre at the University of Bern) and completely paper-free online data entry. Many users work in a hybrid mode with online entry of surgical data and paper-based recording of the patients' perspectives using the Core Outcome Measures Index (COMI) questionnaires. Preoperatively, patients can complete their questionnaires in the outpatient clinic at the time of taking the decision about surgery or simply at the time of hospitalisation. Postoperative administration of patient data can involve questionnaire completion in the outpatient clinic, the handing over the forms at the time of discharge for their mailing back to the hospital later, sending out of questionnaires by post with a stamped addressed envelope for their return or, in exceptional circumstances, conducting telephone interviews. Eurospine encourages documentation of patient-based information before the hospitalisation period and surgeon-based information both before and during hospitalisation; both patient and surgeon data should be acquired for at least one follow-up, at a minimum of three to six months after surgery. In addition, all complications that occur after discharge, and their consequences should be recorded.

A case of ganglioneurocytoma of the spinal cord in a 51-year-old man is reported. Patient presented with a progressively worsening back pain and hyposthenia of lower limbs. Magnetic resonance imaging of the spinal cord revealed an intradural lesion in the T10-11 spinal segments, hyperintense on T1-weighted sequences. Complete resection was achieved. The patient did not show evidence of recurrence 12 months after surgery. On histology, the lesion was composed of round to oval cells with fine granular, slightly eosinophilic to clear cytoplasm suggesting a neurocytic differentiation. Some ganglion cells were observed. Neither significant cytologic atypia nor mitoses were present. The neoplastic cells were strongly positive with synaptophysin and negative with glial fibrillary acid protein. Neurocytomas are uncommon tumors typically arising within the lateral ventricles near the foramen of Monro. Extraventricular neurocytomas have been reported at various sites with rare examples in spinal cord. In the present paper, a case of ganglioneurocytoma of the spinal cord is reported with review of literature and discussion of differences compared to neurocytomas of other sites.

This is a case report of a 15-month-old patient with osteogenesis imperfecta (OI) who sustained atlanto-axial dislocation. Our objective is to report a unique case of traumatic atlanto-axial subluxation in a child with osteogenesis imperfecta associated with bilateral femoral fractures. The management is discussed. Atlanto-axial dislocation occurring with associated osteogenesis imperfecta is very rare. There have been no previous reported cases. A 15-month-old girl with osteogenesis imperfecta sustained a traumatic atlanto-axial dislocation. The child was followed-up through presentation, diagnosis, management and post-discharge. The initial diagnosis was confirmed with a CT scan. The patient was treated conservatively with a halo-traction for 4 weeks followed by a halo jacket for a further 4 weeks. Both appliances were fitted under general anaesthetic. An anatomical reduction was achieved. There was no neurological deficit at any stage. The child has had a successful outcome. She is asymptomatic with a full range of movement at the atlanto-axial joints at 9 months. In conclusion, this paper records our management of this rare problem.

The aim of this paper is to provide a complete overview of the existing methods for quantitative evaluation of spinal curvature from medical images, and to summarize the relevant publications, which may not only assist in the introduction of other researchers to the field, but also be a valuable resource for studying the existing methods or developing new methods and evaluation strategies. Key evaluation issues and future considerations, supported by the results of the overview, are also discussed.

Pelvic girdle pain (PGP) has a high incidence during pregnancy and in some women pain will persist for years. Most studies have used pain as the outcome measure, and little attention is given to functioning or disability. A better understanding of prognostic factors for recovery seems important for clinical care and treatment. The aim of the present paper was to identify prognostic factors for recovery from postpartum PGP and disability, and to determine the impacts of prognostic factors when pain intensity and disability are used as outcome measures. Seventy-eight women with diagnosed PGP were included 6-16 weeks postpartum. Possible prognostic factors were obtained through clinical tests and questionnaires at baseline. The clinical tests were posterior pelvic pain provocation (P4) test, active straight leg raise (ASLR) test and pain provocation of long dorsal sacroiliac ligament (LDL). One year postpartum outcome measures were obtained by Oswestry disability index (ODI ver 2.0) and worst evening pain (VAS 0-100). Multiple linear regression and logistic regression analyses were used to identify significant prognostic factors. At baseline 60% believed they would recover and 40% were uncertain or believed they would not recover. Fifty per cent had a history of low back pain (LBP), and 20% had high emotional distress (HSCL25-item > or =1.75). About 75% had positive LDL and P4 at both sides and 24% had pain located to all three pelvic joints. Forty per cent had ASLR scores of at least 4 (sum score range 0-10). Multivariate analyses showed consistently that ASLR and belief in improvement were statistical significant predictors for both disability and pain as outcome measures. ASLR score <4 predicted 10 points lower ODI and 19 points lower evening pain compared with having ASLR score of at least 4. Pain location was a statistical significant predictor in only one analysis. History of LBP or high psychological distress was not prognostic for recovery. ASLR test and belief in improvement are predictors of clinical significance in women having PGP postpartum.

Elastic fibres are critical constituents of dynamic biological structures that functionally require elasticity and resilience. The network of elastic fibres in the anulus fibrosus of the intervertebral disc is extensive, however until recently, the majority of histological, biochemical and biomechanical studies have focussed on the roles of other extracellular matrix constituents such as collagens and proteoglycans. The resulting lack of detailed descriptions of elastic fibre network architecture and mechanical function has limited understanding of the potentially important contribution made by elastic fibres to healthy disc function and their possible roles in the progression of disc degeneration. In addition, it has made it difficult to postulate what the consequences of elastic fibre related disorders would be for intervertebral disc behaviour, and to develop treatments accordingly. In this paper, we review recent and historical studies which have examined both the structure and the function of the human lumbar anulus fibrosus elastic fibre network, provide a synergistic discussion in an attempt to clarify its potentially critical contribution both to normal intervertebral disc behaviour and the processes relating to its degeneration, and recommend critical areas for future research.

The ankylosed spine is prone to fracture after minor trauma due to its changed biomechanical properties. Although many case reports and small series have been published on patients with ankylosing spondylitis (AS) suffering spine fractures, solid data on clinical outcome are rare. In advanced diffuse idiopathic skeletal hyperostosis (DISH), ossification of spinal ligaments also leads to ankylosis. The prevalence of AS is stable, but since DISH may become more widespread due to its association with age, obesity and type 2 diabetes mellitus, a systematic review of the literature was conducted to increase the current knowledge on treatment, neurological status and complications of patients with preexisting ankylosed spines sustaining spinal trauma. A literature search was performed to obtain all relevant articles concerning the outcome of patients with AS or DISH admitted with spinal fractures. Predefined parameters were extracted from the papers and pooled to study the effect of treatment on neurological status and complications. Ninety-three articles were included, representing 345 AS patients and 55 DISH patients. Most fractures were localized in the cervical spine and resulted from low energy impact. Delayed diagnosis often occurred due to patient and doctor related factors. On admission 67.2% of the AS patients and 40.0% of the DISH patients demonstrated neurologic deficits, while secondary neurological deterioration occurred frequently. Surgical or nonoperative treatment did not alter the neurological prospective for most patients. The complication rate was 51.1% in AS patients and 32.7% in DISH patients. The overall mortality within 3 months after injury was 17.7% in AS and 20.0% in DISH. This review suggests that the clinical outcome of patients with fractures in previously ankylosed spines, due to AS or DISH, is considerably worse compared to the general trauma population. Considering the potential increase in prevalence of DISH cases, this condition may render a new challenge for physicians treating spinal injuries.

The aim of this study was to test the hypothesis that imbalance in patients with a severe deformity of the spine is associated with an increase in the sensory integration disorder. This paper is a case comparison study. Patients were divided into three groups: able-bodied (n = 53), observation (n = 23), and pre-brace (n = 26) groups. Time domain parameters (sway area, position and displacement) and structural posturographic parameters [mean distance (MD) and mean peak (MP)] were calculated from the COP excursion using a force platform. A sensory integration disorder could be an important factor in the progression of the scoliotic curve. Significant differences were found in time domain between observation, pre-brace and able-bodied groups. The results for the structural posturographic parameters showed significant differences between the pre-brace and the able-bodied groups (P = 0.018 MD and P = 0.02 MP) demonstrating a perturbation in sensory integration system by an increase of imbalance. The absence of statistical difference between the observation and the pre-brace groups for the structural posturographic parameters indicates a perturbation of sensory integration system associated with curve progression. Our study has demonstrated that the pre-brace group is less stable than the able-bodied group. The severity of scoliosis in pre-brace scoliotic girls could be related to an increase in the sensory integration disorder.

It is a measurement of Cobb's angles between adolescent (AIS) and juvenile (JIS) idiopathic scoliosis who had stable curves (variation <5 degrees) in more than three visits. Main objective of this paper is to measure inter- and intra-observer reliability of measurements between AIS and JIS who had stable curves in regular follow-up. Twenty-nine JIS and 44 AIS patients who had stable curves without bracing were identified using PACS system. Two observers independently measured Cobb's angle twice on first, during follow-up and final radiogram using computer-based digital radiogram. Both observers were given pre-decided level of upper and lower end plates. Inter- and intra-observer reliability of the measurement was calculated using Pearson correlation-coefficient test between JIS and AIS group. There was no significant difference in Cobb's angle in all measurements by both observers either in JIS (p = 0.756, range 0.706-0.815; ANOVA) or AIS (p = 0.871, range 0.795-0.929; ANOVA) group which suggested that there is no significant difference in Cobb's angle in repeated measurements. Intra-observer reliability for JIS (r = 0.600, range 0.521-0.751; Pearson test) was less than AIS (r = 0.969, range 0.943-0.984; Pearson test); and similarly, inter-observer reliability for JIS (r = 0.547, Pearson test) was also less than AIS (r = 0.961, Pearson test) which indicates that Cobb's angle measurement is less reliable in patients who have juvenile idiopathic scoliosis. Using the identical condition for measurements in both the groups, we could find only one reason for less reliability in JIS group and that is poor demarcation of the vertebral end-plates in this group. This poor inter- and intra-observer reliability in JIS due to ill-defined endplates can be reduced by measuring all previous curves along with latest curves at the same time during the follow-up of patients with JIS to decide about the progression of curves and treatment options.

Recent basic science studies on discogenic low back pain have provided new knowledge about this condition. This paper reviews some of these results and presents an overview of the following findings. The rat lumbar intervertebral disk may be innervated non-segmentally through the paravertebral sympathetic nerve and segmentally through the sinuvertebral nerves, and also by dichotomizing sensory fibers. The exposure of the nucleus pulposus (NP) to the outer annulus fibrosus (AF) may induce nerve injury and ingrowth into the disk. Nerve growth factor (NGF)-sensitive neurons are predominant in the rat intervertebral disk, which indicates that hyperalgesic responses can be induced by inflammation. NGF in the NP may promote axonal growth. Lumbar fusion may inhibit nerve ingrowth into the degenerated disk and reduce the percentage of calcitonin gene related peptide (CGRP)-positive neurons.

The implantation of lumbar disc prostheses based on different design concepts is widely accepted. This paper reviews currently available literature studies on the biomechanics of TDA in the lumbar spine, and is targeted at the evaluation of possible relationships between the aims of TDA and the geometrical, mechanical and material properties of the various available disc prostheses. Both theoretical and experimental studies were analyzed, by a PUBMED search (performed in February 2007, revised in January 2008), focusing on single level TDA. Both semi-constrained and unconstrained lumbar discs seem to be able to restore nearly physiological IAR locations and ROM values. However, both increased and decreased ROM was stated in some papers, unrelated to the clinical outcome. Segmental lordosis alterations after TDA were reported in most cases, for both constrained and unconstrained disc prostheses. An increase in the load through the facet joints was documented, for both semi-constrained and unconstrained artificial discs, but with some contrasting results. Semi-constrained devices may be able to share a greater part of the load, thus protecting the surrounding biological structure from overloading and possible early degeneration, but may be more susceptible to wear. The next level of development will be the biomechanical integration of compression across the motion segment. All these findings need to be supported by long-term clinical outcome studies.

It is a retrospective analytic study of 1,009 transpedicular screws (689 thoracic and 320 lumbosacral), inserted with free-hand technique in neuromuscular scoliosis using postoperative CT scan. The aim of paper was to determine the accuracy and safety of transpedicular screw placement with free-hand technique in neuromuscular scoliosis and to compare the accuracy at different levels in such population. All studies regarding accuracy and safety of pedicle screw in scoliosis represent idiopathic scoliosis using various techniques such as free-hand, navigation, image intensifier, etc., for screw insertion. Anatomies of vertebrae and pedicle are distorted in scoliosis, hence accurate and safe placement of pedicle screw is prerequisite for surgery. Between 2004 and 2006, 37 consecutive patients, average age 20 years (9-44 years), of neuromuscular scoliosis were operated with posterior pedicle screw fixation using free-hand technique. Accuracy of pedicle screws was studied on postoperative CT scan. Placement up to 2 mm medial side and 4 mm lateral side was considered within-safe zone. Of the 1,009 screws, 273 screws were displaced medially, laterally or on the anterior side showing that 73% screws (68% in thoracic and 82.5% in lumbar spine) were accurately placed within pedicle. Considering the safe zone, 93.3% (942/1009, 92.4% in thoracic and 95.3% in lumbar spine) of the screws were within the safe zone. Comparing accuracy according to severity of curve, accuracy was 75% in group 1 (curve <90 degrees ) and 69% in group 2 (curve >90 degrees) with a safety of 94.8 and 91.2%, respectively (P = 0.35). Comparing the accuracy at different thoracic levels, it showed 67, 64 and 72% accuracy in upper, middle and lower thoracic levels with safety of 96.6, 89.2 and 93.1%, respectively, exhibiting no statistical significant difference (P = 0.17). Pedicle screw placement in neuromuscular scoliosis with free-hand technique is accurate and safe as other conditions.

Disc degeneration is a common disorder. Although the back pain that can develop in association with this is rarely life-threatening, the annual cost in terms of morbidity, lost productivity, medical expenses and workers' compensation benefits is significant. Surgical intervention as practised currently is directed towards removing the damaged or altered tissue. Development of new treatment modalities is critical as there is a growing consensus that the strategies used currently for symptomatic degenerative disc disease may not be effective. Accordingly, there is a need to develop an entirely new way to treat this disorder; regenerative medicine and tissue engineering approaches appear particularly promising in this regard. This paper reviews some of the challenges that currently are limiting the clinical application of this approach to the treatment of disc degeneration.

Scaffolds represent important components for tissue engineering. However, researchers often encounter an enormous variety of choices when selecting scaffolds for tissue engineering. This paper aims to review the functions of scaffolds and the major scaffolding approaches as important guidelines for selecting scaffolds and discuss the tissue-specific considerations for scaffolding, using intervertebral disc as an example.

Spine surgeons are becoming increasingly aware of sacral insufficiency fractures as a complication after lumbosacral fusions. We present four patients who suffered from sacral fractures after multi-segmental posterior lumbosacral fusion together with a systematic review of the literature that yielded six papers reporting on 12 cases. Summarizing these 16 cases, the typical patient suffering from this complication is a female, elderly individual [66.4 +/- 12.3 (mean +/- SD) years of age, 95% confidence interval 57.89-71] undergoing multilevel fusion of 4.9 +/- 3.4 (95% CI 3.1-6.8) segments. Due to nonspecific clinical complaints and inconclusive imaging there has been a median delay in diagnosis of 5 (IQR 3-6, range 1-49) weeks after onset of pain. It remains unclear whether this complication is rare or rather under-diagnosed. Fortunately, these fractures are predominantly benign conditions that respond well to conservative management in the majority of cases, depending on location.

With an official life time of over 5 years, Spine Tango can meanwhile be considered the first international spine registry. In this paper we present an overview of frequency statistics of Spine Tango for demonstrating the genesis of questionnaire development and the constantly increasing activity in the registry. Results from two exemplar studies serve for showing concepts of data analysis applied to a spine registry. Between 2002 and 2006, about 6,000 datasets were submitted by 25 centres. Descriptive analyses were performed for demographic, surgical and follow-up data of three generations of the Spine Tango surgery and follow-up forms. The two exemplar studies used multiple linear regression models to identify potential predictor variables for the occurrence of dura lesions in posterior spinal fusion, and to evaluate which covariates influenced the length of hospital stay. Over the study period there was a rise in median patient age from 52.3 to 58.6 years in the Spine Tango data pool and an increasing percentage of degenerative diseases as main pathology from 59.9 to 71.4%. Posterior decompression was the most frequent surgical measure. About one-third of all patients had documented follow-ups. The complication rate remained below 10%. The exemplar studies identified "centre of intervention" and "number of segments of fusion" as predictors of the occurrence of dura lesions in posterior spinal fusion surgery. Length of hospital stay among patients with posterior fusion was significantly influenced by "centre of intervention", "surgeon credentials", "number of segments of fusion", "age group" and "sex". Data analysis from Spine Tango is possible but complicated by the incompatibility of questionnaire generations 1 and 2 with the more recent generation 3. Although descriptive and also analytic studies at evidence level 2++ can be performed, findings cannot yet be generalised to any specific country or patient population. Current limitations of Spine Tango include the low number and short duration of follow-ups and the lack of sufficiently detailed patient data on subgroup levels. Although the number of participants is steadily growing, no country is yet represented with a sufficient number of hospitals. Nevertheless, the benefits of the project for the whole spine community become increasingly visible.

Over the last couple of years the European Spine Journal has become truly international with papers from all over the world, and at the same time it has increased its size. Professor Mulholland has selected and reviewed some 40 papers from over 200 published in 2007 and that he felt were of particular interest to practicing surgeons and would influence their management of patients, or papers that challenged established beliefs. Papers dealing with back pain, spondylolysis, tumors, spinal stenosis, spinal infection, clinical examination, lumbar disc herniation, spinal fractures, etc. are reviewed and their significance assessed. The aim of the review is to encourage readers to read the papers themselves, hopefully stimulated by the trenchant comments of the reviewer, both critical and laudatory.

Intervertebral disc (IVD) degeneration is an often investigated pathophysiological condition because of its implication in causing low back pain. As human material for such studies is difficult to obtain because of ethical and government regulatory restriction, animal tissue, organs and in vivo models have often been used for this purpose. However, there are many differences in cell population, tissue composition, disc and spine anatomy, development, physiology and mechanical properties, between animal species and human. Both naturally occurring and induced degenerative changes may differ significantly from those seen in humans. This paper reviews the many animal models developed for the study of IVD degeneration aetiopathogenesis and treatments thereof. In particular, the limitations and relevance of these models to the human condition are examined, and some general consensus guidelines are presented. Although animal models are invaluable to increase our understanding of disc biology, because of the differences between species, care must be taken when used to study human disc degeneration and much more effort is needed to facilitate research on human disc material.

In this paper authors present two cases of multiple schwannomas without the features of neurofibromatosis (NF). The authors retrospectively reviewed the hospital charts, radiology films, operative notes and pathology slides of these two patients. There was no family history of neurofibromatosis. The two patients had contrast enhanced MRI, which was negative for vestibular schwannomas. Both underwent surgical excision of symptomatic lesions. Histopathology confirmed these lesions as schwannomas. Molecular genetic analysis in case 1 demonstrated two distinct mutations of the NF2 gene in two different schwannomas, with concomitant loss of heterozygosity in both tumours. In contrast peripheral blood lymphocytes did not reveal mutations of NF2. The authors recommend surgery for symptomatic lesions. Asymptomatic tumours can be monitored. Regular follow up is essential as they may develop fresh lesions at any time. The relevant literature is discussed.

Lumbar radicular pain is a fairly common health problem, yet its risk factors are far from clear. There are no published systematic reviews on associations between cardiovascular or lifestyle risk factors and lumbar radicular pain or sciatica. The aim of this systematic literature review was to assess associations between these risk factors and lumbar radicular pain or sciatica. We conducted a systematic search of the Medline database for all original articles on lumbar radicular pain or sciatica published until August 2006. Twenty-two papers from 19 studies were included in the review. Overweight or obesity was associated with sciatica in most of the case-control and cohort studies. Some studies showed an increased risk of lumbar radicular pain in smokers with a long smoking history or in those with high levels of physical activity. A few case-control studies showed an association between serum C-reactive protein and sciatica. No consistent associations were found for serum lipids levels or high blood pressure. In summary, the associations of overweight, long smoking history, high physical activity and a high serum C-reactive protein level with lumbar radicular pain or sciatica were substantiated by the present review. However, more prospective studies are needed in order to further clarify these associations and the mechanisms of action.

The development of Charcot's arthropathy of the spine secondary to spinal cord injury is rare and reports in the literature concerning it's surgical management are limited. Arthrodesis is the recommended treatment for painful and unstable neuropathic joints. Traditionally this involves extensive debridement of the affected joint with anterior and posterior instrumented fusion and autograft to bridge the defect. This paper reviews the reported surgical management of post-traumatic spinal neuroarthropathy in the recent literature and presents a case where sound fusion was achieved by a shortening osteotomy and end-to-end apposition of the fresh bleeding bony surfaces of the adjacent vertebral bodies. The patient reported marked improvement of symptoms post-operatively without any complications of surgery. CT scan at 13 months confirmed successful bony union. Clinical follow up was completed to 3 years. This technique eliminated the need for anterior surgery and extensive autograft thus reducing surgical morbidity.

In spite of advancements in neuro-imaging and microsurgical techniques, surgery for intramedullary spinal cord tumors (ISCT) remains a challenging task. The rationale for using intraoperative neurophysiological monitoring (IOM) is in keeping with the goal of maximizing tumor resection and minimizing neurological morbidity. For many years, before the advent of motor evoked potentials (MEPs), only somatosensory evoked potentials (SEPs) were monitored. However, SEPs are not aimed to reflect the functional integrity of motor pathways and, nowadays, the combined used of SEPs and MEPs in ISCT surgery is almost mandatory because of the possibility to selectively injury either the somatosensory or the motor pathways. This paper is aimed to review our perspective in the field of IOM during ISCT surgery and to discuss it in the light of other intraoperative neurophysiologic strategies that have recently appeared in the literature with regards to ISCT surgery. Besides standard cortical SEP monitoring after peripheral stimulation, both muscle (mMEPs) and epidural MEPs (D-wave) are monitored after transcranial electrical stimulation (TES). Given the dorsal approach to the spinal cord, SEPs must be monitored continuously during the incision of the dorsal midline. When the surgeon starts to work on the cleavage plane between tumor and spinal cord, attention must be paid to MEPs. During tumor removal, we alternatively monitor D-wave and mMEPs, sustaining the stimulation during the most critical steps of the procedure. D-waves, obtained through a single pulse TES technique, allow a semi-quantitative assessment of the functional integrity of the cortico-spinal tracts and represent the strongest predictor of motor outcome. Whenever evoked potentials deteriorate, temporarily stop surgery, warm saline irrigation and improved blood perfusion have proved useful for promoting recovery, Most of intraoperative neurophysiological derangements are reversible and therefore IOM is able to prevent more than merely predict neurological injury. In our opinion combining mMEPs and D-wave monitoring, when available, is the gold standard for ISCT surgery because it supports a more aggressive surgery in the attempt to achieve a complete tumor removal. If quantitative (threshold or waveform dependent) mMEPs criteria only are used to stop surgery, this likely impacts unfavorably on the rate of tumor removal.

To describe different currently available tests of multimodal intraoperative monitoring (MIOM) used in spine and spinal cord surgery indicating the technical parameters, application and interpretation as an easy understanding systematic overview to help implementation of MIOM and improve communication between neurophysiologists and spine surgeons. This article aims to give an overview and proposal of the different MIOM-techniques as used daily in spine and spinal cord surgery at our institution. Intensive research in neurophysiology over the past decades has lead to a profound understanding of the spinal cord, nerve functions and their intraoperative functional evaluation in anaesthetised patients. At present, spine surgeons and neurophysiologist are faced with 1,883 publications in PubMed on spinal cord monitoring. The value and the limitations of single monitoring methods are well documented. The diagnostic power of the multimodal approach in a larger study population in spine surgery, as measured with sensitivity and specificity, is dealt with elsewhere in this supplement (Sutter et al. in Eur Spine J Suppl, 2007). This paper aims to give a detailed description of the different modalities used in this study. Description of monitoring techniques of the descending and ascending spinal cord and nerve root pathways by motor evoked potentials of the spinal cord and muscles elicited after transcranial electrical motor cortex, spinal cord, cauda equina and nerve root stimulation, continuous EMG, sensory cortical and spinal evoked potentials, as well as direct spinal cord evoked potentials applied on 1,017 patients. The method of MIOM, continuously adapted according to the site, stage of surgery and potential danger to nerve tissues, proved to be applicable with online results, reliable and furthermore teachable.

Surgical instrumentation planning for the correction of scoliosis involves many difficult decisions, especially with the introduction of multi-segmental and other instrumentation technologies. A preliminary study has shown a high variability in planning among a small group of surgeons. The purpose of this paper was to evaluate and analyze the selection of fusion levels and instrumentation choices among a more extended group of scoliosis surgeons. Thirty-two experienced spinal deformity surgeons were asked to provide their preferred posterior instrumentation planning for five patients with adolescent idiopathic scoliosis (AIS) using a graphical worksheet and the usual preoperative X-rays. Overall, the number of implants used ranged from 8 to 30 per patient (mean 16; SD 6): 71% of these were mono-axial screws, 20% multi-axial screws, and 9% hooks. The selected superior and inferior instrumented vertebrae varied up to six levels. The following significant groups of strategies were identified: A- "All Pedicle Screws Constructs" [N(A) = 103; 66%]; B- "All Hooks constructs" [N(B) = 5; 3%]; C- "Hybrid Constructs" [N(C) = 48; 31%]. A top-to-bottom attachment sequence was selected in 49% of all cases, a bottom-up in 46%, and an alternate order in 4%. A large variability in preoperative instrumentation strategy exists in AIS within an experienced group of orthopedic spine surgeons. The impact of such choices on the resulting correction is questioned and will need to be determined with adequate clinical, biomechanical, and computer simulation prospective studies.

Destruction of the second cervical vertebra leads to a highly unstable situation. Reconstruction is difficult because the axis plays a central role in rotatory movements and has a unique function in redistributing axial loads. The axis transfers the axial load of the two lateral masses of the atlas to three surfaces on the third cervical vertebra: the two articular facets and the vertebral body. As reconstruction is difficult and the instability in this region is life threatening, pathological processes are often treated less radically compared to other areas of the cervical spine. However, this more moderate approach may result in worse outcomes and prognoses. This paper presents the development of a new implant (C2 prosthesis) and two illustrative cases describing the implementation of this new implant. The C2 prosthesis provides anterior support and therefore allows a more radical surgical approach.

With the advent of segmental pedicle screw fixation that enables more powerful corrective forces, it is postulated that an additional anterior procedure may be unnecessary even in severe deformities. The purpose of this paper is to evaluate the results of a posterior procedure alone using segmental pedicle screw fixation in severe scoliotic curves over 70 degrees . Thirty-five scoliosis patients treated by pedicle screw fixation and rod derotation were retrospectively analyzed after a minimum follow-up of 2 years (range 2-10.4). The mean age of patients was 15.3 years (range 9.8-34.2). Diagnoses were idiopathic scoliosis in 29, neuromuscular scoliosis in 3 and scoliosis associated with Marfan syndrome in 3. Scoliosis consisted of single thoracic curve in 18, double thoracic in 5 and double major in 12. Twenty-five patients showed a major thoracic curve greater than 70 degrees (range 70-100), and different ten patients showed a major lumbar curve greater than 70 degrees (range 70-105), pre-operatively. The deformity angle, lowest instrumented vertebral tilt (LIVT) and spinal balance were measured. Pre-operatively there were nine patients with coronal decompensation. The pre-operative thoracic curve of 80 +/- 9 degrees with the flexibility of 45 +/- 11% (45 +/- 11 degrees in side-bending film) was corrected to 27 +/- 10 degrees at the most recent follow-up, showing a correction of 66% (53 degrees) and loss of correction of 3.0% (3.7 degrees). The pre-operative lumbar curve of 79 +/- 12 degrees with the flexibility of 62 +/- 14% (30 +/- 11 degrees in side-bending film) was corrected to 33 +/- 14 degrees at the most recent follow-up [59% (46 degrees) curve correction, 3.5% (3.0 degrees) loss of curve correction]. The pre-operative LIVT of 30 +/- 8 degrees was corrected to 11 +/- 6 degrees, showing a correction of 62% (19 degrees). Residual coronal decompensation was observed in three patients postoperatively. Pre-operative thoracic kyphosis of 27 degrees (range 0-82) improved postoperatively to 31 degrees (range 14-53). In conclusion, posterior segmental pedicle screw fixation without anterior release in severe scoliosis had satisfactory deformity correction without significant loss of curve correction. In this series a posterior procedure alone obviated the need for the anterior release and avoided complications related anterior surgery.

The principal author was confronted few years ago with the case of a 38-year-old woman with a 5-month history of ill-defined L5 sciatic pain that was referred to an orthopaedic department for investigation and eventual surgical treatment for what was suspected to be herniated disc-related sciatica. Removal of her enlarged uterus found unexpectedly close to the sacroiliac joint upon lumbar MRI abolished her symptoms. Review of the literature showed that the lumbosacral trunk is vulnerable to pressure from any abdominal mass originating from the uterus and the ovaries. Physiological processes in the female patient and gynaecological diseases may be the source of sciatica, often not readily searched for, leading to fruitless investigations and surgical treatments. The aim of the paper is to highlight gynaecological and obstetrical causes of sciatica and sciatica-like symptoms. To prevent unproductive expenses and morbidity, a thorough gynaecological examination should be done even though neurological examination may be suggestive of a herniated intervertebral disc, and the cyclic pattern of pain related to menses should be routinely asked for.

New noninvasive techniques, amongst them structured light methods, have been applied to study rachis deformities, providing a way to evaluate external back deformities in the three planes of space. These methods are aimed at reducing the number of radiographic examinations necessary to diagnose and follow-up patients with scoliosis. By projecting a grid over the patient's back, the corresponding software for image treatment provides a topography of the back in a color or gray scale. Visual inspection of back topographic images using this method immediately provides information about back deformity, but it is important to determine quantifier variables of the deformity to establish diagnostic criteria. In this paper, two topographic variables [deformity in the axial plane index (DAPI) and posterior trunk symmetry index (POTSI)] that quantify deformity in two different planes are analyzed. Although other authors have reported the POTSI variable, the DAPI variable proposed in this paper is innovative. The upper normality limit of these variables in a nonpathological group was determined. These two variables have different and complementary diagnostic characteristics, therefore we devised a combined diagnostic criterion: cases with normal DAPI and POTSI (DAPI < or = 3.9% and POTSI < or = 27.5%) were diagnosed as nonpathologic, but cases with high DAPI or POTSI were diagnosed as pathologic. When we used this criterion to analyze all the cases in the sample (56 nonpathologic and 30 with idiopathic scoliosis), we obtained 76.6% sensitivity, 91% specificity, and a positive predictive value of 82%. The interobserver, intraobserver, and interassay variability were studied by determining the variation coefficient. There was good correlation between topographic variables (DAPI and POTSI) and clinical variables (Cobb's angle and vertebral rotation angle).

This article reports about the internet based, second multicenter study (MCS II) of the spine study group (AG WS) of the German trauma association (DGU). It represents a continuation of the first study conducted between the years 1994 and 1996 (MCS I). For the purpose of one common, centralised data capture methodology, a newly developed internet-based data collection system ( http://www.memdoc.org ) of the Institute for Evaluative Research in Orthopaedic Surgery of the University of Bern was used. The aim of this first publication on the MCS II was to describe in detail the new method of data collection and the structure of the developed data base system, via internet. The goal of the study was the assessment of the current state of treatment for fresh traumatic injuries of the thoracolumbar spine in the German speaking part of Europe. For that reason, we intended to collect large number of cases and representative, valid information about the radiographic, clinical and subjective treatment outcomes. Thanks to the new study design of MCS II, not only the common surgical treatment concepts, but also the new and constantly broadening spectrum of spine surgery, i.e. vertebro-/kyphoplasty, computer assisted surgery and navigation, minimal-invasive, and endoscopic techniques, documented and evaluated. We present a first statistical overview and preliminary analysis of 18 centers from Germany and Austria that participated in MCS II. A real time data capture at source was made possible by the constant availability of the data collection system via internet access. Following the principle of an application service provider, software, questionnaires and validation routines are located on a central server, which is accessed from the periphery (hospitals) by means of standard Internet browsers. By that, costly and time consuming software installation and maintenance of local data repositories are avoided and, more importantly, cumbersome migration of data into one integrated database becomes obsolete. Finally, this set-up also replaces traditional systems wherein paper questionnaires were mailed to the central study office and entered by hand whereby incomplete or incorrect forms always represent a resource consuming problem and source of error. With the new study concept and the expanded inclusion criteria of MCS II 1, 251 case histories with admission and surgical data were collected. This remarkable number of interventions documented during 24 months represents an increase of 183% compared to the previously conducted MCS I. The concept and technical feasibility of the MEMdoc data collection system was proven, as the participants of the MCS II succeeded in collecting data ever published on the largest series of patients with spinal injuries treated within a 2 year period.

The classification presented in this paper is the first specifically designed to guide surgical treatment of L5-S1 spondylolisthesis in children and adolescents. It also presents objective criteria to differentiate between low- and high-dysplastic spondylolisthesis and incorporates recent knowledge in the study of sagittal spinopelvic balance. The proposed classification is based on the following: (1) the degree of slip, (2) the degree of dysplasia, and (3) the sagittal spinopelvic balance. To classify a patient, the degree of slip is quantified first to determine if it is low-grade, high-grade, or a spondyloptosis. Then, the degree of dysplasia is evaluated based on seven criteria, in order to separate patients with low- and high-dysplastic spondylolisthesis. Finally, the sagittal spinopelvic balance is assessed from the measurement of the pelvic incidence (PI), sacral slope (SS), and pelvic tilt (PT). For low-grade spondylolisthesis, it is classified as low PI/low SS (nutcracker type) or high PI/high SS (shear type). For high-grade spondylolisthesis, it is classified as high SS/low PT (balanced pelvis) or low SS/high PT (retroverted pelvis). Such a comprehensive classification could allow to better evaluate and compare available surgical techniques, and to optimize the treatment of L5-S1 spondylolisthesis. Because the classification was designed so that groups are organized in an ascending order of severity, it becomes easier and more intuitive to develop an associated surgical algorithm because the complexity of the surgery should increase as the severity of the spondylolisthesis increases. A tentative treatment algorithm is proposed but it is not definitive because further studies are required to define the most appropriate treatment for each group.

The results of lumbar fusion in chronic low back pain (LBP) patients vary considerably, and there is a need for proper patient selection. Lumbosacral orthoses have been widely used to predict outcome, however, with little scientific support. The aim of the present study was to determine the value of a pantaloon cast test in selecting chronic LBP patients for lumbar fusion or conservative management. First, a systematic review of the literature was carried out in which two independent reviewers identified studies in Medline, Cochrane and Current Contents databases. Three papers met the selection criteria. In the only study with a control group, a significantly better outcome after fusion compared to conservative treatment was found in patients who reported significant pain relief while in a cast (i.e. a positive cast test). The results of lumbar fusion, however, were not significantly different for patients with a positive and those with a negative cast test. In addition to the review, a clinical cohort study of 257 LBP patients, who had been allocated to either lumbar fusion or conservative management by a temporary external transpedicular fixation trial, was performed. Prior to allocation, all had undergone a pantaloon cast test. Patients with no history of prior spine surgery and with a positive pantaloon cast test had a better outcome after lumbar fusion than those treated conservatively (P = 0.002, chi (2 )test). In patients with previous spine operations the outcomes were poor and the test was of no value. From the literature and the present patient cohort, it was concluded that only in chronic LBP patients without prior spine surgery, a pantaloon cast test with substantial pain relief suggests a favorable outcome of lumbar fusion compared to conservative management. The test has no value in patients who have had previous spine surgery.

Smith and Nephew (Endoscopy division, Andover, MA, USA) have estimated that 60,000 Intra-Discal Electrothermal Therapy (IDET) procedures have been performed world wide up to June 2005. Despite the large number of procedures performed, a critical appraisal of the evidence of efficacy of IDET has not appeared in the literature. This paper reviews the current evidence of clinical efficacy for IDET obtained via a systematic review of the literature. Studies were included if they used at least one of four specified primary outcome measures; pain intensity as assessed by a visual analogue score (VAS), global measurement of overall improvement, back specific functional status such as Oswestry disability Index (ODI) and return to work. Levels of evidence were assigned according to the hierarchy described by the Oxford Centre for Evidence-Based Medicine (www.cebm.net). Papers addressing possible mechanisms of action of IDET were not considered as the focus of the literature review was clinical effectiveness. Eleven prospective cohort studies (level II evidence) were reported on a total of 256 patients with a mean follow-up of 17.1 months (range 12-28 months). The mean improvement in the VAS for back pain was 3.4 points (range 1.4-6.5) and the mean improvement in ODI was 5.2 points (range 4.0-6.4). A total of 379 patients were reported in five retrospective studies (level III evidence). Between 13 and 23% of patients subsequently underwent surgery for low back pain within the study period. Two randomised controlled trials of IDET have been reported in the literature. The first randomised 64 patients (37 to IDET, 27 to Sham). The advantage for IDET patients amounted to 1.3 points on the VAS and seven points on the ODI. The second study randomised 57 subjects (38 to IDET, 19 to Sham) and showed no benefit from IDET over placebo. The evidence for efficacy of IDET remains weak and has not passed the standard of scientific proof.

The paper reports on auto fluorescence phenomena of inter-vertebral human discs. It systematically investigates the auto fluorescence effects of ex vivo disc specimen and reports on surgical cases to demonstrate the potential value of the new method. The paper offers biologic explanations of the phenomenon and discusses the potential value of the UV auto fluorescence technique as a diagnostic tool. Intra- and postoperative observations are made by a surgical microscope with an integrated UV light source. Quantitative measurements were carried out using a photon counter and a spectrometer ex vivo. The auto fluorescence phenomenon allows the differentiation of traumatized and degenerated disc tissue intraoperatively in some cases, it allows the differentiation of bony and collagen endplate in cervical disc surgery. The source of the auto fluorescent light emission are amino acids of the collagen molecules. The proteoglycan components and the liquid components of the disc do not show relevant auto fluorescence. Emission wavelength of disc material is equivalent to color perception. It differs due to different collagen composition of the intervertebral disc components from yellow-green to blue-green and can be visualized in situ by naked eye.UV-auto fluorescence of inter-vertebral discs is a new clinical tool that has the potential to differentiate disc material from the anatomical surrounding, to distinguish between different fractions of the disc and to give information on the quality and status of the disc material. Since the technology has just emerged, it needs further investigations to quantify the clinical observations reported in this paper.

The vertebral endplates are critical for maintaining disc function yet like other components of the disc are vulnerable to degeneration. This paper provides an overview of the development and normal function of the endplates as well as an impression of what happens when they undergo progressive degeneration. Recent research suggests that the degenerative process can be retarded or reversed.

The current evidence for total disc replacement was assessed by performing a systematic review of the published literature. This search identified two randomised controlled trials (RCTs), two previous systematic reviews, seven prospective cohort studies, eleven retrospective cohort studies and eight case series. The RCTs involved the use of the Charité artificial disc and the Pro-Disc II total disc replacement. All papers analysed were classified according to their level of evidence as defined by the Centre for Evidence Based Medicine, Oxford, UK (www.cebm). For degenerative disc disease at L4/5 or L5/S1, both the clinical outcome and the incidence of major neurological complications following insertion of the Charité artificial disc were found to be equivalent to those observed following a single level anterior lumbar interbody fusion 2 years following surgery. However, only 57% of patients undergoing total disc replacement and 46% of patients undergoing arthrodesis met the four criteria listed for success. The range of flexion/extension was restored and maintained with the Charité artificial disc. The role for two or three level disc replacement in the treatment of degenerative disc disease remains unproven. To date, no study has shown total disc replacement to be superior to spinal fusion in terms of clinical outcome. The long-term benefits of total disc replacement in preventing adjacent level disc degeneration have yet to be realised. Complications of total disc replacement may not be known for many years. There are numerous types of disc prostheses and designs under study or in development. Well designed prospective RCTs are needed before approval and widespread application of this technology.

The purpose of this study was to investigate the use of magnetic resonance (MR) imaging and image processing software to determine the functional cross-sectional area (FCSA) (the area of muscle isolated from fat) of the lumbar paraspinal muscles. The measurement of the morphology of the lumbar paraspinal muscles has become the focus of several recent investigations into the aetiology of low back pain. However, the reliability and validity of determining the FCSA of the lumbar paraspinal muscles using MR imaging are yet to be reported. T2 axial MR scans at the L1-S1 spinal levels of six subjects were obtained using identical MR systems and scanning parameters. Lean paraspinal muscle, vertebral body bone and intermuscular fat were manually segmented using image analysis software to assign a grey scale range to the MR signal intensity emitted by each tissue type. The resultant grey scale range for muscle was used to determine FCSA measurements for each of the paraspinal muscles, psoas, quadratus lumborum, erector spinae and lumbar multifidus on each scan slice. As various biological, instrument and measurement factors can affect MR signal intensity, a sensitivity analysis was conducted to determine the error associated in calculating FCSA for paraspinal muscle using a discrete grey scale range. Cross-sectional area and FCSA measurements were repeated three times and reliability indices for the FCSA measurements were obtained, showing excellent reliability, intra class correlation coefficient (mean=0.97, range 0.90-0.99) and %SEM (mean=2.6%, range 0.7-4.8%). In addition, the error associated with miscalculation of the grey scale range for the MR signal intensity of muscle was calculated and found to be low with an error of 20 grey scale units at the upper end of the muscle's grey scale range resulting in a very small error in the measured muscle FCSA. The method presented in this paper has a variety of practical applications in areas such as evidence-based rehabilitation, biomechanical modelling and the determination of segmental inertial parameters.

The objective of this study was to determine the prevalence of neck pain (NP) in the world population and to identify areas of methodological variation between studies. A systematic search was conducted in five databases (MEDLINE, EMBASE, CINAHL, OSH-ROM, and PsycINFO), followed by a screening of reference lists of relevant papers. Included papers were extracted for information and each paper was given a quality score. Mean prevalence estimates were calculated for six prevalence periods (point, week, month, 6 months, year, and lifetime), and considered separately for age, gender, quality score, response rate, sample size, anatomical definition, geography, and publication year. Fifty-six papers were included. The six most commonly reported types of prevalence were point, week, month, 6 months, year, and lifetime. Except for lifetime prevalence, women reported more NP than men. For 1-year prevalence, Scandinavian countries reported more NP than the rest of Europe and Asia. Prevalence estimates were not affected by age, quality score, sample size, response rate, and different anatomical definitions of NP. NP is a common symptom in the population. As expected, the prevalence increases with longer prevalence periods and generally women have more NP than men. At least for 1-year prevalence Scandinavian countries report higher mean estimates than the rest of Europe and Asia. The quality of studies varies greatly but is not correlated with the prevalence estimates. Design varies considerably and standardisation is needed in future studies.

Description of a workshop entitled "Sharing Guidelines for Low Back Pain Between Primary Health Care Providers: Toward a Common Message in Primary Care" that was held at the Fifth International Forum on Low Back Pain in Primary Care in Canada in May 2002. Despite a considerable degree of acceptance of current evidence-based guidelines, in practice, primary health care providers still do not share a common message. The objective of the workshop was to describe the outcomes of a workshop on the sharing of guidelines in primary care. The Fifth International Forum on Low Back Pain Research in Primary Care focused on relations between stakeholders in the primary care management of back pain. Participants in this workshop contributed to an open discussion on "how and why" evidence-based guidelines about back pain do or do not work in practice. Ways to minimise the factors that inhibit implementation were discussed in the light of whether guidelines are mono-disciplinary or multidisciplinary. Examples of potential issues for debate were contained in introductory presentations. The prospects for improving implementation and reducing barriers, and the priorities for future research, were then considered by an international group of researchers. This paper summarises the conclusions of three researcher subgroups that focused on the sharing of guidelines under the headings of: (1) the content, (2) the development process, and (3) implementation. How to share the evidence and make it meaningful to practice stakeholders is the main challenge of guideline implementation. There is a need to consider the balance between the strength of evidence in multidisciplinary guidelines and the utility/feasibility of mono-disciplinary guidelines. The usefulness of both mono-disciplinary and multidisciplinary guidelines was agreed on. However, in order to achieve consistent messages, mono-disciplinary guidelines should have a multidisciplinary parent. In other words, guidelines should be developed and monitored by a multidisciplinary team, but may be transferred to practice by mono-disciplinary messengers. Despite general agreement that multi-faceted interventions are most effective for implementing guidelines, the feasibility of doing this in busy clinical settings is questioned. Research is needed from local implementation pilots and quality monitoring studies to understand how to develop and deliver the contextual understanding required. This relates to processes of care as well as outcomes, and to social factors and policymaking as well as health care interventions. We commend these considerations to all who are interested in the challenges of achieving better-integrated, evidence-based care for people with back pain.

During the past 30 years various treatment protocols for hangman's fractures have been attempted. In order to guide the management of hangman's fractures, different classifications have been introduced. However, opinions on operative or nonoperative treatment have not yet been solidified. To evaluate both conservative and operative management of hangman's fractures in the published literature and to provide appropriate guidelines for treatment of hangman's fractures, a systematic review of the literature regarding the management of hangman's fractures was performed. An English literature search from January 1966 to January 2004 was completed with reference to treatment of hangman's fractures. The classification for treatment guidance from the literature was also reviewed. Regarding a primary therapy for hangman's fractures, there were 20 papers (62.5%) that advocated for a conservative treatment and 11 of the remaining 12 papers suggested that conservative treatment was suitable for some stable fractures. The classification of Effendi et al. modified by Levine and Edwards was used widely. Most hangman's fractures could be managed successfully with traction and external immobilization, especially in Effendi Type I, Type II and Levine-Edwards Type II fractures. It is necessary for Levine-Edwards Type IIa and III fractures to be treated with rigid immobilization. Only for some stable Type I and Levine-Edwards Type II injuries, nonrigid external fixation alone was sufficient. Rigid immobilization alone was necessary for most cases. Surgical stabilization is recommended in unstable cases when there is the possibility of later instability, such as Levine-Edwards Type IIa and III fractures with significant dislocation. The classification system proposed by Effendi et al. and modified by Levine and Edwards provided a clinically reasonable guideline for successful management of hangman's fractures.

Vertebral osteomyelitis due to mucormycosis is a rare but fulminant and fatal disease. Only one case has been reported in literature, with postmortem diagnosis. The present paper reports a female case of mucormycosis spondylodiscitis and vertebral osteomyelitis after lumbar disc puncture and radio frequency nucleoplasty. She subsequently underwent two surgical debridements, continuous local irrigation and drainage, together with local and systemic Amphotericin B treatments. The infection was controlled 4 months after the second debridement; however, there was no improvement in the neurological function at the most recent follow-up, 16 months after the surgery. The experience of this patient, though a single case, supports early recognition, surgical debridement, systemic and local antifungal treatment, closed irrigation and drainage as the keys to successful treatment.

The use of polymer-based bioresorbable materials is now expanding to the realm of spinal interbody fusion. Bioresorbable polymers have important advantages over metals, because they are temporary, much less stiff, and radiolucent. Most promising is a group of alpha-polyesters, in particular polylactide acids (PLAs). Their biocompatibility is excellent, and they have sufficient stiffness and strength to provide initial and intermediate-term stability required for bone healing. However, polylactides have characteristics that make them vulnerable to complications if not properly controlled. Degradation rate strongly depends on polymer type, impurities, manufacturing process, sterilization, device size, and the local environment. The fact that larger implants degrade faster is contra-intuitive, and should be considered in the design process. Also optimal surgical techniques, such as careful bone bed preparation, are required for a successful application of these materials. The purpose of this paper is to highlight the specific properties of these bioresorbable polymers and to discuss their potential and limitations. This is illustrated with early preclinical and clinical data.Bioresorbable cage technology is just emerging: their time-engineered degradation characteristics allow controlled dynamization in interbody applications, facilitating spinal fusion. Their radiolucency improves image assessment of fusion healing. Acceptance and use of bioresorbable implants may increase as further research and clinical studies report on their safety, efficacy, and proper usage.

Within the framework of evidence-based medicine high-quality randomised trials and systematic reviews are considered a necessary prerequisite for progress in orthopaedics. This paper summarises the currently available evidence on surgical and other invasive procedures for low back pain. Results of systematic reviews conducted within the framework of the Cochrane Back Review Group were used. Data were gathered from the latest Cochrane Database of Systematic Reviews 2005, Issue 2. The Cochrane reviews were updated using the evidence summary on surgery and other invasive procedures from the COST B13 European Guidelines for the Management of Acute and Chronic Non-Specific Low Back Pain. Facet joint, epidural, trigger point and sclerosant injections have not clearly been shown to be effective and can consequently not be recommended. There is no scientific evidence on the effectiveness of spinal stenosis surgery. Surgical discectomy may be considered for selected patients with sciatica due to lumbar disc prolapses that fail to resolve with the conservative management. Cognitive intervention Combined with exercises is recommended for chronic low back pain, and fusion surgery may be considered only in carefully selected patients after active rehabilitation programmes during 2 years time have failed. Demanding surgical fusion techniques are not better than the traditional posterolateral fusion without internal fixation.

The number of economic evaluations in the field of spinal disorders and methodological studies have increased in the last decade. The objective of this paper is to provide an overview of current views on economic evaluations in the field of spinal disorders and to facilitate clinicians to interpret and use results from these studies. A full economic evaluation compares both costs and effects of two or more interventions. Key elements of economic evaluations such as identifying adequate alternatives, analytical perspective, cost methodology, missing values and sensitivity analyses are addressed. Further emphasis is placed on the interpretation of results of economic evaluations conducted alongside randomised clinical trials. Incremental cost-effectiveness ratios, cost-effectiveness planes, acceptability curves and cost-effectiveness thresholds are discussed. The contents may aid in taking the efficacy 'hurdle' in the field of spinal disorders.

Today there is growing awareness among spine surgeons of the advantages in using registers to facilitate the analyses and reporting of treatment outcome. The Swedish Spine register is among the first to be used on a national scale and annual reports are published in international journals. In this paper we discuss our experiences and lessons learned from a paper-based version in 1993, to an online web-based solution in 2005. We emphasise the advantages of registers being owned by the national spine society, a support function available during working hours, online feedback to participating departments and professional assistance in designing a register program for web use. Hopefully, our experiences will be of help to colleagues who are planning to start registering.

At present, there is an increasing international trend towards evidence-based health care. The field of low back pain (LBP) research in primary care is an excellent example of evidence-based health care because there is a huge body of evidence from randomized trials. These trials have been summarized in a large number of systematic reviews. This paper summarizes the best available evidence from systematic reviews conducted within the framework of the Cochrane Back Review Group on non-invasive treatments for non-specific LBP. Data were gathered from the latest Cochrane Database of Systematic Reviews 2005, Issue 2. The Cochrane reviews were updated with additional trials, if available. Traditional NSAIDs, muscle relaxants, and advice to stay active are effective for short-term pain relief in acute LBP. Advice to stay active is also effective for long-term improvement of function in acute LBP. In chronic LBP, various interventions are effective for short-term pain relief, i.e. antidepressants, COX2 inhibitors, back schools, progressive relaxation, cognitive-respondent treatment, exercise therapy, and intensive multidisciplinary treatment. Several treatments are also effective for short-term improvement of function in chronic LBP, namely COX2 inhibitors, back schools, progressive relaxation, exercise therapy, and multidisciplinary treatment. There is no evidence that any of these interventions provides long-term effects on pain and function. Also, many trials showed methodological weaknesses, effects are compared to placebo, no treatment or waiting list controls, and effect sizes are small. Future trials should meet current quality standards and have adequate sample size.

A critical evaluation of existing scientific evidence of treatment efficacy can be an important part of communicating risk and benefits of treatment options to patients during the course of clinical practice. A checklist of key methodological issues to examine when reading a research study is presented and discussed. Steps in reading a paper include: identifying the research question; identifying the manner in which subjects get enrolled in the study; identifying the treatments and outcomes used; identifying the study design and the comparisons being made; evaluating the study methods for the possibility of bias and uncontrolled confounding; assessing whether the statistical analysis used is appropriate for the study design; assessing whether the study has sufficient statistical power to demonstrate hypotheses being tested. Finally, procedures for grading and evaluating evidence, as used by systematic review groups and international best evidence synthesis consensus groups is briefly described.

The prevalence of low back pain is high, and the intervertebral (IV) disc is regarded as one of the major causes. Various approaches have been reported to either slow down disc degeneration or to repair/regenerate the disc. So far, the effect of the mechanical environment has not been addressed in these approaches, although several investigations have shown its influence on other mesenchymal tissues. In this paper, we propose that the biophysical stimuli from the mechanical environment can directly influence cell type, as well as their metabolic activity during repair/regeneration of the IV disc. To demonstrate the potential of this idea, data from the literature, as well as explorative experimental results, are presented.

Chordoma is a rare bone tumor that originates from the remnants of the notochord. These tumors have axial distribution particularly at the upper and lower ends of the vertebral column. This paper reports a rare occurrence of a chordoma in the posterior elements of the L5 vertebra. A differential diagnosis of a benign tumor (giant cell tumor, aneurysmal bone cyst or osteoblastoma) was made initially. Other differential diagnoses included plasmacytoma and metastasis. The tumor was removed enbloc. Histopathological examination revealed the tumor mass to be chordoma. There were no clinical or radiological signs of recurrence at 21 months follow-up. Chordomas are tumors of the axial skeleton. However, they may occur in unusual sites in ectopic notochordal tissue. The case is being presented for its unusual site of occurrence.

The literature reports on the safety and efficacy of titanium cages (TCs) with additional posterior fixation for anterior lumbar interbody fusion. However, these papers are limited to prospective cohort studies. The introduction of TCs for spinal fusion has resulted in increased costs, without evidence of superiority over the established practice. There are currently no prospective controlled trials comparing TCs to femoral ring allografts (FRAs) for circumferential fusion in the literature. In this prospective, randomised controlled trial, our objective was to compare the clinical outcome following the use of FRA (current practice) to the use of TC in circumferential lumbar spinal fusion. Full ethical committee approval and institutional research and development departmental approval were obtained. Power calculations estimated a total of 80 patients (40 in each arm) would be required to detect clinically relevant differences in functional outcome. Eighty-three patients were recruited for the study fulfilling strict entry requirements (>6 months chronic discogenic low back pain, failure of conservative treatment, one- or two-level discographically proven discogenic low back pain). The patients completed the Oswestry Disability Index (ODI), Visual Analogue Score (VAS) for back and leg pain and the Short-Form 36 (SF-36) preoperatively and also postoperatively at 6, 12 and 24 months, respectively. The results were available for all the 83 patients with a mean follow-up of 28 months (range 24-75 months). Five patients were excluded on the basis of technical infringements (unable to insert TC in four patients and FRA in one patient due to the narrowing of the disc space). From the remaining 78 patients randomised, 37 received the FRA and 41 received the TC. Posterior stabilisation was achieved with translaminar or pedicle screws. Baseline demographic data (age, sex, smoking history, number of operated levels and preoperative outcome measures) showed no statistical difference between groups (p<0.05) other than for the vitality domain of the SF-36. For patients who received the FRA, mean VAS (back pain) improved by 2.0 points (p<0.01), mean ODI improved by 15 points (p=<0.01) and mean SF-36 scores improved by >11 points in all domains (p<0.03) except that of general health and emotional role. For patients who received the TC, mean VAS improved by 1.1 points (p=0.004), mean ODI improved by 6 points (p=0.01) and SF-36 improved significantly in only two of the eight domains (bodily pain and physical function). Revision procedures and complications were similar in both groups. In conclusion, this prospective, randomised controlled clinical trial shows the use of FRA in circumferential lumbar fusion to be associated with superior clinical outcomes when compared to those observed following the use of TCs. The use of TCs for circumferential lumbar spinal fusion is not justified on the basis of inferior clinical outcome and the tenfold increase in cost.

The Deputy Editor has explained in his editorial the reason for this review. I found it a challenging but very rewarding project. The overall quality of papers was so good that it was very difficult to select the necessarily few which space would allow me to review. Inevitably I am influenced by my particular interests, and hence very many excellent papers will not be discussed; failure to discuss a paper is not a reflection on its quality or importance. Criticisms of papers again reflect my own prejudices.