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Humans show many asymmetries. Heart, lungs, liver and other viscera are either to one side, or differ on the two sides, and most people also have an asymmetric brain, with a majority of people being right-handed and having language processing in the left hemisphere of the brain. In this talk I will look at some recent advances in our understanding of the biology of asymmetry.
Aside from a few major successes, there have been many problems replicating significant associations between polymorphic gene variation and complex diseases. There are several reasons for this, of which population structure is widely considered to be the most important. Population structure will affect both the validity and power of experiments and may be particularly important when relative risks are slight or the alleles involved are rare. With low relative risks and/or rare alleles, sample sizes need to be much larger than those often used in case-control studies and as sample size increases, the amount of population structure needed to perturb the results decreases. To address this problem, there are several statistical methods available that attempt to allow for the effect of population structure to be taken into account. However, these methods are not really satisfactory and so the only suitable alternative is to design the studies with greater care and a powerful approach may be to characterise genetically both the cases and controls. Individuals from the controls can then be chosen to match the cases so as to minimise the stochastic differences between the two populations. We are therefore assembling a UK control population as a resource for future studies. It will comprise samples from 3500 individuals, who will have been carefully selected from throughout the UK. Rural regions will be targeted to avoid the admixture observed in large urban environments and volunteers will be sought who were born in the same place as their parents and grandparents to ensure historical integrity. The collection will be genotyped for around 3000 markers, with the aim of identifying about 200 ancestrally informative markers (AIMs). These AIMs will then be used to match controls to cases.
G = Gm(1-β(_-_m)); where β=1.68 MPa-1 was the empirically determined constant. (The subscript m signifies the ‘baseline’ growth and physiological stress). The vertebral and discal contributions to human adolescent spinal growth velocity were measured from stereo-radiographs of 208 patients of with scoliosis. The estimates of level-specific spinal loading asymmetry, together with the relationship expressing growth sensitivity to load were included in an analysis that was used to estimate the resulting asymmetrical vertebral growth, and its contribution to the progression of a scoliosis curvature. The initial geometry represented a lumbar scoliosis of 26° Cobb, averaged and scaled from measurements of fifteen patients’ radiographs. Spinal growth during each of the adolescent years was estimated from growth curves obtained from cross-sectional logistic-correlation of the radiographically determined spinal and vertebral heights versus age.
Supported by the Fondation Yves Cotrel, Institut de France.
Problems of vertebral growth plate metabolism regulation at different stages of ontogenesis are insufficiently covered in the literature. However, the study of function mechanism of provisional cartilage of vertebral growth plate is a practical and theoretical basis of pathogenesis model of idiopathic scoliosis and Scheuermann’s disease both associated with growth disorders.
Due a peculiar architectonics, growth plate molecules have inner spaces comparable in size with Golgi’s vesicles. Metabolites, small molecules, and water freely penetrate through these molecules. Diffuse molecules together with type II thin collagenic fibres, minor collagenes, and structure-forming growth plates perform barrier function. Besides barrier function, diffuse molecules perform information function inside a chondron, forming a kind of information field. Signals of this field are perceived by chondroblast receptors, and the cell gene apparatus expression is carried out through second messengers. Thus, either stimulation of proliferative activity with subsequent differentiation during intensive growth, or interruption of these processes (period of growth delay) occurs. Single chondrons unite into chains in proliferation zones. Cell interaction inside chondron occurs due transmembrane structures, as a contact coordination of functions of cells with inherent high specificity. Concentration of diffuse molecules of growth plate (aggrecan) in proliferation zones is the highest on evidence of histochemical and ultrastructural assays. Besides, diffuse molecules are the short-distance regulators of DNA synthesis the mechanism of action of which is realised through the system of receptors on a cellular membrane. Hence, contact intercellular interactions are one of the mechanisms controlling cell division. These are so-called extracellular factors of chondroblast proliferation regulation. Thus, the process of growth represents a complex two-stage mechanism of proliferation and differentiation of chondroblasts, and adequate osteogenesis. All three processes provide harmonious spine formation, and disturbance of one of them results in pathology development.
Work supported by Fondation Cotrel
The purpose of the present study was to investigate the role of E2 on the responsiveness of the AIS cells to the melatonin, to determine the expression of estrogens receptors (ERα and ERβ) in AIS tissues and to clarify the impact of estrogen receptor gene polymorphisms in the pathogenesis of AIS.
Supported by the Fondation Yves Cotrel, Institut de France
wild-type (controls) (n=25); shams (surgical controls) (n=20); pinealectomised (n=76). The experimental data was used to adapt a FEM previously developed to simulate the scoliosis deformation process in human (Villemure et al. 2002). The FEM consists of 7 thoracic vertebrae and the first lumbar, the intervertebral discs and the zygapophyseal joints. The geometry was measured on specimens using a calliper. The material properties of human spines were used as initial approximation. The growth process included a baseline growth (0.130 mm/day) and a growth modulation behaviour proportional to the stress and to a sensitivity factor. It was implemented through an iterative process (from the 14th to the 28th day). Asymmetric loads (2–14 Nmm) were applied to represent different paravertebral muscle abnormalities influenced by the induced melatonin defect.
It is accepted that the development of scoliosis has a close relationship with physical growth, but the aetiology and mechanism of the disease remain unknown. Few studies have assessed the bone microarchitecture and histomorphological findings in vertebrae. After the occurrence of scoliosis, those include secondary changes caused by mechanical compression. It is important to investigate those data in the period prior to the occurrence of scoliosis.
Study Two: Sixty female Broiler chickens were divided into three groups: the control group (group C, n=20), the sham operation group (group S, n=20), and the pinealectomy group (group P, n=20). Each group was then subdivided into two groups according to the time of sacrificing: 3 days after the operation (group 3-C, 3-S, 3-P, n=10), and six days after the operation (group 6-C, 6-S, 6-P, n=10). Decalcified thin sagittal sections were made using a tartrate-resistant acid phosphatase (TRAP) stain. Histological examinations of the growth plate, trabecular structure and osteoclast number were performed.
Study Two: Nine out of ten chickens in group 6-P showed scoliosis deformity, while the presence of scoliosis was unclear in any of chickens in group 3-P. The osteoclast number increased significantly in group 3-P, compared to groups 3-C and 3-S, and the trabecular thickness was greater in group 3-P than in groups 3-C and 3-S. There was no significant change in the growth plate or in other aspects of the trabecular structure, except for trabecular thickness, in any of the groups. The results of study one showed that the change of microarchitecture might be caused by Wolff’s law and was the secondary response to the scoliotic deformity. Therefore, it was difficult to clarify the cause of scoliosis using micro CT. In study 2 we found that the number of osteoclast increased in pinealectomised chickens after 3 days postoperatively, just before scoliosis began to develop. We also found there was no change in the growth plate. These outcomes suggest that there are no relationships between changes in the growth plate and the development of scoliosis. However, the change in osteoclast number may have a relationship with the development of scoliosis through changes in bone modelling.
CA of AIS and controls reached <
40% of the Chinese calcium DRI (1000 mg/d). Both CA and weight-bearing PA were correlated with BMD in AIS (P<
0.04 &
P=0.002 respectively). Both CA and PA were independent predictors on the variations of aBMDs (P<
0.03) and vBMDs (P<
0.04) in AIS after controlling for confounders in multivariate analysis. Regarding bone turn-over rate, bALP in AIS was 38.6% higher than the controls from 13-y onwards (P<
0.005) while Dpd of AIS was 30.4% lower than controls at age 15-y (P=0.003). Furthermore, bALP in AIS was negatively correlated with age-adjusted BMD (r=−0.34, P<
0.001) while the correlation was weaker in the controls (P=0.14, P<
0.002).
The assessment of vestibular function throws new light on scoliosis. Vestibular morphological anomalies are frequent in scoliosis. This communication has two aims:
to correlate the dysfunctions of the semi-circular canal system with morphological anomalies. to include the vestibular assessment in the management of the scoliotic subject. These anomalies are demonstrated by graphic modelling from MRI images (see abstract of Dr. Rousié). The examination of the proprio-oculo-labyrinthine system is done by Videonystagmography (VNG) and Videooculography (VOG). We able to test both horizontal and vertical canal function to give a 3D vestibular assessment. We use these tests to measure primitive vestibular dissymmetry (PVD). We compare the 3D endolymphatic morphology with the 3D vestibular function.
In the In the The difference between the results obtained with the caloric test and the kinetic tests is in connection with the phenomena of central compensation. On the vestibular level there is a close connection between the scoliosis, the vestibular morphological anomalies and the vestibular examination.
The vestibular assessment and vestibular rehabilitation are necessary because of the close connections between the anomalies of the proprio-oculo-labyrinthin and the scoliosis.
Analysis of balance is emerging as an important parameter in spinal deformity. Force plate technology permits a quantitative study of balance through centre of pressure (COP) measurement. COP measurements obtained from the force plate approximate the projected centre of gravity. In a standing subject the COP reflects the projected centre of gravity however repeatability and reliability of such analysis is lacking. COP measurements were obtained from eight asymptomatic volunteers (mean age 32) with no history of back pain or previous spinal surgery. Each subject stood on a Zebris force plate platform for 30 seconds daily. 15 sets of data were acquired for each subject. For one subject, an additional 15 sets of data were collected on one day for comparison to the longitudinal data. Intra- versus inter-subject reliability analysis revealed a Cronbach’s alpha value >
0.9 for the following COP movement parameters: distance travelled over 30 seconds, distance travelled in the first and last five seconds, and average speed. Comparison of the mean intra- versus inter-subject coefficients of variation revealed significant differences for all parameters (p<
0.004). COP movement parameters are reliable in terms of intra-subject repeatability and can detect significant individual subject movement patterns. This suggests that COP movement patterns over time are idiosyncratic for each individual. While the repeatability of COP measurement has been established, the sensitivity to change with pathology and in response to treatment for spinal pathology remains to be evaluated.
Control group (CG):32 subjects, 26W. &
6M., fr. 8 to 51. AIS group (AISG):93 subjects, 77W. &
16M., fr. 6 to 63. AIS were classified according to – Amplitude of spine deformation (d°) G1: 8 to10°, G2: 10 to 15°, G3:15 to 40° – Location of deformation (Ponsetti class.): TL=thoracolumbar, T=thoracic, L=lumbar.
Step1: 3D Basicranium measurements in both groups with Brainvisa processing: ( Step2: 3D anatomical study of semicircular canals in both groups with original modelling software.
AIS showed a pathognomic increase of these Human traits. Inside AIS subgroups, TL &
G3 revealed highest levels of asymmetry and rotation. We will discuss, thanks to AIS homozygosis twins in mirror, genetic origins for these specific P.B. &
Cerebellum asymmetries. Modelling of semi-circular canals revealed significative malformations in AIS compared to normal group. Again, T.L. and G3 revealed highest scores of canals anomalies. We highlighted a specific malformation in AIS: abnormal connexion between lateral &
posterior canal. We will demonstrate, thanks to same AIS twins, genetic origins of this malformation and propose a genetic hypothesis to link the different results.
Nachemson [2] drawing upon the theses of Sahlstrand [3] and Lidström [4] articulated the view there are more girls than boys with progressive AIS for the following reason. The maturation of postural mechanisms in the nervous system is complete about the same time in boys and girls. Girls enter their skeletal adolescent growth spurt with immature postural mechanisms – so if they have a predisposition to develop a scoliosis curve, the spine deforms. In contrast, boys enter their adolescent growth spurt with mature postural mechanisms so they are protected from developing a scoliosis curve. We term Nachemson’s concept the neuro-osseous timing of maturation (NOTOM) hypothesis [1,5] The earlier sexual and skeletal maturation of girls may have an evolutionary basis through natural selection. Curve progression in AIS is associated with acceleration of the adolescent growth spurt [6]. Postural sway involves proprioceptive, vestibular and visual input to the central nervous system. In normal children there is a significant reduction in postural sway amplitude between six to nine years and 10–14 years [7,8]. In 1071 normal children aged 6–14 years postural sway is more stable in girls from 6–9 years and over 10 years there is no sex effect [9]; all these findings fit the Nachemson concept. But in view of a subsequent report on 64 normal children aged 3–17 years showing the change with age is limited to boys [10] the age and sex effect of postural sway in healthy children needs further evaluation. In AIS children stabilometry findings are conflicting and observed greater postural sway may be secondary to the curve. In the siblings of scoliotics Lidström et al [11] concluded that postural aberration is a factor in the aetiology of AIS.
The possibility that AIS aetiology involves undetected neuromuscular dysfunction is considered likely by several workers [1,2]. Yet in the extensive neuroscience research of idiopathic scoliosis certain neurodevelopmental concepts have been neglected. These include [3]:
a CNS body schema (“body in the brain”) for posture and movement control generated during development and growth by establishing a long-lasting memory, and pruning of cortical synapses at puberty. During normal development the CNS has to adapt to the rapidly growing skeleton of adolescence, and in AIS to developing spinal asymmetry from whatever cause. Examination of publications relating to the CNS body schema, parietal lobe and temporo-parietal junction [4,5] led us to a new concept: namely, that a delay in maturation of the CNS body schema during adolescence with an early AIS deformity at a time of rapid spinal growth results in the CNS attempting to balance the deformity in a trunk that is larger than the information on personal space (self) already established in the brain by that time of development. It is postulated that this CNS maturational delay allows scoliosis curve progression to occur – unless the delay is temporary when curve progression would cease. The maturational delay may be primary in the brain or secondary to impaired sensory input from end-organs [6], nerve fibre tracts [2,7,8] or central processing [9,10]. The motor component of the concept could be evaluated using transcranial magnetic stimulation [11].
The aetiology of idiopathic scoliosis, despite of long-lasting efforts to disclose it, remains unknown. The purpose of the study was to evaluate the spine development after pinealectomy or cortical sensory motor area damage in the growing rats.
These statistically significant differences were found: higher surgery weight in PIN, longer surgery time in PIN and SMCA, lower lordosis in PIN and higher in CRDU, differences of all groups in kyphosis and in an end weight.
These damages could cause a disorder of balance between smaller inhibitory and greater facilitating area of CNS, controlling the muscular tone and resulting in the development of lordosis and scoliosis due to muscle imbalance.
While previous studies have highlighted possible aetiological factors for adolescent idiopathic scoliosis (AIS), research employing gait measurements have demonstrated asymmetries in the ground reaction forces, suggesting a relationship between these asymmetries, neurological dysfunction and spinal deformity. Furthermore, investigations have indicated that the kinematic differences in various body segments may be a major contributing factor. This investigation, which formed part of a wider comprehensive study, was aimed at identifying asymmetries in lower limb kinematics and pelvic and back movements during level walking in scoliotic subjects that could be related to the spinal deformity. Additionally, the study examined the time domain parameters of the various components of ground reaction force together with the centre of pressure (CoP) pattern, assessed during level walking, which could be related to the spinal deformity. Although previous studies indicate that force platforms provide good estimation of the static balance of individuals, there remains a paucity of information on dynamic balance during walking. In addition, while research has documented the use of CoP and net joint moments in gait assessment and have assessed centre of mass (CoM)–CoP distance relationships in clinical conditions, there is little information relating to the moments about CoM. Hence, one of the objectives of the present study was to assess and establish the asymmetry in the CoP pattern and moments about CoM during level walking and its relationship to spinal deformity. The investigation employed a six camera movement analysis system and a strain gauge force platform in order to estimate time domain kinetic parameters and other kinematic parameters in the lower extremities, pelvis and back. 16 patients with varying degrees of deformity, scheduled for surgery within a week took part in the study. The data for the right and left foot was collected from separate trials of normal walking. CoP was then estimated using the force and moment components from the force platform. Results indicate differences across the subjects depending on the laterality of the major curve. There is an evidence of a relationship between the medio-lateral direction CoP and the laterality of both the main and compensation curves. This is not evident in the anterior-posterior direction. Similar results were recorded for moments about CoM. Subjects with a higher left compensation curve had greater deviation to the left. Furthermore, the results show that the variables identified in this study can be applied to initial screening and surgical evaluation of spinal deformities such as scoliosis. Further studies are being undertaken to validate these findings.
Custom SNP pools were designed for the candidate regions at a density of 1 SNP/58Kb. DNA from 550 individuals (AD group) were genotyped using the Illumina platform. A total of 1536 SNP markers were attempted, of which 1324 were released; 519 SNPs were genotyped on 9q32-24 and 805 SNPs genotyped on 16p12-q22. The map was generated using NCBI dbSNP chromosome report on Build 34. Overall missing rate was 0.06%; the overall duplicate error rate was 0.05%. FIS was analysed both as a qualitative trait with an arbitrary threshold, and as a quantitative trait, or the degree of lateral curvature. Model independent sib-pair linkage analysis was performed on the subsets (SIBPAL, S. A. G. E. v4.5).
Chromosome 9: Multipoint model-independent qualitative analysis (threshold at ten degrees) did not result in any p values of <
0.05. When the threshold was set at 30 degrees, several regions with p values of <
0.005 were observed. One region spanned 10 Mb, and coincides with the region found to be most suggestive of linkage at the 0.05 level for the quantitative analysis which was 6 Mb in length. Chromosome 16: Multipoint model-independent qualitative analysis (threshold at ten degrees) resulted in a region spanning 23Mb with p values of <
0.05. The region included both regions adjacent to the centromere. When analysis was performed at a threshold of 30 degrees, the p values became more significant within a region of 30 Mb significant at the 0.05 level. The region best defined at a 0.01 level was located in an 8 Mb region on the q arm.
Idiopathic scoliosis has been studied through centuries, but problems of its aetiology and pathogenesis up till now are the subjects of considerable discussion. Pathogenetic mechanism of the spine deformity development in idiopathic scoliosis (IS) was established on the basis of in-depth morphological and biochemical investigations of structural components of the spine in patients with IS (surgical material) (Zaidman A.M., et al. 2001). It was shown that IS develops on the basis of disturbance of proteoglycans (PG) synthesis and formation in vertebral growth plates. Decrease of chondroitin sulphate component of PG and increase of keratan sulphate one, as well as decrease in degree of sulphating of glycosaminoglycan (GAG) chains and increase of non-acetilated sugars – all this evidences for conformational changes in proteoglycans. The found keratan sulphate-related fraction is likely a marker of genetic changes in PGs in idiopathic scoliosis. Structural changes in PGs in combination with reduce of quantity of diffuse molecules which perform trophic and informational function, and disorders of receptor function of chondroblast membranes (ultra structural and histochemical findings) are the factors of disorders in regulation mechanisms of vertebral growth plate cells and matrix differentiation and reproduction. Long-term studies (Zaidman A.M., et al., 1999–2003) demonstrated a major-gene effect in Idiopathic Scoliosis. The next stage was major gene localization by the method for candidate gene testing. The aggrecan gene with known polymorphism of the number of tandem repeats in exon G3 was considered to be one of these candidate genes. Various alleles of this gene provide attachment of different number of chondroitin sulfate chains to a proteoglycan core protein, thereby changing functional properties of cartilage. The aggrecan gene AGC1 coding a core protein of aggrecan molecule has been localised to region 15q2b. In anald families nine alleles of aggrecan gene have been identified, among them three alleles with tandem repeats numbers of 25, 26, and 27 prevailed. We did not reveal preferable transmission of any of these alleles to the proband The absence of reliable association of IS with polymorphism of exon G3 can not be interpreted as a non-linkage of the whole aggrecan gene to IS development determination. As the linkage of other proteoglycans to IS development has not been excluded, we perform the RT-PCR and immunoblot analyses of the expression of main PG genes and their protein products in cultivated chondroblasts isolated from vertebral growth plates in 15 patients with III–IV grade IS (surgical material). The study has shown that aggrecan gene expression is significantly decreased in cultivated chondroblasts from patients with IS, what correlates with a decrease of synthesed protein product, both in cells (chondrocytes) isolated from IS patients and in cultural media. The presence of keratan sulphate-related fraction and keratan sulphate increase are associated with luminicene increase. In present we perform a sequencing of aggrecan genome.
Since the first pathography of Idiopathic Scoliosis (IS) and Scheuermann’s disease (SD) clinicians consider these two pathologies as separate nosological entities. The reason for this is different clinical implications of diseases. SD is known to be more common in boys, while IS is a sad privilege of girls. Kyphotic spinal deformity is typical for patients with Scheuermann’s disease while scoliotic one for patients with idiopathic scoliosis. Schmorl’s nodes are found more frequently in SD. Both deformities are attributed to the growth asymmetry, anterior growth plates are affected in SD and lateral ones – in IS. Despite different clinical presentations, these two nosologies have the same pathogenetic mechanism and semiology. To our regret, there are no reports on comparative morphological and biochemical investigations of SD and IS. Long-term studies have given rise to the question of a single nature of scoliotic and kyphotic spine deformities.
The potency for synthesis and structural organization of chondroblasts isolated from vertebral body growth plates of patients with IS and SD were subjects of morphological, biochemical, and ultrastructural analyses. Qualitative and quantitative composition of growth plates was investigated in culture mediums.
Morpho-histochemical study of the spine structural elements has revealed the same changes in patients with IS and patients with SD:
Disturbance of structural and chondral organization of cells and matrix in vertebral body growth plate. Decrease of chondroitin sulfate content and increase of keratan sulfate content. Lower response to oxidation-reduction enzymes in cytoplasm of chondroblasts. Change of the ultrastructural organization of cells: Golgi complex with flat vacuoles and enlarged cisterns of endoplasmic reticulum. Extracellular matrix with fragmented collagen fibrils and small fragments of proteoglycans.
Our knowledge of the incidence of scoliosis and scoliosis surgery is based on a few small scale studies. The National Health Service (NHS) in the United Kingdom has long collected data on hospital based activity. We have used a five year English database (1998–2002) of hospital admission statistics to study age-adjusted admission rates for scoliosis (code M41 in the International Classification of Diseases, 10th revision) and for two scoliosis surgery codes (V41 ‘instrumental correction of deformity of spine’ and V42 ‘other correction of deformity of spine’ (the latter includes ‘anterolateral release of spine for correction of deformity’).
Social deprivation – we were able to study this, and admission rates appeared independent of social deprivation. Availability of spine surgeons – this may be an explanation, but not very convincing. Scoliosis surgery is concentrated in 15 centres that do not obviously link with the variations we found. Variation in decision making about referral and/or treatment (by general practitioners, patients or surgeons). This is possible, but cannot be studied using our data. Regional genetic variation. Some of our maps were consistent with concepts of local biological variation, but are not very convincing. Incomplete or inaccurate coding in routine hospital statistics. Cannot be studied using our database alone.
Recent literature has reported multiple critical regions identified through linkage analyses to be potentially relevant in relationship to the aetiology of FIS. This is supportive of the concept that FIS is a complex genetic disorder resulting from multiple genetic interactions and variants. While these areas harbour multiple genes, the work to date has been crucial to our ability to focus and hopefully eliminate massive areas on the genome that are irrelevant to this disorder. As one reviews these genes, however, one should develop a potential algorithm for prioritization of candidate genes. Additionally, one should delve into potential biological mechanisms in relationship to the creation of a spinal deformity. If you were a gene causing scoliosis, what would you look like and how would you function? One approach to prioritization of candidate genes may be based on the virtue of their direct potential as a biological basis for the deformity, such as genes that encode for a protein of known function, the function of homologous proteins, and the tissue expression pattern. Within the localised region of chromosome 9, one such gene is COL5A1, a precursor for collagen type V alpha chains, a fibrillar forming collagen ubiquitously distributed within the connective tissues. A second group of genes may be those genes encoding regulatory proteins of the extracellular matrix. Transmembrane 4 superfamily, member 6 (TM4SF6) localised on the critical region on Xq22 is believed to span the cellular membrane with a role in cellular adhesion within the matrix. A third group of genes may maintain a temporal and/or spatial pattern of expression that may relate to the building of the axial skeleton itself. The Iriquois genes isolated on chromosome 5 play multiple roles in embryonic development including anterior/posterior and dorsal/ventral patterning of the central nervous system. Lastly, genes that do not have an intuitive relationship to scoliosis, but are localised within areas of strong linkage, will need to undergo analysis. Multiple examples exist within the reported critical regions within the literature to date. Another approach to the review of candidate genes within the regions is to think of known genetic disorders in which, 1) scoliosis is recognised as an element of the phenotype, and, 2) the gene and the biological mechanism of the disorder is well known. Immediate potential examples that come to mind are that of known collagen disorders such as osteogenesis imperfecta. The assumption that scoliosis is solely a result of mechanical load imposed upon abnormal connective tissue may be more elementary than what is truly occurring. Another example may be that of neurofibromatosis (gene – NF1). While this particular gene is localised near one of the identified regions, unfortunately, the biological function of the gene in relationship to phenotypic findings is still unknown. In conclusion, genetic research related to FIS to date has driven us to unbelievable expectations within a relatively short period of time. Further understanding of this complex disease will best be accomplished with thoughtful experimental, orderly design ultimately to have an impact in the therapeutic treatment of this disorder.
Primary Cobb angle, Secondary Cobb angle, Coronal C7-midsacral plumb line, Apical Vertebra Translation (AVT) of primary curve, AVT of the secondary curve, Upper instrumented vertebra (UIV) translation, UIV tilt angle, Lower instrumented vertebra (LIV), 8) LIV tilt angle Apical Vertebra Rotation (AVR) of the primary curve, Sagittal C7-posterior corner of sacrum plumb line T5-T12 angle, T12-S1 angle, shoulder height difference. The percentage improvements for each were noted. Correlation was sought between Total SRS score, each of the five individual domains and various radiographic parameters listed above by quantifying Pearson’s Correlation Coefficient (r).
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. coronal views of the line of spinous processes on the surface of the back and the line estimated to be through the centres of the vertebrae; lateral asymmetry, a parameter analogous to Cobb angle, is calculated from the latter. sagittal views of the line of spinous processes on the surface of the back, including kyphosis and lordosis data. 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.
The widely used classification systems (King and Lenke) are useful for documentation of the deformities. Unfortunately explicit guidelines for surgery are not clear. A multi-centre database with pre and postoperative patient data including photographic images and x-rays will be very useful in decision making. It will allow surgeons to find similar cases in the database that will help them in their decision making for surgical planning and execution. Furthermore it will provide extensive data to perform outcome studies, and to develop general treatment guidelines. Surgery for spinal deformities will become more evidence based and less dependent on the individual surgeons judgement.
The patient data can also be stored and printed as a PDF-file, so that it can be used as a patient chart and for patient information purposes. Scolisoft allows the user to select patients based on all the individual characteristics, e.g. curve classification. For pre-operative planning of a specific deformity, a cohort of patients with the same deformity (patient demographics, curve pattern, bending films etc) can be selected and the postoperative results viewed. With the same selection tool, cohorts of patients can be selected for outcome studies. Furthermore Scolisoft provides the possibility of discussing difficult cases with other spine surgeons using the system. Finally, complications are registered according to the existing Scoliosis Research Society complication registry system.
The system already has the possibility for documenting other spine pathology such as sagittal plane deformities, fractures and spondylolisthesis.
Scoliosis is the consequence of vertebral rotation. Each vertebra turns about a different axis which results into a global torsion of the spine. This torsion will yield characteristic modifications. On the frontal x-ray view one can notice the maximum projection of the deformity, usually estimated by means of the Cobb angle, whereas on the sagittal x-ray view a flat back will be observed. Indeed, scoliosis flattens sagittal physiological curvatures. Hyperkyphosis may occur only between two scoliotic curves (two adjacent flat back segments) or in case of vertebral rotation higher than 90° when the sagittal projection corresponds to frontal structures. In this last case, the maximum deformity is projected on the sagittal view. The vertebral rotation will also pull on the ribs, thus creating the rib hump.
Over the last decades, Harrington developed the distraction-compression technique, then Eduardo Luque proposed the spinal translation technique, and latter on Cotrel and Dubousset developed the rod rotation method that revolutionised spine surgery. By pulling on the concave side of the spine, the distraction-compression technique is intended to reduce the deformity shaft while dragging along the apex in a pure translation movement. The distraction is applied mainly onto the flexible segments, far from the apex. Therefore, the apex will hardly modify its relative position with regard to the other vertebrae. Besides, there is a high risk of spinal cord stretching on the concave side at the apex level. Furthermore, this technique is often associated with a high rate of post-operative flat back and requires postoperative cast and brace wear as the fixation remains fragile. Last but not least, the traction technique does not solve the rotation problem. On the contrary, traction increases the torsion forces and leads to higher rotation constraints. The spinal translation used to be performed by means of metallic wires passing under the lamina that were tightened around the rod. This technique of scoliosis correction was based on a totally different correction mechanism with regard to Harrington’s one. Indeed, medialisation of the apex results into a spontaneous increase of the intervertebral gap at the extreme levels of the curve. This distraction is automatic, and as a matter of fact it is impossible to apply it as the wires are sliding on the rod. The problem with spinal translation is that it cannot control rotation, neither with screws nor with hooks. Frontal X rays show that the anterior spine will always be located outside the rods pulling the posterior arch. This technique was improved by Asher and Chopin, who introduced screws and hooks. However it is still very difficult to decide on which side one should work, i.e. concave or convex side. The problem of rotation is still unsolved as anterior spine projection onto the x-rays is still next to and outside the rods. Rod rotation is the most popular technique nowadays as it allows rather good global correction. However, the thoracic correction does not follow the pathology path and therefore has no impact of vertebral rotation. This technique allows only slight adjustments, often very difficult to perform especially in the frontal plane. In 1993, we reviewed 52 scolioses operated with the rod rotation technique. All patients had undergone pre- and post-operative CT scan, so we could estimate the rotation correction. The results were highly disappointing as the vertebral rotation at the LEV (lower end vertebra) decreased of only 2.3°, while at the UEV (upper end vertebrae) level it was 1.1° higher after surgery, and at the apex level it remained almost unchanged (0.4° smaller). In conclusion, correction was obtained by vertebral translation, horizontalisation, forward and backward pushing of the vertebra, without any derotation. Several examples clearly reflected this mechanism, proved by the mobilization of the vertebrae with regard to the aorta. When looking at the path described by the vertebra, one can easily notice that the different techniques described above do not allow to follow the deformity path. Thus, the thoracic vertebra goes frontward and turns to the right. This circular movement has a posterior centre of rotation. Vertebral translation does not follow this path as it moved about the arch cord. The rod rotation performs a circular movement about an anterior centre of rotation. The correction and deformity paths describe an ellipse. We can conclude that these techniques will lead to high constraints within the spine. Hence the risk of neurological structures damage during correction manoeuvres. At the lumbar level, the apex moves backwards and to the left. Thus, it will describe an arch about a posterior rotation centre. The vertebra traction will move along the cord of this arch while the rod rotation will strictly follow the reverse pathology path. As the convex rod is linked to a hook or a screw, it will lead to a combined force of internal traction and anterior push. This convex push increases rotation by turning the screw in the sense of pathologic deformity. Therefore, the projections of the screws on the frontal x-rays will be oriented outside the rod, while the normal axis of the pedicle is about 20° oblique oriented toward the inside.
However, when performing in situ contouring, some security rules have to be strictly respected. First of all, the rod must be free to move, so implants must be closed around the rod but remain unlocked until the correction manoeuvres are finished. The rod mobility will allow the automatic spine stretching/shortening without dangerous constraints. Vertebrae must slide along the rod by means of the implants, i.e. screws and hooks, solidly attached to them. In other words, the spine, i.e. vertebrae, must be mobilised. To do so, the benders must be placed close to the implants. The other reason is to avoid high lever arms that would lead to high risky forces (loads). The correction principles are based on the vertebrae movement in space in order to enable a frontal and sagittal correction while working into the axial plane. To do so, the rod must have specific mechanical features: initial short elastic and long plastic domains. The correction manoeuvres on the rod will modify this mechanical behaviour and at the end of the correction manoeuvres the plastic domain will decrease wile the elastic one will increase. An initially too elastic rod would require stronger manoeuvres with regard to the residual correction, which may present some supplementary risk for neurological structures. The levels to be instrumented are selected as usual, as in situ contouring does not modify rules usually used in order to determine the strategic vertebrae. The strategic vertebrae are selected depending on the information provided by bending tests. Thus all discs that do not open in both directions will be included into the fused segment.
The rod will be contoured towards the inside and backwards for all instrumented levels. These manoeuvres will allow the medialisation of the apex while restoring kyphosis. At the same time, these actions will lead to a derotation of the apex. The contouring manoeuvres are performed iteratively starting from the apex towards the limits of the curvature through successive manoeuvres in the frontal plane and in the sagittal plane. Contouring is over when required correction is obtained and when the rod modified its mechanical behaviour and became too elastic to allow further contouring. The apex follows the deformity path. Thus the vertebra moves backwards and towards the inside, describing a circular movement similar to the deformity path in the opposite sense. Therefore, three-dimensional correction of both mild and severe (>
100°) thoracic scolioses. However, the purpose of the surgery should not be to have a straight vertical rod, but to obtain the best possible spinal balance with the best possible correction in the three planes.
To do so, derotation blocks are placed on the screws heads so that the assistant can turn them while the surgeon is performing the forward contouring manoeuvres that will allow lordosis restoration. This mobilization perfectly follows the deformity path and replaces the spine between the rods. This technique may be used both for mild and severe scoliosis correction in the three planes. To facilitate correction and to maintain it on a long term basis, posterior release and posterior fusion may not always enough. In this case, anterior release and grafting may be required. Anterior approach may be facilitated by video assistance. Thoracoscopy will be preferred between T3 and T11, while video assistance is recommended for the thoracolumbar and lumbar regions. Anterior release associated with in situ contouring does provide significant correction especially in severe scoliosis as well as in stiff curvatures in the adult.
We could consider that the pedicular hook prevents from important detorsion in the thoracic spine, as it will not allow important derotation of vertebrae. This is why we had to design a new pedicular implant that was meant to provide bilateral support during correction manoeuvres. The so called bipedicular implant is linked to the vertebra at the costo-vertebral joint level holds the pedicle on its lateral side. This new implant enables a double action, i.e. posterior traction combined with concave medialisation and convex push. Thus the vertebra moves as a wheel, describing a global movement of derotation. We have used this implant for two years now and we had no particular drawbacks as far. No tolerance problems were noted either. Derotation blocs allow for the combination of rotation movements at the thoracic and lumbar levels while the rod is contoured to reach the best possible curve correction.
Reductions in radiation exposure of x8 to x10 fold in 2D, and x800 to x1000 in 3D. It gives data from standing imaging compared with supine in a CT scanner. It allows imaging of the skeleton from head to foot, which in CT imaging demands excessive radiation. It allows surface reconstruction from head to foot It can be used with a force plate to indicate gravity forces It, uniquely, can give a view of the skeleton from the top It can measure thoracic cage volume It can assess the effects of bracing When combined with other non-invasive methods of measurement, can help to define operative procedures Overall it provides a new approach to assessing spinal deformity both in the horizontal plane and in volumetric measurement.
Examination of sitting children and consequent testing of muscular tightness can be useful in understanding the different disturbances of growth that keep the spine apparently away from an optimal configuration and thereby optimal function. Prolonged sitting of children exists only 200 years or less.
- Better understanding of the role of the central nervous system, especially the cord and roots in proper and improper growth of the human spine. - Clarifying that lordosis and good function at the tho-racolumbar junction at the end of growth can be a condition sine qua non for normal configuration and function of the spine in adult life.
- Present obvious important and consistent clinical observations in children in sitting and supine position with early and advanced adolescent deformities, both kyphotic and scoliotic by photographic studies and video fragments. - Present results of own study in which a lordotic force give significant correction of all curves in Adolescent Idiopathic Scoliosis. - Revisit the, for the greater part unknown, experimental work on growth and deformation of the spine by Milan Roth in German and Czech literature to disclose a tension-based balancing system between central cord and the osseous and discoligamentary spine (uncoupled neuro-osseous growth). - Relate these clinical and experimental findings with common knowledge about adolescent spinal deformities and mechanical laws on tensile and compressive forces in structures.
Extended clinical examination of children with proven or suspected spinal deformities revealed a complex of consistent findings in different sitting positions and functional tests in supine and standing positions.
Anatomical and biomechanical consequences of keeping the spine upright in standing, but more important in the sitting positions seems to fit. Children do sit for prolonged periods only in the last one or two centuries! It can be shown that the presence of these tension related clinical signs are easily leading to high compressive forces with deformation of the ventral parts in the TL-junction while sitting In literature evidence of torsion facilitating anatomical features can be found to clarify why some spines deform in scoliosis an not in pure kyphosis
diagnosis of AIS King type II and III, younger than 21 years, not operated before. A total of 247 patients met the inclusion criteria and they were divided in two groups:
thoracic curve less than 90° and more than 90°. In the group (A) there were 168 patients (male/female – 11/157, mean age 15.3 years), in the group (B) – 79 patients (male/female – 8/71, mean age 15.5 years). Coronal curve flexibility was assessed on supine side-bending AP radiographs. According the type of surgical technique the patients were divided in four groups:
I - CDI correction II - CDI + skeletal traction III - anterior apical release with interbody fusion and CDI IV - anterior apical release, skeletal traction and CDI. All the operations in the groups III and IV were performed in one session.
So, CDI adds only 9.1° to side-bending correction (Gr. I) and skeletal traction gives 5.8° more (Gr. II). Anterior release with CDI improves preoperative correction by 14.7° (Gr. III) and the same procedure with skeletal traction – by 30.0° (Gr. IV). Consequently the part of the skeletal traction varies from 5.8° to 6.2°. Anterior release in its turn gives 14.7° of additional correction per se and 20.9° with skeletal traction. In the group (B) mean thoracic curve before surgery was 109°, on the side-bending films 90.6° and after surgery 54°. The corresponding data according the type of surgery are presented in Table 2. So, CDI adds 26.3° to side-bending correction (Gr.I) and skeletal traction gives only 1.9° more (Gr.II). Anterior release with CDI improves preoperative correction by 25.9° (Gr.III) and the same procedure with skeletal traction – by 40.6° (Gr.IV). Consequently the part of the skeletal traction varies from 1.9° to 14.7°. Anterior release in its turn does not give additional correction per se and 12.2° – with skeletal traction.
Recently we showed in patients treated with Harrington instrumentation with sublaminar wiring (second generation technique) that the correction of the lumbar curve was not a reflection of the thoracic correction. So it is interesting to know whether with the use of third generation instrumentation techniques and more sophisticated classification systems the correlation of the unfused lumbar cure becomes more predictable.
Open anterior surgery, including release and instrumentation, is a widely used technique for correction of dorsal and dorsolumbar curves. In the past we have used various different devices to maintain correction. These include Dwyer cable, Zeilke rods, Webb-Morley rods, vertebral staples and the Kaneda system. Any of these can be combined with posterior correction, stabilization and grafting. Several of these techniques have been successfully adapted for the treatment of our cases in Egypt. We encounter severe deformities due to their late presentation. Over the last five years we have used anterior endoscopic release. All had posterior instrumentation.
The results are very encouraging regarding degree of correction; hospital stay; and costs as compared with our historical series of conventional two-stage surgery. There are a number of constraints on using endoscopic techniques. Surgeons require long training and close co-operation. It is contraindicated in those cases with adhesions and patients unfit for one lung anaesthesia. We found the technique is safe and effective. We recommend it for treatment of rigid curves to gain good results and to reduce hospital costs.
Anterior instrumentation is an established method of correcting King I adolescent idiopathic scoliosis. Posterior segmental pedicle screw instrumentation, with its more powerful corrective force over hooks, could offer significant advantages. The purpose of our study is to compare the results of anterior instrumentation versus segmental pedicle screw instrumentation in adolescent idiopathic thoracolumbar scoliosis. A retrospective analysis was conducted on 36 consecutive female patients with adolescent idiopathic thoracolumbar scoliosis who had surgery from December 1997. All had a minimum of two year follow-up. Eleven patients had posterior surgery performed on them. Mean age at surgery was similar between both groups. Length of surgery was significantly shorter in the posterior group (189 minutes versus 272 minutes). Length of hospital stay was shorter in the posterior group (6.2 days versus eight days). Estimated blood loss, duration of analgesia, and ICU stay did not differ significantly between the two groups. No complications were encountered in both groups at latest follow-up. The magnitudes and flexibility of the thoracolumbar curves did not differ significantly between the two groups. The number of levels in the major curve was also similar between the groups. Fusion levels were shorter in the anterior group (mean 4.1 versus 5.0). The percentage correction of scoliosis was similar between the two groups at all stages of follow-up, being 74% at one week post-surgery, 70% at six months post-surgery, 68% at one year post-surgery and latest follow-up in the anterior group; and 71% at one week post-surgery, 67% at six months post-surgery, 68% at one year post-surgery, and 67% at latest follow-up in the posterior group. Thoracolumbar sagittal alignment at T11 to L2 was maintained for both groups throughout the follow-up period. The incidence of proximal junctional kyphosis was higher in the posterior group (p <
0.01). In conclusion, surgical correction of both the frontal and sagittal plane deformity are comparable to anterior instrumentation. Shorter length of surgery and hospital stay are the potential benefits of posterior surgery. Posterior segmental pedicle screw instrumentation offers significant advantage, and is a viable alternative to standard anterior instrumentation in idiopathic thoracolumbar scoliosis.
Posterior instrumented fusion is an established surgical treatment for majority of AIS cases. In the past decade, thoracoscopic instrumentation and fusion has emerged as a viable alternative to conventional posterior techniques in situations that require selective thoracic fusion. Most reports comparing the two techniques have focused on physician-based outcomes such as curve correction and maintenance of the surgical correction with both methods being comparable. Recently, the SRS-24 has been used to evaluate patient-based outcomes after scoliosis surgery. The instrument assesses seven equally-weighted domains that look at pain, self-image, general function, activity level, change in self-image and function post-surgery, and satisfaction with the procedure. It has been used to evaluate differences between AIS and normal patients, and in different degrees of AIS deformity. The instrument has not been used in comparing different methods of surgical treatment for similar curve types. We applied the SRS-24 prospectively to our patients who had undergone either thoracoscopic (TG) or posterior (PG) instrumented fusion, and had been followed-up for at least 12-months postoperatively. There were 42 patients in TG and 42 patients in PG. The mean age at time of surgery, pre-operative Cobb angles, and number of spinal segments fused were similar in both groups. The mean follow-up period at the time the SRS instrument was administered was 26 (± 13.5) months for TG and 30.7 (± 12.1) months for PG. The postoperative Cobb angle on the latest follow-up was significantly better for TG compared to PG (17 versus 25.1 degrees, respectively; p <
.001). Upon comparing the SRS domain scores between both groups, a significant difference was noted only in the patient satisfaction domain with TG scoring better than PG (p <
.02). The first four SRS-24 domain scores for TG and PG were also compared to the corresponding domain scores of 97 patients who had scoliosis but were not candidates for surgery (SG), as well as to the scores of 72 patients who did not have scoliosis (NG). SG, TG, and PG were comparable with regards to pain and all three were significantly lower compared to NG (F=14.828, p <
.0001). General function and activity level scores of TG were significantly lower compared to the other three groups (F=4.870, p <
.003 and F=4.793, p <
.003, respectively). Despite this, the self-image domain scores of both TG and PG were not significantly different from NG, with SG scoring significantly poorer compared to the other three groups (F=3.183, p <
.02). In summary, thoracoscopic instrumented fusion resulted in better curve correction compared to posterior instrumented fusion and was achieved with less spinal segments being fused. This was despite the finding that patients who underwent thoracoscopic surgery had lower physical function and activity level scores. Additionally, both surgical techniques resulted in patients whose perception of themselves was comparable to those patients who did not have scoliosis. The SRS-24 was not able to detect any differences between the two surgical methods in all domains except for overall patient satisfaction which was significantly better in the thoracoscopic group.
Thoracoscopic spinal instrumentation and fusion has emerged as a viable alternative to open anterior and posterior techniques for the treatment of thoracic adolescent idiopathic scoliosis. Furthermore, the morbidity associated with thoracoscopy is limited, and the cosmetic result more desirable because of the minimal skin and chest wall dissection required with this method. However, the technique is technically demanding and has been perceived as having a steep learning curve. The objective of our study is to anal the initial series of 50 patients performed by a single surgeon, with respect to the coronal and sagittal alignment on radiographs, as well as a review of the peri-operative data and complications. Fifty consecutive patients who underwent thoraco-scopic instrumentation and fusion were divided into two groups for the purpose of this study: the first 25 cases (1st group) and the second 25 cases (2nd group). The minimum follow-up of these cases was 12 months (range 12 to 67 months). Data collected included the operative time, intra-operative blood loss, number of levels instrumented, length of the hospital stay, the number of days in the ICU, and the duration of analgesia. No major complications, such as neurological deficit, vascular injury, or implant failure were observed. No significant difference was encountered between the groups in terms of age and menarche at surgery, pre-operative curve magnitude and flexibility, sagittal profile, as well as the number of levels in the curve pre-operatively. The second group had significantly better coronal deformity correction at one week post-operatively (9.5 degrees versus 16.3 degrees, p <
0.001), six months post-operatively (12.1 degrees versus 18.9 degrees, p <
0.001), and at latest follow-up (15.1 degrees versus 19.5 degrees, p <
0.05). The percentage correction of scoliosis was significantly better in the second group at one week postoperatively (p <
0.001), six months post-operatively (p <
0.001), and at latest follow-up (p = 0.014). The percentage change in thoracic kyphosis and lumbar lordosis after surgery was not significantly different between both groups at various times of follow-up. There was no difference between both groups with regards to the number of levels fused, hospital stay, and duration of parenteral analgesia. Operative time was significantly less in the second group (302 minutes versus 372 minutes, p <
0.001). Estimated blood loss was also less in the second group (170 cc versus 266 cc, p = 0.04). The length of ICU stay was also shorter in the second group (1.8 days versus three days, p = 0.004). From the loess (locally-weighted regression) fit, the learning curve is estimated to be 30 cases with regards to the operative time, ICU duration, and the coronal plane deformity correction. The learning curve associated with thoracoscopic spinal instrumentation is acceptable. The complication rates remained stable throughout the surgeon’s experience. Thoracoscopic anterior instrumented fusion is a viable surgical alternative to standard posterior fusion and instrumentation for adolescent idiopathic scoliosis requiring selective thoracic fusion.
Research project supported by La Fondation Yves Cotrel de l’Institut de France
Research project supported by La Fondation Yves Cotrel de l’Institut de France
In our earlier study we found 61% of the controls taken swimming in the first year of life had vertical spinous process asymmetry. In the subsequent smaller study the incidence even higher (83%).
The evidence reported in our earlier paper suggests that infants introduced to indoor heated swimming pools in the first year of life show an association with spinal asymmetries including progressive AIS and in controls vertical spinous process asymmetry. Subject to confirmation of our observations consideration should be given to chemical risk factors, possible portals of entry, environmental epigenomics and disease susceptibility to altered spinal development. Subsequent controls confirm that the introduction to indoor heated swimming pools in the first year of life is associated with the development of spinal asymmetries.
Genetic factors and impairment of central nervous system (CNS) are known factors in aetiology of adolescent idiopathic scoliosis. MRI pathology of CNS (brain asymmetry, syringomyelia) was found. Perinatal pathology could cause damage of CNS.
In the AIS group, the mean onset of right thoracic curve was 12,2 years, apex vertebrae were T7 – T11 (T8 in 8 cases, T8–9 in 5, T9 in 12 cases), mean Cobb angle measured 49,0 degrees (SD 14,500), thoracic kyphosis T3-T12 19,9 (SD 12,167), lumbar lordosis T12-S1 –53,1 (SD 8,338). A questionnaire was created to identify parental age, diseases, mother diseases and remedies during pregnancy, pregnancy duration, child resuscitation, childbirth pathology, incubator, jaundice duration, diseases during the first year of life, beginning of sitting and standing, right or left handing. Results have been processed by software Statistica 7.1. StatSoft, Inc. (2005). For evaluation of potential difference between AIS and N groups two-sample t-test for continuous parameters was used. Two-sample t-test and Fisher test were testing the hypothesis that the values of parameters make no difference between two groups (on the 0,05 significant level).
- Occurrence of familiar scoliosis in AIS group – nine out of 39, 0 in N group. - Child diseases during the first year of life in N group –18 out of 28 in N, 10 out of 39 AIS. - Early sitting in AIS group (6,5 months), 7,6 in N. - More males in N group (15 out of 28), 8 out of 39 in AIS.
AIS has different image than paralytic scoliosis or scoliosis accompanying some diseases of the spinal cord in electromyographical and electroneurographical examinations (EMG and ENG). These differences are concerned to different progression, characteristic properties in skeletal system pathology or curves angles at the thoracic and lumbosacral spine. There are always two sites in patients with AIS where changes in transmission from the motor cortex to the motoneuronal centres in lumbosacral region appear. These phenomena were shown in motor evoked potentials studies which were induced with the magnetic field (MEP) in areas of motor cortex and recorded from centres of cervical and lumbosacral spinal cord as well as from muscles of upper and lower extremities. Changes in efferent transmission are greater twice in recordings from muscles of lower extremities and in oververtebral recordings at L5-S1 regions what suggests, that secondary slowing down takes place at the level of the apical thoracic vertebrae of primary curve (mostly at Th7–8), predominantly on the concave than convex side of scoliosis. MEP study confirmed a previous finding with somatosensory evoked potentials (SEPs) similarly about two focuses of disturbances in of afferent transmission on the spinal centres-supraspinal centres pathway. MEP showed changes in the efferent transmission on the supraspinal centres-spinal motor generator pathway. Such changes are not observed in scolioses other than idiopathic. Results of the complex neurophysiological studies suggest that the primary origin of AIS is the brain stem area at the level of thalamus where changes of afferent and efferent transmission are detected. There is a close relationship of this structure with the pineal gland and secretion of neurotransmitters at this level in correlation to disturbances in melatonin secretion and other neurohormones. Disorders in melatonin secretion and other neurohormones may induce a scoliosis what was shown in previous genetic and experimental neurophysiological studies on animals, together with cutting of the pineal stalk. Some aspects of this problem were also mentioned in our previous clinical neurophysiological studies [1–3]. Results of studies suggest that in patients with AIS, there are structural and functional changes in the area of thalamus, which cause disturbances in afferent and efferent transmission at this level. Pathology in the pineal secretion of neurohormones can be one of the factors influencing the formation and progression of AIS, as a disease of probably secondary origin to the functional changes in brain. Results of MEP studies discussed in this report confirm that the primary origin of AIS takes place at the level of the brain stem but not in the spinal cord.
Radiological diagnosis is not the only tool in detection, monitoring of progress and making easy to undertake a decision about the surgical scoliosis correction. The below presented algorithm of scoliosis monitoring with complex and repetitive (comparative) neurophysiological examinations facilitates the doctor’s decision about method of the conservative treatment or just the moment of surgical intervention [3, 14]. Neurogenic changes in muscles can be found in early stages of the spine deformation – usually when the Cobb’s angle is over 100 [1]. Vertebral rotation and curvature progression follow simultaneously leading to deformation of the spinal cord together with the local ventral roots compression and sometimes inflammation of them. The structure of the grey matter especially in the ventral horn changes its form more on the convex side of scoliosis. Cell bodies together with the axonal hillocks in the motoneuronal pools show deformations comparing to the analogical area of the concave side. This produce discrete unilateral axonopathy in both efferent fibers of peroneal and tibial nerves in scoliotic patients at the age of about 10. This can be found in electroneurographical (ENG) recordings of M and F potentials even at the angle of scoliosis of 100 [10, 14]. Both parameters of the amplitudes and conduction velocities in M-wave studies are decreased and the frequency of F wave recording is diminished what suggests pathological asymmetrical changes just at the level of the ventral root. That is why electromyographical (EMG) recordings show asymmetrical, according to the ventral root somatotopical innervation, selective (found only in some muscles) deficits in frequency and amplitude of motor units action potentials, predominantly in girls. These girls have scoliosis accelerating the most with angle changes of 50 per year [2] that rapidly deepens the neurogenic changes. Other significant evaluation of the scoliosis acceleration is using the somatosensory evoked potentials (SEPs) for recording progression of pathology in the afferent transmission within the long ascending spinal cord pathways running in dorsal, dorsolateral and lateral funiculi [4, 5]. Changes in parameters more amplitude than conduction velocity from SEPs studies recorded at the cervical level are more visible on the concave than convex side of scoliosis. These changes are correlated with increasing the Cobb’s angle at the apical thoracic vertebrae (Th7–8) while peripheral sensory transmission remains only slightly disturbed [6, 7]. These changes were found to be twice greater when recording of SEPs was performed over cranially on the contralateral side of the scalp to the stimulation site at the ankle (tibial nerve than peroneal nerve fibers excitation) both in mothers and their daughters [4]. This points at the strong inhibition of the afferent transmission at the level of the brain stem (probably thalamus or medial lemniscus). During the comparative SEPs recordings at the cervical level, when parameters of waves change dramatically (or even they disappear), this may suggest that the lateral angle of scoliosis exceeded 450 with great acceleration of the torsion [9]. Somatosensory evoked potential recordings during the surgical correction of scoliosis showed only rarely the immediate improvement of the afferent transmission [7, 8, 11]. However, they make sure a surgeon about lack of blockade within the spinal pathways which comes from derotation and distraction procedures performed on the spine during implantation of the corrective instrumentation. First visible results of improvement in the SEPs parameters recorded postoperatively are usually seen a week after the surgery [14]. The above analogical phenomena but referring to the efferent transmission were shown in motor evoked potentials studies which were induced with the magnetic field (MEP) in areas of motor cortex and recorded from centres of cervical and lumbosacral spinal cord as well as from nerves and muscles of upper and lower extremities [12,13, 15]. Usually when AIS reaches the Cobb’s angle of 200 at the age of 25 and does not progress more it can be assumed, that its development is finished. In these patients the signs of neurogenic changes found in EMG examinations performed in lower extremities, paravertebral and gluteal muscles do not progress, too [14].
To develop a model that incorporates pedicle growth and growth modulation into an existing finite element model of the thoracic and lumbar spine already integrating vertebral growth and growth modulation Using the model to investigate whether pedicle asymmetry, either alone or combined with other deformations, could be involved in scoliosis pathomechanisms.
Patterns of extra-spinal skeletal length asymmetry have been reported for upper limbs [1] and ribcage [2] of patients with upper spine adolescent idiopathic scoliosis. This paper reports a third pattern in the ilia. Seventy of 108 consecutive adolescent patients referred from routine scoliosis school screening during 1996–1999 had lower spine scoliosis – lumbar (LS), thoracolumbar (TLS), or pelvic tilt scoliosis (PTS). Radiologic bi-iliac and hip tilt angles were both measurable in 60 subjects: LS 18, TLS 31, and PTS 11 (girls 44, boys 16, mean age 14.6 years). Cobb angle (CA), apical vertebral rotation (AVR) and apical vertebral translation from the T1-S1 line (AVT) were measured on standing full spine radiographs (mean Cobb angle 14 degrees, range 4–38 degrees, 33 left, 27 right curves). Bi-iliac tilt angle (BITA) and hip tilt angle (HTA) were measured trigonometrically and iliac height asymmetry calculated as BITA minus HTA (corrected BITA=CBITA) and directly as iliac height asymmetry. Iliac height is relatively taller on the concavity of these curves (p<
0.001). CBITA is associated with Cobb angle, AVR and AVT (each p<
0.001).
In schoolchildren screened for scoliosis about 40% have minor, non-progressive, lumbar scolioses secondary to pelvic tilt with leg-length and/or sacral inequality [1] not reported with preoperative thoracic curves [2]. Forty-nine of 108 consecutive adolescent patients referred from routine scoliosis school screening during 1996–1999 had lower spinal scoliosis with measurable radiological sacral alar and hip tilt angles – lumbar scoliosis 18, thoracolumbar scoliosis 31 (girls 41, boys 8, mean Cobb angle 16 degrees, range 4–38 degrees). In standing full spine antero-posterior radiographs measurements were made of Cobb angle and pelvic asymmetries as sacral alar and iliac heights (left minus right). From anthropometric measurements derivatives were calculated as ilio-femoral length (total leg length minus tibial length) and several length asymmetries, namely: ilio-femoral length asymmetry, total leg length inequality and tibial length asymmetry (all left minus right). Ilio-femoral length asymmetry correlates significantly with sacral alar height asymmetry (girls negatively r= − 0.456, p=0.002, boys positively r=0.726 p=0.041) but not iliac height asymmetry (girls p=0.201) from which three types are identified. Total leg length inequality but not tibial length asymmetry in the girls is associated with sacral alar height asymmetry (r= − 0.367 p=0.017 &
r=0.039 p=0.807 respectively). Interpretation is complicated by total leg lengths each including some ilium in which there is asymmetry [3]. But lack of association between ilio-femoral length asymmetry and iliac height asymmetry suggests that the femoral component is more important than iliac component in determining the associations between sacral alar height asymmetry and each of ilio-femoral length asymmetry and total leg length inequality.
Sacral alar height asymmetry and leg length asymmetries. The evidence suggests that sacral alar height asymmetry is not secondary to the leg length inequalities at least in most girls (negative correlations) and is more likely to result from primary skeletal changes in femur(s) and sacrum. Sacral alar height asymmetry and Cobb angle. Scoliosis progression and iliac height asymmetry [3] appear to need factors additional to those that determine ilio-femoral length asymmetry – for in the girls Cobb angle is associated with both sacral alar height asymmetry and iliac height asymmetry (each p<
0.001) but not with either ilio-femoral length asymmetry (p=0.249) or total leg length inequality (p=0.650). The additional factors may be biomechanical [4], and/or biological in the trunk [5] and central nervous system [6].
In idiopathic scoliosis the detection of extra-spinal left-right skeletal length asymmetries in the upper limbs, ribs, ilia and lower limbs [1–7] begs the question: are these asymmetries unconnected with the pathogenesis, or are they an indicator of what may also be happening in immature vertebrae of the spine? The vertebrate body plan has mirror-image bilateral symmetries (mirror symmetrical, homologous morphologies) that are highly conserved culminating in the adult form [8]. The normal human body can be viewed as containing paired skeletal structures in the axial and appendicular skeleton as a) separate left and right paired forms (e.g. long limb bones, ribs, ilia), and b) united in paired forms (e.g. vertebrae, skull, mandible). Each of these separate and united pairs are mirror-image forms – enantiomorphs. In idiopathic scoliosis, genetic and epigenetic (environmental) mechanisms [9–11] may disturb the symmetry control of enantiomorphic immature bones [12–13] and, by creating left-right endochondral growth asymmetries, cause the extra-spinal bone length asymmetries, and within one or more vertebrae create growth conflict with distortion as deformities (= unsynchronised bone growth concept) [14].
In subjects with lumbar, thoracolumbar or pelvic tilt scoliosis no pattern of structural leg length inequality has been reported [1]. Forty-seven girls of 108 consecutive adolescent patients referred from routine scoliosis school screening during 1996–1999 had lower spinal scoliosis – lumbar (LS) 17, or thoracolumbar (TLS) 30 (mean Cobb angle 16 degrees, range 4–38 degrees, mean age 14.8 years, left curves 25). The controls were 280 normal girls (11–18 years, mean age 13.4 years). Anthropometric measurements were made of total leg lengths (LL), tibiae (TL) and feet (FL) by one observer (RGB) and asymmetries calculated for LL, TL and FL, as absolutes and percentage asymmetries of right/left lengths. There are no detectable changes of absolute asymmetries with age for LL, TL or FL in scoliotic or normal girls. Asymmetries are found in scoliotic girls compared with normals with relative lengthening on the right for each of LL (0.95%) and TL (0.99%) (each p<
0.001), but not FL (0.38%).
Nachemson [2] suggested that there are more girls than boys with progressive AIS for the following reason. The maturation of postural mechanisms in the nervous system is complete about the same time in boys and girls. Girls enter their skeletal adolescent growth spurt with immature postural mechanisms. So, if they have a predisposition to develop a scoliosis curve, the spine deforms. In contrast, boys enter their adolescent growth spurt with mature postural mechanisms so they are protected from developing a scoliosis curve. We termed Nachemson’s concept the neuro-osseous timing of maturation (NOTOM) hypothesis and used it to propose a possible medical treatment for idiopathic scoliosis by delaying puberty through the pituitary using gonadorelin analogues as in idiopathic precocious puberty [3,4]. The prevalence of scoliosis is reported to be increased in rhythmic gymnasts (RGs) in Bulgaria [5] and in ballet dancers (BDs) in the USA [6]. Both groups exhibit delayed puberty, which, at first sight, nullifies the NOTOM hypothesis for idiopathic scoliosis. There are similarities between scoliotic RGs and BDs that include intensive exercise from a young age, dieting, delayed menarche, increased scoliosis prevalence (RGs 12%, BDs 24%), mild scoliosis curves (10–30 degrees), and presumably generalised joint laxity. Other differences in addition to country of origin and exercises, include certain anthropometric features and importantly in RGs, thoracolumbar and lumbar curves and, in BDs, right thoracic curves. While constitutional and environmental factors may determine the scoliosis, the different curve types in RGs and BDs suggest that the exercise pattern over many years determines which type of scoliosis develops, although not the curve severity.
It is customary to analyse scoliosis as a mechanical failure: first there is a straight spine (=normal), then an habitual and collapsing posture (=disease) and finally, structural remodelling (Hueter-Volkmann effect = scoliosis). This hypothesis makes two practical predictions:
There is a disease process causing the pathological posture. The purpose of gatherings such as this is to identify this pathology, thus far without success. Early diagnosis will permit early non-operative treatment which will halt or reverse the remodelling and reduce the occurrence of severe deformity and the need for corrective spinal surgery. The failure of school scoliosis screening to achieve this end is well documented, but the consequence for the underlying hypothesis has not been analysed. Screening failed, not because it was unable to detect scoliosis, but because scoliosis did not behave as the hypothesis predicted.
We are comparing the above two techniques with 25 patients in each group operated by 3 surgeons. The first group had conventional laminoplasty and the second group underwent the skip laminectomy. The groups were comparable in age, sex, pathology and clinical presentation. Both these group had clinical outcome measurements using SF 12 questionnaires, pre and postoperative clinical assessment with standard tools performed by independent surgeon and a specialist spinal physiotherapist. We also routinely performed pre and postoperative MRI scans to assess the adequacy of decompression.
Pre and post procedure pain and physical function scores were noted using the standard SF 36 questionnaire, as well as whether subsequent surgery was required. Mean follow up time was seven months (range 2–13 months).
>
70% patients reported improvement in neck disability index and >
50% patients reported improvement in myelopathy disability index.
There is an increasing awareness of the need to avoid of homologous blood transfusion in elective surgical practice. This stems from a better appreciation of the adverse effects of homologous blood transfusion and increasing pressure on blood stocks because of increasing restrictions on potential donors. This study examines the effect of using modern blood conservation methods on the subgroup of our patients having surgery for adolescent idiopathic scoliosis. We chose this group because it is a homogenous group of patients of similar age, all of whom had major surgery of a similar severity, and in whom there were few contraindications to our blood conserving strategies. We studied 78 consecutive patients with adolescent idiopathic scoliosis who underwent surgery. They were divided into two groups. Patients in the study group had one or more modern blood conservation measures used perioperatively. The patients in the comparison group did not have these measures. There were 46 patients in the study group and 32 in the comparison group. Eight patients who had anterior only surgery, were excluded. The two groups did not differ in age, body weight, and number of levels fused or the type of surgery. Only 2 patients in the study group were transfused with homologous blood and even these transfusions were off protocol. Wastage of the autologous predonated units was minimal (6/83 units predonated). In contrast all patients in the comparison group were transfused homologous blood. There was significant decrease (p = 0.005) in the estimated blood loss when all the blood conservation methods were employed in the study group. Using blood conservation measures, lowering the hemoglobin trigger for transfusion and education of the entire team involved in the care of the patient can prevent the need for homologous blood transfusion in patients undergoing surgery for adolescent idiopathic scoliosis.
We describe a technique using orthoganol imaging on a radiolucent table, used in a series of patients in whom we have inserted a total of over 2000 screws.
Furthermore, the lateral to medial or ‘toeing in’ of screw placement gives greater pull out strength to each screw by increasing the ‘volume’ of bone that has to be overcome before failure by pull out occurs. In addition this trangulation technique allows insertion of :screws of greater diameter than the pedicle and decreases the chance of broaching medially.
We describe results of a new ‘two needle technique’ of selective nerve root blocks done through posterior triangle of neck in the management of cervical radiculopathy with 2 year results.
Unpaired “t” test was used to compare the magnitude of correction in both groups. The mean follow up period was 6.7 months (range:3–18). The mean corrections of Cobb angle, AVR and AVT, in group I were 61.1% (range:48.5–83.9), 33.3% (range:8.6–100) and 62.9% (range:43.2–91.4), respectively. In Group 2 the corrections were: 57.4% (range:21.4–81.7), 57.2% (range:16.7–100) and 58.7% (range:34–80.9). There is no statistically significant difference between the correction of Cobb angle or AVT in both groups (P=0.479 and 0.443 respectively). However, the pedicle screws proved to be more effective at correcting the AVR (P= 0.017). No complications occurred and correction has been well maintained.
We performed a retrospective review of case notes and X-rays. A control group of 22 patients, in whom anterior surgery was completed, matched to age, sex and type of curve, was used.
Of the seven patients with lost signal three were syndromic and four were associated with syrinx. In all seven, loss of signal occurred on clamping of segmental vessels. All seven had no residual neurological deficit post-operatively and had uncomplicated posterior correction the following week. All four patients in whom inadequate correction was achieved after anterior release and repositioning had idiopathic curves. Of these two were thoracic and two were thoracolumbar. Mean pre-operative Cobb angle was 67 (range 59–85) compared to a mean of 56 (range 42–68) in the control group. Mean pre-operative stiffness index was 91% (range 85%–100%) compared to a mean stiffness index of 65% (range 53–80) in the control population.
Predictive value for traction view according to standing Cobb angle was P=0.1 for Cobb angles (50–59), P=0.1 for Cobb angles (60–69), P= 0.01 for Cobb angle (70–79), P=0.01 for Cobb angle (80–90). P value for the difference between fulcrum bending views, traction views and post op correction P=0.001 in favour of traction views, the mean curve flexibility was 33%, 55% for fulcrum and traction respectively. Mean fulcrum bending and traction correction index were 232%, 123% respectively.
We present in this study our experience in wide decompression, gradual acute reduction and fusion performed in a single sitting, for high grade spondylolisthesis in 17 adolescent cases. Between 1994 and 2005 we undertook surgical management of 17 adoloscents with high dysplastic Spondy-lolisthesis. All our patients were young females except for one with average age of 13.9 years. All of our cases involved the lumbosacral junction. 8/14 cases presented with frank spondyloptosis (Grade5). Of the remaining 9 cases, 5/14 cases were grade4 and 4/14 were grade3 dysplastic spondylolisthesis respectively. Our indication for surgery in all these patients was unremitting back pain, radicular pain, abnormal posture, gait abnormalities and progressive slip. All these patients underwent single stage wide decompression, posterior instrumentation and reduction of the slips and postero lateral fusion. Since 1999 in addition to the above we routinely performed inter body fusion with cages in lumbosacral segment (9/17 cases). All patients’ spondylolistheses were reduced to <
grade2.16/17 of our patients had a very satisfactory outcome. Our average follow-up of these patients is 4 years (range 1–9 years).4/17 of our patients developed some dorsiflexion weakness postoperatively and all recovered within 3 months of operation.1 patient developed deep postoperative infection necessitating the removal of the implant. We conclude that acute correction of high grade spondylolisthesis is a demanding procedure. The newer instrumentation (improved sacral fixation) made reduction less difficult and the final outcome is highly satisfying for the patient and the surgeon.
The mean pre-operative cephalic (cervico-thoracic) Cobb angle of 37.1degrees, corrected to 22 degrees, with progression to 26.6 degrees. The mean pre-operative caudal (lumbar) Cobb angle of 26.4degrees, corrected to16.2 degrees, this later progressed to 20.6 degrees. Coronal plane translation measured 1.68 cm at latest follow up [range 0.5–5.1cm]. The thoracolumbar longitudinal growth measured a mean of 8.81cm (approx0.8 cm/year) with a recorded lengthening of 2.54 cm (approx 0.23cm/year) in the instrumented segmented. Half the patients did not require further surgery.
We report 28 complications. 22 early included 4 dural tears, cardiac decompensation with reduction, 5 neurological deficits including a parpaplegia secondary to haematoma which was evacuated and the patient made a good recovery at 6 months, 2 UTIs, IVI infection, superficial wound infection and extension of metalwork due to early proximal decompensation. Late complications included infection (8 years), removal of prominent metalwork, radiculopathy due to screw (6 months) and 3 pseudarthroses. There was no statistically significant correlation of complication with weight, ASA grade or smoking.
Scoliosis and hip subluxation/dislocation are common and often coexistent problems encountered in patients with cerebral palsy (CP). The underlying mechanism may be related to muscle imbalance. Surgical correction may become necessary in severe symptomatic cases. The effect of surgical correction of one deformity on the other is not well understood. We retrospectively reviewed a series of 17 patients with total body cerebral palsy with diagnoses of both scoliosis and hip subluxation who had undergone either surgical correction of their scoliosis (9 patients) or a hip reconstruction to correct hip deformity (8 patients). In all patients, the degree of progression of both deformities was measured, radiographically, using the Cobb angle for the spine and the percentage migration index for hip centre of rotation at intervals before and at least 18 months post surgery. All patients who underwent scoliosis correction had a progressive increase in the percentage of hip migration at a rate greater than that prior to scoliosis surgery. Similarly, patients who underwent a hip reconstruction procedure demonstrated a more rapid increase in their spine Cobb angles post surgery. There may be a relationship between hip subluxation/dislocation and scoliosis in CP patients. Surgery for either scoliosis or hip dysplasia may in the presence of both conditions lead to a significant and rapid worsening of the other. The possible negative implications on the overall functional outcome of the surgical procedure warrants careful consideration to both hip and the spine before and after surgical correction of either deformity. In selected cases there may be an indication for one procedure to follow soon after the other.
A 2002 study by Goldberg et al showed that surgery before age 10 for infantile onset idiopathic scoliosis (diagnosis <
4 years, Cobb angle =>
10°) preserved neither respiratory function nor cosmesis, and has not been contradicted. In 2005, Mehta re-emphasised scoliosis correction by serial cast-bracing, while Thompson et al reported satisfactory results with growing rods. An analysis of the status quo of a cohort of patients with infantile idiopathic scoliosis (other diagnoses and syndromes excluded), managed by cast-bracing, was undertaken, asking whether interim progress was acceptable or demanded a change of protocol. Of 35 patients born between October 1993 and December 2002,15 have completely resolved, age at diagnosis 1.6 ± 0.96 years, Cobb angle 20.3°±11.9, RVAD 11.1°±13.8, latest age 4.1± 2.3. 20 were prescribed cast-bracing, age at diagnosis 1.8±0.9 years, Cobb angle 47.3°±12.6, RVAD 29.6±24.5, age at treatment was 2.1±1.0 years. Cobb angle (p<
0.001) and RVAD (p=0.001) were larger in the treated group, but age at presentation was the same (p=0.473). Surgery was performed on 3 children unresponsive to initial casting, at ages 3.2, 3.6 and 3.7, and in 3 at ages 8.6, 10.1 and 11 years. 3 children, aged 6.0, 8.1 and 11.3 are out of brace with straight spines and 11 are stable in brace. Infantile idiopathic scoliosis seems programmed to resolve or progress according to initial severity and in line with growth rate. Those who respond to casting in infancy generally remain stable until near puberty when surgery is uncontroversial. Those who progress relentlessly and immediately in cast remain the issue, as reports of newer methods include a wide range of ages and diagnoses and give their outcome in terms of Cobb angle only. It has not yet been shown that any treatment will alter their prognosis so constant analysis of all outcome parameters is essential.
A group of 20 children who underwent spinal fusion for neuromuscular scoliosis were assessed using a postural and functional measure pre-op, post-op, and at 3 and 12 months post-op. In addition, each patient was asked to record three goals for undergoing the surgery. At one year post op, patient/carers were asked to grade on a scale of 0 – 10, how satisfied they were that the goals had been achieved. Nineteen patients had clear pre-op goals for the surgery relating to functional activities. The most frequent goals stated for the non-ambulant children were- sitting for longer periods (7/46), making dressing easier (7/46) and sitting more upright (6/38). There were 15 other functional goals stated. The ambulant children stated- appearing straighter (3/12), increase in confidence (2/12), reducing pain (2/12) and maintaining respiratory function (2/12). There were 3 other functional goals stated. Seventeen patients completed the study, 2 were lost to follow up, 1 died. The average satisfaction rate from goals achieved 1 year post-op was 7.9/10.
A consecutive series of 20 children with neuromuscu-lar scoliosis (age range 2–18 years) undergoing surgical correction were evaluated using 2 standard functional assessment tools, the Seated Postural Control Measure (SPCM) which assesses posture and function, and the Pediatric Evaluation of Disability Inventory (PEDI) which records functional ability in the domains of self-care, mobility and social function. The patients were evaluated pre-operatively and then at 2 weeks, 3 and 12 months post-operatively. Complete data is presented for all patients at 3 months and 13 of 20 patients at 1 year follow up, the remaining data is to be collected. The SPCM demonstrated an improvement in posture in 95% from pre-op to 2 weeks post-op, with 25% demonstrating some regression at 3 months. Most maintained or improved this at 1 year. The PEDI demonstrated a reduction in mobility at 3 months but at 1 year 60% returned to preop status.
The purpose of the study is to assess changes in cortical activity in chronic low back pain patients with and without illness behaviour.
After informed consent, all subjects underwent fMRI scanning. Experimental pain was induced by thermal stimulation of the right hand. Straight leg raising (SLR) was performed following visual clues indicating that a leg raise was either definitely, possibly or not going to occur. Finally, clinical LBP was simulated by direct vibrotactile stimulation of the lumbar spine to a VAS threshold of 7/10. The individual fMRI scans were independently referenced to anatomical markers and corrected for motion. Inter group analysis was performed using cluster-corrected thresholds of p<
0.05.
When clinical LBP was simulated, the outcome was strikingly different with the Copers showing increased cortical activity particularly in the dorsolateral prefron-tal cortex and regions associated with cognitive pain processing and inhibition of subcortical pain pathways.
The purpose of this study is to determine whether the mode of anaesthesia chosen for patients undergoing lumbar microdiscectomy surgery has any significant influence on the immediate outcome in terms of safety, efficacy or patient satisfaction. This prospective randomised study compared safety, efficacy and satisfaction levels in patients having spinal versus general anaesthesia for single level lumbar micro-discectomy. Fifty consecutive healthy and cooperative patients were recruited and prospectively randomised into two equal groups; half the patients received a spinal anaesthetic (SA), the remainder a general anaesthetic (GA). Each specific mode of anaesthesia was standardised. Comprehensive postoperative evaluation concentrated on documenting any complications specific to the particular mode of anaesthesia, recording the pace at which the various milestones of physiological and functional recovery were reached, and the level of patient satisfaction with the type of anaesthesia used. The results showed no serious complication specific to their particular mode of anaesthesia in either group. Thirteen out of 25 SA patients required temporary urinary catheterisation (9 males, 4 females) while among the GA group 4 patients required urinary catheterisation (4 males and 1 female). Post-operative pain perception was significantly lower in the SA group. The SA patients achieved the milestones of physiological and functional recovery more rapidly. While both groups were satisfied with their procedure, the level of satisfaction was significantly higher in the SA group. In conclusion, lumbar spinal microdiscectomy can be carried out with equal safety, employing either spinal or general anaesthesia. While they require more temporary urinary catheterisation associated with the previous use of intrathecal morphine, patients undergoing SA suffer less pain in association with their procedure and recover more rapidly. Blinded to an extent by not having experienced the alternative, both groups appeared satisfied with their anaesthetic. However, the level of satisfaction was significantly higher in the SA group.
The patients were divided into two groups, A and B. The first, Group A, in which only Dynesys was used and the second, Group B, in which Dynesys was used adjacent to one or more fused segments.
The ROM of the end plate angle at the instrumented segments in Group A reduced from 5.72o to 1.44o{difference 4.28o(p=0.005)} and in Group B reduced from 6.00o to 2.17o,{difference 3.83o(p=0.001)}. The ROM of the end plate angle at the level above instrumentation in Group A reduced from 8.2o to 5.1o {reduction 3.1o(p=0.085)}, while in group-B increased from 7.3o to 7.5o, a difference of 0.2o (p=0.877). The mean anterior disc height in Group A reduced by 2.1mm (p<
0.001) from 9.59mm to 7.44mm. The posterior disc height also reduced from 6.56mm to 6.26mm, a difference of 0.3mm, (p=0.434). In Group B, the anterior disc height reduced by 1.98mm (pre-op=9.04mm, post-op= 7.06mm, p=0.001) and the posterior height by 0.35mm (pre-op 6.14mm to post op 5.79mm, p=0.443)
Results: Oswestry; Roland Morris Pre program 34 average: s.d. 158.8; s.d. 4.5 Post program 19 average: s.d. 174.3; s.d. 4.8 Patient Global assessment: Much better 64; 47% Excellent 62; 49.6% Better: 52; 38% Good: 43; 34.4% Unchanged: 2; 9% Fair: 16 ; 2.8% Worse: 7; 5% Poor: 4; 3.2% Data on the impact upon work was available for 121 of the patients. Pre program 71 of the 121 had been seriously affected in the workplace. Work follow up was 79% and at follow up only 22 out of 96 were seriously affected in the workplace. A significant improvement. 43 had an injury at work, RTA or similar significant event, 89 did not. The ODI improved by 18 points in the attributable event group and 13 in the non event group. Similar results were found for the Roland score. There was no significant difference between the two groups.
All pre-operative parameters were significantly higher compared with the Normal group (back pain VAS 6.3 and 3.8; leg pain VAS 7 and 4.7; ODI 61 and 34.4 respectively). At 1 year follow-up, 23% of the somatising patients became psychologically Normal; 36% became At Risk; 11% became Distressed Depressed; and 30% remained Distressed Somatisers. The postoperative VAS for back and leg pain of the 11 patients who had become psychologically Normal was 3.4 (pre-op 6.8) and 3.2 (pre-op 6.6) respectively. In the 14 patients who remained Distressed Somatisers the corresponding figures were 5.6 (pre-op 7.8) and 6.7 (pre-op 7.0). The postoperative ODI of the 11 patients who had become psychologically Normal was 26.4 (pre-op 55.5). In the 14 patients who remained Distressed Somatisers the corresponding figures were 56.7 (pre-op 61.7). These differences are statistically significant.
We report a consecutive series of 200 patients who underwent Dynesys flexible stabilisation in the management of intractable lower back pain.
Group 1 - Cases where implantation was used as an adjunct to other procedures including decompression, discectomy, or posterior lumbar interbody fusion. (32 male, 36 female, Mean age 56years (range 31–85)). Group 2 - Patients with back pain and/or sciatica in which no other procedure was used. (65 male 67 female, Mean age 58years (range 27–86)) All patients were profiled prospectively using the Oswestry Disability Index (ODI), SF36 and Visual Analogue Scale (VAS). Patients were reviewed post-operatively using the same measures at 3, 6 &
12 months, and yearly thereafter. Follow-up was 95% at 2 to 5 years.
Group 2 – Mean ODI fell from 49 pre-op to 28 at four years Similar trends were observed in both groups with a fall in VAS and improvement in SF36.
At 6 months, there was a significant increase in the spinal canal and foraminal dimension. However at 2 years there was a reduction in these dimensions such that there was no significant difference from the preop-erative measurements.
The patients were divided into two groups, A and B. The first, Group A, in which only Dynesys was used and the second, Group B, in which Dynesys was used adjacent to one or more fused segments.
The ROM of the end plate angle at the instrumented segments in Group A reduced from 5.72o to 1.44o{difference 4.28o(p=0.005)} and in Group B reduced from 6.00o to 2.17o,{difference 3.83o(p=0.001)}. The ROM of the end plate angle at the level above instrumentation in Group A reduced from 8.2o to 5.1o {reduction 3.1o(p=0.085)}, while in group-B increased from 7.3o to 7.5o, a difference of 0.2o (p=0.877). The mean anterior disc height in Group A reduced by 2.1mm (p<
0.001) from 9.59mm to 7.44mm. The posterior disc height also reduced from 6.56mm to 6.26mm, a difference of 0.3mm, (p=0.434). In Group B, the anterior disc height reduced by 1.98mm (pre-op=9.04mm, post-op= 7.06mm, p=0.001) and the posterior height by 0.35mm (pre-op 6.14mm to post op 5.79mm, p=0.443)
Parameters studied included position of the Aorta and Inferior Vena Cava, the levels and angles of their bifurcation and the all too important ascending lumbar vein. We also commented on the most accessible (visible) disc part in relation to surrounding vessels.
The purpose of the study was, to investigate how often the diagnosis of “Scheuermann’s disease” was made in radiological reports to General Practitioners, to determine the precise nature of the disease being described, and to evaluate the management of patients by GP’s who receive such radiological reports. A computerised search of radiological reports to local GP’s revealed fifty reports over a two and a half period which included the diagnosis of “Scheuermann’s disease”. Assessment of these radiographs by a Consultant Radiologist indicated that ten of these patients had classical Scheuermann’s (abnormal thoracic kyphosis associated with disc and end plate irregularities), and forty had so called lumbar/type two Scheuermann’s (disc and end plate irregularities of the thoraco lumbar spine without deformity). A questionnaire was sent out to GP’s which consisted a case history of a middle aged patient with typical symptoms of degenerative low back pain without deformity, including a radiological report indicating the “possibility of Scheuermann’s disease”, on the basis of features typical of Scheuermann’s lumbar/type two. 86% of GP’s indicated that they would inform their patients that they had “Scheuermann’s disease” using that term, but 48% did not appreciate the meaning of the term in the context of the case history. We conclude that the majority of radiological reports to GP’s which include the diagnosis “Scheuermann’s disease” relate to lumbar/type two Scheuermann’s, and that the nature of the radiological diagnosis, invariably passed on to the patient, is often misunderstood by the GP. This may well result in patients presenting to spinal clinicians with unnecessary anxiety due to concerns of possible serious pathology. We would recommend that spinal clinicians encourage their radiological colleagues to avoid the use of the words “Scheuermann’s disease” in radiological reports to GP’s except when describing classical adolescent thoracic kyphosis.
We investigated the effect of neck dimension upon cervical range of movement. Data relating to 100 subjects healthy subjects aged between 20 and 40yrs was recorded with respect to age, gender and ranges of movement in three planes. Additionally two commonly used methods of measuring neck motion, chin-sternal distance and uniplanar goniometer, were assessed against a validated measurement tool the CROM goniometer (Performance Attainment Associates, Roseville, MN). Using multiple linear regression analysis it was determined that sagittal flexion (P= 0.0021) and lateral rotation (P<
0.0001) were most closely related to neck circumference alone whereas lateral flexion (P<
0.0001) was most closely related to a ratio of circumference and length. The uniplanar goniometer has some usefulness when assessing neck motion, comparing favourably to chin-sternal distance that has almost no role. Neck dimension should be incorporated into cervical functional assessment. One should be wary about recorded values for neck motion from non-validated measurement tools.
Neuromuscular scoliosis is a difficult condition to treat. Curve severity, secondary pelvic obliquity and poor respiratory function can make operative treatment and post operative care challenging. The benefits to the child in terms of improved sitting position and trunk posture can be considerable. We present a large consecutive series of patients with neuromuscular scoliosis treated surgically at our institution. The aim of this work was to study the clinical and radiographic impact of surgery for neuromuscular scoliosis. Data was gathered from patient records and radiographs for all cases of neuromuscular scoliosis treated surgically between April 2002 and Feb 2005. 52 cases were identified. They fell into 2 surgical groups: single stage posterior correction and two stage anterior and posterior correction. All posterior instrumentation was transpedicular. Complications, length of stay, and change in severity of sagittal and coronal plane deformity were recorded. Average pre-operative Cobb angle was 85°. There were 16 patients with additional sagittal plane deformity. Average percentage improvement of Cobb angle was 59%. The correction was better in two stage procedures. Pelvic obliquity was improved in those who were obligatory sitters. Fusion rate was 83% for those followed up more than 1 year. ITU stay was longer in single stage procedures. Complication rate was 58%. We have shown that with appropriate patient selection the correction of neuromuscular scoliosis can achieve good results with high fusion rates. Two stage correction confers correctional advantage on those who have sufficient respiratory reserve to tolerate it.
The current work compares, in the patients with acute spinal cord injuries (SCI), the rate of early complications in those who were operated ‘out of hours’ to the patients who had their surgical interventions performed on the elective trauma list. In a two-year study, all the complications occurring within the first month of surgery were recorded. Patients who had their operative procedure between 22.00 pm and 8.00 am comprised the ‘out of hours’ group, while the other group included patients operated on daytime spinal trauma lists. Each group had 22 patients. The demographics, injury patterns, time relapse to admission and theatre, the surgical procedure, its duration, the postoperative results and early complications were retrospectively analysed and compared for the two groups. There were 38 males. 20 patients had complete SCI and 26 had thoracic spine involvement. Road traffic accident was the cause of injury in 26 patients. Two patients received steroids following the injury. The average admission time was 3 days. Surgery occurred on an average within 48 h (range 1–20 days). The mean theatre time was 2.8 h for the emergency group and 3.4 h for the elective cases. Early postoperative complications were chest infections (5), urinary tract infections (7), superficial wound infections (2), and pulmonary embolism (1). The incidence of complications was higher in cervical injuries, polytrauma, complicated procedures and individuals requiring intensive care. No significant differences were noted between the two groups. Operating non life-saving emergency cases on elective list constitutes good clinical practice. Various reviews including the National Confidential Enquiry into Patient Outcomes and Deaths (NCEPOD) suggest that operating out of working hours poses a substantial risk to the patient’s health and safety. This study emphasizes that complications relate to the injury level, associated injuries and the procedure itself, rather than to the timing of surgery.
The clinical and radiological outcome of 34 patients who were treated with PDN-Solo and PDN-Solo XL devices for symptomatic degenerative lumbar discs is described. 34 patients had PDNs implanted in their lumbar spines between September 2002 and August 2004. Suitable patients, with proven discogenic back pain, who failed at least six months of conservative treatment, were fully consented prior to surgery. The approach was retroperitoneal in all cases except at L5/S1 when it was transperitoneal. The primary clinical outcome measure was the Low Back Outcome Score (LBOS). X-rays were taken at these follow-up points to assess the integrity and effectiveness of the implants. 36 operations were performed in 15 males and 19 females (including 2 early revision PDNs). All patients were between 20 and 65 years old, with a mean age of 42. 17 patients were treated with PDN alone and 17 with PDN as an adjunct to an interbody fusion. There were 10 device related complications, two being amenable to early PDN revision and six requiring revision to fusion. Two patients remain symptom-free. According to the LBOS, only 19 of 29 patients who have not been revised to fusion have had successful outcomes (65.5% of unrevised patients, 56% of all patients). Final follow-up x-rays show that when the PDN remains intact the disc space height is very similar to its neighbours. If the device has dissociated, the disc is narrowed. Fifty years after lumbar disc nucleus replacement was first attempted by Fernstrom, the success rate is no higher and the reasons for revision are the same. Clearly there has to be a major improvement in this technology before it can be widely adopted. Until such a time as that improvement has occurred, we cannot recommend this device as a treatment for back pain.
Recent work has demonstrated that intra-operative contamination of spinal surgical wounds is relatively common. The most frequently isolated wound contaminants are Intra-operative wound samples were taken from 94 patients undergoing spinal surgery. Samples including skin, subcutaneous tissue and wound washings were processed, inoculated onto agar and incubated under both aerobic and anaerobic conditions for a period of 2 weeks. Bacterial growth was identified using commercially available biochemical test galleries. Thirty-six bacterial isolates were identified. The predominant bacteria isolated included The antibiotic that performed best against The antibiotic that performed best against The results of this study demonstrate that ciprofloxacin, cefuroxime and cefamandole are effective against the majority of
SAM was performed in C-scan mode(gate width 50ns, depth 3500ns) and acoustical data collected along X–Y plane/depth Z. A B- mode scan acquired acoustic data along X–Z plane/ depth A. Time-of-Flight (TOF) scan used to create 3D-like images based on distance between the top of the disc and maximum penetration depth. The IDET catheters were heated according to the 900C 16.5-minute protocol. Discs were subjected to SAM using identical protocols as described. The ROIs were incised and analysed using μNMR. A custom made device was fabricated to prevent rotational effects of varying orientation of the specimen in the magnetic field.
Non-linear regression analysis of Signal Intensity Ratios of 30 different regions using SPSS showed a significant change in T1 weighting on μMRI by a median factor of 40 ( IQR + 16) for the LPL and 20(IQR + 8) for LAL regions. Significant relaxation difference (p<
0.001) caused by “magic angle”effects wer noted in LPL compared to RPL.
The average rate of publication in medicine following presentation is 45% Although the quality of the scientific work is not the only factor to determine publication, and nor is the quality of the presentations the only factor to assess in evaluating a meeting, the rate of publication and citation rate provide an indicator of the quality and scientific level of meetings.
Routine inclusion of imaging of the SI joint as part of lumbosacral spine MRI for back pain and sciatica shows only 3% positive results. SI joint should be imaged only if clinically suspected.
Five specimens were implanted for each group 1) with pedicle screw (into L3 and L5) and tested with/without Synex (expandable) cage anteriorly, 2) implanted with a Synex cage and Double screw+rod Ventrofix system, 3) Synex cage and Double screw+ Single rod Ventrofix construct and 4) Synex cage and Single screw+ Single rod Ventrofix system.
The double screw/ single rod system is less effective than the Ventrofix System but is comparable to the pedicle screw construct. The single screw/ single rod construct leads to unacceptable movement about the axis of the inferior screw particularly in extension with a ROM much greater than the intact spine (p<
0.001)
To date, 80 patients have been recruited into the study of which 34 have been randomised to receive the booklet. At 6 months post-surgery all of these patients are requested to complete a questionnaire on the booklet. This questionnaire contained forced-choice questions on readability, style, information level, believability, length, content and helpfulness. Further open questions concern the booklet’s messages, giving patients the opportunity to identify anything they did not like or understand, voice any concerns that were not covered, and say if they thought the booklet would change what they did after surgery. Finally, they were asked their overall rating of the booklet on a scale from 1 to 10. Feedback is very positive. The average overall rating of the booklet was 8.6/10. Over 80% found it easy to read, interesting, and of appropriate length. Over 80% also stated they had learnt new and helpful information. All subjects stated that they would recommend the booklet to a friend, and the majority stated that they frequently referred to the booklet. The predominant messages received and understood by the patients were related to the safe benefits of early activation and return to normal activities. The results show that spinal surgery patients appreciate evidence-based information in booklet form, and suggest that this booklet may be an important adjunct to post-operative management of spinal patients.