Ebook: Research into Spinal Deformities 3

The third biannual Meeting of the International Research Society of Spinal Deformities was held on 26-30 May 2000, at the Château du Marand, in Clermont Ferrand, France.

In a retrospective evaluation of the development of the activities of the Society during the six years that have elapsed since its formation, it is easy to identify the growing interest and appreciation of our Meetings. This is evidenced not only by the steadily increasing number of participants but also by the large variety and the scientific rigor of the presented papers. The fact that the research results presented have gone in diverging but eventually reciprocally inclining directions, is in line with the objective of the Society “to provide a forum for presentation and encouragement of research relating to spinal deformity and to disseminate the results of such research” with the aim of rendering maximal degree of benefit for the child with spine deformity.

Seventy-nine oral presentations, three key-note lectures, two debates and numerous poster exhibitions, covering every aspect related to spinal deformities, given by young researchers as well as by internationally well reputed scientists, and the – sometimes feverish – discussions that followed, prove the intensity and the high quality of research on the issue under study. In the presented reports of current research, the spinal deformity has been meticulously analysed from biological, physiological and biomechanical points of view with the target of establishing improved methods for diagnosis and prognosis and of achieving optimal methods for conservative and operative treatment of the patient.

The rich sources for new multifacetted knowledge and the opportunity for exchange of opinions, provided during the days of the Meeting, have contributed to a better understanding of the difficulties in deciphering the intricate mechanisms of the causation and the development of spinal deformities and of the efforts needed to develop improved methods for treatment. The problems are, however, complex in their nature, and as relevant knowledge never comes to end “…γρασκω δ α1∊1 πολλαομ∊νος”[1] Therefore, new research data are required and are expected from our forthcoming Meetings.

The publication of the Proceedings of the Meeting in the form of a “book” as a complement to the journal system is not only useful for didactic and reference purposes, but also for the introduction and promotion of large-scale programme results and far-reaching new ideas (E.H. Fredriksson); hence the volume at hand will provide the possibility of further study and evaluation of the scientific material in addition to innovative concepts in related fields of research as well as new approaches for restraining the progression, for treatment and, in the long term, for the prevention of the thoracospinal deformity.

Last, but not least, the beautiful rural countryside of the Chateau du Marand, the well-known French hospitality, La cuisine Francaise , the abundance of selected local wines and the banquet on the Puy de Dome with the magnificent panoramic view (which we missedthat misty and windy evening!), have all contributed to creating intellectual and social bonds between active participants and members of our Society.

Thanks to the commitment and hard work of the organising Committee, under the keen leadership of Bernard Peuchot and Alain Tanguy, the third Meeting of the International Research Society of Spinal Deformities was, in every respect, a most successful one.

John A. Sevastik Stockholm, February 2002

[1] “… the older I grow the more I learn” Solon, 640-558 BC; one of the Seven Sages of Greece.

Pinealectomy in young chickens consistently results in scoliosis which has many characteristics similar to those seen in adolescent idiopathic scoliosis. The mechanism underlying this phenomenon remains a mystery and it is not yet entirely clear whether some unidentified aspect of the extensive surgery is the major factor rather than the removal of the pineal gland. Four different types of pinealectomy surgery were performed on young chickens as well as deliberate damage to the cerebral cortex which simulated the extreme of any accidental damage that might occur during surgery. Scoliosis was assessed from weekly radiographs. No differences in incidence of scoliosis, degree of severity or pattern of curve development were observed for any of the experimental groups when compared with controls. In all groups approximately 55% of the chickens developed scoliosis that progressed rapidly. Different pinealectomy procedures and deliberate damage to the cerebral cortex produce scoliosis in young chickens with the same incidence and characteristics. This suggests strongly that the mechanism behind the phenomenon is due to the removal of the pineal gland and not some artifact of the extensive surgery. The pinealectomy model in young chickens is proving to be a good model for studying AIS in humans. An understanding of the mechanism underlying this phenomenon has the potential to provide further insights into the aetiology of AIS and can lead to the development of novel treatement methods.

Background. The correlation of idiopathic scoliosis and cavus foot has been previously reported, [1], This has been ascribed to possible lesions related to muscular imbalance influenced by the central nervous system. The aim of this study is the assessment of this correlation.

Material and Method. 3 544 children were studied, (1 765 boys and 1 779 girls, aged from 6 to 18 years) from a school-screening program of our department. A number of measurements were assessed including the angle of trunk inclination (ATI) in standing and sitting forward bending positions using the Pruijs scoliometer and the morphology of the sole shape using the Harris & Beath footprint mat. The 6 types footprint classification was used for foot shape as it was elsewhere reported [3,4], Type 1 in this classification represents typical and type 2 light cavus foot. In a first main group, 317 children were referred, who presented with ATI≥7°, and were divided into 2 subgroups. The 1^st subgroup included n=264 children with body asymmetry but with no scoliosis and the 2^nd subgroup included n=53 scoliotic children (Cobb angle >10°). The 2^nd main group included 3 227 children without asymmetry. The presence of cavus foot (footprint type 1 and 2) in these 2 groups was searched. Statistical analysis was performed using SPSS package.

Results. n=4 (7.54%) out of the 53 scoliotics had cavus foot [n=l (1.88%) typical and 3 (5.66%) light cavus foot], while n=55 (20.8%) out of 264 non-scoliotic referrals showed n=9 (3.4%) typical and n=46 (17.42 %) light cavus foot. These readings prove that there is no statistical correlation between idiopathic scoliosis and cavus foot. Additionally n=3227 normal symmetric children, n=620 (19.21%), presented cavus foot, [footprints type 1 n=106 (3.28%) and type 2 n= 514 (15.92%)], which is a percentage higher than that of the scoliotic population.

Conclusions. The significant correlation between idiopathic scoliosis and cavus foot as it has been elsewhere reported was not verified in this study. On the contrary it is emphasized that the percentage of cavus foot was traced higher in the general healthy population than that in the small and moderate scoliotic curves studied

School scoliosis screening programmes have consistently produced large numbers of referrals with minimal trunk asymmetry which then must be assessed, evaluated and perhaps investigated and monitored over a period of time before it is felt safe to discharge them as ‘non-progressive.’ Beyond measures to reduce their number, they have received less attention than the more interesting cases requiring treatment or surgery, which they outnumber to a significant extent. Examination of the figures from a historical database shows that the patients have no greater probability of developing significant scoliosis than their ‘normal’ peers . So they should not be classed as scoliosis but they are still relevant to the broader picture of aetiology.

Despite much evidence of its existence, the relation between impaired ANS function and the aetiopathogenesis of AIS has attracted surprisingly little attention. Studies have shown that the left breast of girls with right convex thoracic AIS is significantly more vascular than the right one and that the mean concave minu s convex rib length in women with thoracic IS is significantly greater than the left minu s right rib length in normal women. Moreover in growing rabbits unilateral regional sympathectomy by resection of intercostal nerves carrying sympathetic fibers results in hypervascularity of the soft tissues, increased rib growth on the side of the operation and thoracic scoliosis convex to the opposite side. The results of these and of other reports provide sufficient indication of a relation between ANS dysfunction and IS, and open new views for research on the connection between the aetiology and pathogenesis of the thoracospinal deformity.

Scoliosis may lead to multiple impairments depending on its seriousness. Here we have to make the distinction between direct impairments in the physical field and indirect impairments in the psychosocial field. The findings of different studies indicate that the psychosocial situation in juvenile and adult scoliotic patients is characterized by increased strain.The present study is meant to answer the question in which fields of quality of life female scoliotic patients are impaired and if these impairments are dependent of age or seriousness of illness (Cobb angle).

Between May 1998 and February 1999, 226 female patients with idiopathic scoliosis were surveyed in a special clinic for spinal deformities with the help of different quality of life measuring instruments (SF-36, BFW, STAIK) and were compared with norm values.

Women with idiopathic scoliosis were questioned with the help of an age adapted set of questionnaires containing questions referring to the health related quality of life (SF-36, BFW, STAIK). The results were compared to the norm values and examined in uni- and multivariat procedures (MANOVA) in order to find out if age and seriousness of illness (Cobb angle) have any impact on the quality of life.

In comparison to the norm random sample, the juvenile female scoliosis patients showed a less positive point of view towards life (p = .001) and were easier subject to depressive moods (p = .021). The increased strain of adult patients was shown both in the psychic field (p < .001) and in the physical field (p < .001) (SF-36). These results are largely independent of the seriousness of illness (Cobb angle) and of the patients’ age.

The results indicate that idiopathic scoliosis in children, adolescents and adults can be regarded as a risk factor for the impairment of health related quality of life and thus stress the importance of psychosocial offers during a patient- orientated scoliosis treament in order to improve the management of scoliosis.

There is a controversy in the current literature concerning the age at menarche between scoliotic and nonscoliotic girls. The aim of this study is to elucidate this issue in the Mediterranean school aged girls.

Material and Methods. The menarche of 1 305 nonscoliotic girls (mean age 12,3 years, range 7,41 to 18,41 years , SD 2,5 years) and of 105 scoliotic girls (mean age 14.15 years, range 7.47 to 18.97 years, SD=2.7 years) was studied. These two groups originate from a total population of 4 535 schoolchildren who were examined during school screening (2 245 girls, 2 290 boys). The Angle of Trunk Inclination (ATI) greater or equal to 7°, measured with the Pruijis Scoliometer was used as a pass-fail criterion for radiological examination. The diagnosis of scoliosis was defined as the finding of a Cobb angle greater or equal to 10° on a standing postero-anterior radiograph of the spine. Statistical analysis was performed using the SPSS statistical program.

Results. 476 girls out of 1 305 nonscoliotic girls (36,50%, mean age 14,04 years, range 9.04 to 18,21 years, SD=1.59 years) had menarche (mean age at menarche 12,07 years, SD 1,35 years, range from 7,63 to 14,59 years), while the remaining 829 girls (63,50%, mean age 11,09 years, SD 2,09 years, range 7,41 to 18,47 years) had not any. On the other hand, 77 out of the 105 scoliotic girls had menarche (73,33%, mean age 15,29 years, SD 1,54 years, range 11,35 to 18,97 years). The mean age at menarche of the scoliotic girls was 11,98 years, SD 1,49 years , range 7,7 to 16,72 years. Twenty-eight scoliotic girls had no menarche yet (mean age 10.99 years, range 7.41 to 17.24 years, SD=2.72). There was a predominance of right-sided primary curves in menarche positive scoliotic girls (61%), while menarche negative scoliotic girls showed mainly left sided primary curves (64,3%). This difference is statistically significant (p<0,05). The frequency of the various scoliotic curves in menarche positive scoliotic girls was as follows: right thoracic (32,5%), left lumbar (23,4%) and right thoracolumbar (15,6%) curves. The respective locations of scoliotic curves in girls without menarche were left lumbar (25%), left thoracolumbar (25%) and thoracic curves (14,3%) were equally distributed on both. Delayed onset of menarche or no menarche was observed in 4 scoliotic girls. Furthermore, 2 scoliotic girls mentioned that they had menarche after the age of 15 years and only after hormonal treatment. Despite of the apparent prevalence of the scoliotic girls in the menarche positive population, there is no statistically significant difference between scoliotic and nonscoliotic girls with menarche when the respective ages at menarche are compared.

Conclusion. In this study, there was not a statistically significant difference of the age at menarche between scoliotic and nonscoliotic girls. On the other hand, there was a significant difference between menarche positive and menarche negative scoliotic girls in relation to the laterality of scoliotic curves: the former showed predominantly right sided primary curves while the latter had mainly left sided primary curves.

All lateral spinal radiographs in idiopathic scoliosis show a DRC sign of the thoracic cage, a radiographic expression of the rib hump. The outline of the convex overlies the contour of the concave ribs. The aim of this study is to assess this DRC sign in children with and without Late Onset Idiopathic Scoliosis (LOIS) with 10° -20° Cobb angle, and to examine whether in scoliosis the deformity of the thorax or that of the spine develops first.

Methods and material. The radiographs of 133 children referred to hospital in a school screening study were examined. There were 47 boys and 86 girls, 13.28 and 13.39 years old respectively. The Cobb angle was measured and the radiological lateral spinal profile (LSP) was appraised from an angle made by a line drawn down the posterior surface of each vertebral body (T1-L5) and by the vertical. The children, boys and girls, were divided in 5 groups, namely: 1) with straight spines, 2) with spinal curvature having a Cobb angle <10°, 3) with thoracic, 4) thoracolumbar and 4) lumbar curves 10°-20°. For quantification of the DRC sign, the “rib index” was defined as dl/d2 ratio, where dl expresses the distance from the most extended point of the most projecting rib contour (RC) to the posterior margin of the corresponding to point vertebra and d2 expresses the distance from the posterior margin of the same vertebra to the most protruding point of the least projecting RC. In a symmetric and non-deformed thorax, these two RC lines are superimposed and the “rib index” is 1.

Results: The statistical descriptive of dl and d2 in boys and girls are presented together because they are not statistically different. There are no sex differences of the “rib index” which is 1.45, 1.51, 1.56, 1.59, 1.47 for the 5 respectively aforementioned groups. According to statistical analysis, there is no correlation of the Cobb angle with the “rib index” of thoracic, thoracolumbar and lumbar scoliosis groups. The DRC sign is present in all referrals and scoliotics. The data show a correlation of the “rib index” with each of T2, T3, T4, T5, T6 and T7 LSP in girls with lumbar curvatures.

Discussion: The DRCS primarily appears because of the rib deformation and secondarily because of the vertebral rotation, as it could be present in straight spines with no vertebral rotation. In all our school-screening referrals, (having ATI ≥ 7°), the thorax deformity, in terms of the DRC sign, has already been developed. 70% of these children were scoliotic. The others had a curvature of less than 9° of Cobb angle (10%) or they were children with straight spines (20%) who were followed because of their existing rib hump. The non-scoliotics were 1,5-2 years younger than the ones who had already developed scoliosis, and they had both approximately a “rib index” of 1,5. The DRC sign is present in all referrals . In contrary, there is no scoliotic spine without it, as the DRC sign is always present in scoliotic lateral spinal radiographs with no exception. This observation supports our hypothesis that in idiopathic scoliosis, the deformity of the thorax develops first and then the deformity of the spine follows.

Using previously established values for the smallest detectable difference in topographic parameters, the effectiveness of the Quantec system for monitoring progress in scoliosis was investigated. It was found that, while a significant change in Cobb angle was always accompanied by a meaningful change in at least one topographic parameter, the pattern of shape change was highly individual. It is concluded that deformity in scoliosis is not determined exclusively by the spinal curve.

SYDESCO is a new 3D vision system developed for trunk surface topography. This structured light surface scanner uses the principle of triangulation-based range sensing to infer 3D shape. The complete trunk acquisition is fast (2 seconds). The accuracy of the metric data is ensured by a subpixel image detection and a calibration process, which rectifies image deformations. A preliminary study presents results on 50 children in a gymnastics school. These children, aged between eight to sixteen years, are particularly exposed to spinal deformities. An asymmetry index is calculated from the 3D data to detect the pathologic cases. These results have been compared to an independent medical diagnosis. The system results have been confirmed for 72,1% of the patients.

The standing forward bending position is in general use for the early detection of adolescent idiopathic scoliosis. It also reveals humps caused by leg-length inequality and for this reason some workers have advocated using the sitting forward bending position [5]. Most recently the prone position has been evaluated and even recommended [10]. The introduction of B-mode and subsequently real-time ultrasound to measure rib rotation and spinal rotation has involved using the prone position [7,9]. The numerical description of back humps in scientific studies requires measurements at several levels on the back from Tl-Sl [1]. This paper utilizes 30 subjects referred by school screening for scoliosis from whom 10-level Scoliometer Angle of Trunk Inclinations (ATIs) were obtained twice in each of three positions - standing forward bending, sitting forward bending and prone. The ATIs were converted to 18 levels and (1) analysed for reproducibility, (2) compared in the three positions, and (3) compared with real-time ultrasound data of rib rotation obtained in the prone position. Several statistical methods are used. The reproducibility is best in the sitting and prone positions. While the prone position produces lower ATI readings, R squared values are significantly higher and Residual Mean Square (RMS) values significantly lower than those for each of the standing and sitting forward bending positions. Though the prone position has clear advantages, it is not advocated in clinical practice for various reasons. More research is needed. The evidence supports the view [5] that the sitting forward bending position has advantages for the early detection of adolescent idiopathic scoliosis.

In today’s climate of evidence based medicine, there is an increasing emphasis on objective assessment to monitor treatment effectiveness. Although spinal posture and back shape are commonly assessed by clinicians, current practice is based on subjective findings and unreliable objective tools. Numerous management protocols aim to improve both posture and shape, however data related to normal back shape is quite scarce. The aim of this study was to investigate normal back shape in young adults, in order to produce normative values against which deformity could be defined. The Integrated Shape Imaging System (ISIS) was used to measure the three-dimensional back shape. A convenience sample of 48 normal adults, aged 18-28 volunteered to participate in this study. A small minority of individuals showed no curve (8%), 55% showed a single curve and the rest showed a double one. Right spinal asymmetry was more frequent than the left (77% to 52%). Mean values and 95% confidence intervals were 14.1° (11.7°-16.5°) for upper Lateral asymmetry, 5.6° (3.3° - 7.9°) for lower lateral asymmetry, 24.9mm (20.6mm -29.2mm) for thoracic kyphosis and 14.9mm (12.5mm -17.2mm) for lumbar lordosis. Increasing upper lateral asymmetry correlated with decreasing thoracic kyphosis (p=0.01). Maximum skin surface angle correlated positively with only upper lateral asymmetry (p<0.0001). Similar topographical interrelationships have been demonstrated in scoliosis. It is important that clinicians in relevant disciplines objectively assess all three dimensions of back shape, as our research shows that changes in one plane are associated with changes in the other two planes.

Rasterstereography has been shown to be a reliable method for three- dimensional surface measurement of idiopathic scoliosis with Cobb angles up to 50°. In this study, 25 patients with severe idiopathic scolioses (Cobb angles 47°-92°) were examined before and after operation (VDS instrumentation). The a.p. radiographs were digitized according to the Drerup method . The similarity of rasterstereographic and radiometric data was quantified by the rms. differences between the rasterstereographic and radiographic curves of lateral deviation and vertebral or surface rotation. The average rms. differences were 5.8 mm for lateral deviation and 4.4° for vertebral and surface rotation, which is about 40% higher than for mild to medium scolioses.

A Minolta VIVID 700 portable non-contact 3D laser scanner was evaluated on 15 subjects with idiopathic scoliosis. The 3D map was compared to two structured light pattern (lines and dots) techniques to determine the reliability, ease of use, speed, and quality. The parameters used for the clinical assessment of scoliosis were measured twice for the Minolta and light projection systems. The edges of the image and areas where occlusion typically occur were examined. The absolute distance in calculated depth between adjacent points was examined to determine errors. The Minolta system and the dot pattern produced regular grids of points. The light projection pattern produced an irregular grid, with more resolution along the video line and less resolution between projected lines, resulted in a somewhat jagged appearance of the surface map. The Minolta system was less sensitive to edge effects, occlusion, and sharp transitions of depth. The comparison of clinical parameters showed good results between repetitions but moderate results between techniques.

The importance of trunk movement in human gait has been established by many studies. However, these investigations have examined trunk/pelvis motion or the pelvic/thoracic motion in isolation to lower limb kinematics. Studies quantifying spinal deformities and the range of spinal and trunkal movement have concentrated on spinal/back movement, with the subject performing tasks, such as flexion, while maintaining a static position. There is also a paucity of data detailing the real relative motion between the back and lower limb during gait, an important consideration when testing the Nottingham ‘flag-pole’hypothesis for spinal curvature generation.

Research into the use of opto-electronic gait analysis systems to measure dynamic back movements has shown the capability of these systems in producing repeatable patterns of back movements. While using a motion analysis system, if a relationship between the spinal movement and lower limb kinematics could be established, such a relationship would provide a new opportunity for range of movement studies in conditions like scoliosis. Furthermore, establishing such a relationship would allow investigation into the influence of one segment over another during locomotion.

This present study has examined the movement of markers placed on the back and pelvis, used in three-dimensional opto- electronic systems for gait studies, in relation to the markers placed on the lower limbs. The results of a pilot study have highlighted relative movements between various segments in simple tasks like flexion, lateral bending and negotiating steps, which have implications for spinal deformity generation. The findings also demonstrate the points to be considered in order to define dynamic trunk and spinal movement. Further ongoing studies are being undertaken to validate the findings.

The reliability and accuracy in the measurement of landmark points using a 3-D digitizer on a static back phantom are reported. The results show the systems clinical reliability as a low cost, portable and flexible method for recording back posture. Consistent results are demonstrated for a single measurer and good agreement was found between two measurers. Few intrinsic errors were found in the devices performance.

Various investigations into anatomical landmarks that could be employed in spine and back surface measurement have highlighted the usefulness of the spinous processes of the vertebra and the posterior superior iliac spines of the pelvis. Earlier studies used an opto-electronic gait analysis system to examine the motion of skin markers and compared results with similar inter-vertebral movement recorded through radiographs. Consistent patterns of movement suggested a relationship between spinal and back surface motion. Further investigations into the use of opto-electronic gait analysis systems to measure dynamic back movements showed the capability of producing repeatable patterns of back movements. However, these studies, mainly measuring the range of movement (ROM) of spine, have not examined the effects of marker placements. While most ROM studies concentrate on stationary repetitive flexion/extension and bending movements, spinal ROM during walking and in scoliosis has not been widely reported. Spinal range of motion is an important indicator of spinal function and is used in the determination of disability and compensation.

The present study has evaluated the placement of markers on the back and pelvis, used in three-dimensional opto-electronic systems for gait and movement studies. Various marker configurations have been compared and reported. The findings highlight the drawbacks of previously reported techniques, and particularly indicate that skin movement can adversely affect findings. However, the results confirm the feasibility of application of this technique to investigate dynamic trunk and spinal movement in both normal and deformed spines.

Portable optical profilometer for measurement and analysis of the human back shape has been developed. The driving user friendly software includes correction of distortion of the observation lens, data calibration, three-dimensional Z-axis rotation of the patient normalizing his position, calculus of the curvature map (second derivative), and precise indication of different characteristic points of the back including the spinous processes line. This instrument enables the examination of the back in both erected and bent positions.