Ebook: Research into Spinal Deformities 8
Idiopathic scoliosis remains a fascinating and enigmatic disease, and research in the area of spinal deformities involves a broad range of specialties, from etiology to molecular biology and growth regulation. The International Research Society of Spinal Deformities (IRSSD) promotes a multidisciplinary approach to scoliosis and spinal problems, with a strong emphasis on research in the field of etiology, as well as the clinical effectiveness of a wide range of interventions. The society has been active in one form or another for three decades, encouraging open discussion in all areas related to spinal deformities. This book presents the proceedings of the 9th biennial IRSSD meeting, held in Poznan, Poland, in July 2012. It includes peer-reviewed short papers or abstracts summarizing the 129 papers and posters included in the program, and covers all aspects of spinal deformity research, including etiology, genetics, biology, growth, metabolism, biomechanics, imaging technologies, innovations in treatment and treatment outcomes. This current overview of topics related to spinal deformities provides the opportunity for readers to learn more about the latest developments in this field, and it contributes to the advancement of study and research into spinal deformities for the benefit of patients.
In July 2012 the International Research Society of Spinal Deformities (IRSSD) held its ninth biennial meeting in Poznan, Poland.
IRSSD was founded in 1994but its history starts in VermontUSAwhere a group of researchers first met in 1980 to discuss moiré topography techniques for the assessment of trunk deformity in scoliosis. The inaugural workshops were organized by Drs. Morey Moreland, Malcolm Pope and Gordon Armstrong and focused on instrumentation, school screening, quantification & computerization. Multidisciplinary participation from both public and private sector, and participants from Japan, USA, Canada and European countries, contributed to the debates and discussion. Following the success of this meeting, a series of biennial meetings devoted to Surface Topography and Spinal Deformity were organized. After Vermont, chronologically and geographically, the meetings were held: 1982 in Munster, Germany, hosted by Drs. Burkhard Drerup, Wolfgang Frobin & Eberhard Hieholzer; 1984 in Oxford, UK, organized by Allan Turner-Smith & J. Derek Harris; 1986 in Canada organized by Ian Stokes, James R. Pekelsky & Morey Moreland; and 1990 in Lisbon, Portugal hosted by A. Alberti. This latter meeting was the last that focused on surface topography. A meeting that drew together the fields of Spinal Deformity & Surface Topography and 3-D Scoliotic Deformities was then held in 1992, in Montreal, Canada, at which discussions were held to decide whether a new Society embracing both Spinal Deformity & Surface Topography and 3-D Scoliotic Deformities, should be formally established. Two years later in 1994, in Pescara, Italy, further discussions during the meeting on Three-Dimensional Analysis of Spinal Deformities, hosted by Moreno D'Amico, Aricia Merolli and Giorgio C. Santambrogio led to The International Research Society of Spinal Deformities (IRSSD) being officially founded.
The creation of the new society reflected a desire to consolidate the momentum of the preceding meetings and also to broaden their scope. Subsequently, the first IRSSD meeting was held in 1996 in Sweden, hosted by John Sevastik, and included aetiology & pathomechanisms of scoliosis as main topics. The second meeting was held in 1998 in Vermont and was hosted by Ian Stokes, who introduced new topics: molecular biology & regulation of spinal growth. In the years since, the society has continued to cover a broad range of issues related to scoliosis. The third meeting was subsequently held in 2000 in Clermont Ferrand, France, hosted by Alain Tanguy and Bernard Peuchot, the fourth in 2002 in Athens, Greece, organized by Dr. Theodoros B. Grivas, the fifth meeting in 2004 in Vancouver, Canada, hosted by Bonita J. Sawatzky and S.J. Tredwell, the sixth meeting in 2006 in Ghent, Belgium, organized by Dirk Uyttendaele, the seventh meeting in 2008 in Liverpool, England, organized by Peter H. Dangerfield, the eighth meeting in 2010 in Montréal, Canada, organized by Carl-Eric Aubin, Ian A.F. Stokes, Hubert Labelle, and Alain Moreau and finally the ninth IRSSD meeting in 2012 in Poznan, Poland, organized by Tomasz Kotwicki.
The society promotes a multidisciplinary approach to scoliosis and spinal problems, with a strong emphasis on research in the field of etiology as well as the clinical effectiveness of a wide range of interventions. In one form or another, the IRSSD has been active for three decades, during which time it has encouraged open discussion in all areas related to spinal deformities. Contribution, involvement and interaction among people from all over the world has been a highlight of its activities. As Keith Bagnall said “IRSSD has always been a vehicle to carry the initial, small flicker of the flame. In the past, some of these flames have grown to become forest fires while others have simply died for whatever reason”.
This book contains the Proceedings of the 9th IRSSD 2012 meeting: peer-reviewed short papers or abstracts summarizing the 129 papers and posters included in the program. It covers all aspects of spinal deformity research, including etiology, genetics, biology, growth, metabolism, biomechanics, imaging technologies, innovations in treatment, and treatment outcomes. These scientific proceedings provide the opportunity for readers to learn more about the latest development in this field that will be presented and discussed during the meeting.
We would like to thank all the participants: the authors for sharing their work with us, as well as the members of the scientific committee, chaired by Dr. Theodoros B. Grivas, MD, PhD. The members of the scientific committee, who deserve a particular acknowledgment, divided into groups to review the various topics of the meeting program, namely for Biomechanics, Movement, Posture: Jim Raso, Carl-Éric Aubin, Moreno D'Amico, Yvan Petit, Nachi Chockalingam, Rene M. Castelein, Konstantinos Sultanis, Aleksander Kabsch; for Genetics and Etiology: Alain Moreau, Keith Bagnall, Peter Dangerfield, Nelson Tang; for Growth and Metabolism: Florina Moldovan, Isabelle Villemure, Ian Stokes, Nathalie Alos, Wlodzimierz Samborski; for Imaging and Measurements: Winnie Chu, Tomasz Kotwicki, Delphine Perie, Farida Cheriet; for Treatment: Theodoros B. Grivas, Hans-Rudolf Weiss, Jack Cheng, Hubert Labelle, Jean-Marc Mac-Thiong, Francisco Javier Sanchez Perez-Grueso, Tiziana Greggi, Jacek Durmala, Seung Woo Suh; and finally, for Quality of Life: Lorenzo Aulisa, Jose Maria Climent, Juan Bago, Maciej Glowacki and Nobumasa Suzuki.
We do hope that this book, representing the state of the art in scoliosis research in 2012, will stimulate further studies which will lead us closer to an understanding of idiopathic scoliosis, which remains a fascinating and enigmatic disease. We hope that this meeting will be a unique opportunity to meet in Poznan, Poland, in order to discuss the topics related to spinal deformities, and to advance the study and research into spinal deformities for the benefit of patients.
Tomasz Kotwicki and Theodoros B. Grivas
Poznan, April 30th 2012
Although considerable progress had been made in the past two decades in understanding the etiopathogenesis of adolescent idiopathic scoliosis (AIS), it still lacks an agreed theory of etiopathogenesis. One problem may be that AIS results not from one cause, but several that interact with various genetic predisposing factors. There is a view there are two other pathogenic processes for idiopathic scoliosis namely, initiating (or inducing), and those that cause curve progression. Twin studies and observations of family aggregation have revealed significant genetic contributions to idiopathic scoliosis, that place AIS among other common disease or complex traits with a high heritability interpreted by the genetic variant hypothesis of disease. We summarize etiopathogenetic knowledge of AIS as theories of pathogenesis including recent multiple concepts, and blood tests for AIS based on predictive biomarkers and genetic variants that signify disease risk. There is increasing evidence for the possibility of an underlying neurological disorder for AIS, research which holds promise. Like brain research, most AIS workers focus on their own corner and there is a need for greater integration of research effort. Epigenetics, a relatively recent field, evaluates factors concerned with gene expression in relation to environment, disease, normal development and aging, with a complex regulation across the genome during the first decade of life. Research on the role of environmental factors, epigenetics and chronic non-communicable diseases (NCDs) including adiposity, after a slow start, has exploded in the last decade. Not so for AIS research and the environment where, except for monozygotic twin studies, there are only sporadic reports to suggest that environmental factors are at work in etiology. Here, we examine epigenetic concepts as they may relate to human development, normal life history phases and AIS pathogenesis. Although AIS is not regarded as an NCD, like them, it is associated with whole organism metabolic phenomena, including lower body mass index, lower circulating leptin levels and other systemic disorders. Some epigenetic research applied to Silver-Russell syndrome and adiposity is examined, from which suggestions are made for consideration of AIS epigenetic research, cross-sectional and longitudinal. The word scoliogeny is suggested to include etiology, pathogenesis and pathomechanism.
The normal spine is not a symmetrical structure, as has been appreciated for a long time. The reason why the main thoracic vertebrae in idiopathic scoliosis predominantly rotate to the left at the infantile age and to the right at the adolescent age is unclear. We provided an in-depth analysis of the rotational patterns of the normal growing and adult spine in relation to closure of the neurocentral junctions, organ anatomy and the convexity of the curve in idiopathic scoliosis. We believe that the delicate upright human spino-pelvic balance can be disturbed by a multitude of offenses and consequently an idiopathic scoliosis will develop due to the rotational instability. From our results it can be concluded that once this rotation starts to occur, it will naturally follow the pre-existent rotational patterns that we have demonstrated to exist already in the normal spine.
Significantly lower circulating leptin level has been reported in adolescent idiopathic scoliosis (AIS) compared to healthy adolescents. It was hypothesized that leptin dysfunction might be involved in the etiopathogenesis of AIS. In this study, a scoliosis model of bipedal amputated mice with high central leptin activity was established to validate this hypothesis. Three days after bipedal amputation, the mice were randomly divided into two groups: then 8 mice were injected in the hypothalamus with lentivirus vectors which expressed leptin, whereas the remaining 8 were injected with lentivirus vectors expressing GFP (control vector). X-rays were obtained at 20th week to determine the development of spinal deformity. After that all mice were sacrificed, and blood samples were collected. Then peripheral leptin levels were measured by an ELISA kit. Comparisons for the incidence of scoliosis and the severity of the curves were performed between groups. The body weight was found to be slightly lower in the leptin-vector-treated C3H/HeJ mice when compared with control mice. Significantly higher peripheral serum leptin level was found in leptin-vector-treated mice than control mice. Scoliosis was observed in all leptin-vector-treated mice with an average Cobb angle of 28.2°, and in 4/8 of control with an average Cobb angle of 23.5°. The incidence of scoliosis was significantly higher in leptin-vector-treated mice than in control group, although no significant difference was found in terms of curve severity. The results of this study indicated that the high central leptin activity might not only increase the risk of developing a scoliosis in bipedal mice but also contribute to the progression of scoliosis. The high central leptin activity might play an important role in the etiopathogenesis of scoliosis.
Introduction. Trunkal back asymmetry is considered very important for the selection of children at risk of developing scoliosis. Traditionally, this asymmetry as thoracic or lumbar hump is the main indicator for referral of subjects with idiopathic scoliosis (IS) to clinics from school-screening programs. This asymmetry is also used as the most important sign for further assessment at scoliosis clinics. There are reports suggesting that an epigenetic risk factor for IS is maternal age at birth. However, the influence of maternal age on the development of trunkal asymmetry during growth has not been reported. This report aims to assess if maternal age at birth impacts trunkal asymmetry, and how this parameter may dictate the epigenotypic expression of the trunkal asymmetry of a child.
Material and methods. The sample examined: 11832 (5855 males and 5977 females) children and adolescents (5-17 years old, mean age: 11.34±2.79) were screened at their school for back trunkal asymmetry and/or scoliosis. The measurements: The Prujis scoliometer was used to examine the students in standing and sitting forward bending positions. If at least one of child's measured angles was equal to or exceeded 6 or 7 degrees of scoliometer reading, it was labelled as “Asymmetry-6” and “Asymmetry-7” respectively. The age, standing height and body weight of children and maternal age were also documented, among other parameters. The maternal age at birth and children's BMI were subsequently calculated. The statistical analysis: Asymmetries were tested for correlation with maternal age at birth which was transformed to a categorical variable using 5-year intervals. Pearson's χ2 test was used for the univariate analysis, while logistic regression was used for quantitative univariate and multivariate analysis. Statistical significance level was set to p<.05. SPSS and STATATM v. 11.0 statistical packages were used for the analysis.
Results. Univariate analysis: Univariate analysis showed that the prevalence of asymmetry-6 in boys tended to significantly decrease as mother's age at birth increased (mother's age at birth: <19, 20-24, 25-29, 30-34, 35-39, >40 years, % of asymmetry-6: 11.5%, 9.5%, 8.5%, 7.6%, 5.2%, 5.3%, respectively, (p=0.026). This trend, although present, was not significant in girls. The prevalence of asymmetry-7 also showed a decreasing trend, which was only significant in boys (mother's age at birth: <19, 20-24, 25-29, 30-34, 35-39, >40 years, % of asymmetry-7: 8.7%, 5.9%, 5.9%, 4.6%, 2.6%, 3.5%, respectively, p=0.010). Maternal age at birth, as a continuous variable, was inversely associated with the appearance of asymmetry-6 in both boys and girl s (OR: 0.966, 0.982, 95%CIs: 0.947-0.985, 0.965-0.999, p: 0.001, 0.040, respectively). This was also the case for asymmetry-7 only in boys: (OR: 0.961, 0.982, 95%CIs: 0.938-0.985, 0.962-1.003, p: 0.001, 0.088, respectively). Multivariate analysis: The significant and inverse effect of maternal age at birth on the appearance of asymmetry in boys remained even after adjusting for child's BMI and age. For one year increase of maternal age at birth, the odds of the boys being asymmetrical6 were reduced by 2.8% (OR:0.972, 95% CIs: 0.953-0.992, p: 0.005), adjusting for child's age and BMI. For one year increase of maternal age at birth, the odds of the boys being asymmetrical7 were reduced by 3.2% (OR:0.968, 95% CIs: 0.945-0.992, p: 0.010), adjusting for child's age and BMI. However, the aforementioned correlations were not significant for girls in both cases.
Discussion and conclusions. The influence of maternal age at birth on the development of trunkal asymmetry during growth has not been previously assessed, as evidenced from literature review. The findings of this report indicate that maternal age as an environmental factor in the general population, may possibly influence epigenetically, the occurrence of the initial presentation of trunkal asymmetry in males more than females, as well as IS during growth. Consistent findings reported from the USA, Edinburgh and Sweden reveal increased maternal age as a risk factor for AIS, suggesting maternal factors can predispose to it. It seems that males are more affected by this factor but, unexpectedly in this study, by younger and not older mothers, as reported for AIS in the literature. Low-birth weight associated with younger parental age may also be associated with increased trunkal asymmetry particularly of boys, an hypothesis that need testing.
The importance our findings is based on the belief that the intra-uterine environment is crucial in programming the fetus for various health and disease outcomes throughout life.
The aim of this study was to determine the influence of lateral thoracotomy on the development of scoliosis in subjects undergoing repair of coarctation of the aorta (CoAo) and patent ductus arteriosus (PDA).
A group of 133 patients with CoAo and PDA was evaluated. Forty-five patients with CoAo and 38 with PDA were operated on using lateral thoracotomy (operative group) while 12 patients with CoAo and 31 with PDA were treated using balloon dilatation and stent or coil implantation (non-operative group). Clinical examination and the evaluation of spinal roentgenograms were performed. Among the operated patients 46.6% of those with CoAo and 39.5% of those with PDA had clinical scoliosis. In the non-operated patients scoliosis was present in only 16.6% of those with CoAo and 12.9% of those with PDA. Scoliosis ranged between 10° and 42° and it was mild in the majority of cases. In 90.4% of the operated scoliotic patients with CoAo and 73.3% of those with PDA the curve was thoracic and in 47.6% of the CoAo group and 53,3% of the PDA group the curve was left sided. All curves were right sided in non-operated subjects. Scoliosis in the operated group was higher in males than in females (63.3% versus 60% in CoAo and 68.2% versus 37.5% in PDA). The prevalence of scoliosis after thoracotomy was significantly higher than after non-surgical methods of treatment of both CoAo and PDA as well as in the general population. The rate of single thoracic and the rate of left thoracic curves in patients after thoracotomy is higher than in patients treated non-surgically or in idiopathic scoliosis. The rate of scoliosis after thoracotomy is higher in males than females especially following thoracotomy for PDA.
Recently, several genome wide association studies suggested IL-17RC, CHL1, DSCAM and CNTNAP2 genes polymorphisms were associated with AIS. To confirm these associations, we performed this case-control study using data from 648 AIS patients and 573 healthy adolescent of Chinese Han population. A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was performed to detect the genotypes of polymorphic loci: rs708567 rs279545 in IL-17RC gene, and rs2055314, rs331894, rs2272524, rs2272522 in CHL1 gene, and rs2222973 in DSCAM gene, and rs2710102, rs11770843 in CNTNAP2 gene. Statistical analysis of genotype frequencies between AIS patients and controls were performed by χ2 test. Our results show that both the genotype frequency and allele frequency of loci rs708567 were significantly different between AIS patients and controls (P = 0.023, 0.028, respectively). As for polymorphic loci rs279545, rs2222973, rs279545, rs2055314, rs331894, rs2272524, rs2272522, no significant difference was found between AIS patients and controls either genotype or allele frequencies (p>0.05). Overall, our study found a significant association of IL-17RC gene polymorphisms with AIS in a Chinese Han population, indicating IL-17RC gene may be as a susceptibility gene for AIS; While CHL1, CNTNAP2 and DSCAM genes were not associated with AIS, suggesting that those genes may not be involved in the etiopathogenesis of AIS. However, association study of these genes with AIS in other races is needed to clarify the role of these genes in the etiology of AIS.
MESP2, HES7 and DUSP6 genes have been proved to be involved in the etiopathogenesis of congenital scoliosis (CS) in animal embryo studies, however, whether this association was detected in human CS patients also remains unknown. One hundred sporadic and non-syndromic CS patients and 100 age-matched normal controls were included in this study. Mutation screening of gene exons were performed by DNA sequencing. However, no mutation or new single nucleotide polymorphism was found in the exons of MESP2, HES7 and DUSP6 genes in CS patients and normal controls. MESP2, HES7 and DUSP6 genes may not be involved in the etiopathogenesis of sporadic and non-syndromic CS in Chinese Han population.
Deep paravertebral muscles and female sex hormones are potential elements participating in idiopathic scoliosis development. Estrogen acts through estrogen receptors: ESR1 and ESR2. There are no studies describing ESR2 expression in back muscles in girls with idiopathic scoliosis. The aim of this study was to evaluate ESR2 expression levels in back muscles on both sides of the spinal curve and correlation between the expression level and scoliosis parameters. Asymmetrical ESR2 expression in deep paravertebral muscles was found: 11 girls had higher expression level on the convex side and 5 girls had higher expression level on the concave side of the curvature. Patients with ESR2 (convex/concave) ratio ≥ 1 presented positive correlation between ESR2 ratio and Cobb angle.
Revision of older knowledge on spinal deformities shows causing factors in all day life and the source of rotational forces in men in respiration. The role of lordosis as a causative factor can change towards a correcting force, supported by different studies. The thoracolumbar spine is the originating area of many deforming processes.
Using older and new concepts on aetiology a new brace technique with thoracolumbar lordotic intervention in adolescent scoliotic and kyphotic deformities was created. The technique with symmetrical forces in the sagittal plane only on the thoracolumbar joint and its effect on the formative function of the extending muscles is explained.
Since 1996 in Russia the screening of the child population is carried out using the diagnostic system TODP. The purpose of the study - to explore gender and age features of the postural formation. The most significant differences in the postural formation between boys and girls have been identified in the sagittal plane. A strong correlation between the development of structural scoliosis and growth of the body for both genders was revealed in the frontal plane.
The study of the back muscles bioelectric activity in 216 children in the age between 10-15 years showed that the total paravertebral muscles bioelectrical activity on the convex side of the proximal curve and on the concave side of its distal part is higher compared with that on the opposite side. Analysis of H-reflex and M-responses in 302 patients in the age between 10-15 years created a normative database. This allows, in comparison with the total individual electrophysiological parameters, to determine patient's progression risk.
Brain structures with bioelectric activity (BA) different from BA of the same structures in healthy peers were revealed using an original 3DLocEEG analysis of EEGs that solves so-called “reverse EEG task”. These were the following structures: thalamus, pineal gland, hypothalamic area, including suprahiasmatic nuclei, and infratemporal cortex. The shift of BA focus to structures of the left hemisphere including left thalamus was recorded in patients with AIS; the shift increased both with worsening of deformation and increasing progression activity. This was not observed in healthy children (aged 7–14 years), although it is natural for older adolescents (15–17 years) and healthy adults. In other words, the interhemispheric asymmetry of brain BA in children with AIS becomes typical for the definitive brain much earlier. This phenomenon may be used for future development of a method for prediction of deformation progression patterns. A number of differences obtained in comparative analysis of EEGs, processed by 3DLocEEG method, between right-side and left-side AIS allow us to hypothesize about aetiology and pathogenesis differences of these two AIS clinical forms. Data obtained suggest that brain structures play a much more important role in aetiology and pathogenesis of AIS right-side forms compared with left-side ones. Primary subclinical dysfunctions of brain regulatory systems leading to disturbances of spinal cord and brain associated growth and subsequently to scoliosis development are supposed to play the main role in pathogenesis of right-side AIS forms (or their substantial part). Evidently, the major reason for manifesting these latent dysfunctions is an overstrain of central nervous system (CNS) adaptation-compensation mechanisms during the pubertal period.
A physiologic sagittal alignement of the spine with lumbar lordosis and thoracic kyphosis is the most stable position of the spine, while in patients with Idiopathic Scoliosis (IS) the sagittal profile of the spine is flattened or inversed. It has been shown that a correction of the sagittal profile also corrects coronal plane deformity in patients with IS. Therefore sagittal corrections seems to play an important role in the conservative treatment of IS. Within the “Best Practice” PT program simple tools are used to correct scoliosis in 3D. One of these tools is the sagittal realignment of the scoliotic pattern of weight bearing. The impact different weight bearing (WB) patterns might have are subject of this investigation.
Materials and Methods: 13 healthy subjects (females only, age range from 18 to 45 years) have been investigated with the help of suface topography (DiersŸ Formetric) in two different patterns of weight bearing (WB forefoot / WB heel). Kyphosis anglelordosis anglethe inflection point (IP) between the lordotic and the kyphotic curve have been investigated.
Results: There was a significant increase of lumbar lordosis angle (49.5° to 51.1°; p=0.047) in WB forefoot. No change of thoracic kyphosis angle has been detected. IP had a tendency to slip more cranially, however this was not significant. Conclusions: WB on the forefoot increases lordosis angle and by this stabilizes the spine. The different patterns of WB do not seem to change the angle of thoracic kyphosis.
In idiopathic scoliotic patients, dynamical intervertebral efforts acting between vertebrae seem to be correlated with the spinal deformity. The quantification of these efforts, which is useful for the orthopedic surgeons to set up their surgical planning is the final objective of the present research. As a first step, we focus in this contribution on the geometrical reconstruction of the spine and especially on the rotation sequences between vertebrae in a multibody approach. The reconstruction process is performed in the standing position with possible bending, using an optimization process based on geometrical data reconstructed from radiographs. The obtained results will serve as input for the subsequent gait motion for which the limited set of geometrical information must be compensated.
Growth modification is under investigation to treat pediatric spine deformities. A hemiepiphyseal staple construct has been shown to alter growth and create physeal structural gradients in an in vivo porcine model. A finite element model (FEM) of a motion segment with and without implant was developed based on preliminary experimental results of initial post-operative motion segment compressive properties. The nonlinear tangent stiffness determined from the model correlated well with the experiments for the native segment, whereas after addition of the implant, the model overestimated the stiffness. The current purpose was to determine the effect of implant-bone contact conditions and initial disc displacement conditions, include growth effects, and compare FEM and experimental results at each stage. A 3D FEM was developed from a CT scan of a porcine T7-T8 segment. The annulus was modeled as an incompressible anisotropic hyperelastic material, and the nucleus as an incompressible fluid. A CAD model of the implant was constructed. Load-displacement curves in compression were determined from a nonlinear analysis performed under different initial and bone-implant interface conditions. Contact conditions were a) perfect, b) friction of 0.1-0.3, or c) soft contact. Initial conditions were that implant insertion induced a) no change in stress or strain in the disc, b) a 2˚ angulation with a centrally located neutral axis and no residual stresses, and c) both stress and coronal plane displacement gradients. Growth modulation effects were added using a published linear relationship between compressive stress and growth rate. A 2 month PO time was simulated. Altering bone – implant surface contact conditions from perfect to either friction or soft contact decreased the stiffness, but all models remained stiffer than experimental results. An initial disc angulation without residual stress did not affect stiffness, whereas stiffness increased with an initial angle and compressive stress. The growth simulation results predicted 32% of control growth on the side ipsilateral to the implant and 81% on the contralateral side. Reductions in growth were similar in pattern, but overestimated, experimental histomorphometric changes.
There are assumptions that leg length discrepancy (LLD) may cause low back pain by creating pelvis obliquity and lumbar scoliosis. Although individuals with LLD develop compensatory movements in the lower limbs and pelvis during walking, few investigations have attempted to identify kinematic variables of the upper body. This study aims to gain an understanding of how simulated LLD influences three-dimensional motion of the pelvis and spine. Seven male participants were required to walk barefoot at a preferred speed. Three LLD conditions (1, 2, and 3cm) were simulated using modified pieces of high density EVA attached to the right foot. An optoelectronic motion analysis system was used to record kinematic data of the pelvis and spine (lumbar, lower and upper thoracic segments) for each condition. Differences in range of motion and patterns of movement for the pelvis and lumbar spine were minimal between barefoot and LLD conditions. These observations could be attributed to various kinematic compensatory strategies within the lower limbs which require further in-depth investigation.
Leg Length Discrepancy (LLD) is very often associated to Low Back Pain (LBP), but still controversial is the use of underfoot wedge correction (heel rise) to re-balance pelvis and trunk posture. In a review of our last 5 years clinical activity we observed that more than 70% out of 300 LBP patients presented a LLD. In more than 80 % we ascertained, via Baropodography, the presence of underfoot asymmetric load, during standing. More durable therapy recovery effect has been observed when LLD correction had been adopted. These reasons led us to start a study to assess if a Full 3D multifactorial Posture evaluation approach, by means of Opto-electronic device associated to foot pressure maps recording, was able to quantitatively discriminate the clinically observed phenomena. On a 94 LBP (av. age 46.3±16 Y range 15-82 Y) patients sample, 83 (88%) have been found to improve posture when LLD was corrected. The 94 patients showed a mean lower limb discrepancy of μ=8±3.2mm associated to a mean scoliotic lumbar curve μ=10.5°±5.1° Cobb (frontal plane), mean Spinal offset μ=6.6±4.9mm and mean Global offset 10.7±8.8mm. The applied paired t-test comparison (indifferent vs. corrected orthostasis) showed significant (p < 0.05) postural improvements could be obtained in the whole or in a part of the considered parameters, both in rebalancing and in spine deformities reduction after the application of suitable under-foot wedge. The joint 3D opto-electronic and foot pressure map approach proved to be effective to control several clinical parameters with statistical significance.