A prospective randomized controlled trial of the natural history of idiopathic scoliosis versus treatment with the SpineCor brace. Sosort Award 2011 winner.

AIM: The purpose of this randomized controlled trial was to evaluate the efficacy of the Dynamic SpineCor brace for early idiopathic scoliosis (15°-30°) compared to the natural evolution of the disease. 68 patients participated in this study (32 treated and 36 controls) with at least 5 years follow-up. METHODS: The inclusion criteria were: 1) high risk of evolution: family history and/or proven progressive; 2) no significant pathological malformation of the spine; 3) initial Cobb angle between 15° and 30°; 4) risser 0, 1 or 2. Assessment of brace efficacy included the percentage of patients who have 5º or less curve progression and the percentage of patients who have 6º or more progression at skeletal maturity. RESULTS: At five-year follow-up a correction was achieved in 50% of treated patient and only in 9.5% of controls, stabilization in 42.3% treated and 47.7% in controls and progression in 26.9% for the treated group and 42.8% for controls. For the control patients we considered as a failure if the Cobb angle worsened by more then 5° from the original angle and the patient then received treatment. CONCLUSION: The results 5 years after the treatment suggested that the SpineCor brace reduced the probability of the progression of early idiopathic scoliosis comparing with its natural history. Moreover, the positive outcome appears to be maintained in the long term.

Horizontal body and trunk center of mass offset and standing balance in scoliotic girls.

In adolescent idiopathic scoliotic girls, postural imbalance is attributed to a sensory rearrangement of the motor system on the representation of the body in space. The objectives of this study were to test if the anteroposterior (AP), mediolateral (ML) and resultant body-head and trunk center of mass (COM) horizontal offsets were similar in able-bodied and scoliotic girls and if these offsets were related to the center of pressure displacements. A total of 21 adolescent idiopathic scoliosis girls and 20 able-bodied girls participated in this study. Their body COM position and that of the head and trunk were estimated according to Damavandi et al. (Med Eng Phys 31:1187-1194, 2009). The COP range and speed in both AP and ML axes were calculated from force plate measurements in quiet standing. The AP offset of the able-bodied group was anterior to the body COM by 11.0 ± 15.9 mm, while that of the scoliotic group was posterior to it by -17.3 ± 11.2 mm. The able-bodied group maintained their head-trunk segment COM more to the right by 14.1 ± 13.1 mm, while that of the scoliotic group was nearly over their body centerline. The scoliotic girls presented higher values for COP range and COP speed than the able-bodied girls. The resultant COM offset was correlated with both the ML COP range and speed only for the scoliotic girls. The small ML COM offset in the scoliotic girls was attributed to a compensatory action of the spinal deformity in the frontal plane resulting in a backward resultant COM offset to regain postural balance concomitant to an increase in the ML neuromuscular demand.

[Molecular and genetic aspects of idiopathic scoliosis. Blood test for idiopathic scoliosis]. / Molekulare und genetische Aspekte der idiopathischen Skoliose. Bluttest bei idiopathischer Skoliose.

Spinal deformities, and particularly scoliosis, are the most frequent forms of orthopedic deformities in children and adolescents. About 1-6% of the population has scoliosis. This disorder leads to severe spinal deformities and predominantly affects adolescent girls.Although the multifactorial origin of adolescent idiopathic scoliosis (AIS) is broadly recognized, the genetic causes of AIS are still largely unknown. Our previous studies suggested a generalized dysfunction of melatonin transduction (the hormone that is primarily produced in the brain and epiphysis). In the meantime we have demonstrated that such a defect of signal transduction is caused by chemical alterations, which inactivate the function of the inhibitory G protein-coupled melatonin receptors. This discovery has led to the development of the first blood test to detect children without symptoms who are at risk of developing scoliosis. Since a single function (cellular reaction to melatonin) is determined, the unique advantage of this test is that it can be performed without knowledge of mutations in defective genes that could provoke the onset of AIS.

Reliability of a computer-aided color-coded video-based system for clinical assessment of the foot.

UNLABELLED: There is a need for a user-friendly system that can provide quick and reliable assessment of foot disorders. The study described in this report was undertaken to determine the inter-rater and intra-rater reliability of a computer-aided, color-coded, video-based system developed for the assessment of foot alignment in patients with and without pes cavus deformity. Initially, 15 pedal angles were repetitively measured 7 times on 6 color-coded images of both feet, in 20 healthy adults. From the 7 repetitive measurements, the intra-class correlation was calculated and analysis of variance was used to estimate the minimum number of trials that would be necessary to identify a statistically significant difference in the measurements. To determine intra-rater reliability, 5 examiners evaluated a single set of data taken from 10 subjects. Additionally, data were obtained for 20 subjects with pes cavus deformity. The average intra-class correlation coefficient (ICC) for the anglular measurements for 2 to 7 trials was 0.98 +/- 0.06, while the intra-rater reliability was 0.90 +/- 0.14. No statistically significant differences were observed between right and left foot angles in able-bodied subjects; whereas, in the pes cavus group, 8 different angular measurements were observed to be statistically significantly different. The results of this investigation indicate that a computer-aided, color-coded, video-based system can be used to make reliable measurements of postural alignment in patients with and without pes cavus. LEVEL OF CLINICAL EVIDENCE: 5.

Biomechanical modeling of anterior spine instrumentation in AIS.

This study is part of a larger project regarding the development of a Spine Surgery Simulator (S3), which has shown good results for posterior instrumentation surgeries. The aim was to develop a biomechanical model for the anterior instrumentation of the scoliotic spine. A biomechanical model using flexible mechanism was developed and surgical manoeuvres (instrumentation, rod installation and compression) were reproduced. Validation of the model was done by comparing the results for the instrumented part of the spine to the post-operative data (analytical Cobb angles in the frontal and sagittal planes, plane of maximum deformity, etc.). To date, surgeries of four patients operated by thoracotomy were reproduced. Preliminary results show that anterior instrumentation of the scoliotic spine can be adequately modelled using pre-operative geometric data and using mechanical properties from literature. Once validated with a larger sample of cases, the anterior instrumentation model could be implemented into S3 and used by orthopaedic surgeons to test various instrumentation strategies in virtual reality before performing the actual surgery.

[Bone integration and apposition of porous and non porous metallic orthopaedic biomaterials]. / Intégration et apposition osseuses des biomatériaux orthopédiques métalliques poreux et non poreux.

The objective of this study was to evaluate the functionality of two intervertebral fusion implants, a porous nickel-titanium and a conventional titanium cage system in a sheep model. Eighteen sheep each received the two-implant devices at L2-L3 and L4-L5 lumbar levels. The sheep were sacrificed at three different postsurgical periods: three, six and 12 months. Lumbar segments were harvested. Qualitative (macroscopic and microscopic) and quantitative (histomorphometric) histological analysis were carried out on histological slides. The results indicated that a porous nickel-titanium had obtained a better osseointegration than the titanium implant. The functionality of two implants seemed to be influenced by the implant structure and shape. However, biocompatibility of two implants seemed comparable.

Porous titanium-nickel for intervertebral fusion in a sheep model: part 2. Surface analysis and nickel release assessment.

Porous titanium-nickel (PTN) devices represent an alternative to traditional cage implants. PTN materials possess an interconnecting network of pores with capillarity properties that may promote bone ingrowth, long-term fixation, and intervertebral fusion without the need for bone grafting. However, their considerable surface area and nickel content may elicit concerns over sensitization potential. Therefore, PTN surface corrosion and nickel release resistance must be carefully studied. To evaluate this possibility, a PTN interbody fusion device (IFD) was compared to a conventional nonporous cage made of TiAlV, a well-known biocompatible biomaterial, in a sheep model. PTN and TiAlV IFDs were inserted at two non-contiguous lumbar sites for 3, 6, and 12 months postsurgery. Their surface was then evaluated by scanning electron microscopy (SEM) combined with backscattered electron analysis (BSE). No evidence of surface corrosion was observed either pre- or postimplantation, regardless of device type. Dosage of nickel ions was also performed with the use of inductively coupled plasma-mass spectrometry (ICP-MS). Blood nickel levels were observed to be within acceptable levels at all postinstrumentation times. Nickel content in PTN-adjacent tissue, as well as in detoxification and remote organs, was equivalent both in PTN-treated and control sheep. Therefore, porous titanium-nickel demonstrated resistance to both in vivo surface corrosion and nickel ion release and compared very well with a conventional titanium implant in the course of a 12-month sheep study.

Acute postural adaptations induced by a shoe lift in idiopathic scoliosis patients.

The objective of this study was to identify acute spinal and three-dimensional postural adaptations induced by a shoe lift in a population of idiopathic scoliosis (IS) patients. Forty-six IS patients (mean age: 12 +/- 2 years) were evaluated radiologically and with a stereovideographic system for pelvic obliquity. Based on the initial postural and radiological evaluation, a pertinent shoe lift height was chosen for each with the result that 12 patients were tested with 5-mm (S5) lifts, 20 patients were tested with 10-mm (S10) lifts, and 14 patients with 15-mm (S15) lifts. The posture for all 46 patients was then re-evaluated and a spinal radiograph obtained for 14 patients. The implementation of a shoe lift independent of the type of curve and amplitude significantly decreased the Cobb angle. As expected there was a change in the vertical height of the left tibial plateau and greater trochanter that induced a change in pelvic tilt. There was also a significant increase in the vertical height of S1 and T1. There was a significant change in the left and right iliac bone version, as well as a decrease in the difference in version between these two bones. The implementation of the shoe lifts also changed the lateral shift of the pelvis. A relative change between the shoulders and pelvis for tilt and anteroposterior shift was also found to be significant. In conclusion, using a shoe lift resulted in acute postural adaptations which specifically affected the spine and the three-dimensional position and orientation of the pelvis and shoulder girdle.

Study of biodegradation behavior of chitosan-xanthan microspheres in simulated physiological media.

Microspheres of a polyelectrolyte complex hydrogel were prepared from chitosan and xanthan after interaction between the two polyionic polymers. Their biodegradation was studied vs. chitosan. Simulated gastric fluid (SGF, pH 1.2) and intestinal fluid (SIF, pH 7.5) both as biodegradation media and phosphate buffered saline (PBS, pH 7.4) as a negative control were used. The degradation studies were performed at 37 degrees C at 240 rpm permanent stirring to mimic the physiologic conditions. High performance liquid chromatography (HPLC) was carried out to quantify the chitosan degradation products using glucosamine (GA) and N-acetyl-D-glucosamine (N-Ac-GA) as references. The peaks area integration method was used to determine the amount of each degradation product as a function of incubation time in the media. The effect of the media on the morphological structure of microspheres was assessed by scanning electron microscopy. From HPLC studies, it appeared that in SGF and SIF the major degradation products were glucosamine (GA) and N-acetyl-D-glucosamine (NAc-GA). In the first 15 days, oligochitosan fractions were released from the complex, whereas N-acetyl-D-glucosamine was detected in the media after this period. The degradation kinetics were assessed by the measurement of the cumulative degradation products, which showed faster degradation of chitosan than the complex in SGF and SIF. SEM micrographs showed an enhancement of microsphere porosity as a function of incubation time in the simulated physiological media. Our results suggest a better control of the degradation kinetics when chitosan is complexed to xanthan.

Etiology of idiopathic scoliosis: current trends in research.

Current population studies characterize idiopathic scoliosis as a single-gene disorder that follows the patterns of mendelian genetics, including variable penetrance and heterogeneity. The role of melatonin and calmodulin in the development of idiopathic scoliosis is likely secondary, with indirect effects on growth mechanisms. Reported abnormalities of connective tissue, skeletal muscle, platelets, the spinal column, and the rib cage are all thought to be secondary to the deformity itself. Although no consistent neurological abnormalities have been identified in patients with idiopathic scoliosis, it is possible that a defect in processing by the central nervous system affects the growing spine. The true etiology of idiopathic scoliosis remains unknown; however, it appears to be multifactorial.

A noninvasive anthropometric technique for measuring kyphosis and lordosis: an application for idiopathic scoliosis.

STUDY DESIGN: Cross-sectional measurement of the sagittal geometry of adolescent idiopathic scoliosis patients. OBJECTIVES: To evaluate the accuracy of a noninvasive anthropometric approach for the measurement of kyphosis and lordosis. SUMMARY OF BACKGROUND DATA: Noninvasive approaches were developed to estimate the sagittal curvatures of the spine. However, the magnitude of the estimation error could be high for an important proportion of patients, which leads to a difficult clinical application. METHODS: The group was composed of 124 female patients with a mean age of 13.5 years (SD 2. 7 years) with Cobb angles ranging from 4 degrees to 66 degrees. Kyphosis and lordosis were measured on the lateral radiograph. The spine sagittal curvature of the same patients was also estimated using the spatial localization of skin markers placed overlying the spinous processes. These coordinates served as input into a simple trigonometric model. Data were collected by means of a stereovideographic technique (Motion Analysis Corp., Santa Rosa, CA). RESULTS: The intraclass correlation coefficient between both approaches was 0.94 for kyphosis and 0.91 for lordosis; the mean absolute differences were 5 degrees (SD 4 degrees ) and 6 degrees (SD 6 degrees ), respectively. The difference was less than 10 degrees in 91% of the patients for kyphosis, and in 79% for lordosis. CONCLUSIONS: The proposed technique appears to give more representative results than those presented in the literature. It has the advantage of being part of a global noninvasive postural evaluation. Using this approach in a systematic manner could help reduce radiograph exposure while keeping track of the spine sagittal curvatures.

In vitro and in vivo biocompatibility of chitosan-xanthan polyionic complex.

A novel hydrogel, CHITOXAN(TM) (CH-X), has potential as a vehicle for controlled drug delivery. The hydrogel is obtained by complexation of two polysaccharides, chitosan and xanthan. In the present work we investigated the biocompatibility of the complex using in vitro and in vivo models. The cytotoxic effects of CH-X microspheres as well as their degradation products at different concentrations were assessed on fibroblasts (fibroblast cell line L-929) using 3-(4,5-dimethylthiazole-2yl)-2,5-triphenyl tetrazolium) (MTT). The test is based on mitochondrial dehydrogenase cell activity as an indicator of cell viability. Interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) cytokines as well as nitric oxide (NO) production by macrophages (macrophage cell line J-774) were examined as indicators of cell activation. In vivo biocompatibility assessment was performed for 1 to 12 weeks. This study was performed using tablets obtained after compression of CH-X particles implanted at the subcutaneous level in male Wistar rats. CH-X biocompatibility and degradation were investigated using histological studies. Light and transmission electron microscopy (TEM) analyses were used to determine the foreign-body reaction and phagocytosis of the implants by macrophages. Fibroblast exposition to CH-X particles and degradation products did not show cytotoxic effects as measured by MTT test. TNF-alpha production was dependent on CH-X particles concentration, whereas IL-1beta production was found to be dose independent. CH-X extract products stimulated TNF-alpha secretion when used at the highest concentration (10 mg/mL), notably after 28 days' degradation time. No effect was observed on IL-1beta production when CH-X extracts were used in comparison to the control. The effects of CH-X particles on NO secretion were similar as on TNF-alpha. Histological studies showed that CH-X tablets broke down into particles which progressively degraded into smaller fragments. A significant fraction of the fragments was ingested by the macrophages after 12 weeks of implantation. Light microscopy studies showed a weak foreign-body reaction as a function of time and the fibrous layer thickness decreased with time of implantation.

Pre-, intra-, and postoperative three-dimensional evaluation of adolescent idiopathic scoliosis.

The authors measured and compared the pre-, intra-, and postoperative three-dimensional shape of the spine during corrective surgery to quantify the specific contribution of positioning, anesthesia, surgical exposure, surgical instrumentation, and postural adaptation of the thoracic and lumbar spine. In 58 adolescent girls with idiopathic scoliosis undergoing corrective surgery by a posterior approach, the three-dimensional geometry of the thoracic and lumbar spine was documented in the standing position before and after surgery using a three-dimensional reconstruction technique based on multiplanar radiography, and the intraoperative three-dimensional geometry was measured using a three-dimensional magnetic digitizer before and after installation of the first rod. Prone positioning, anesthesia, and surgical exposure are responsible for a considerable decrease in all curves in the frontal and sagittal plane. Instrumentation with the first rod produces additional substantial and favorable three-dimensional changes with partial restoration of the normal sagittal curves and sagittal shift of the plane of maximum deformity. Although no loss of correction was observed in the frontal plane when patients resumed their standing position, a "spring-back" effect on the spine was noted in the sagittal plane and a loss of three-dimensional correction was seen in the orientation of the plane of maximum deformity. Surgeons can use the knowledge of these various changes to achieve better results by more careful attention to the preoperative positioning of patients and to curve correction in the sagittal plane when instrumentation is applied to the spine.

A three-dimensional radiographic comparison of Cotrel-Dubousset and Colorado instrumentations for the correction of idiopathic scoliosis.

STUDY DESIGN: A prospective clinical study comparing two instrumentation systems for the correction of idiopathic scoliosis. OBJECTIVES: To measure the short-term three-dimensional changes in the shape of the spine after corrective surgery and compare the Cotrel-Dubousset instrumentation to the more recent Colorado instrumentation to determine whether one system provides better three-dimensional correction. SUMMARY OF BACKGROUND DATA: Adequate three-dimensional correction of scoliotic deformities has been reported with the Cortrel-Dubousset instrumentation system. During the past decade, a new generation of more versatile and user-friendly spinal implants has appeared, but there are no reports available to indicate whether similar or better correction can be obtained with these newer systems. METHODS: The three-dimensional geometry of the thoracic and lumbar spine was documented in the standing position using a three-dimensional reconstruction technique based on multiplanar radiography in 67 adolescents with idiopathic scoliosis undergoing correction by a posterior approach. Changes in spinal shape were measured 3 days before and 1 month after the surgery in 31 patients with Cotrel-Dubousset instrumentation and 36 patients with Colorado instrumentation. RESULTS: In both groups, adequate three-dimensional correction of the scoliotic deformities was documented for thoracic and lumbar curves, with significant changes in the frontal plane, in the plane of maximum curvature, and in its orientation. When comparing both groups, better correction was obtained in the frontal plane with the Colorado instrumentation (65% vs. 48% with Cotrel-Dubousset), a finding that may be explained by the significantly greater proportion of pedicle screws used in this group. CONCLUSION: Both instrumentation techniques achieve an effective and comparable three-dimensional correction of the scoliotic deformities.

Quantification of mechanoreceptors in the canine anterior cruciate ligament.

Ten canine anterior cruciate ligaments (ACLs) were harvested while preserving their bony attachments. Specimens were stained using a modified gold chloride technique, divided into thirds, and serially sliced at 0.5 microns. The slides were viewed to count the mechanoreceptors present. The average numbers of receptors found were: proximal 67, middle 43, and distal 18 (ANOVA: P < 0.001). The statistical test (Sheffé) revealed that the proximal third contained a greater mean number of receptors (S = 3.8). No significant difference was found between the number of receptors in the middle and distal thirds (S = 0.85).

Relationship between gibbosity and Cobb angle during treatment of idiopathic scoliosis with the SpineCor brace.

The objective of this study was to quantify the relationship between gibbosity and spinal deformation expressed by the angle of Cobb before and during treatment with a brace for different classes of idiopathic scoliosis patients. As part of the standard treatment with the Dynamic Corrective Brace (SpineCor), 89 idiopathic scoliosis patients underwent an initial radiological examination and gibbosity measurement with a scoliometer wearing and not wearing the brace. The 89 patients were classified in relation to the apex of the scoliosis curves: thoracic (n = 29); thoracolumbar (n = 40); lumbar (n = 7) and double (n = 13). With the dynamic corrective brace, the patients showed a mean decrease of 8.3 degrees for the major Cobb angle, and a mean decrease of 2.3 degrees for their gibbosity. There was a significant positive relationship between gibbosity and Cobb angle with and without the brace for the thoracic and thoracolumbar curves. A linear regression analysis identified a small mean estimation error for the thoracic curves (7.4 degrees no-brace; 2.7 degrees with brace) and thoracolumbar curves (5.2 degrees no-brace; 5.3 degrees with brace), indicating a predictive potential of the scoliometer. The measure of gibbosity with the scoliometer provides a fairly reliable estimation of Cobb angle at the initial clinical examination of a scoliosis patient. However, when initial Cobb angle and gibbosity are considered, the measure of gibbosity when wearing a brace provides the clinician with a highly reliable estimation of the Cobb angle while in a brace. This relationship also exists for the follow-up with a brace, permitting a judgement of the patient's evolution under the treatment with SpineCor.

[Comparison of the reliability of two 3D acquisition systems used for the study of anthropometric and postural parameters]. / Comparaison de la fidélité de deux systèmes d'acquisition 3D sur l'étude de paramètres anthropométriques et posturaux.

The goal of this study is to compare the between trials and between session reliability of the postural geometry (PG) and anthropometrical evaluations, obtained by the FreePoint (FP) system and the Motion Analysis System (MA). The potential of automatization of the anthropometric evaluation is also evaluate through the comparison of height measurements obtained by the two 3D systems and traditional anthropometrical tools. The PG of 15 adult control subjects (x: 25 years, SD: 6) evaluated on two occasions (1 week interval) and a mannequin on one occasion were evaluated with both systems. Each evaluation involved the identification of 52 anatomical landmarks followed by the acquisition of 5 trials with each system. The 3 dimensional position of the anatomical landmarks serves to define a postural model including the shoulder girdle, spinous processes (T1 to S1), thorax, pelvis, lower extremities and base of support. Postural parameters were calculated, including rotations, tilts, versions, kyphosis, lordosis, right and left Cobb, anteroposterior shifts, (AP), mediolateral shifts (ML) and vertical heights. The between trials and between session results demonstrate a strong correspondence of the 15 anthropometric heights and the 20 postural parameters between the three systems, permitting the proposal of a broadened clinical utilisation of the FreePoint system. However, the validity of these measures is influenced by the reliability of the anthropometric landmarking, natural oscillation of the body and the intra-specific variation of the posture of each subject.

[Experimental scoliosis in the minipig: study of vertebral deformations]. / La scoliose expérimentale chez le mini-porc: étude des déformations vertébrales.

UNLABELLED: The purpose of this study was to attempt an induction of a scoliotic deformation in the minipig by means of unilateral epiphysiodesis of the neurocetral cartilage (NCC) of 5 consecutive vertebrae, in order to understand the vertebral deformities genesis in the scoliotic pathology. The vertebral deformities induced in this quadruped have been compared to those of the pseudo-biped (chicken: induction of the scoliosis by means of pinealectomy) and to the known vertebral deformities in the human idiopathic scoliosis. MATERIAL AND METHODS: Eight Yucatan minipigs (1 month old) have been used. In the tested group (4 minipigs) underwent an epiphysiodesis (compression with a screw) on the NCC from T5 to T9. The control group (2 minipigs) underwent a perforation of the NCC without a screw placement from T5 to T9. The sham group (2 minipigs) underwent only a sus-periosted vertebral muscles clearing on the right side at the thoracic level. An X-ray follow-up at 1, 6 and 12 months has been performed. The minipigs have been sacrificed between 12 an 13 months post-operatively. The vertebrae were dissected for the macroscopic anatomic analysis. RESULTS: The X-ray follow-up shows an unfinished resorption of the curvature after one year post-operatively. The horizontal deformity of the vertebrae was more marked in those with the compressed (screw) NCC. The vertebral deformities in the minipig are similar to those found in the human and chicken. CONCLUSIONS: Although the curvatures are benign and often spontaneously resolvent, the comparison of the induced vertebral deformities to those obtained in a chicken (post-pinealectomie) and the human suggest that the NCC is likely involved in the vertebral deformities in the horizontal plan. Therefore the minipig does not seem to be a good experimental model for the scoliosis.

[Reductibility of idiopathic scoliosis during orthopedic treatment]. / La réductibilité des scolioses idiopathiques dans le traitement orthopédique.

Non-operative treatment of idiopathic scoliosis is long and difficult. For the patient and the therapist it is particularly important to define early the therapeutic prognosis. The goal of this study is to verify if the initial reducibility at the beginning of treatment with the dynamic corrective brace (Spinecor) would be valid as a prognostic factor, allowing a more effective prognostic judgement of the final outcome treatment. This is a prospective study which includes 99 scoliosis patients (88 female, 11 male), with a mean age of new 12.6 years, treated by the dynamic corrective brace for progressive idiopathic scoliosis curves (29 degrees mean Cobb angle). The initial Cobb angle was compared to the pre-therapeutic Cobb angle. The results demonstrate that the reducibility of the scoliotic curves with the brace at the beginning of treatment provides a significant global prognostic index but is difficult to apply individually. Other factors should be considered, such as the impact of growth velocity on the spinal deformity at the onset of the adolescent growth spent as well as vertebral deformities diagnosed around the apex.