[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.

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.

Intraoperative comparison of two instrumentation techniques for the correction of adolescent idiopathic scoliosis. Rod rotation and translation.

STUDY DESIGN: A prospective and controlled comparative study of two instrumentation techniques used for the correction of adolescent idiopathic scoliosis. OBJECTIVE: To measure the three-dimensional intraoperative correction obtained with a rotation maneuver as compared with that obtained with a translation maneuver of the first instrumentation rod inserted to determine the difference, if any, in the two techniques for achieving three-dimensional correction. SUMMARY OF BACKGROUND DATA: Adequate three-dimensional correction of scoliotic deformities has been reported with the Cotrel-Dubousset instrumentation using the rod-rotation maneuver. More recently, however, authors of studies with newer instrumentation systems have claimed that better correction can be obtained using a translation technique. So far, no report has clearly demonstrated the three-dimensional changes obtained with this more recent instrumentation technique. METHODS: The changes in position of thoracic and lumbar vertebrae exposed during surgery were documented using a three-dimensional magnetic digitizer in 70 adolescents with idiopathic scoliosis undergoing correction by a posterior approach. Vertebral positions were measured intraoperatively before and after the surgical maneuver in 39 patients with the Cotrel-Dubousset instrumentation (rod rotation) and in 31 patients with the Colorado instrumentation (translation). RESULTS: In both groups, adequate three-dimensional correction of the scoliotic deformities was documented, with significant changes in the frontal and sagittal planes and in the orientation of the plane of maximum deformity for thoracic and lumbar curves. On the other hand, no significant differences were documented between the two procedures except in the frontal plane where a tendency for greater correction was observed for thoracic curves with the translation technique. CONCLUSIONS: The two instrumentation techniques are equally able to achieve a comparable and effective three-dimensional correction of the scoliotic deformities. The use of either a rotation maneuver or a translation technique during surgery does not result in any significant measurable difference in three-dimensional correction.

[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.

[Classification of left thoracolumbar scoliosis according to its radiologic morphology and its postural geometry]. / Classification des scolioses thoraco-lombaires gauches selon leur morphologie radiologique et leur géométrie posturale.

Idiopathic scoliosis is a tridimensional (3D) deformation of the spine associated with postural geometry (PG) disorganisation. Conventional classification of scoliosis is primarily based on the analysis of PA X-rays. This is a descriptive classification that forms heterogeneous groups. Diagnosis, prognosis and treatments are then developed around partial information. The goal of this project was to divide the left thoracolumbar (TLG) class in two subgroups using exhaustive analysis of the PA and lateral X-rays, and the evaluation of postural deformations. The quantification of the PG of 14 control subjects and 20 scoliotic patients (TLG) was realised using a stereovideographic approach. For each patient, PA and lateral X-rays were done using a digital X-ray apparatus. The TLG group shows common pathological characteristics but is forming a relatively heterogeneous group. When this class is divided in two subgroups, 9 postural parameters appeared to be different from the control group, each subgroup showing specific postural characteristics. The 3D quantification of pertinent radiological parameters and the PG evaluation should allow the classification of idiopathic scoliosis patients. Furthermore, these groups of patients could be characterised, in order to improve the diagnosis, the prognosis and the treatment, with a brace or surgically.

[Stereovideographic evaluation of the postural geometry of healthy and scoliotic patients]. / Evaluation stéréovidéographique de la géométrie posturale du sujet sain et scoliotique.

Idiopathic scoliosis principally characterised by a deformation of the vertebral column can also be associated to postural abnormalities. The validity and reliability of current quantitative postural evaluations has not been thoroughly documented, frequently limited by a two dimensional view of the patient, and do not include the whole posture of the patient. The purpose of this study is to 1) quantify within and between-session reliability of a stereovideographic Postural Geometry (PG) evaluation and 2) to investigate the sensitivity of this technique for the postural evaluation of scoliosis patients. The PG of 14 control subjects and 9 untreated scoliosis patients were evaluated with 5 repeat trials, on two occasions. Postural geometry parameters that describe the position and orientation of the pelvis, trunk, scapular girdle and head were calculated based on the 3-dimensional co-ordinates of anatomical landmarks. The mean between and within-session variability across all parameters were 12.5 mm, 2.8 degrees and 5.4 mm and 1.4 degrees respectively. The patient group was heterogeneous with some noted pathological characteristics. This global stereovideographic postural geometry evaluation appears to demonstrate sufficient reliability and sensitivity to follow-up on the posture of scoliosis patients.

[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.

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.

Vertebral deformities and scoliosis.

Scoliosis, especially idiopathic scoliosis, is a complex three-dimensional deformity of the spine in which the vertebral deformities are known, cuneal deformation being the most commonly known deformity but not the only one. We report here data concerning these specific vertebral deformities in chickens. A pinealectomy was performed in a controlled series of animal experiments. This technique induces progressive scoliosis in more than 80% of chickens, with the advantage of being non-aggressive to the spine. Vertebrae included in major thoracolumbar curves were observed in 17 chickens (11 male, 6 female) and classified into three types of vertebral deformities. Vertebral deformity type 1 is characterized by three-dimensional corporeal torsion, which defines the horizontal disorientation of the curve. Vertebral deformities type 2 and 3 define lateral imbalance in the election plane of the curve. Radiological and anatomical data collected throughout the progression of the scoliosis indicate that there is a correlation between structural vertebral deformities and growth/maturation patterns. We compare our results with those reported in literature concerning human idiopathic scoliosis and experimental animal scoliosis.

[Vascularization of the common fibular nerve]. / Vascularisation du nerf fibulaire commun.

The vascularization of the common fibular nerve (CFN) let us suppose that one have to take anatomy and physiology of vasa nervorum in consideration in the genesis of neurologic lesions. This study is based on fresh cadavers dissections, with intra arterial injection of minimum colored latex. The results emphasize the causes of the CFN susceptibility while compression and stretching injury.

[Radiographic study of the lumbar spine bearing weight in weight lifters]. / Etude radiographique du rachis lombaire en charge chez l'haltérophile.

Radiographies of lumbar spine at rest in standing position and upon a force of 100kg were undertaken in 19 young sportsmen. If comparison between two pictures demonstrated important modification in few subjects, statistical study shown only little variations. Clinical studies in weight lifters demonstrated effectively few lesions with a good training, it's possible to modifiate pelvic orientation and this pelvic support permits a optimal posture for the lumbar spine.

[Reliability of cutaneous markers in kinetic studies of the human thoracic and lumbar spine]. / Fiabilité des repères cutanés dans l'étude cinétique du rachis thoracique et lombaire chez l'homme.

The use of cutaneous markers as an accurate method of measuring spine motion was studied in five cadaveric spine samples and two live subjects. The markers were placed on the skin over the spinous processes, a particularly suitable site in thin subjects for determining the displacement of the underlying skeletal segments because the deep layer of the skin is in adherence with their fibrous surrounding sheath. Fairly close correlations were obtained in the sagittal and frontal planes between the two sets of measurements. However in the transversal plane the technique is unreliable because of tightening of the skin.

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.

[Long term complications of splenic artery ligation for haematologic problems in the child. A study of 7 cases]. / Les suites lointaines des ligatures de l'artère splénique dans les rates "hématologiques" de l'enfant. A propos de sept observations.

Since 1983, the authors have performed a surgical ligation of the splenic artery in 7 patients suffering hypersplenism due to hematological diseases (4 Minkowski-Chauffard, 2 Betathalassemia Major, 1 Idiopathic Thrombocytopenic purpura). The immediate post operative course and long-term outcome of the patients were evaluated on clinical and biological grounds. The early post operative period was not influenced by the underlying hematological disorder. In all patients the hemoglobin, erythrocyte and platelet counts significantly increased and were related to functional hyposplenism. Delayed outcome depended on the underlying disease. Patients with Betathalassemia returned to preoperative status within months; thus, the only advantage of the arterial ligation was to transiently decrease the requirements in blood transfusion. Two patients with Minkowski-Chauffard disease did not present further episodes of acute hemolysis and did not required additional blood transfusion. On the other hand, the other two patients with Minkowski-Chauffard disease progressively returned to preoperative status, including severe episodes of hemolysis, and required a splenectomy be performed. Since the arterial supply to the spleen remains inchanged after the operation, it may be expected that the results (i.e. long-duration hyposplenism) could be improved by performing extensively devascularization of the spleen to complete the ligation of the splenic artery.

Acute systematic and variable postural adaptations induced by an orthopaedic shoe lift in control subjects.

A small leg length inequality, either true or functional, can be implicated in the pathogenesis of numerous spinal disorders. The correction of a leg length inequality with the goal of treating a spinal pathology is often achieved with the use of a shoe lift. Little research has focused on the impact of this correction on the three-dimensional (3D) postural organisation. The goal of this study is to quantify in control subjects the 3D postural changes to the pelvis, trunk, scapular belt and head, induced by a shoe lift. The postural geometry of 20 female subjects (X = 22, sigma = 1.2) was evaluated using a motion analysis system for three randomised conditions: control, and right and left shoe lift. Acute postural adaptations were noted for all subjects, principally manifested through the tilt of the pelvis, asymmetric version of the left and right iliac bones, and a lateral shift of the pelvis and scapular belt. The difference in the version of the right and left iliac bones was positively associated with the pelvic tilt. Postural adaptations were noted to vary between subjects for rotation and postero-anterior shift of the pelvis and scapular belt. No notable differences between conditions were noted in the estimation of kyphosis and lordosis. The observed systematic and variable postural adaptations noted in the presence of a shoe lift reflects the unique constraints of the musculoskeletal system. This suggests that the global impact of a shoe lift on a patient's posture should also be considered during treatment. This study provides a basis for comparison of future research involving pathological populations.

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.

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.