Search PubMed⌕ Search

Biomedical subjects

J Dubousset

Publications and source records attributed to J Dubousset.

At least 19 recordsLinked to original sources

Intralesional Ethibloc injections in primary aneurysmal bone cysts: an efficient and safe treatment.

OBJECTIVE: Ethibloc is a fibrogenic and thrombogenic agent recently proposed for the treatment of bone cysts. The purpose of this study is to report the results of direct Ethibloc injection in primary aneurysmal bone cyst (ABC) in children. DESIGN AND PATIENTS: Seventeen patients, aged from 2 to 18 years (mean 8 years), were treated with either a single injection (14 patients) or supplementary injections (3 patients) of Ethibloc. The histological diagnosis was assessed following surgical biopsy and was retrospectively reviewed. The mean follow-up was 5 years (range 18 months to 11 years). RESULTS: At 5 year follow-up, 14 of 17 patients demonstrated complete healing manifest by increased cortical and septal thickening. Surgical excision was required in three patients, in two of whom the ABC increased rapidly in size despite the injection, and in one of whom the healing was incomplete. We observed inflammatory reactions in 16 of 17 patients with local pain and fever. Three patients developed a small cutaneous fistula which resolved spontaneously in a few weeks. No major complications such as deep infection, pulmonary embolism, epiphyseal necrosis or malignant degeneration were observed. CONCLUSION: Percutaneous direct Ethibloc injection is a safe, efficient and noninvasive treatment for ABC. The authors highlight the frequent local reactions.

Adolescent↗

Explicit calibration method and specific device designed for stereoradiography.

The three-dimensional geometry of the human spine is noteworthy information that can be obtained by stereoradiographic methods. These methods are based on the identification of anatomical structures in several views which are obtained by rotation of a patient standing on a turntable. Calibration algorithms for computer vision or photogrammetry are well documented, but they generally yield calibration devices which are cumbersome for the use in clinical stereoradiography. This paper presents a calibration method adapted to a two-view stereoradiography calibration (frontal and lateral incidences) and based on a simplified geometric modeling of the radiological environment. The a priori knowledge yields four calibration equations related to the vertical and horizontal planes of both views, leading to a specific calibration procedure and device. Moreover this device is attached to the stereoradiographic system (directly integrated on the turntable) in order to facilitate clinical applications. A validation was performed on 26 dried lumbar vertebrae in order to evaluate clinical situation. The mean accuracy of the stereoradiographic reconstruction was 1.2mm.

Aged↗

Prevention of ankle valgus after vascularized fibular grafts in children.

Ankle valgus after the use of vascularized fibular grafts is a specific complication of the donor site ankle in the growing child. Incidence of this deformity and prevention strategy are documented poorly. The goal of the current study was to evaluate the rate of such deformities and to analyze efficiency of two prevention methods. Charts of 20 children surgically treated for sarcomas of long bones with a mean followup of 4.1 years were studied retrospectively. Ankle valgus was considered if the tibiotalar angle on radiographs with the patient standing was 5 degrees or greater in valgus than that of the opposite ankle, and deformity was considered severe if it required surgical treatment. Prevention was done in some patients with a tibiofibular syndesmotic screw or with reconstruction of the fibula using a tibial autograft. Valgus occurred in nine patients (45%) and was severe in five (25%). Valgus prevention with a syndesmotic screw was efficient and lacking in complications, whereas patients with fibula reconstruction had a high incidence of deformity and relevant complications. The authors recommend using a tibiofibular screw in all patients whose growth plates are open in the lower limbs at the time of surgery.

Adolescent↗

Non-metastatic Ewing's sarcoma of the ribs: the French Society of Pediatric Oncology Experience.

From 1984 to 1997, 57 consecutive patients with non-metastatic Ewing's sarcoma of the ribs were treated according to multimodal French Society of Pediatric Oncology (SFOP) protocols EW 84, EW 88 and EW 93. The results of treatment were reviewed and analysed. Median age was 12 years. 34 patients had large tumours (greatest tumour dimension > or = 8 cm); pleural effusion was noted in 26. A tumour-positive margin after surgery was noted in 15 patients. Histological response after chemotherapy was assessed in 34 patients. 34 patients received radiation therapy. With a median follow-up of 5 years, the projected overall and relapse-free survival rates were 69 and 62%, respectively. The major site of relapse was local. None of the following was significant in predicting relapse: tumour size, gender, age at diagnosis, existence of pleural effusion, level of rib tumour, rib component, type of local control, surgical margin (positive or negative). Response to chemotherapy was the sole significant prognostic factor (P=0.004). Patients with pleural effusion had a higher percentage of relapse if they were treated without local radiation therapy. Our study confirms the prognostic significance of response to initial chemotherapy. Radiation therapy may be withheld in selected cases, but seems necessary in patients with pleural effusion.

Adolescent↗

Rotationplasty after failure of a knee prosthesis for a malignant tumour of the distal femur.

Failure of massive knee endoprostheses implanted for malignant tumours of the distal femur in children presents a difficult problem. We present the results of rotationplasty undertaken under these circumstances in four boys. They had been treated initially at a mean age of 9.5 years for a stage-IIB malignant tumour of the distal femur by resection and implantation of a massive knee endoprosthesis. After a mean period of eight years and a mean of four operative procedures, there was failure of the endoprosthesis because of aseptic loosening in two and infection in two. Function was poor with a mean Musculoskeletal Tumor Society score of 7.5/30, and considerable associated psychological problems. At a mean follow-up of 4.5 years after rotationplasty there was excellent function with a mean score of 27.5/30 and resolution of the psychological problems.

Adolescent↗

[Thoracic scoliosis: exothoracic and endothoracic deformations and the spinal penetration index].

PURPOSE OF THE STUDY: We reviewed retrospectively our patients with thoracic lordoscoliosis and conducted a conceptual analysis of the patients with airway compression and atelectasia due to anterior protrusion of the vertebral bodies in order to describe the pathological conditions involved and the management methods used. Our goal was to develop a new concept for quantifying thoracic deformation. The individual cases discussed here have been reported earlier, but this is the first series analysis to date. MATERIAL AND METHODS: Eighteen patients, aged 7.3 to 18 years, with thoracic lordoscoliosis due to a variety of causes, mostly neuromuscular disorders (12 cases), are described. Most patients were treated by anterior subtotal periosteal resection of the vertebral body followed by posterior instrumentation and arthrodesis. RESULTS: Atelectasia disappeared with a normalization of blood gases but the effect was variable on vital capacity. The analysis of the CT studies led to the concept of spinal deformity as an endothoracic deformation resulting from protrusion of the vertebral body into the thorax, the endothoracic vertebral hump. This concept was developed and quantified leading to the definition of a new index: the spinal penetration index. The spinal penetration index was obtained by tracing a line tangent to the posterior curve of the concave and convex ribs on each CT slice to determine a relationship between the real thoracic surface and theoretical thoracic surface measured with this tangent and the circumference of the thoracic cage. The index was expressed as a percent of the endothoracic surface occupied by the protruding veterbral body and the associated ribs. Calculated for each successive CT slice for the entire height of the thorax yielded a spinal penetration index quantifying the thoracic volume occupied by the spine. For the control population, we used CT series of the thorax obtained to search for pulmonary metastases in patients with malignant tumors. This gave a theoretical volume of 8 to 10% occupied by the spine in normal subjects. In our patients with lordoscoliotic deformations we obtained real volumes of 15, 20 and even 50%. DISCUSSION: The spinal penetration index is an important morphological index of thoracic anatomy that measures the real volume of the functional thoracic cavities and which must be differentiated from vital capacity which measures both volume and function. This index can be used for pre- post-operative comparisons and constitutes a first step in 3-D assessment of thoracic spine deformations. It can also be used to classify spinal deformations and to make general recommendations concerning the management of both endothoracic humps and exothoracic rib humps.

Adolescent↗

Pathologic mechanism of experimental scoliosis in pinealectomized chickens.

STUDY DESIGN: This study was designed to investigate the pathologic mechanisms of idiopathic scoliosis using experimentally induced scoliosis in chickens. OBJECTIVE: To understand the process of producing a scoliotic deformity in pinealectomized chickens. SUMMARY OF BACKGROUND DATA: Pinealectomy in chickens consistently produces scoliosis with anatomic characteristics similar to those of human idiopathic scoliosis. Pinealectomized chickens are an important animal model for the study of idiopathic scoliosis. METHODS: In this study, 40 chickens were divided into two groups; 20 chickens treated with pinealectomy and 20 with a sham operation as control subjects on the second after hatching. The chickens in both groups then were killed at intervals ranging from 1 to 20 weeks after surgery. Their spines were examined visually and radiologically for the presence of a scoliotic curve and vertebral deformities. RESULTS: Rotational lordoscoliosis developed in pinealectomized chickens. The chickens with severe scoliosis were characterized by apically wedge-shaped vertebrae. In contrast, no scoliosis with any vertebral deformity developed in any of the chickens that received a sham operation. CONCLUSIONS: Because there normally is evidence of lordosis in the thoracic spine of chickens, the rotational instability of the spine induced by pinealectomy may produce a scoliotic deformity as a secondary phenomenon. Pinealectomy in chickens consistently produces scoliosis with anatomic characteristics similar to those of human idiopathic scoliosis. The authors believe that disturbance of the equilibrium and the posture mechanism associated with a defect in melatonin synthesis after pinealectomy may promote the development of rotational lordoscoliosis.

Animals↗

Decreased bone mineral density in neurofibromatosis-1 patients with spinal deformities.

A cross-sectional study was carried out to obtain data on the bone mineral density status of a group of neurofibromatosis-1 patients with spinal deformities, and to search for possible accompanying changes in the bone mineral turnover. Neurofibromatosis-1 is a heredofamiliar disorder that is associated with a variety of skeletal anomalies (mostly spinal deformities) in 10-50% of patients. Intraoperatively, a poor vertebral bone quality has been observed. Efforts have been made to identify factors preventing curve progression, to optimize operational planning and to explain the pathomechanism. As part of the preoperative evaluation, dual-energy X-ray absorptiometry was used to assess the bone mineral density of the lumbar spine in 12 patients with neurofibromatosis-1, supplemented by laboratory blood/urine investigations. A significant decrease in bone mineral density of the lumbar spine was measured. An inverse relation was suggested between the severity of scoliosis and the lumbar spine Z-scores. No pivotal alterations were identified in the laboratory measurements. The bony tissue abnormality observed intraoperatively in neurofibromatosis-1 patients may be described as a diminution of the axial bone mineral density. The biochemical parameters do not support the presence of hyperparathyroidism, renal disorders or other associated diseases influencing the bone mineral turnover. The evaluation of bone mineral density in the course of the preoperative planning is proposed in neurofibromatosis-1; the exact background and the role of a possible osteoporosis in the prognosis remain to be elucidated.

Absorptiometry, Photon↗

The AP diameter of the pelvis: a new criterion for continence in the exstrophy complex?

OBJECTIVE: Reconstructive surgery of bladder exstrophy remains a challenge. By using CT of the pelvis, we suggest a new pre- and post-operative investigative procedure to define the AP diameter (APD) as a predictive criterion for continence in this anomaly. PATIENTS AND METHODS: Three axial CT slices were selected in nine children with exstrophy who had undergone neonatal reconstructive surgery. The three levels selected were the first sacral plate, the mid acetabular plane and the superior pubic spine. We used combined slices to measure: APD = distance between the first sacral vertebra and the pubic symphysis. Pubic diastasis (PD). Three angles defined on the transverse plane of the first sacral vertebra--iliac wing angle, sacropubic angle and acetabular version. RESULTS: In exstrophy, the angles demonstrate opening of the iliac wings and the pubic ramus, and acetabular retroversion compared to controls. Comparisons between controls, continent and incontinent patients reveal that in continent patients, APD increases with growth and seems to be a predictive criterion for continence, independent of diastasis of the pubic symphysis. CONCLUSIONS: We believe that CT of the pelvis with measurements of the APD should be performed in all neonates with bladder exstrophy before reconstructive surgery and for better understanding of the malformation. The APD seems to be predictive and may be a major criterion for continence, independent of PD.

Bladder Exstrophy↗

[Possible role of the pineal gland in the pathogenesis of idiopathic scoliosis. Experimental and clinical studies].

The unexpected finding in 1959 by Marie-Jeanne Thillard that pinealectomy in young chickens gives way to spinal deformities was confirmed by the authors. In another experiment they found that injected melatonine to the chick at adequate dose and at the same time as surgery, lessen or even totally prevents the occurrence of deformities. On the other hand, at too low dose or delayed after pinealectomy melatonine injection, may not prevent the deformity which will be persisting or even increasing. In a subsequent series of experiments on the rat, pinealectomy results in decreasing the plasmatic amount of melatonine as well as giving way to spinal deformities. The nature of these deformities observed here is dependent on the stature between of the animal. The normal quadrupede rat develops after pinealectomy a standard scoliosis. Inversely the scoliotic deformity occurs when the animal has been forced to a bipede condition, which may be achieved by removing its forelimbs when baby, then forcing it to stand and remain in erect posture by high enough feeding. Melatonine depressing and erect position are in two conditions, when associated, likely to give way to experimental scoliosis. In human, a low nycthemeral level of plasmatic melatonine is correlated with progressive scoliosis. The level of platelets calmoduline, when is normally modulated by melatonine, has been proved by Kindsfater to be increased in progressive scoliosis. Then raises the hypothesis that human idiopathic scoliosis may be due to an inherited disorder of neuro-transmitters from neuro-hormonal origin, associated with bipedal condition, where an horizontal localized neuro-muscular imbalance starts and produces the scoliotic deformity of the fibro-elastic and bony structures axial spinal pilar.

Animals↗

Progressive rotational dislocation in kyphoscoliotic deformities: presentation and treatment.

STUDY DESIGN: Progressive rotational dislocation of the spine has been described as the most serious evolutive risk of kyphoscoliosis. A retrospective chart review was conducted on 11 patients with this deformity. OBJECTIVES: To delineate the clinical and radiologic characteristics of this entity to facilitate early diagnosis and treatment. The outcome after treatment was analyzed to point out the rationale for appropriate treatment. METHODS: The characteristic radiologic feature was a short sharp angled kyphosis (average 112) at the junction of two lordoscoliotic curvatures. The etiology of the spinal deformity was neurofibromatosis in four patients and various dysplastic conditions in seven patients. Two patients had congenital vertebral defects. Structural weakness of the bone was therefore a basic feature. Neurologic impairment was identified in three patients (one complete, two incomplete). Four patients had a nonunion after a previous attempt at spinal fusion: two after a combined anterior and posterior fusion with an anterior approach from the convexity and two after a posterior fusion alone. All patients underwent complete circumferential stabilization through anterior strut-grafting and posterior fusion. An anterior approach from the concavity was performed systematically with tibial strut grafts inserted in a palisade fashion. Preoperative correction of the deformity was performed by progressive controlled elongation in a Stagnara elongation cast. Cotrel-Dubousset instrumentation was used in two patients, Harrington instrumentation was used in two patients, and cast immobilization alone was used in seven patients. RESULTS: The average follow-up period was 5 years 5 months. All but one patient achieved successful spinal fusion. Loss of correction at the latest follow-up evaluation was less than 3 degrees in nine patients. The two patients with incomplete neurologic deficits were improved, but the patient with the complete deficit remained unchanged after surgery. CONCLUSIONS: Awareness of the possibility of a progressive rotational dislocation in dystrophic forms of kyphoscoliosis should allow for an early diagnosis and stabilization. The percentage of patients having a neurologic deficit in this series was significantly less important than in the initial report. Early anterior strut grafting from the concavity of the scoliotic curvature and posterior fusion is recommended.

Adolescent↗

[Segmental instrumentation in idiopathic scoliosis. Role of the upright frontal plate for determination of the area of fusion].

PURPOSE OF THE STUDY: To analyze post operative imbalance after C.D.I. (Cotrel Dubousset Instrumentation) for idiopathic scoliosis according to the fused area, particularly the lower level of fusion. To recall a classification for determination of fusion area based on preoperative standing coronal radiograph. PATIENTS AND METHODS: To be included in this study the patients had to have an adolescent idiopathic scoliosis, at least two years of post operative follow up. 122 patients met the criteria; mean follow up was 3 years, 5 months (minimum 2 years, maximum 9 years). Scoliotic curves were classified as single structural (81), double structural (41). Balance was clinically analyzed by plumbline, radiographically by a plumbline dropped from C7 to the sacrum and measuring deviation from the midpoint of the sacrum in centimeters. A curve with a deviation of 10 mms or less was considered as balanced. RESULTS: Imbalance in single structural curves was 70% when using stable vertebra (King) or "other vertebra" (beyond stable vertebra or one or two levels upper stable vertebra). Using end vertebra (J. Moe), (elected vertebra - C. Salanova) imbalance was 10%. In double structural (41 cas) imbalance was 50% using stable, or "other vertebra" 10% when elected vertebra was fused. DISCUSSION: In this study there was a strong relationship between the lower level of fusion and imbalance.

Adolescent↗

[Conservative surgical treatment of osteogenic sarcoma of the limb in children and adolescents].

PURPOSE OF THE STUDY: Advances in chemotherapy protocols over the last 20 years have considerably improved the prognosis and functional outcome in patients with osteogenic sarcoma. We report here the results of a cooperative study conducted under the auspices of the French Society of Pediatric Oncology (SFOP). Twenty-nine oncology centers participated in this retrospective national multicentric study. MATERIALS AND METHODS: The study included 153 patients with osteogenic sarcoma of the limb who were treated by the OS87 protocol with conservative surgery between 1987 and 1994. The OS87 protocol consisted in conservative or non-conservative surgery combined with pre- and postoperative chemotherapy. The following inclusion criteria were used: age under 20 years, tumor localization in a limb (pelvis and spine excluded), no metastasis at diagnosis, biopsy proven osteogenic sarcoma. RESULTS: Mean age at diagnosis was 13 years. The knee localization predominated (80 p. 100). 82.5 p. 100 of the patients had grade IIB disease (Enneking classification). For the 187 patients included in the protocol surgery was non-conservative in 20 p. 100 of the cases and conservative in 80 p. 100. The choice of the surgical technique (arthroplasty, allograft, autograft, resection without reconstruction) depended on the patient's age and school situation. Data analyzed here concerned only those patients who had conservative treatment. Mean follow-up was 64 months. The actuarial survival curve plateaued at 71 p. 100 at more than 6 years. Early and late complications were numerous and variable (mechanical, infectious, local recurrence). Secondary amputation was required in 10 p. 100 of the patients. The overall functional outcome of the preserved limbs was nevertheless good with rapid restoration of self-sufficiency despite major surgery and a high number of reoperations (about 65 p. 100 of cases). DISCUSSION: In light of the frequency and the seriousness of the complications, these results are modest. Patients and family should be advised of the risk, particularly the risk of secondary amputation which may be required early due to contaminated excision or at mid term due to major non-cancerological complications. As survival has been improved, functional capacity must be preserved for several years. This orients surgery towards more "biological" reconstruction which can provide greater longevity than arthroplasty.

Adolescent↗

[Vascularized peroneal reconstruction after bloc resection of tumors or congenital malformations of the upper limb in children].

Limb salvage surgery is the standard care for most malignant tumor affecting the extremities in the child, and a vascularized fibula transfer is probably the most popular microsurgical option to reconstruct long-bone defects. Between 1994 and 1999, nine children with intractable diseases of the upper limb were treated using free vascularized fibula grafts (one patient had resection in 1983 and initially prosthetic reconstruction, then fibula transplant in 1996). There were 6 boys and 3 girls. Mean age was 10 years (between 6 and 16). Eight patients had defects after sarcoma resection, one had an aggressive enchondroma. The reconstructed sites were the humerus (= 6), the radius (n = 3). The length of the bone defect ranged from 8 to 19 cm (mean: 14.4 cm). The fibula head with the cartilage and the growth plate was used in 3 children. One girl, 4.5 years old with congenital pseudoarthrosis of radius and cubitus had a resection and reconstruction with a U shaped fibula transplant. One patient died from lung and brain metastasis, two years after the reconstruction. There were no local recurrences. The complications were numerous but usually benign; fracture of the grafted fibula n = 7, necessity of additional bone grafts (n = 4) malunion (n = 1) needed reoperation, pseudoarthrosis (n = 2) with reoperation, ankle valgus (n = 1) required reoperation, necrosis of the fibula head (n = 1), radial inclination (n = 1). The ten patients had bone union. The mean period required to obtain radiographic bone union was 5 months. The functional results of the remaining patients were evaluated according to the scale of ENNEKING. The results ranged from 21 to 30 points. Our results were satisfactory with regard to pain, emotional acceptance, manual dexterity. The vascularized fibula graft is indicated in children with large bone defects, more than 8 cm in the humerus, radius and ulna.

Adolescent↗

Pathogenesis of idiopathic scoliosis. Experimental study in rats.

STUDY DESIGN: A radiographic examination of pinealectomized rats to observe the development of scoliosis and halt the condition by administration of melatonin. OBJECTIVES: To discover whether pinealectomy has the same effect in mammals as shown in the chicken, and to determine whether the bipedal condition is important for development of scoliosis. SUMMARY OF BACKGROUND DATA: Pinealectomizing chickens shortly after hatching consistently resulted in scoliosis closely resembling human idiopathic scoliosis. It has not been determined whether this phenomenon is restricted solely to chickens, or if this experimental model is applicable to other animals, especially those more closely related to humans. METHODS: A sham operation in five bipedal rats served as the control in this study. Pinealectomy was performed in 10 quadrupedal rats, pinealectomy in 20 bipedal rats, and pinealectomy with implantation of melatonin pellet in 10 bipedal rats. Spinal radiographs were used to measure the degree of scoliosis at 3 months after surgery. RESULTS: Scoliosis developed only in pinealectomized bipedal rats and not in quadrupedal rats. It developed in none of the sham operation group and in only 1 of 10 pinealectomized bipedal rats with melatonin treatment. CONCLUSIONS: Melatonin deficiency secondary to pinealectomy alone does not produce scoliosis if the quadrupedal condition is maintained. The bipedal condition, such as that in chickens or humans, plays an important role in the development of scoliosis. The findings suggest a critical influence of a postural mechanism for the development of scoliosis.

Animals↗

Establishment, characterisation and partial cytokine expression profile of a new human osteosarcoma cell line (CAL 72).

Permanent human osteosarcoma cell lines are important tools for the study of bone cancer. As representative of an osteoblastic phenotype, they partly reflect their normal osteoblastic counterparts and, thus, may represent appropriate models to investigate the mechanisms involved in bone remodelling and in haematopoietic differentiation. In the present work, we describe a new human cell line, CAL 72, obtained from an osteosarcoma of the knee of a 10-year-old boy. These cells grow in continuous culture, and karyotypic analysis has revealed clonal abnormalities in number and structure, especially loss of chromosome Y. These cells exhibit morphological, immuno-histochemical and molecular characteristics of the osteoblastic lineage. Using RT-PCR, we have shown that the CAL 72 cell line expresses high levels of mRNA coding for several cytokines, such as G-CSF, GM-CSF, IL-1beta and IL-6. In view of this expression profile, the CAL 72 phenotype appears to be closer to normal primary osteoblasts than other reported osteosarcomas. Moreover, these cells express mRNA for both HGF and its receptor c-MET, suggesting that this autocrine loop might contribute to the invasiveness of the tumour from which CAL 72 originated.

Alkaline Phosphatase↗

Ischio-vertebral dysplasia: a distinct entity.

BACKGROUND: Kyphoscoliosis is a complication of some bone dysplasias, including cleidocranial dysplasia. OBJECTIVES: We report a distinct disorder with defective ossification of the ischial rami, severe kyphoscoliosis and normal clavicles. Early recognition of this syndrome allows prevention of complications. MATERIALS AND METHODS: All patient cases (aged 1 day to 33 years) were selected according to the above criteria, with special attention to radiological findings, family history and follow-up (5-30 years). RESULTS: In all eight patients, we observed the following: (a) Severe thoracic scoliosis of early onset and rapid progression, leading to rotatory dislocation. Spinal cord compression occurred in four cases with respiratory problems related to chest deformity. (b) Bilateral and symmetrical incomplete ossification of the ischial rami. (c) Peculiar facies with retrognathia. (d) Normal clavicles. Three patients were from the same family (grandmother, mother and daughter). CONCLUSION: Ischio-vertebral dysplasia seems to represent a true entity, with radiological and genetic findings that make it distinct from cleidocranial dysostosis. The association of kyphoscoliosis and these pelvic abnormalities is specific for this condition. Neurological and respiratory complications can be avoided if the condition is recognised early and early treatment is instituted.

Abnormalities, Multiple↗