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ABSTRACT: Numerous options exist for intercalary segmental reconstruction after bone tumor resection. We present the extension of a
recently developed surgical two-stage technique that involves insertion of a cement spacer, induction of a membrane, and reconstruction
of the defect with cancellous and cortical bone autograft in a 12-year-old child. The boy was referred to our center for treatment
of a right femoral diaphyseal Ewing’s sarcoma. The first stage involved resection of the tumor and reconstruction with a locked
intramedullary nail and a polymethylmethacrylate cement spacer. Seven months after the initial procedure during which adjuvant
chemotherapy was given, the second-stage procedure was performed. The cement was removed and cancellous and cortical bone
autograft was grafted in the membrane created around the cement spacer. Touchdown weightbearing was allowed immediately, partial
weightbearing was resumed 6weeks after the operation, and full weightbearing was allowed 4months later. Successive plain
radiographs showed rapid integration of the autograft to the host bone with bone union and cortical reconstitution. The principle
of the induced membrane reconstruction seems applicable to intercalary segmental reconstruction after bone tumor resection
in children.
Clinical Orthopaedics and Related Research 04/2012; 467(2):572-577. · 2.53 Impact Factor
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La Revue du praticien 04/2012; 62(4):535-6.
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ABSTRACT: Infantile myofibromatosis is characterized by proliferation of benign fibrous tumors arising in skin, subcutaneous tissue, muscle, or bone. Solitary and multicentric forms are described. Few reports are available in the pediatric population.
To improve the knowledge of this rare tumor in infants, the authors present a series of all cases of infantile myofibromatosis treated in their institution over a 9-year period in order to propose treatment guidelines based on their experience and a review of the literature.
The authors report a series of 9 cases, 8 solitary forms and 1 multicentric form with visceral involvement treated from 2000 to 2009. Median age was 10 months (range: 2 days-14 years). Six patients with solitary forms underwent primary surgical resection leading to remission. Only biopsy was performed in 1 case, followed by tumor regression with no recurrence. The last patient with a solitary form was treated by chemotherapy and then surgery allowing remission. The patient with a multicentric form presented complete regression of tumors after 1 year of vinblastine and methotrexate combination chemotherapy.
Infantile myofibromatosis is a rare soft tissue tumor mainly concerning infants. Surgery is the treatment of choice for solitary forms when excision is possible. Close follow-up may be proposed in the case of inoperable sites. In multicentric life-threatening forms, chemotherapy promotes tumor regression and the vinblastine and methotrexate combination is effective with few long-term adverse effects.
Pediatric Blood & Cancer 10/2011; 59(1):115-20. · 1.89 Impact Factor
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Clinical dysmorphology 04/2011; 20(2):114-6. · 0.47 Impact Factor
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ABSTRACT: Achondroplasia (ACH), the most common form of human dwarfism is caused by a mutation in the Fibroblast Growth Factor Receptor 3 (FGFR3) gene, resulting in constitutive activation of the receptor. Typical radiological features include shortening of the tubular bones and macrocephaly, due to disruption of endochondral ossification. Consequently, FGFR3 has been described as a negative regulator of bone growth. Studying a large cohort of ACH patients, a delay in bone age was observed shortly after birth (for boys p=2.6×10(-9) and for girls p=1.2×10(-8)). This delay was no longer apparent during adolescence. In order to gain further insight into bone formation, bone development was studied in a murine model of chondrodysplasia (Fgfr3(Y367C/+)) from birth to 6weeks of age. Delayed bone age was also observed in Fgfr3(Y367C/+) mice at 1week of age followed by an accelerated secondary ossification center formation. A low level of chondrocyte proliferation was observed in the normal growth plate at birth, which increased with bone growth. In the pathological condition, a significantly high level of proliferative cells was present at birth, but exhibited a transient decrease only to rise again subsequently. Histological and in situ analyses suggested the altered endochondral ossification process may result from delayed chondrocyte differentiation, disruption of vascularization and osteoblast invasion of the femur. All these data provide evidence that FGFR3 regulates normal chondrocyte proliferation and differentiation during bone growth and suggest that constitutive activation of the receptor disrupts both processes. Therefore, the consequences of FGFR3 activation on the physiological process of bone development appear to be dependent on spatial and temporal occurrence. In conclusion, these observations support the notion that FGFR3 has a dual effect, as both a negative and a positive regulator of the endochondral ossification process during post-natal bone development.
Bone 11/2010; 47(5):905-15. · 4.02 Impact Factor
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ABSTRACT: Thanatophoric dysplasia is a lethal chondrodysplasia caused by heterozygous fibroblast growth factor receptor 3 (FGFR3) missense mutations. Mutations have been identified in several domains of the receptor. The most frequent mutations (p.R248C, p.S249C, p.Y373C) create a cysteine residue within the extracellular domain, whereas the others eliminate the termination codon (p.X807R, p.X807C, p.X807G, p.X807S, p.X807W). Here, we report a unique patient with thanatophoric dysplasia and a double de novo FGFR3 mutation, located on the same allele, (c.[1620C>A;1454A>G]), which corresponds to p.[N540K;Q485R]. The p.N540K mutation is associated with 60% of patients with hypochondroplasia and the p.Q485R mutation is a novel mutation located in a highly conserved domain of FGFRs. Evidence for the structural impact of the two concurrent missense mutations was achieved using protein alignments and three-dimensional structural prediction, in agreement with our modeling of the FGFR3 structure. In this patient with thanatophoric dysplasia, we conclude that the presence of the double FGFR3 missense mutation on the same allele alters the receptor structure, holding the receptor in its fully activated state, thus leading to lethal chondrodysplasia.
American Journal of Medical Genetics Part A 06/2009; 149A(6):1296-301. · 2.39 Impact Factor
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ABSTRACT: Numerous options exist for intercalary segmental reconstruction after bone tumor resection. We present the extension of a recently developed surgical two-stage technique that involves insertion of a cement spacer, induction of a membrane, and reconstruction of the defect with cancellous and cortical bone autograft in a 12-year-old child. The boy was referred to our center for treatment of a right femoral diaphyseal Ewing's sarcoma. The first stage involved resection of the tumor and reconstruction with a locked intramedullary nail and a polymethylmethacrylate cement spacer. Seven months after the initial procedure during which adjuvant chemotherapy was given, the second-stage procedure was performed. The cement was removed and cancellous and cortical bone autograft was grafted in the membrane created around the cement spacer. Touchdown weightbearing was allowed immediately, partial weightbearing was resumed 6 weeks after the operation, and full weightbearing was allowed 4 months later. Successive plain radiographs showed rapid integration of the autograft to the host bone with bone union and cortical reconstitution. The principle of the induced membrane reconstruction seems applicable to intercalary segmental reconstruction after bone tumor resection in children.
Clinical Orthopaedics and Related Research 12/2008; 467(2):572-7. · 2.53 Impact Factor
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ABSTRACT: Fibroblast growth factor receptor 3 (FGFR3) is a key regulator of skeletal development and activating mutations in FGFR3 cause skeletal dysplasias, including hypochondroplasia, achondroplasia and thanatophoric dysplasia. The introduction of the Y367C mutation corresponding to the human Y373C thanatophoric dysplasia type I (TDI) mutation into the mouse genome, resulted in dwarfism with a skeletal phenotype remarkably similar to that of human chondrodysplasia. To investigate the role of the activating Fgfr3 Y367C mutation in auditory function, the middle and inner ear of the heterozygous mutant Fgfr3(Y367C/+) mice were examined. The mutant Fgfr3(Y367C/+) mice exhibit fully penetrant deafness with a significantly elevated auditory brainstem response threshold for all frequencies tested. The inner ear defect is mainly associated with an increased number of pillar cells or modified supporting cells in the organ of Corti. Hearing loss in the Fgfr3(Y367C/+) mouse model demonstrates the crucial role of Fgfr3 in the development of the inner ear and provides novel insight on the biological consequences of FGFR3 mutations in chondrodysplasia.
Biochimica et Biophysica Acta 12/2008; 1792(2):140-7. · 4.66 Impact Factor
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ABSTRACT: To better understand anatomical and functional outcomes of coxa vara in chondrodysplasia according to the initial presenting hip morphology, disease type, and impact of surgery.
Clinical and radiographic records of 19 children (35 hips) diagnosed with coxa vara and with osteochondrodysplasia were reviewed. We classified the hip radiographic findings into 2 groups: (a) group I, coxa vara with a fragmented and/or nonossified head; and (b) group II, coxa vara with a regular femoral head. Surgical indications in coxa vara included decreased range of hip motion (usually diminished abduction, extension, and internal rotation), coxa vara with progression documented on regular follow-up hip radiographs, and/or severe coxa vara with a Hilgenreiner epiphyseal angle (HEA) of 60 degrees or more. Follow-up was until the completion of growth and, for some patients, into early adulthood. Mean follow-up was 8 years.
Twenty-five hips were operated on in 13 patients. In 23 hips, the procedure was a valgus osteotomy fixed by pins and wire. A pelvic extension osteotomy without valgus osteotomy was performed in one patient (2 hips). Coxa vara recurred in 7 hips. In 4 of these hips, repeat surgery with hypervalgus osteotomy was indicated to stop epiphyseal slipping (3 hips) or to improve the arc of motion (1 hip). Functional outcomes were poor in coxa vara associated with poor epiphyseal development (nonossified or fragmented epiphysis) as seen in spondyloepiphyseal dysplasia congenita, spondyloepimetaphyseal dysplasia, Kniest disease, and multiple epiphyseal dysplasia. Coxa vara with physeal instability as observed in spondylometaphyseal dysplasia resulted in deformity recurrence postoperatively during growth. In contrast, outcome was better in cases of coxa vara with nonphyseal/nonepiphyseal involvement, that is, good femoral head morphology, stable physis, and good articular cartilage, as seen in cases of metaphyseal dysplasia and cleidocranial dysplasia.
Coxa vara with physeal and epiphyseal involvement and severe impairment of the articular cartilage has a poor prognosis even after reconstructive surgery. In coxa vara with an abnormal physis, there were numerous postsurgical recurrences of the deformity during growth if the physis was not stabilized at the time of valgus osteotomy. In these cases, we should delay osteotomy until an HEA greater than 60 degrees. Coxa vara in which only the metaphysis of the femoral neck is involved, the deformity is milder and often requires no treatment. Indications for surgery in this group are increasing coxa vara, Trendelenburg gait, or an HEA greater than 60 degrees.
Journal of pediatric orthopedics 10/2008; 28(6):599-606. · 1.23 Impact Factor
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ABSTRACT: Osteogenesis imperfecta (OI) is basically divided into four clinical types, I-IV. Type IV clearly represents a heterogeneous group of disorders. Here we describe two OI patients in the same family. They would typically be classified as having type IV, but are distinguishable from other OI type IV patients by the improving and resolving course of their disease. Mutation screening did not identify mutations affecting glycine codons or splice sites in the coding regions of the two collagen I genes. Genome-wide screening of DNA samples from the two homozygous patients identified one region of high concordance of homozygosity on chromosome 11 on the long arm (11q23.3-11q24.1).
American Journal of Medical Genetics Part A 08/2008; 146A(14):1807-14. · 2.39 Impact Factor
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ABSTRACT: Hereditary multiple exostoses (HME) is an autosomal-dominant disorder characterized by the development of benign tumours, multiple osteochondromas (exostoses), growing outward from the metaphyses of long bones. Birth prevalence is estimated to be one in 50,000, and the severity of the disease is variable. Osteochondromas may cause complications including pain, deformities and shortening of the long bones, restricted motion of joints, nerve or blood vessel compression, and malignant transformation (5% of cases) in adulthood. HME is a genetically heterogeneous disorder and is associated with mutations in EXT1 or EXT2 genes, which are both tumour suppressor genes. EXT genes encode glycosyltransferases, termed 'exostosins', which are involved in the biosynthesis of heparan sulphate. Enchondromatosis (or Ollier disease) is characterized by the presence of intra-osseous benign cartilaginous tumours. The estimated prevalence of the disease is one in 100,000. An asymmetrical distribution of cartilage lesions is observed in the disease. The number, size and location of the enchondromas can be extremely variable between patients. Clinical problems caused by enchondromas include skeletal deformities, limb length discrepancy, pain and the potential risk for malignant change to chondrosarcoma (20-50% of cases). The condition in which multiple enchondromas is associated with haemangiomas is known as 'Maffucci syndrome'. Ollier disease and Maffucci syndrome are not usually inherited disorders.
Bailliè re s Best Practice and Research in Clinical Rheumatology 04/2008; 22(1):45-54. · 2.65 Impact Factor
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La Revue du praticien 07/2007; 57(11):1245-54.
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La Revue du praticien 04/2007; 57(5):561-9.
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ABSTRACT: Kyphosis is a sagittal deviation of the spine that presents as an anterior spinal curvature. It is a frequent reason for consultation during adolescence. It is necessary to know how to differentiate between a simple postural kyphosis that is flexible and reducible, and requires no further investigation, from a true kyphosis that requires at minimum a radiological evaluation with films of the entire spine, in AP and lateral views. If vertebral epiphysitis is most often at the origins of the sagittal vertebral deviations encountered in daily practice, the other causes pose diagnostic and therapeutic problems that are often more complex. They include congenital, paralytic, infectious, cancerous and post-traumatic kyphosis, or kyphosis due to constitutional bone diseases. Surgical treatments, that have only an exceptional place in treatment of the regular kyphosis of the adolescent, are potentially indicated in all of the other situations.
La Revue du praticien 02/2006; 56(2):157-64.
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ABSTRACT: Traumatic hip dislocation in childhood is a rare consequence of violent trauma. After reduction, outcome is usually favourable although epiphyseal necrosis can occur. Reduction must be carried out as soon as possible and is achieved easily, although if the labrum is involved, surgery may be required to achieve complete reduction.
To analyze a retrospective series of traumatic hip dislocations in children, describing the therapeutic and imaging strategy.
A total of 42 patients were studied. Their mean age was 10 years 3 months. All relevant radiographic, CT, MRI and radionuclide bone scan examinations were reviewed. Special attention was paid to associated lesions.
In 22 patients the dislocation was caused by low-energy trauma. Road traffic accidents accounted for 17 dislocations. An acetabular fracture was present in six patients and the femoral head was fractured in three. Reduction was easily achieved in 31 patients. In 11 patients the postreduction radiograph and CT showed joint space asymmetry secondary to labral entrapment. Only two patients developed epiphyseal necrosis.
It has been difficult to define and evaluate accurate principles for a medical imaging strategy in this group of patients. Analysis of plain radiographs is essential before and after reduction of the joint, and it is important to perform postreduction CT in every patient whose joint space remains widened. A radionuclide bone scan should be performed between the second and third weeks after injury to assess epiphyseal vascularity. With the use of specific sequences, MRI may be an alternative modality to assess epiphyseal vitality.
Pediatric Radiology 01/2005; 34(12):970-9. · 1.67 Impact Factor
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ABSTRACT: We reviewed 5 cases of type I epiphyseal fracture with dislocation of the femoral head from the acetabulum in adolescent patients. All children had an open reduction and screw fixation. In all cases, the femoral head developed avascular necrosis. The clinical result after a mean of 3-9 years' follow-up was good according to the Merle d'Aubigné-Postel scale. Despite necrosis, 2 heads developed spherically after treatment: one which had a primary physeal resection and fixation, the other after an autogenous bone graft in the screw track following removal of the screw.
Acta Orthopaedica Scandinavica 03/2003; 74(1):49-52.
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ABSTRACT: Traumatic dislocation of the hip in childhood is uncommon and can be a consequence of minor trauma. The authors report a series of 35 dislocations in skeletally immature patients. Most were isolated posterior dislocations without acetabular lesions. In 75% of cases, reduction of the dislocation was easy. Nine children required surgery to remove interposed joint capsule and/or osteochondral fragments to achieve anatomic reduction. Outcomes were generally good, except in one patient in whom a displaced fracture of the femoral physis was followed by total head avascular necrosis. One case of partial necrosis had a satisfactory outcome. Epiphyseal necrosis, though uncommon, appeared to be inconsistent to prevent and hard to predict. Bone scan seems to be more effective than MRI for the detection of necrosis.
Journal of Pediatric Orthopaedics 25(2):138-44. · 1.16 Impact Factor
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ABSTRACT: Large segmental resections of malignant bone tumours in children require a reconstruction of the segment which has been removed by oncology surgery. A number of prosthetic and biological techniques are now used. The child's capacity to repair the limb sometimes enables high quality reconstructions to be performed.
Soins. Pediatrie, puericulture
