Thierry Odent

Fractures of the odontoid process: a report of 15 cases in children younger than 6 years.

Fractures of the odontoid process are rare in children. We retrospectively reviewed 15 cases in children younger than 6 years, with an average follow-up of 4 years and 3 months. Eight of these patients had neurologic involvement; magnetic resonance imaging (MRI) changes were seen in the spinal cord at the cervicothoracic junction in six. This neurologic injury was thought to be due to the major anterior displacement of the upper spine, causing spinal cord stretch at the spinal apex of the cervical and thoracic spine. Eight patients secured in forward-facing car seats were injured as the result of motor vehicle accident. Conservatively treated fractures fused without problem. By contrast, the three cases operated on as the initial management of the fracture had complications postoperatively.

Traumatic hip dislocation in childhood.

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.

Scoliosis in Patients With Prader-Willi Syndrome

OBJECTIVE. Our goals were to determine the prevalence and estimate the evolution of spinal deformities in patients suffering from Prader-Willi syndrome; find out which kind of spine deformity predominates regarding genotype and clinical patterns; and evaluate the affect of growth-hormone treatment on the onset and progression of spinal deformities. PATIENTS AND METHODS. This was a retrospective longitudinal, clinical, and radiologic study. One hundred forty-five children followed between 1980 and 2006 were studied in 2 referral centers for Prader-Willi syndrome. Genetic testing confirmed the diagnosis in 133 patients. Ninety-three patients (64%) received growth-hormone therapy. For statistical analysis, age-adjusted comparison between groups was performed by using multivariate logistic regression. RESULTS. Mean age of the patients was 10.2 ± 6.2 years. Sixty-three (43.4%) patients were afflicted with scoliosis. Scoliosis frequency steadily rose with age, and a large majority of patients were affected at skeletal maturity (66.7%). Scoliosis prevalence was not affected by the genotype or by growth-hormone treatment. Patients with higher BMI values had an increased risk of developing a kyphotic deformity in association with scoliosis. We found a statistical association between kyphotic deformity and the need for surgical treatment. CONCLUSIONS. Scoliosis is a major concern for patients with Prader-Willi syndrome, and a regular (annual) systematic back examination is mandated. The role of growth-hormone treatment on the natural history of scoliosis could not be determined, and careful monitoring during treatment is recommended.

Cementless hip arthroplasty in juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease in children. The hip is usually affected later, and its involvement is the most common cause of disability in JIA. Failure of medical and preventive treatment, significant joint destruction, or multiarticular involvement may necessitate total hip arthroplasty (THA) to restore good function. Related clinical trials show initially good THA results in most of the series, but long-term outcomes are uncertain due to a significant arthroplasty loosening rate in the initial years, particularly with cemented stems. The authors report the results of 62 noncemented THAs in 34 children with JIA after an average follow-up of 6 years (range 3-13). Mean age at surgery was 18.3 years (range 11.8-31) and 14 of the 34 children had active disease. Clinical results were good for hip function but less for global function. There were no infections. Two acetabular cups early in the series failed due to poor primary fixation and had to be revised. Survivorship analysis was performed with the Kaplan-Meier method. At 13 years, the survival rate was 100% for the femoral component and 90.1% for the acetabular component.

Treatment of hip dysplasia in patients with mucopolysaccharidosis type I after hematopoietic stem cell transplantation: results of an international consensus procedure

BackgroundMucopolysaccharidosis type I (MPS-I) is a lysosomal storage disorder characterized by progressive multi-organ disease. The standard of care for patients with the severe phenotype (Hurler syndrome, MPS I-H) is early hematopoietic stem cell transplantation (HSCT). However, skeletal disease, including hip dysplasia, is almost invariably present in MPS I-H, and appears to be particularly unresponsive to HSCT. Hip dysplasia may lead to pain and loss of ambulation, at least in a subset of patients, if left untreated. However, there is a lack of evidence to guide the development of clinical guidelines for the follow-up and treatment of hip dysplasia in patients with MPS I-H. Therefore, an international Delphi consensus procedure was initiated to construct consensus-based clinical practice guidelines in the absence of available evidence.MethodsA literature review was conducted, and publications were graded according to their level of evidence. For the development of consensus guidelines, eight metabolic pediatricians and nine orthopedic surgeons with experience in the care of MPS I patients were invited to participate. Eleven case histories were assessed in two written rounds. For each case, the experts were asked if they would perform surgery, and they were asked to provide information on the aspects deemed essential or complicating in the decision-making process. In a subsequent face-to-face meeting, the results were presented and discussed. Draft consensus statements were discussed and adjusted until consensus was reached.ResultsConsensus was reached on seven statements. The panel concluded that early corrective surgery for MPS I-H patients with hip dysplasia should be considered. However, there was no full consensus as to whether such a procedure should be offered to all patients with hip dysplasia to prevent complications or whether a more conservative approach with surgical intervention only in those patients who develop clinically relevant symptoms due to the hip dysplasia is warranted.ConclusionsThis international consensus procedure led to the construction of clinical practice guidelines for hip dysplasia in transplanted MPS I-H patients. Early corrective surgery should be considered, but further research is needed to establish its efficacy and role in the treatment of hip dysplasia as seen in MPS I.

Complications of scoliosis surgery in Prader-Willi syndrome.

Study Design. Retrospective case series of 16 consecutive patients. Objective. To evaluate the results of scoliosis surgery in Prader-Willi syndrome (PWS) with special emphasis on the complications and their risk factors. Summary of Background Data. PWS is a rare genetic disorder characterized by obesity, hypotonia, and frequent scoliosis. The literature dealing with scoliosis surgery in PWS consists of only few case reports. Surgical treatment was reported to be difficult with frequent and severe complications. Methods. Sixteen patients (3 males, 13 females) in 63 presenting scoliosis and PWS were operated on between 1974 and 2004. Preoperative, postoperative and last follow-up clinical and radiologic data were analyzed. Complications, treatment, and outcome were investigated. Results. Mean age at scoliosis diagnosis was 6.2 years (range 0.5–13.5). Mean age at surgery was 12.3 years (range 5–15). Mean follow-up was 5.4 years (range 2–18). There were 9 major complications (4 severe kyphosis above fusion, 2 deep infections, 1 transient paraplegia, 1 pseudarthrosis, 1 delayed wound healing). The 4 kyphosis required reoperation, 3 of which were complicated with permanent spinal cord injury. Minor complications affected 6 patients. Conclusion. Scoliosis surgery is frequently necessary in PWS and is associated with high rate of complications. These are often related to specific features of this syndrome the surgeon should recognize and consider.

Fracture-avulsion de la tubérosité tibiale antérieure chez l’adolescent: À propos de 22 cas et revue de la littérature

PURPOSE OF THE STUDY Fracture of the anterior tibial tubercle is exceptional in adolescents. The purpose of this work was to better understand the circumstances of such fractures, identify potential complications, and assess outcome of different therapeutic options. MATERIAL AND METHOD This was a retrospective analysis of a consecutive series of 22 children with avulsion fracture of the anterior tibial tubercle. The circumstances of the fracture were noted. The Ogden classification was used to establish the radiological type. Associated lesions were also noted as were any complications. Two types of treatment were given: orthopedic or surgical (several types). The functional outcome was assessed at last follow-up. RESULTS Mean age at fracture of the anterior tibial tubercle was 13 years (range 12-16) in 14 boys and 7 girls. It occurred after a jump or reception after a jump in 22 of the children. Five patients presented symptomatic homo- or contralateral anterior tibial apophysitis before the accident. The fracture was not displaced (type IA) in ten patients and was treated orthopedically. In twelve patients, the fracture was displaced (type IB, II, or III) and required osteosynthesis. Immobilization was maintained for four weeks on average (range 3-7). Associated lesions were observed in half of the twelve displaced fractures, with five cases of patellar ligament avulsion and three cases of meniscal injury. There were no complications with type IA fractures. For the twelve displaced fractures, complications were observed in seven children: hematoma (n = 2), infrapatellar hypoesthesia (n = 2), complete rupture of the patellar ligament 38 months after surgery (n = 1), recurvatum with leg length discrepancy (n = 1), and stiff knee (n = 1). Mean follow-up was two years (range 9 months-8 years). The functional outcome was excellent in all patients with a non-displaced fracture and in seven of the twelve patients who underwent surgical treatment. DISCUSSION Non-displaced fracture of the anterior tibial tubercle I children (type IA) should be considered as a separate entity responding very well to orthopedic treatment. The other cases of displaced fracture generally require surgery which enables an assessment of often associated lesions. The prognosis of displaced fractures of the anterior tibial tubercle is more sever due to the associated lesions and potential complications. We describe the second case of recurvatum and leg length discrepancy following fracture of the anterior tibial tubercle. CONCLUSION Displaced fracture of the anterior tibial tubercle in adolescents is often associated with soft tissue injury (patellar ligament, menisci). Surgery is indispensable and provides good functional results.Resume Le but de ce travail etait de mieux connaitre les circonstances de survenue, les caracteristiques et le pronostic des fractures de la tuberosite tibiale chez l’adolescent. Vingt-deux enfants ayant presente une fracture-avulsion de la tuberosite tibiale anterieure ont ete revus retrospectivement. Les caracteristiques cliniques, radiologiques, les lesions associees et l’evolution ont ete precisees pour chaque fracture. La fracture etait survenue 15 fois sur 22 apres un saut ou la reception d’un saut chez des enfants âges de 13 ans en moyenne. Elle etait non deplacee (type IA) dans 10 cas et a ete traitee orthopediquement. Dans 12 cas, la fracture etait deplacee et a necessite une osteosynthese. Parmi ces 12 cas, des lesions associees ont ete retrouvees une fois sur deux (5 cas d’avulsion du ligament patellaire), et des complications sont survenues chez 7 patients. Le recul moyen est de 2 ans. Le resultat fonctionnel est excellent chez tous les patients ayant eu une fracture non deplacee et chez 7 patients sur 12 ayant eu une intervention chirurgicale. Le traitement orthopedique est reserve aux fractures non deplacees. Dans les autres cas, le traitement est chirurgical et l’intervention permet de reparer les lesions frequemment associees. Les auteurs decrivent le deuxieme cas de recurvatum et d’inegalite de longueur dans les suites d’une fracture de la tuberosite tibiale. Les fractures deplacees de la tuberosite tibiale anterieure chez l’adolescent sont souvent associees a des lesions des parties molles (ligament patellaire, menisques). Le traitement orthopedique donne d’excellents resultats fonctionnels pour les fractures non deplacees, mais l’intervention chirurgicale est generalement indispensable en cas de deplacement et permet d’obtenir de bons resultats fonctionnels.

Delayed bone age due to a dual effect of FGFR3 mutation in Achondroplasia

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.

Reliability and validity of the French-Canadian version of the scoliosis research society 22 questionnaire in France.

Study Design. Outcome study to determine the internal consistency, reproducibility, and concurrent validity of the French-Canadian version of the Scoliosis Research Society 22 (SRS-22 fcv) patient questionnaire in France. Objective. To determine whether the SRS-22 fcv can be used in a population from France. Summary of Background Data. The SRS-22 has been translated and validated in multiple countries, notably in the French-Canadian language in Quebec, Canada. Use of SRS-22 fcv seems appropriate for evaluating adolescent idiopathic scoliosis in France. However, French-Canadian French is noticeably different from the French spoken in France, and no study has investigated the use of a French-Canadian version of a health-quality questionnaire in another French population. Methods. The methods used for validating the SRS-22 fcv in Quebec were adopted for use with a group of 200 adolescents with idiopathic scoliosis and 60 healthy adolescents in France. Reliability and reproducibility were measured by the Cronbach &agr; and intraclass correlation coefficient (ICC), construct validity by factorial analysis, concurrent validity by the Short-Form of the survey, and discriminant validity by analysis of variance and multivariate linear regression. Results. In France, the SRS-22 fcv showed good global internal consistency (Cronbach &agr; = 0.87, intraclass correlation coefficient = 0.92), a coherent factorial structure, and high correlation coefficients between the SRS-22 fcv and Short-Form of the survey (P < 0.001). However, reliability and validity were slightly less than that for the instruments original validation and the validation of the SRS-22 fcv in Quebec. These differences could be explained by language and cultural differences. Conclusion. The SRS-22 fcv is relevant for use in France, but further development and validation of a specific French questionnaire remain necessary to improve the assessment of functional outcomes of adolescents with scoliosis in France. Level of Evidence: N/A

Traitement des arthrites septiques de hanche chez l’adulte drépanocytaire par prothèse totale de hanche

Resume Cette etude retrospective analyse le traitement de 10 arthrites septiques de hanche chez les patients drepanocytaires par prothese totale de hanche. La destruction de la hanche s’est produite malgre le traitement medical et la mise au repos de l’articulation par traction suspension. Le traitement a consiste en une resection tete et col suivie d’une traction suspension pendant 45 jours et la pose d’une prothese totale de hanche. Le recul actuel est compris entre 2 et 12 ans. Au recul moyen de 6 ans, deux recidives infectieuses ont ete observees sur les protheses implantees. L’arthroplastie a permis a ces patients de retrouver une activite fonctionnelle satisfaisante, alors qu’en preoperatoire ils etaient impotents du fait de la hanche touchee par l’arthrite infectieuse, et d’autant plus que leur hanche controlaterale etait porteuse d’une osteonecrose.