Interest of T1 parameters for sagittal alignment evaluation of adolescent idiopathic scoliosis patients.

PURPOSE: In the last few years several reports stressed the importance of sagittal alignment in adolescent idiopathic scoliosis (AIS) patients. It was recently reported that T1 slope, defined as the angle between the superior endplate of T1 and the horizontal, correlates strongly with overall sagittal parameters. The aim of this study was to assess the impact of T1 parameters (T1-slope and T1-tilt) on sagittal alignment of AIS hypokyphotic patients preoperatively and postoperatively. METHODS: Twenty-nine AIS patients with <20° preoperative hypokyphosis were included in a retrospective study. Surgery systematically comprised hybrid construct with screws below T11, sublaminar bands at thoracic level and a lamino-laminar claw on the upper instrumented vertebra. Preoperative, postoperative and 2-year follow-up radiological assessment included Cobb angle, T1 slope, T1 sagittal tilt, regional sagittal parameters and pelvic parameters. RESULTS: In the series as a whole, coronal Cobb angle was significantly reduced postoperatively (58° vs. 17°; p < 0.001), thoracic kyphosis significantly improved (12.4° vs. 25.6°; p < 0.001) and cervical lordosis significantly restored (6.2° kyphosis vs. 4.1° lordosis; p < 0.001). There was a significant modification in T1-slope (10.2° vs. 18.2°; p < 0.001). Preoperatively, T1 slope was significantly correlated with T1 tilt (r = 0.427; p = 0.029). Postoperatively, T1 slope was significantly correlated with T1 tilt (r = 0.549; p = 0.002), thoracic kyphosis (r = 0.535, p = 0.005) and cervical lordosis (r = -0.444, p = 0.03). Restoration of cervical lordosis was significantly correlated to changes of T1-slope (r = -0.393, p = 0.032), which was significantly correlated to postoperative thoracic kyphosis. CONCLUSION: According to these results, T1 seems to be of major interest in postoperative modifications of sagittal alignment. T1 slope and sagittal tilt are good indicators of postoperative changes for regional (cervical lordosis and thoracic kyphosis) and global parameters. We therefore consider these parameters as essential in the assessment of AIS patients. Further studies and correlation with clinical scores will, however, be necessary in order to confirm the present findings.

Sublaminar bands: are they safe?

BACKGROUND: Sublaminar bands (SB) are frequently used as implants in spine deviation correction. PURPOSE: Our purpose is to demonstrate their safety on a large series of patients. STUDY DESIGN: This is a retrospective study. METHODS: Our department treated 378 spine deviations on children and adolescents via a hybrid posterior technique (lumbar screws, hook and thoracic SB). Each surgery was undertaken using anesthesiologic and a neurophysiologic monitoring using somatosensory evoked potentials (SSEP) and neurogenic mixed evoked potentials (NMEP). An alert was described as an amplitude decrease of 50 % and/or a latency increase of 10 %. Data were analyzed using Student or Wilcoxon tests. RESULTS: We used 2,223 SB in 378 operative procedures. We described ten neurophysiologic alerts during the passage of the band under the lamina. There were no significative differences between the two groups concerning the age and the severity of the deformation (p > 0.05). These neurophysiologic alerts were associated with a dysautonomic trouble (hypertension and bradycardia). The lesional level was determined using a spinal electrode. In six cases, the responsible SB was removed. Three patients had post-operative neurologic deficiency (0.8 %) without complete recovery for one of them (localized incomplete sensitive deficiency). Within the group of 378 patients, 21 alerts were reported due to a screw or a hook, or during the correction manoeuver, without dysautonomic trouble. CONCLUSION: SB neurologic complications rate is as high as other implants' complication rate. Simultaneous hemodynamic and neurophysiologic change is an argument for vegetative response due to SB passage. Their optimal use requires a strict learning of their insertion under the lamina to be as less traumatic as possible. SB are as safe as any other spine implants.

Reciprocal sagittal alignment changes after posterior fusion in the setting of adolescent idiopathic scoliosis.

PURPOSE: Surgical adolescent idiopathic scoliosis (AIS) management can be associated with loss of thoracic kyphosis and a secondary loss of lumbar lordosis leading to iatrogenic flatback. Such conditions are associated with poorer clinical outcomes during adulthood. The aim of this study was to evaluate sagittal plane reciprocal changes after posterior spinal fusion in the setting of AIS. METHODS: Thirty consecutive adolescents (mean age 14.6 years) with AIS Lenke 1, 2 or 3 were included in this retrospective study with 2 year follow-up. Full-spine standing coronal and lateral radiographs were obtained preoperatively, at 3 and 24 months postoperatively. Coronal Cobb angle, thoracic kyphosis (TK) and lumbar lordosis (LL) were measured. Surgical procedure was similar in all the cases, with use of pedicular screws between T11 and the lowest instrumented vertebra (≥L2), sublaminar hooks applied in compression at the upper thoracic level and sub-laminar bands and clamps in the concavity of the deformity. Statistical analysis was done using t test and Pearson correlation coefficient. RESULTS: Between preoperative and last follow-up evaluations a significant reduction of Cobb angle was observed (53.6° vs. 17.2°, p < 0.001). A significant improvement of the instrumented thoracic kyphosis, TK (19.7° vs. 26.2°, p < 0.005) was noted, without difference between 3 and 24 months postoperatively. An improvement in lumbar lordosis, LL (43.9° vs. 47.3°, p = 0.009) was also noted but occurred after the third postoperative month. A significant correlation was found between TK correction and improvement of LL (R = 0.382, p = 0.037), without correlation between these reciprocal changes and the amount of coronal correction. CONCLUSION: Results from this study reveal that sagittal reciprocal changes occur after posterior fusion when TK is restored. These changes are visible after 3 months postoperatively, corresponding to a progressive adaptation of patient posture to the surgically induced alignment. These changes are not correlated with coronal plane correction of the deformity. In the setting of AIS, TK restoration is a critical goal and permits favorable postural adaptation. Further studies will include pelvic parameters and clinical scores in order to evaluate the impact of the noted reciprocal changes.

Value of diffusion-weighted images in differentiating mid-course responders to chemotherapy for osteosarcoma compared to the histological response: preliminary results.

BACKGROUND: Preoperative diffusion-weighted MRI (DW-MRI) has been described as an efficient method to differentiate good and poor responders to chemotherapy in osteosarcoma patients. A DW-MRI performed earlier during treatment could be helpful in monitoring chemotherapy. OBJECTIVE: To assess the accuracy of DW-MRI in evaluating response to chemotherapy in the treatment of osteosarcoma, more specifically at mid-course of treatment. MATERIALS AND METHODS: This study was carried out on a prospective series of adolescents treated for long-bone osteosarcoma. MR examinations were performed at diagnosis (MRI-1), at mid-course of chemotherapy (MRI-2), and immediately before surgery (MRI-3). A DW sequence was performed using diffusion gradients of b0 and b900. The apparent diffusion coefficients (ADC1, ADC2, ADC3, respectively), their differentials (ADC2 - ADC1 and ADC3 - ADC1), and their variation (ADC2 - ADC1/ADC1 and ADC3 - ADC1/ADC1) were calculated for each of these three time points. RESULTS: Fifteen patients were included. Patients with no increase in ADC showed a poor response to chemotherapy on their histology results. At mid-course, the three calculated values were significantly different between good and poor responders. ADC2 - ADC1 enabled us to detect, with 100% specificity, four out of seven of the poor responders. There was no significant difference in the values at MRI-3 between the two groups. CONCLUSION: DW-MRI performed both at baseline and mid-course of neoadjuvant chemotherapy is an efficient method to predict further histological response of osteosarcoma. This method could be used as an early prognostic factor to monitor preoperative chemotherapy.

A study of 28 flat bone osteosarcomas: prognostic factors and early and long-term outcome.

Limited information is available on clinical management of Flat Bone Osteosarcomas (FBOS). We retrospectively analysed prognostic factors and outcome. Twenty-eight patients were treated in our institution. Survival curves were obtained by the Kaplan-Meier method and compared with the log-rank test. The overall survival (OS) rates at 5 and 10 years were 52.4% and 45.8% respectively. The event-free survival (EFS) rates at 5 and 10 years were 41.5%. The factors influencing EFS in univariate analysis were location, metastatic disease at diagnosis, effect of neoadjuvant chemotherapy, histological response and adequate local tumour control. Location, metastatic disease at diagnosis, effect of neoadjuvant chemotherapy, histological response and local recurrence were statistically correlated with OS. Multivariate analysis retained metastatic disease at diagnosis as prognostic factors of EFS and OS. Our results suggest a more favourable outcome of FBOS as the use of a treatment scheme based on the protocols for long bone osteosarcomas. However, an adequate local treatment is essential to ensure a better outcome.

Percutaneous treatment of osteoid osteoma by laser thermocoagulation under computed tomography guidance in pediatric patients.

To evaluate the efficiency of laser thermocoagulation under computed tomography (CT) guidance in the treatment of osteoid osteoma within a strictly pediatric group. Twenty-five patients aged 4 to 17 years were treated under CT by laser thermocoagulation. The nidus measured on average 10.1 mm. Pain relief was the main item for evaluation of the effectiveness of our treatment. Follow-up ranged from 3 months to 61 months (mean, 26 months). Technical success was achieved in 100%. Thermocoagulation proved to be initially effective in 24 of 25 children (96%) and had a positive long-term effect in 23 of 25 children (92%). We had four minor complications and one severe complication (partial osteonecrosis of the talus). Laser thermocoagualation is an effective treatment for osteoid osteoma in pediatric patients.

[Ankle injury without fracture in children: cast immobilization versus symptomatic treatment. Impact on absenteeism and quality of life]. / Traumatisme de la cheville sans fracture chez l'enfant : immobilisation plâtrée versus traitement symptomatique. Impact sur l'absentéisme et la qualité de vie.

UNLABELLED: Treatment methods for ankle injury in children are numerous and have comparable results. The impact on absenteeism and quality of life is an interesting criterion to consider in order to help doctors in their initial treatment choice. OBJECTIVE: The objective of this study was to compare two therapeutic strategies for ankle injury without fracture in children in terms of the impact on school absenteeism, parents' professional absenteeism, and quality of life. The strategies compared were cast immobilization of the ankle and a purely symptomatic treatment with no immobilization. MATERIALS AND METHOD: We conducted a prospective, comparative, and randomized study. The population comprised children between 8 and 15 years of age, consulting for a first episode of ankle injury in a pediatric-emergency department of a hospital center in Marseille, France. A clinical and radiographical report was systematically done. Children were seen after 1 week to provide the clinical monitoring, assess the child's and parents' absenteeism, and assess the quality of life. RESULTS: Sixty-two patients were studied. There was no difference in clinical progression after 7 days between the two treatment groups. Quality of life was also comparable. However, the children's absenteeism and the parents' absenteeism were higher in the casted group.

[Complications of prophylactic pinning for unilateral upper femur epiphysis slipping: retrospective analysis of 62 operated cases]. / Complications du vissage controlatéral préventif en cas d'épiphysiolyse fémorale supérieure unilatérale : à propos d'une série rétrospective de 62 cas opérés.

PURPOSE OF THE STUDY: The appropriate treatment for unilateral slipping of the upper epiphysis of the femur is controversial. Prophylactic surgical treatment raises the risk of bilateralization. The procedure is often unnecessary as the natural history of epiphyseal slipping is often favorable when the displacement is minimal. We analyzed the complications of systematic prophylactic treatment in order to determine the optimal attitude. MATERIAL AND METHODS: This was a retrospective series of 62 children who underwent surgery for unilateral slipping of the superior femoral epiphysis between 1996 and 2005. Prophylactic treatment of the healthy hip was instituted systematically. The complications were noted according to Paley. We searched for factors of risk of complications, studying the bone maturity indexes, the characteristic features of the healthy femur epiphysis and the surgical technique used. RESULTS: There were seven complications, six following prophylactic treatment and one after material removal. The rate of complications reached 11.3%. Five of the complications were minor: two local infections with favorable outcome and three patients who complained of pain in the hip at mobilization, which had totally resolved at one year. One moderate complication was noted: spiral fracture of the upper femur starting from the screw head and treated with plate fixation. The outcome was favorable. There was one severe complication: osteoarthritis of the hip joint with septicemia on day 3. The outcome was unfavorable with necrosis of the femoral head, resection and use of a spacer. A total hip arthroplasty was performed at one year. DISCUSSION: Complications were globally more frequent and more severe compared to series using prophylactic screwing. The major infection complication (osteoarthritis) observed in this series has not been reported elsewhere. There was probably a center effect since we recruited all of the most complex cases in our region. We were unable to identify any factor predictive of complications. There is apparently no clear choice between systematic prophylactic treatment and careful surveillance. Prophylactic treatment in selected patients might be the key to a successful preventive approach.

[Ankle injuries without fracture in children. Prospective study with magnetic resonance in 116 patients]. / Traumatismes de la cheville sans fracture chez l'enfant. Etude prospective par résonance magnétique de 116 patients.

PURPOSE OF THE STUDY: Appropriate assessment of ankle injuries in children and adolescents is a common emergency room problem. Many imaging techniques have been proposed, but with no consensus on the reality of anatomic lesions in ankles free of fractures, complicating the therapeutic decision. We analyzed the lesions observed with magnetic resonance imaging (MRI) in a large number of acute ankles in children. MATERIAL AND METHODS: This prospective study was conducted in a pediatric emergency room. The study population included all children aged eight to 15 years who presented an isolated injury of the ankle without fracture on the plain x-ray. History taking and physical examination were standardized. MRI was performed within three days of the initial physical examination. All the radiographic documents were examined by an experienced radiologist blinded to the results of the physical examination. RESULTS: During the study period, 116 patients were included. One hundred two MRI series were examined. Minor ligament injury was noted in 20 patients and ligament tear in five, including three with a closed distal tibial growth plate. Minor bone injury was noted in 42 patients and fracture in seven. None of these fractures were visible on the plain x-ray, even after knowledge of the MRI. Injuries were more frequent in boys. Injuries were more frequent when the pain was localized on the lateral aspect of the ankle and when there was an edema. DISCUSSION: Despite an abundant literature on ankle sprains, prospective studies are scarce in the pediatric population. We have found that MRI is particularly well-adapted for children because it allows a complete examination of anatomic lesions involving the bone or ligaments without the inconveniences of injections, pain, or radiation. Our clinical and imaging findings show that ankle sprains are real in children. We were however unable to identify any clinical factors predictive of ligament and/or bone injury. Other studies should be conducted to better understand the nosological context of ankle sprain in children and adolescents. Further study will enable a better evidence-based approach to individually adapted therapy.

[Pelvic incidence reliability in spine sagittal balance]. / Etude de la fiabilité des mesures de l'incidence pelvienne dans l'analyse de l'équilibre sagittal du bassin.

PURPOSE OF THE STUDY: The pelvic incidence (PI) is an anatomic parameter independent of the spatial orientation of the pelvis. However, measuring the PI remains a technically difficult task. PI is determined from radiographic construction which has several consequences. Imperfect radiographic incidence may compromise optimal conditions for measurement. Anatomic remodeling of the sacral plate can also have an impact on rigorous measurement of the PI. Several solutions have been proposed in the literature in order to obtain equivalent measurements. The proposed methods (Duval-Beaupere, Vialle) appear logical, but remain to be validated. The purpose of this study was to determine whether the angle measured on the plain x-ray is affected by the radiographic quality of the image and to determine whether the "variant pelvic incidence" (VPI) using a reference constituted by the posterior aspect of the sacrum, can be accepted as a valid equivalent to PI in the event of anatomic remodeling. MATERIAL AND METHODS: This was a prospective study conducted in 50 patients. The PI and the VPI were measured on 3D computed tomography reconstructions which allowed three series of measurements: in a strictly lateral view, in a view with the position of the femoral heads shifted in the horizontal plane, and a view with the position of the femoral heads shifted in the vertical plane. Statistical analysis was applied to compare the three series of measures in order to search for a significant difference for the two angles under consideration (PI and VPI) dependent on the position of the pelvis. RESULTS: There was no significant difference in PI as a function of the position of the femoral heads: the coefficients of variation were all greater than 0.98 (p<0.01). For VPI, there was a significant difference between the theoretical ideal position and the horizontal shift of the femoral heads (p<0.05). Average measurements of PI and VPI were statistically different for each individual (p<0.05), with no identifiable relationship between the two values (PI and VPI). DISCUSSION: Pelvic incidence is a reliable measure, even if the quality of the x-ray is not perfect. Conversely, the variant, using the posterior aspect of the sacrum, is highly dependent on pelvic orientation, with significant differences with position. We were unable to establish a relation between PI and VPI. In practice, it would be licit to consider that the straight line between the two femoral heads indicates the center of the femoral heads. On the contrary, it would not be wise to consider the posterior aspect of the sacrum as a reliable reference.

[Informative value of the popliteal angle in walking cerebral palsy children]. / Peut-on se fier à l'angle poplité chez l'enfant paralysé cérébral marchant?

PURPOSE OF THE STUDY: In clinical practice, it is generally accepted that hamstring tightness results in incomplete knee extension when the hip is in flexion and in smaller conventional and modified popliteal angles. Similarly, a difference between the conventional popliteal angle and the modified popliteal angle (popliteal differential) would be associated with a permanent deficit in knee extension. The purpose of this study was to determine whether these two hypothesis correlate with clinical findings. MATERIAL AND METHODS: The series was composed of 35 walking cerebral palsy children, 16 girls and 19 boys, mean age 11+/-3.6 years with a pathological conventional popliteal angle. These children walked using the jump knee (n=24) or the crouch knee (n=11) pattern. Permanent hip flexion and the conventional and modified popliteal angles were noted. SPSS version 10.1.3 for Window was used to search for a correlation between the popliteal differential and the presence of permanent hip flexion using several values for the popliteal differential (5, 10, 15, 20, and 30 degrees ). Data were adjusted for age and gender. RESULTS: The statistical analyses demonstrated a significant relationship between the presence of permanent hip flexion and a popliteal differential strictly less than 10 degrees and between the absence of permanent hip flexion and a popliteal angle greater or equal to 10 degrees . These statistically significant results, which demonstrated the opposite of what was expected, were independent of age and gender. DISCUSSION: Our findings demonstrate that examination of the knee joint is indispensable but insufficient. The conventional popliteal angle is not a reliable indicator of hamstring tightness. The normal value of the modified popliteal angle has not been established so that it is impossible to determine what a pathological angle is. We do not know whether measurement of this angle is sufficient to establish indications for surgery. In the future, the development of muscle models coupled with gait analysis should enable more reliable prediction of outcome after surgery. At the present time, we recommend repeated physical examination using a standardized protocol, taking into consideration, several parameters including spasticity, selectivity and muscle force and to perform quantified gait analysis before scheduling hamstring lengthening surgery for walking cerebral palsy children.

[Fat embolism during limb lengthening with a centromedullary nail: three cases]. / Embolie graisseuse au cours des allongements de membres par clou centromédullaire: à propos de trois cas.

Several methods are available for progressive limb lengthening, including centromedullary nailing, external fixation, or a combination. Each technique has its own advantages and drawbacks. In trauma victims, use of centromedullary nailing is associated with potentially fatal fat embolism. This fatal outcome might also occur during limb lengthening, particularly in bilateral procedures. To our knowledge, fat embolism has not been reported with the use of centromedullary nail for limb lengthening. This was a multicentric study of three cases of fat embolism, including one fatal outcome. In all, 36 centromedullary lengthening nails were inserted in the three centers before these acute episodes. The first two cases occurred during single-phase bilateral procedures, the third during unilateral lengthening. Fat embolism could result from several factors, as reported in the literature. While the bilateral nature of the procedure has been incriminated, the observation of an embolism during a unilateral procedure suggests other factors may be involved. Considerable increase in endomedullary pressure during reaming and insertion of the nail has been demonstrated. At the same time, there is the question as to whether the reduction of the diminution of medullary pressure by corticotomy would be an efficient way of reducing the risk of fat embolism. Based on the analysis of our three cases, we suggest that the best way to avoid fat embolism might be to drill several holes within the area of the osteotomy before reaming, in order to reduce endomedullary pressure. This can be achieved via a short skin incision, sparing the periosteum before low energy osteotomy. Since applying this protocol, the three centers have implanted 17 lengthening nails, without a single case of fat embolism.

[Salter and Harris type-II distal femoral physeal fracture-separations at adolescent age: a new therapeutic approach (preliminary study)]. / Fractures-décollements épiphysaires de type SalterII de l'extrémité distale du fémur chez l'adolescent : nouvelle proposition thérapeutique (étude préliminaire).

PURPOSE OF THE STUDY: The prognosis of distal femoral physeal fracture-separation is poor in children. In adolescents, more than half of the cases are classified as Salter and Harris type-II. The gold-standard treatment for a displaced fracture combines anatomic reduction with internal fixation with a pin or screw, preserving the growth cartilage. Despite this treatment, the rate of mid- and long-term complications has been high in the literature, most problems being related to leg length discrepancy and misalignments (genu valgum and genu varum). In order to avoid these problems, for adolescents, we propose and osteosynthesis system which bridges the entire growth cartilage with a blade-plate. Depending on the bone age, puberty and thus potential for further growth, we combine this osteosynthesis with a contralateral distal femoral epiphysiodesis to prevent invalidating leg length discrepancy. MATERIAL AND METHODS: We reviewed retrospectively the cases of 21 patients aged 11 to 15 years treated between 1990 and 2005 for Salter and Harris type-II distal femoral physeal fracture- separation. Clinical and radiographic outcome was compared between the 16 patients treated with the classical internal fixation system or cast immobilization and the five patients treated with a blade-plate. A complete physical examination was available for the follow-up in all cases. A full stance view was used for the radiographic analysis. The mean follow-up was 6.7 years (range 2-17), minimal two years. RESULTS: In patients treated with the classical fixation system or a plaster cast, four of 16 (25 %) developed frontal misalignment of more than 5 degrees and five of 16 (32 %) leg length discrepancy of more than 2cm. No misalignment or leg length discrepancy (>2cm) was observed among the five patients treated with a blade-plate. DISCUSSION: The results observed in our patients treated with the classical fixation systems are comparable with those reported by others. Our patients treated with the blade-plate system constitute the only series with no cases of frontal misalignment or invalidating leg length discrepancy after this type of fracture. We used contralateral distal femoral epiphysiodesis in all patients whose predictable leg length discrepancy at the end of growth was greater than 2cm, that is 11-3.5 years (bone age) in girls and 13-14.5 years in boys. CONCLUSION: Internal fixation techniques bridging the growth cartilage are the only techniques used for Salter and Harris type-II distal femoral physeal fracture-separation in adolescents which have been able to prevent posttraumatic knee misalignment (genu valgum or genu varum). Leg length discrepancy can be prevented by a contalateral distal femoral epiphysiodesis when the fracture occurs in a child or early puberty.

[Melorheostosis and anterior cruciate ligament tear in a 15-year-old female]. / Mélorhéostose et entorse du ligament croisé antérieur chez une jeune fille de 15 ans.

We report the case of a 15-year-old girl who suffered an indirect knee trauma. The standard X-rays revealed a tract of ivory-like bone partially obstructing the medullary canal of the femur and the tibia. Magnetic resonance imaging produced a hypointense signal on the T1 and T2 sequences. The radiographic diagnosis was melorheostosis which was confirmed on the biopsy specimen which ruled out other diagnoses. The MRI also revealed a tear of the anterior cruciate ligament, treated conservatively. Clinical and radiological surveillance were proposed for the melorheostosis.

[Progressive correction of the hand in the congenital radial clubhand]. / Centralisation progressive de la main dans la main bote radiale congénitale.

The therapeutic objective of a congenital radial clubhand is to obtain, at the end of the growth, a functional hand, that is a hand with a thumb, in the axis of the forearm with the most cosmetic aspect as possible. The challenge lies in the fact that the hand is not in the axis of the forearm. Thus, some authors realize a surgical centralization or radialization by doing a direct release of the retracted soft tissues. On the other hand, it is possible to correct the hand without any invasive surgery by using an external fixator allowing to correct the hand progressively. The Taylor Spatial Frame fixator is a system of external fixation which allows, by using a software, to realize this correction accurately.

[Radiography of scoliosis: comparative dosimetry between conventional technique and digital fluorography]. / Radiographie des scolioses: dosimétrie comparée entre la technique conventionnelle et la fluorographie numérique.

OBJECTIVE: Compare the irradiation delivered in conventional radiography and digital radiography by image intensifier during a scoliosis workup. PATIENTS AND METHODS: Our prospective randomized study included 105 patients, all of whom were identified according to sociodemographic parameters as well as criteria evaluating the quality of the full front spinal x-ray at PA incidence. The entry dose at the scapula and the exit dose in interorbital, thyroid, mammary, and hypogastric projection was measured by thermoluminescent dosimeters. RESULTS: The results of 71 girls and 28 boys, aged a mean 13.8 years with a mean weight of 47 kg were analyzed. At equal image quality, the entry dose was not significantly different between the two techniques; the mean exit dose reduction was 64% during digital acquisition. This reduction involved the interorbital (162%), mammary (43%), and thyroid (309%) regions. However, this system is more irradiating in the hypogastric region (34%). CONCLUSION: The dosimetric evaluation of the different imaging techniques used to explore the entirety of the spine should be part of radiologists' quality standard used to document their work and their choices.

[Osteoid osteoma of the inferior articular process of L5 associated with a bilateral spondylosis: a case report]. / Ostéome ostéoïde de l'articulaire inférieure de L5 associé à une spondylolyse bilatérale: à propos d'un cas chez un enfant de 5 ans.

We report the case of an 8-year-old boy who presented an osteoid osteoma of L5 associated with bilateral spondylolysis involving the same vertebra. Diagnostic bone scintigraphy is highly contributive in children presenting back pain. For us, it is the first intention exploration in patients with isthmic lysis seen on the plain x-ray. Symptomatic spondylolysis is the most frequent cause of back pain in children and is much more frequent than vertebral osteoid osteoma. The presence of isthmic lysis associated with focal uptake on the bone scintigraphy is highly suggestive of symptomatic spondylolysis. In this context, magnetic resonance imaging should be performed for both diagnostic purposes and prognostic assessment. The degree of bone and soft tissue edema in the present case was unusual for symptomatic spondylolysis. Complementary computed tomography finally established the diagnosis of osteoid osteoma of the posterior vertebral arch. To our knowledge, the association of osteoid osteoma with bilateral spondylolysis on the same vertebra has not been described elsewhere. In children, the diagnosis of symptomatic spondylolysis can only be established after ruling out other causes of back pain. The diagnosis of osteoid osteoma must be kept in mind.

[Fracture of the intercondylar eminence of the tibia type II in children: 20 surgically-treated cases]. / Fracture de l'éminence intercondylienne du tibia de type II chez l'enfant: à propos de 20 cas traités chirurgicalement.

PURPOSE OF THE STUDY: The purpose of this study was to detail therapeutic indications for fractures of the intercondylar eminence of the tibia with little displacement and preservation of the posterior hinge (type II fracture in the Zarincznyj classification). MATERIAL AND METHODS: We reviewed retrospectively a multicentric serie of type II fractures of the intercondylar eminence observed in children treated surgically. There were twenty patients, ten girls and ten boys, mean age 11.9 years (range 6-16). Imaging included plain x-rays of the knee (anteroposterior and lateral views) in all patients as well as computed tomography (5 patients) and magnetic resonance imaging (1 patient). Surgical treatment was performed in all cases, on average six days after trauma (range 0-25). A medial parapatellar arthrotomy was used in all cases. A non-resorbable thread was used for fixation associated with an anchor in the last four cases. Clinical and radiological assessment was reviewed at mean 3.7 years follow-up. RESULTS: All children had resumed their sports activities at the same level as before the accident within 4.8 months on average. None of the children suffered from an unstable knee or functional impairment at last follow-up. The Lysholm score was 88.9 on average (range 70-100) at three months postoperative and 99.2 (range 89-100) at last follow-up. DISCUSSION: There is currently agreement that non-displaced fractures of the anterior intercondylar eminence of the tibia should be treated orthopedically and that forms with displacement require surgery. Conversely, the type II fractures with an anterior gap but a preserved posterior hinge, the appropriate treatment remains a subject of debate. In our experience, surgery would appear to be preferable to orthopedic management. Surgery enables putting correct tension on the anterior crucicate ligament and limits the risk of residual laxity which, even though rarely associated with instability, could in the long-term lead to osteoathritic degradation or meniscal damage. CONCLUSION: Surgical treatment of fractures of the intercondylar eminence of the tibia with little displacement and preservation of the posterior hinge provides satisfactory results and the best guarantee of long-term stability.

[A pediatric case of rupture of the brachial artery and radial nerve palsy secondary to proximal humeral exostosis]. / Rupture de l'artère brachiale et paralysie radiale secondaire à une exostose proximale de l'humérus chez une enfant de 14 ans.

Rupture of the brachial artery associated with radial nerve palsy in a context of exostosis of the proximal humerus has not been described to date in the literature. Our patient was a fourteen-year-old girl with a history of violent pain occurring suddenly with no prodrome or triggering factor. The pain was localized at the level of the proximal left humerus. Physical examination revealed the presence of a hematoma and complete motor radial nerve palsy. The diagnosis was not confirmed by computed tomography with contrast injection but was confirmed by magnetic resonance imaging which eliminated malignant transformation of the exostosis. After checking the neurovascular bundles and evacuating the hematoma, treatment consisted in resection of the exostosis and arterial repair with an autologous venous graft. We discuss the diagnostic and therapeutic challenges which present vascular complications due to exostosis.