Surgical technique for one-stage posterior hemivertebrectomy.

One-stage posterior hemivertebrectomy is a safe and effective technique as long as the surgical team is well prepared and has the appropriate instrumentation. All available means must be used to minimize intraoperative blood loss. The various surgical steps are completed while following various precautionary measures. Lastly, the surgical team must be able to manage certain intraoperative hazards. LEVEL OF EVIDENCE: IV.

Clinical and radiographic evolution of graduate patients treated with magnetically controlled growing rods: results of a French multicentre study of 90 patients.

PURPOSE: The purpose of this study was to investigate patients with early-onset scoliosis (EOS) who completed their electromagnetic lengthening rod program to assess the demographics of this population and to analyze the evolution of clinical and radiological parameters and the occurrence of complications. METHODS: This was a multicenter study with 10 French centers. We collected all patients with EOS who had undergone electromagnetic lengthening between 2011 and 2022. They had to have reached the end of the procedure (graduate). RESULTS: A total of 90 graduate patients were included. The mean follow-up time over the entire period was 66 months (25.3-109). Of these, only 66 patients (73.3%) underwent definitive spinal arthrodesis at the end of the lengthening phase, whereas 24 patients (26.7%) kept their hardware in situ with a mean follow-up time from the last lengthening of 25 months (3-68). Patients had an average of 2.6 surgeries (1-5) over the entire follow-up. Patients had an average of 7.9 lengthenings for a mean total lengthening of 26.9 mm (4-75). Analysis of the radiological parameters showed a percentage reduction in the main curve of 12 to 40%, depending on the etiology, with an average reduction of 73-44°, and an average thoracic height of 210 mm (171-214) for an average improvement of 31 mm (23-43). There was no significant difference in the sagittal parameters. During the lengthening phase, there were a total of 56 complications in 43 patients (43.9%; n = 56/98), of which 39 in 28 patients (28.6%) resulted in unplanned surgery. In the graduate patients, there were a total of 26 complications in 20 patients (22.2%), all of which resulted in unscheduled surgery. CONCLUSION: MCGR, allow to decrease the number of surgeries, to progressively improve the scoliotic deformity and to reach a satisfactory thoracic height at the price of an important complication rate linked in particular to the complexity of the management of patients with an EOS.

Vertebral Body Tethering in AIS Management-A Preliminary Report.

Vertebral Body Tethering (VBT) is a recently developed surgical technique for the treatment of progressive and severe scoliosis in patients with significant growth potential. It has been used since the first exploratory series, which showed encouraging results on the progressive correction of the major curves. This study reports on a retrospective series of 85 patients extracted from a French cohort, with a follow-up at a minimum of two years after a VBT with recent screws-and-tether constructs. The major and compensatory curves were measured pre-operatively, at the 1st standing X-ray, at 1 year, and at the last available follow-up. The complications were also analyzed. A significant improvement was observed in the curve magnitude after surgery. Thanks to growth modulation, both the main and the secondary curves continued to progress over time. Both the thoracic kyphosis and lumbar lordosis remained stable over time. Overcorrection occurred in 11% of the cases. Tether breakage was observed in 2% of the cases and pulmonary complications in 3% of the cases. VBT is an effective technique for the management of adolescent idiopathic scoliosis patients with residual growth potential. VBT opens an era of a more subtle and patient-specific surgical management of AIS that considers parameters such as flexibility and growth.

Side bending radiographs and lowest instrumented vertebra in adolescent idiopathic scoliosis: A French quality-of-care study.

BACKGROUND: Determining which spinal levels to instrument during surgical treatment of Lenke Type 1 adolescent idiopathic scoliosis (AIS) depends on the reducibility of the primary and secondary curve patterns. This reducibility can be evaluated in several ways, with the most popular being radiographs in bending for moderate thoracic and lumbar curvatures. Hypothesis Side-bending radiographs will alter the choice of the lowest instrumented vertebra (LIV) for the surgical treatment of AIS. METHODS: Thirteen experienced French spine surgeons were invited to perform surgical planning on 23 patients based on stereoradiographs with and without (standing) side-bending views. The surgical planning was repeated a second time to assess the intra- and inter-rater reliability. Variations in the choice of LIV were analyzed for each evaluation. RESULTS: The intra-rater reliability was moderate to substantial. The inter-rater reliability was low to moderate. The study compared 879 surgical plans. Selective fusion was chosen in 0.3% of the plans. The median LIV was L2. The availability of side bending views changed the plan in 39% of cases. However, 36% of the plans were changed in the control (test-retest) condition. No significant difference was found between the variations with side-bending radiographs and "control" variations (p>0.05). CONCLUSION: The use of radiographs in bending has no significant effect on the LIV choice in this study. This result is derived from statistically robust analysis made possible by one of the largest datasets available on this topic. Large inter-rater variability was observed and will be explored further in a future study. LEVEL OF EVIDENCE: II; non-randomized controlled comparative study.

Who needs prenatal counselling with a pediatric surgeon? Experience from a large tertiary care university hospital.

OBJECTIVES: To describe our experience with prenatal counselling for surgical anomalies in a large volume center. The secondary aim is to suggest a list of prenatal abnormalities warranting counselling by a pediatric surgeon. METHODS: We reviewed all prenatal counselling consultations performed by the pediatric surgery team between January 1st, 2015 and December 31st, 2016. RESULTS: A total of 169 patients or couples had a prenatal consultation with a pediatric surgeon. Prenatal work-up included a fetal MRI in 26% of cases, mainly for digestive and thoracic pathologies (56.1% of cases). Consultation with the pediatric surgeon led mainly to recommendations concerning the place of delivery. Induction for reasons related to the fetal anomaly occurred in 22.2% of cases. Most children were surgically treated within the first year of life (63.5%). Correlation between predicted prognosis and actual status at four years of life was 96.9%. Correlation between prenatal and postnatal diagnosis was 87.4%. CONCLUSIONS: Prenatal counselling by a pediatric surgeon allows couples to obtain clear information on the pathology of their unborn child, giving them greater autonomy in their decision to continue the pregnancy.

Elbow dislocation with and without an associated fracture in children: A prospective study of functional outcomes following 3 weeks of immobilization.

INTRODUCTION: The initial management of elbow dislocations in children, emergency reduction and brachial-antebrachial-palmar (BABP) immobilization, remains the most widely used method. Osteosynthesis could be associated in case of fractures. On the other hand, there is no consensus on the duration of immobilization in the recent literature. The objective of this study was to describe the medium-term functional results of a prospective cohort of children presenting with an elbow dislocation immobilized for 3 weeks, with or without an associated fracture. The hypothesis of this study was that 3 weeks of immobilization was sufficient and made it possible to obtain a satisfactory, rapid functional recovery without residual instability. MATERIAL AND METHOD: All children with an elbow dislocation with or without an associated fracture were included. The dislocation was urgently reduced and subsequent surgery could be indicated in the event of associated injuries. All the children had 3 weeks of immobilization with a BABP cast. Radiological and clinical follow-up was carried out for 2 years. The parameters evaluated were: 3 functional scores and the range of motion (ROM) of the elbow. Clinical or radiological complications were sought. RESULTS: A total of 50 children were included, the mean age was 10.6 years (± 2.6). Functional score results were "good' or "excellent' at 3 months of follow-up, "excellent' at 6 months and thereafter. The mean limitation in ROM at the last follow-up was 4.7° (± 7.2°) with all ranges combined. Eighty-two percent of children had a mean limitation in ROM of less than 10°. None of the children presented with a recurrence of elbow dislocation and instability. CONCLUSION: Immobilization of elbow dislocations for 3 weeks in children confers good medium-term functional results without exposing them to the risk of instability, whether or not the dislocation is associated with a fracture. LEVEL OF EVIDENCE: II; Prospective cohort study.

Functional and radiological outcome after forearm plating in children and adolescent fracture.

The literature on forearm overgrowth after plating in traumatic conditions is relatively poor though this technique can be useful when intra-medullary nailing is not sufficient in pediatric cases. The goal of this study was to assess a potential overgrowth after plating and identify impact on function. We conducted a retrospective study of all pediatric patients who underwent open surgery of the radius and/or ulna diaphysis with internal fixation by plating, in our institution, between October 2013 and July 2019. At last follow-up, functional and radiological outcomes were compared between the operated and uninjured forearm. Range of motion (ROM) of the wrist and elbow, clinical scores, radial and ulnar length were measured. A positive bone length discrepancy of more than 2mm was considered as an overgrowth. Were also studied the radio-ulnar index, radial inclination and radiocarpal angle. Thirteen patients were included. The mean age was 12.1 years old (±3.0 years), they were plated on the radius (10 cases) or on the ulna (3 cases). Mean follow- up was 4.4 years (± 1.8). In two cases, the plated bone (radius) was significantly longer than the uninjured one. There was no significant difference regarding radio-ulnar index, radial inclination and radiocarpal angle. The only statistically significant difference between the operated and uninjured forearm was the pronation/supination range, which was greater in the uninjured forearm (mean 160 ±48° versus 175 ±49°, p=0.01). This study confirms the good functional and radiological outcomes after plating even in a skeletally immature forearm. Level of evidence : IV.

Epidemiology of spinal fractures in children: Cross-sectional study.

INTRODUCTION: Epidemiological studies of fractures of the spine in children are all old, mostly single-centre, with series spanning periods of 5 to 20 years. HYPOTHESIS: As lifestyle is constantly changing, notably with an increase in sports activities and improvements in the prevention of road and household accidents, epidemiology has likely changed. OBJECTIVE: To update the description of spinal trauma in children and adolescents compared to the existing literature. MATERIAL AND METHOD: A multicentre cross-sectional study of spinal fracture, dislocation and spinal cord injury without radiological abnormality (SCIWORA) in children was carried out in 15 French university hospital centres, for a period of one year (2016). RESULTS: One hundred and sixty-five children were identified: 85 girls, 80 boys; mean age 11 years (range, 10 months-17 years); median, 12 years 6 months. One hundred and fifty-two children (92%) had fracture, 8 (5%) dislocation (including 7 C1-C2 rotary dislocations), and 5 (3%) SCIWORA. Fractures were multiple in 80 cases (49%), contiguous in 73 cases (91%) and non-contiguous in 7 (9%). Locations were cervical in 25 cases (15%), thoracic in 85 (52%), lumbar in 75 and sacral in 4 (2%). Fracture types comprised 234 vertebral compactions (78%), 25 burst fractures (8%), 5 chance fractures (2%), 2 odontoid fractures, and 33 other lesions. Causes comprised fall in 77 cases (47%), sports accidents in 56 (34%), road accidents in 29 (18%), and others in 3. In 52 cases (32%), there was ≥1 associated lesion: appendicular in 35 cases (67%), thoracic or abdominal in 31 (60%), and head in 16 (31%). Twenty-one cases had multiple lesions (40%). Eighteen cases showed neurological involvement (11%) including 5 SCIWORAs. Neurological complications were more frequent before 9 years of age. CONCLUSION: The epidemiology of spine fractures in children has slightly changed. There are now fewer cervical lesions. Causes are less often road accidents and more often sports accidents. Multi-level lesions remain frequent and the rate of neurological complications is around 10%. Compaction fracture is the most common type.

Medium-term evaluation of leg lengthening by ISKD® intramedullary nail in 28 patients: Should we still use this lengthening system?

INTRODUCTION: Lower-limb lengthening presently uses intramedullary nailing. There are motorized systems and mechanical systems, each with their specific complications. The aim of the present study was to assess the efficacy of ISKD® mechanical nails (Orthofix Inc., Texas, USA) on 3D EOS® imaging, and also complications and functional impact. HYPOTHESIS: The study hypothesis was that nail lengthening is effective but should no longer use the ISKD® system, due to the high rate of specific complications. MATERIAL AND METHODS: A single-center retrospective study included 28 patients (14 female, 14 male) undergoing limb-lengthening by ISKD® nail between 2005 and 2018. Mean age was 29 years. Twenty-four procedures were femoral and 4 tibial. Lengthening and consolidation parameters and residual discrepancy were measured on 3D EOS® imaging. Complications and functional scores were collated. RESULTS: Twenty-eight ISKD® nails were implanted in 28 patients. Mean follow-up was 75 months. Planned lengthening was achieved in 78.5% of cases, for a mean lengthening of 34.5mm. Mean lengthening and consolidation indices were respectively 0.94mm/day and 105 days/cm. Length discrepancy showed significant correction, with improvement in functional scores (p<0.01). The overall complications rate was 67.9%, 76% of which were specific to the ISKD® nail. DISCUSSION: The present study confirmed that nail lengthening is an indication of choice in lower-limb length discrepancy, but that the ISKD® system should no longer be used, due to an excessive rate of specific complications. Complications are due to deficient control of lengthening rate, not found with new-generation motorized nails, which show much fewer complications. LEVEL OF EVIDENCE: IV, retrospective study without control group.

Surgical management of burst fractures in children and adolescents: A Multicentre Retrospective Study.

BACKGROUND: Spinal fractures are rare in children, in whom they contribute only 2% to 5% of all traumatic spinal injuries. The management of burst fractures is well standardised in adults but remains controversial in paediatric patients, due to specific growth-related considerations. The objective of this study was to assess the clinical and radiographic outcomes of surgical management in a multicentre cohort of paediatric patients with burst fractures, in order to devise an optimal therapeutic strategy. HYPOTHESIS: A therapeutic strategy for burst fractures in children and adolescents can be devised based on data from a patient cohort and on previously published information. MATERIAL AND METHODS: Patients younger than 18 years who were managed surgically for one or more burst fractures (Magerl A3) were included in this retrospective multicentre study. Clinical, radiographic, and surgical data were collected before surgery, within 3 months after surgery, and 2 years after surgery. The primary surgical approach was posterior in all patients. Computed tomography (CT) was performed post-operatively to assess the extent of anterior bone loss in order to determine whether anterior fusion was required. The 26 included patients had a mean age of 15±1 years. The thoraco-lumbar spine was involved in 15 (57%) patients. Surgery consisted in correction by instrumentation and posterior fusion only in 14 patients and in posterior correction with anterior fusion in 12 patients. In 10 (38%) patients, the instrumentation extended one vertebra above and one vertebra below the fractured vertebra. RESULTS: Significant correction of the vertebral kyphosis was achieved (17°±11° before vs. 4°±2° after surgery, p=0.001). Anterior and posterior vertebral heights were significantly increased (15±3mm vs. 20±3mm, p=0.01 and 23±4mm vs. 26±4mm, p=0.04, respectively). DISCUSSION: The decision to perform surgery rests on the degree of kyphosis and presence of instability. Anterior bone grafting can be added if the instrumentation is short or a bone defect persists after posterior correction. Correction of the local kyphosis is important to prevent sagittal malalignment with its adverse functional consequences in adulthood. Neural decompression must be performed in patients with neurological deficits. LEVEL OF EVIDENCE: IV.

Divergent Intramedullary Nailing (DIN): A Modified Intramedullary Nailing Technique to Treat Paediatric Distal Tibial Fractures.

INTRODUCTION: Elastic stable intramedullary nailing (ESIN) allows for efficient reduction and stabilization of fractures of the tibial shaft in children and adolescents. However, for fractures of the distal third of the tibia, traditional ESIN could be inappropriate, thus compromising the stability and the healing of the fracture. The aim of this study was to present and to assess a new technique of modified ESIN to treat fracture of the distal third of the tibia, called divergent intramedullary nailing (DIN). METHODS: We performed a retrospective monocentric study. All patients less than 16 years old, managed in our pediatric orthopaedics department, and operated upon according to the DIN technique for a displaced and/or unstable fracture of the distal third of the tibia were included. Demographic and surgical data were collected. X-rays were performed preoperatively, postoperatively, at 6 weeks, and every 6 months. The surgical technique starts as does the classic ESIN. However, nails are not curved, so that they cross only once at the proximal part of the tibia; they are divergent and supported by the medial and lateral distal part of the tibial shaft. This allows for reduction and stabilization of the fracture. RESULTS: A total of 13 patients were included, with a mean age of 10 years and a mean follow-up of 32 months. The size of the nail varied between 2.5 and 4 mm. The mean surgical time was 54 minutes. The DIN technique provided a satisfying reduction (coronal and sagittal angulation <3 degrees) for the 13 fractures. In addition, there was no secondary displacement at 6 weeks. All patients were healed at 6 months, with no clinical torsion or axis malalignment. CONCLUSIONS: The current study confirms the feasibility and the efficiency of the DIN method to treat fracture of the distal third of the tibia.

Efficacy, pain, and overall patient satisfaction with pediatric upper arm fracture reduction in the emergency department.

INTRODUCTION: Immediate closed reduction and cast immobilization performed under sedation in the emergency room is the mainstay management for most isolated displaced or angulated upper limb fractures in children. We aimed to determine if this approach is safe, effective and if patients, parents and staff are satisfied with this approach.Our working hypothesis was this management provides a high satisfaction rate. PATIENTS AND METHODS: Between January 2017 and October 2017 we included 118 children presenting with upper arm fractures amenable to closed reduction under our institutional analgesia protocol. Children received 0.4mg/kg of Oramorph oral solution, they were then evaluated 40minutes later, and if their Face Legs Activity Cry Consolability (for children under 16 years-old) and/or Visual Analog Scale (for children over 6 years-old) were under 4, they underwent closed reduction by an orthopaedic resident under Nitrous oxide. If their pain assessment scale was above 4, they received an extra 0.4mg/kg of Oramorph oral solution and underwent closed reduction 40minutes later under nitrous oxide. These children were managed without hospitalization, as outpatients. Children>6, families and nursing staff were also given a visual satisfaction scale (using a 1-10 score) just before being discharged from the ER in order to evaluate their experience. RESULTS: Closed reduction in the ER was judged satisfactory from an orthopedic point-of-view in 115 cases (97.6%). Parents, children and the nursing team gave the experience in the ER an average satisfaction score of 9 out of 10. CONCLUSION: ER reduction is not only safe and effective but is also associated with a high satisfaction rate amongst children, their families and the nursing staff.

Proximal junctional kyphosis in thoracic adolescent idiopathic scoliosis: risk factors and compensatory mechanisms in a multicenter national cohort.

INTRODUCTION: Proximal junctional kyphosis (PJK) is a frequent complication, up to 46%, in adolescent idiopathic scoliosis surgical treatment (AIS). Several risk factors have been evoked but remain controversial. The purpose of this study was to analyze the incidence of PJK in a multicenter cohort of AIS patient and to determine risk factor for PJK. MATERIALS AND METHODS: Lenke I and II AIS patients operated between 2011 and 2015 (minimum of 2-years follow-up) were included. On fullspine X-rays, coronal and sagittal radiographic parameters were measured preoperatively, postoperatively and at final follow-up. Occurrence of radiological PJK corresponding to a 10° increase in the sagittal Cobb angle, measured between the upper instrumented vertebra (UIV) and UIV + 2, between postoperative and 2-years follow-up X-rays, was reported. RESULTS: Among the 365 patients included, 15.6% (n = 57) developed a PJK and only 10 patients required a revision surgery. Preoperatively, PJK patients had significantly larger pelvic incidence (57° ± 13° vs. 51° ± 12°), larger lumbar lordosis (LL) (63° ± 12° vs. 57° ± 11°) and bigger C7 slope. Postoperatively (3 months), in the non-PJK group, thoracic kyphosis (TK) was increased and LL was not significantly different. However, postoperatively, in the PJK group, no significant change was observed in TK, whereas C7 slope decreased and LL significantly increased. There was also a postoperative change in inflection point which was located at a more proximal level in the PJK group. Between postoperative time and final follow-up, TK and LL significantly increased in the PJK group. CONCLUSION: PJK is a frequent complication in thoracic AIS, occurring 16%, but remains often asymptomatic (less than 3% of revisions in the entire cohort). An interesting finding is that patients with high pelvic incidence and consequently large LL and TK were more at risk of PJK. As demonstrated in ASD, one of the causes of PJK might be postoperative posterior imbalance that can be due to increased LL, insufficient TK or inflection point shift during surgery. These slides can be retrieved under Electronic Supplementary Material.

Long-Term (>10 Years) Results After Endoscopic Injection Therapy for Vesicoureteral Reflux.

OBJECTIVE: Endoscopic injection is an accepted alternative for the treatment of vesicoureteral reflux (VUR) with the most commonly used agent being dextranomer/hyaluronic acid (Dx/HA). There are few reports on very long-term results after this treatment, although the biodegradable nature of the product could indicate that results might deteriorate on the long term. We, therefore, decided to evaluate the efficacy of Dx/HA copolymer endoscopic injection, in terms of recurrence of febrile urinary tract infections (fUTIs) in children, with a follow-up of at least 10 years. MATERIALS AND METHODS: We analyzed the medical data of all children who were diagnosed with VUR and underwent endoscopic injection with >10 years follow-up, in two University Hospitals. We reviewed their medical files and then contacted patients by phone. RESULTS: We found 68 patients who had undergone endoscopic treatment of VUR with a follow-up of minimum 10 years. We were able to contact 53 of these patients of whom 38 were girls, and 36 had bilateral VUR with a total of 89 ureteral units. Mean age at surgery was 86 months (26-136). Mean follow-up was 12.5 years (range: 10.5-15). No child presented postinjection obstruction. Thirteen patients presented with a recurrence of fUTI during the postoperative course of whom 8 presented persistent VUR. All recurrences of fUTI occurred within the first 5 years of follow-up. Four underwent a second injection and 4 underwent open reimplantation. Success rate per patient was 85%. CONCLUSION: Results of endoscopic injection using Dx/HA remain stable over time (>10 years). In our series, recurrences of fUTI occur within the first 5 years of follow-up.

Optimal postoperative immobilisation for supracondylar humeral fractures.

BACKGROUND: Supracondylar humeral fractures (SCHFs) are very common in paediatric patients. In France, percutaneous fixation with two lateral-entry pins is widely used after successful closed reduction. Postoperative immobilisation is typically with a long arm cast combined with a tubular-bandage sling that immobilises the shoulder and holds the arm in adduction and internal rotation to prevent external rotation of the shoulder, which might cause secondary displacement. The objective of this study was to compare this standard immobilisation technique to a posterior plaster splint with a simple sling. HYPOTHESIS: Secondary displacement is not more common with a posterior plaster splint and sling than with a long arm cast. MATERIAL AND METHODS: One hundred patients with extension Gartland type III SCHFs managed by closed reduction and percutaneous fixation with two lateral-entry pins between December 2011 and December 2015 were assessed retrospectively. Postoperative immobilisation was with a posterior plaster splint and a simple sling worn for 4 weeks. Radiographs were obtained on days 1, 45, and 90. RESULTS: Secondary displacement occurred in 8% of patients. No patient required revision surgery. DISCUSSION: The secondary displacement rate was comparable to earlier reports. Of the 8 secondary displacements, 5 were ascribable to technical errors. The remaining 3 were not caused by rotation of the arm and would probably not have been prevented by using the tubular-bandage sling. CONCLUSION: A posterior plaster splint combined with a simple sling is a simple and effective immobilisation method for SCHFs provided internal fixation is technically optimal. LEVEL OF EVIDENCE: IV retrospective observational study.

Bladder Dysfunction in Children with Neurofibromatosis Type I: Report of Four Cases and Review of the Literature.

AIM: Neurofibromatosis type 1 (NF1) is a rare autosomal dominant disorder. Malignant transformation into malignant peripheral nerve sheath tumors (MPNST) can occur. However, urinary tract involvement is rare. We report 4 cases of NF1 with bladder dysfunction. METHODS: A retrospective single center analysis of 4 patients was conducted over a 17-year period, focusing on urinary tract involvement. RESULTS: NF1 was diagnosed at a median of 16.5 months (4-36) and urinary involvement occurred at a median of 5.25 years (4-9) after diagnosis. Bladder dysfunction was due to spinal cord compression in 2 cases, bladder invasion in 1 case, and cerebral lesions in 1 case. Malignant transformation of neurofibromas into MPNST occurred in 2 patients. Mechanisms of urinary involvement in NF1 are diverse and no pre-established protocol of management and follow-up exists. CONCLUSION: Although rare, dysfunction of the bladder can arise in NF1 and innovative strategies then need to be considered. This is best achieved with the help of a multidisciplinary team and a national reference center when available.

Planning for Bone Excision in Ewing Sarcoma: Post-Chemotherapy MRI More Accurate Than Pre-Chemotherapy MRI Assessment.

BACKGROUND: In determining the level of bone resection in Ewing sarcoma, the most suitable time at which to perform magnetic resonance imaging (MRI) remains controversial. Current guidelines recommend that surgical planning be based on MRI performed prior to neoadjuvant chemotherapy. The goal of this study was to determine whether pre-chemotherapy or post-chemotherapy MRI provides greater accuracy of tumor limits for planning bone excision in the management of Ewing sarcoma. METHODS: This was a single-center, retrospective study. MRI was performed using 3 sequences: T1-weighted, T1-weighted with contrast enhancement by gadolinium injection, and a fluid-sensitive sequence (STIR [short tau inversion recovery] or proton-density-weighted with fat saturation). The tumor extent as assessed on pre-chemotherapy and post-chemotherapy MRI was compared with histological measurement of the resected specimen. RESULTS: Twenty patients with Ewing sarcoma of a long bone were included. In 6 cases, the tumor was located on the femur, in 5, the tibia; in 5, the fibula; and in 4, the humerus. The median patient age at diagnosis was 9.7 years. We found greater accuracy of measurements from MRI scans acquired after chemotherapy than from those acquired before chemotherapy. For both pre-chemotherapy and post-chemotherapy MRI, the greatest accuracy was achieved with the nonenhanced T1 sequence. There was no benefit to gadolinium enhancement. The median difference between T1 MRI and histological measurements was 19.0 mm (interquartile range [IQR], 4.3 to 32.8 mm) before chemotherapy and 5.0 mm (IQR, 2.0 to 13.0 mm) after chemotherapy. Adding a minimum margin of 20 mm to the limit of the tumor on post-chemotherapy T1 MRI always led to safe histological margin. CONCLUSIONS: Post-chemotherapy MRI provided a more accurate assessment of the limits of Ewing sarcoma. Surgical planning can therefore be based on post-chemotherapy MRI. Surgical cuts can be, at minimum, 20 mm from the limits as seen on MRI.

Conservative treatment of pediatric thoracic and lumbar spinal fractures: outcomes in the sagittal plane.

To assess sagittal plane spinopelvic balance and functional outcomes in a pediatric cohort of patients with a thoracic and/or a lumbar fracture treated conservatively. A multicentric study retrospectively reviewed radiological and functional outcomes (mean follow-up 49 months) of 48 patients (mean age 12 years) with thoracic and/or lumbar spinal fractures that occurred between 1996 and 2014. Demographic data and radiological spinopelvic parameters were analyzed. Functional outcome was evaluated by a telephone interview. First, a comparison between the initial and the last follow-up full-spine radiographs was performed for the assessment of bone remodeling and sagittal plane balance. Then, patients were classified into two groups (group 1: Risser≤2 and group 2, Risser>2) to assess the influence of skeletal maturity on the restoration of a correct sagittal balance. A total of 62% of the patients were at skeletal maturity at the final follow-up (Risser 4 and 5). Patients with a Risser grade of 2 or less had a higher remodeling potential. The mean residual local kyphosis in thoracic and lumbar fractures was, respectively, 8.2° and 8.7°. The mean thoracic global kyphosis remains stable at the last follow-up, in contrast to lumbar lordosis, which increased significantly. Sagittal plane global measurements on the basis of the C7-plumbline remained unchanged at the last follow-up. There was no change in the pelvic parameters, except for the sacral slope in the group 1 for patients with a lumbar fracture. The current study confirms a greater correction in younger patients (Risser≤2) in spinal fractures and reported that thoracic fractures have a higher remodeling potential than lumbar fracture. A local kyphosis of almost 10° remained at the last follow-up. However, no deterioration in the sagittal plane balance was found. This suggests compensatory mechanisms in adjacent structures for children and adolescents and excludes the only hypothesis of bone remodeling.

Neuropathic pain depends upon D-serine co-activation of spinal NMDA receptors in rats.

Activation of N-methyl-d-aspartate (NMDA) receptors is critical for hypersensitivity in chronic neuropathic pain. Since astroglia can regulate NMDA receptor activation by releasing the NMDA receptor co-agonist d-serine, we investigated the role of NMDA receptor and d-serine in neuropathic chronic pain. Male Wistar rats underwent right L5-L6 spinal nerve ligation or sham surgery and were tested for mechanical allodynia and hyperalgesia after 14 days. Acute intrathecal administration of the NMDA receptor antagonist d-AP5 as well as chronic administration of the glia metabolism inhibitor fluoroacetate significantly reduced mechanical allodynia in neuropathic rats. The effect of fluoroacetate was reversed by acutely administered intrathecal d-serine. Degrading d-serine using acute intrathecal administration of d-aminoacid oxidase also reduced pain symptoms. Immunocytochemistry showed that about 70% of serine racemase, the synthesizing enzyme of d-serine, was expressed in astrocyte processes in the superficial laminae of L5 dorsal horn. Serine racemase expression was upregulated in astrocyte processes in neuropathic rats compared to sham rats. These results show that neuropathic pain depends upon glial d-serine that co-activates spinal NMDA receptors.