Influence of the thoracolumbar junction flexibility on the risk of adding-on after posterior vertebral arthrodesis for thoracic idiopathic adolescent scoliosis.

PURPOSE: The objective was to analyze the role of the thoracolumbar sagittal flexibility on the outcome after posterior spinal fusion of Lenke 1 and 2 adolescent idiopathic scoliosis with last touched vertebra as the lowest instrumented vertebra. METHODS: We included 105 thoracic AIS patients who had a posterior spinal fusion with a 2 years minimum follow-up. Thoracolumbar junction flexibility was assessed on dynamic sagittal X-rays and compared to the standing position. Adding-on was defined according to radiographic Wang criteria. The junction was considered flexible if the variability from the static position to flexion and/or extension was greater than 10°. RESULTS: Mean age of the patients was 14 ± 2 years. The preoperative mean Cobb angle was 61 ± 12.7° and 27.5 ± 7.7° after surgery. Mean follow-up was 3.1 years. Twenty-nine patients (28%) developed an adding-on. Thoracolumbar junction range of motion was higher (p = 0.017) with higher flexibility in flexion (p < 0.001) in the no adding-on group. In no adding-on group, 53 patients (70%) had a flexible thoracolumbar junction, and 23 patients (30%) had a stiff thoracolumbar junction in flexion and flexible in extension. In adding-on group, 27 patients (93%) had a stiff thoracolumbar junction, and 2 patients (7%) had a flexible junction in flexion and stiff in extension. CONCLUSION: The flexibility of the thoracolumbar junction is a determining factor in the surgical outcome after posterior spinal fusion for AIS and should be considered in correlation with the frontal and sagittal alignment of the spine.

Residual acetabular dysplasia in congenital hip dysplasia.

Residual hip dysplasia may exist despite appropriate treatment of congenital hip dysplasia (CHD). The abnormalities chiefly affect the acetabulum and can lead to premature osteoarthritis. Although the main cause is delayed treatment of CHD, primary lesions are also possible and may be worsened by the initial treatment itself. Residual hip dysplasia must be detected during the follow-up of patients with CHD. The antero-posterior radiograph of the pelvis is the main diagnostic tool. However, the importance of non-ossified anatomical structures requires additional investigations such as arthrography and magnetic resonance imaging. The risk of premature osteoarthritis is difficult to predict based only on the imaging-study findings. Hip dysplasia is best treated before 5 years of age. The work-up at this age should allow determination of the best treatment. Surgery is required but should not be performed unnecessarily. The decision rests on the absence of improvement in the radiographic criteria and on the findings from additional imaging studies. The usual treatment is Salter's osteotomy, during which excessive anterior displacement should be avoided. At adolescence, the information provided by radiography in the coronal plane should be completed by a three-dimensional evaluation of the acetabulum and an assessment of the quality of the labrum. The shelf procedure has been proven to relieve pain and to significantly postpone the need for hip arthroplasty, when performed early, before the development of visible osteoarthritis, and on a congruent hip. Chiari's osteotomy has a role to play in complex dysplasia affecting both the acetabulum and the femur. Periacetabular osteotomy is getting more used thanks to cooperation between paediatric and adult orthopaedic surgeons. This osteotomy provides optimal correction in all three dimensions.

Madelung's deformity in children: Clinical and radiological results from a French national multicentre retrospective study.

INTRODUCTION: Madelung's deformity is rare. Treatment often consists in radial or ulnar osteotomy, Vickers' ligament resection or ulnar epiphysiodesis. The present multicenter retrospective study reports clinical and radiographic results in various surgeries. The study hypothesis was that early surgery improves outcome. MATERIAL AND METHOD: Files were analyzed for 36 children (47 wrists) operated on between 1998 and 2015. Mean age at diagnosis was 12 years (range, 6-15 years). Mean follow-up was 7.2 years (range, 2-17.4 years). Two age groups were distinguished: 6-11 and 12-17 years. Endpoints were esthetic, functional (Mayo Wrist Score: MWS) and radiographic [lunate fossa angle (LFA), radial height (RH), lunatum cover rate (LCR), ulnar head translation (UHT), lunatum ascension (LA)]. Techniques mainly comprised distal radius osteotomy (DRO) with ulnar shortening osteotomy (USO), and Vickers' ligament resection (VR), either isolated or associated to osteotomy. RESULTS: Age at surgery guided choice of technique, but did not impact results. VR gave better functional results when performed in young children; it was mainly performed in the 6-11 years age group, providing very satisfactory results (7 out of 8 wrists) with excellent function (7 out of 8), without improving radiographic parameters; in the 12-17 years age group, even when esthetic results were excellent, functional results were only good-to-acceptable (3 out of 5 wrists) and 1 result was poor. DRO+USO was mainly performed in the 12-17 years age group, with very satisfactory or satisfactory results (8 out of 10 wrists) and excellent function (6 out of 10). DRO+USO appeared to be an option of choice, significantly improving radiographic parameters and correcting the deformity (24.5° improvement in LFA (p=0.0033) and 36.2% improvement in LCR (p=0.0103)). DRO+USO+VR was mainly implemented in the 12-17 years age group, with very satisfactory results (3 out of 4 wrists) and excellent-to-good MWS in most cases (3 out of 4), but without significant radiographic improvement. DISCUSSION: Esthetic and functional results were comparable regardless of age, except for VR, which gave better functional results in the 6-11 years age group, but without significant difference. CONCLUSION: The present study showed that, regardless of children's age, surgery provided esthetic, functional and radiographic benefit, although no decision-tree could be drawn up. LEVEL OF EVIDENCE: IV.

Thrombotic risk in children undergoing orthopedic surgery.

Children are physiologically protected against venous thromboembolism (VTE). Specific triggering events or contributing factors have been identified in the majority of reported cases, which differs from the adult pathology where 50% of the thromboses are considered "idiopathic". This is a rare disease in children with an estimated frequency of less than 1/1000. The risk is highest in neonates, then decreases and increases again around 13 years to reach the same level as adults at 16 years. The risk of VTE is clearly higher in certain situations: significant trauma, prolonged immobilization, central venous catheter, stay in intensive care unit, inherited thrombophilia, cancer, obesity, oral contraceptives, etc. Thromboprophylaxis should not be used systematically, even in adolescents. Proper hydration and early mobilization form the basis of mechanical thromboprophylaxis. A prescription is only given after careful analysis of the child's risk factors and the orthopedic context. Thrombotic risk assessment scores - which are based on expert opinion and large VTE registers but have not been evaluated in clinical studies - are currently the most reliable method to evaluate the thrombotic risk in children and to prescribe thromboprophylaxis. Low-molecular weight heparin are the most commonly used thromboprophylaxis agents in children, with good tolerance and efficacy.

Fryns type mesomelic dysplasia of the upper limbs caused by inverted duplications of the HOXD gene cluster.

The HoxD cluster is critical for vertebrate limb development. Enhancers located in both the telomeric and centromeric gene deserts flanking the cluster regulate the transcription of HoxD genes. In rare patients, duplications, balanced translocations or inversions misregulating HOXD genes are responsible for mesomelic dysplasia of the upper and lower limbs. By aCGH, whole-genome mate-pair sequencing, long-range PCR and fiber fluorescent in situ hybridization, we studied patients from two families displaying mesomelic dysplasia limited to the upper limbs. We identified microduplications including the HOXD cluster and showed that microduplications were in an inverted orientation and inserted between the HOXD cluster and the telomeric enhancers. Our results highlight the existence of an autosomal dominant condition consisting of isolated ulnar dysplasia caused by microduplications inserted between the HOXD cluster and the telomeric enhancers. The duplications likely disconnect the HOXD9 to HOXD11 genes from their regulatory sequences. This presumptive loss-of-function may have contributed to the phenotype. In both cases, however, these rearrangements brought HOXD13 closer to telomeric enhancers, suggesting that the alterations derive from the dominant-negative effect of this digit-specific protein when ectopically expressed during the early development of forearms, through the disruption of topologically associating domain structure at the HOXD locus.

RPL13 Variants Cause Spondyloepimetaphyseal Dysplasia with Severe Short Stature.

Variants in genes encoding ribosomal proteins have thus far been associated with Diamond-Blackfan anemia, a rare inherited bone marrow failure, and isolated congenital asplenia. Here, we report one de novo missense variant and three de novo splice variants in RPL13, which encodes ribosomal protein RPL13 (also called eL13), in four unrelated individuals with a rare bone dysplasia causing severe short stature. The three splice variants (c.477+1G>T, c.477+1G>A, and c.477+2 T>C) result in partial intron retention, which leads to an 18-amino acid insertion. In contrast to observations from Diamond-Blackfan anemia, we detected no evidence of significant pre-rRNA processing disturbance in cells derived from two affected individuals. Consistently, we showed that the insertion-containing protein is stably expressed and incorporated into 60S subunits similar to the wild-type protein. Erythroid proliferation in culture and ribosome profile on sucrose gradient are modified, suggesting a change in translation dynamics. We also provide evidence that RPL13 is present at high levels in chondrocytes and osteoblasts in mouse growth plates. Taken together, we show that the identified RPL13 variants cause a human ribosomopathy defined by a rare skeletal dysplasia, and we highlight the role of this ribosomal protein in bone development.

A new form of severe spondyloepimetaphyseal dysplasia: clinical and radiological characterization.

We report on two patients with a severe form of spondyloepimetaphyseal dysplasia (SEMD). Both patients show normal birth length, early postnatal growth deficiency, severe short stature, flexion contractures in the hips, bowing of the legs with genu varum. Skeletal radiographies show platyspondyly and characteristic vertebral body shape with central indentation of endplates, progressive, and severe metaphyseal changes, very small and irregular proximal femoral epiphyses with severe coxa vara, absence of calcifications, and mild metaphyseal irregularities in upper limbs. The similarities in the skeletal radiographs with SEMD type Strudwick and SEMD matrilin 3 type prompted us to analyze the COL2A1 and MATN3 genes. Direct sequencing of genomic DNA failed to identify any mutation in COL2A1 for both patients and MATN3 sequencing for Patient 1 identified only one heterozygous variant with no predicted damaging effect inherited from an unaffected parent. We therefore conclude that this form of SEMD probably differs from SEMD matrilin 3 type and does not belong to the spectrum of type II collagenopathies. The similarities between our two patients allowed us to propose that they might show a new form of SEMD.

Treatment of early-onset Gorham syndrome with 8-year follow-up.

A case of Gorham disease with several years of follow-up is reported. At birth he had a mass in the thigh which was had pathology demonstrating a lymphangioma. By age 3 years, he had lymphedema of the ipsilateral foot and discrepant leg lengths. Radiography revealed heterogenous dystrophy of the bones and osteolysis of the hallux. At age 6, a spontaneous fracture of the right tibia was treated with surgery. Histopathology of a bone sample demonstrated bone remodelling, fibrous tissue, and large vascular lacunas within bone tissue, bordered by cells expressing the lymphaticmarker D2-40. At 8 years old, lymphedema of the right inferior leg had increased, leg lengths still differed, but other clinical signs were absent.

Retrospective French nationwide survey of childhood aggressive vascular anomalies of bone, 1988-2009.

OBJECTIVE: To document the epidemiological, clinical, histological and radiological characteristics of aggressive vascular abnormalities of bone in children. STUDY DESIGN: Correspondents of the French Society of Childhood Malignancies were asked to notify all cases of aggressive vascular abnormalities of bone diagnosed between January 1988 and September 2009. RESULTS: 21 cases were identified; 62% of the patients were boys. No familial cases were observed, and the disease appeared to be sporadic. Mean age at diagnosis was 8.0 years [0.8-16.9 years]. Median follow-up was 3 years [0.3-17 years]. The main presenting signs were bone fracture (n = 4) and respiratory distress (n = 7), but more indolent onset was observed in 8 cases. Lung involvement, with lymphangiectasies and pleural effusion, was the most frequent form of extraosseous involvement (10/21). Bisphosphonates, alpha interferon and radiotherapy were used as potentially curative treatments. High-dose radiotherapy appeared to be effective on pleural effusion but caused major late sequelae, whereas antiangiogenic drugs like alpha interferon and zoledrenate have had a limited impact on the course of pulmonary complications. The impact of bisphosphonates and alpha interferon on bone lesions was also difficult to assess, owing to insufficient follow-up in most cases, but it was occasionally positive. Six deaths were observed and the overall 10-year mortality rate was about 30%. The prognosis depended mainly on pulmonary and spinal complications. CONCLUSION: Aggressive vascular abnormalities of bone are extremely rare in childhood but are lifethreatening. The impact of anti-angiogenic drugs on pulmonary complications seems to be limited, but they may improve bone lesions.