Residual hip dysplasia in children: osseous and cartilaginous acetabular angles to guide further treatment-a pilot study.

In case of residual hip dysplasia (RHD) in children, pelvic radiographs are sometimes insufficient to precisely evaluate the entire coverage of the femoral head, when trying to decide on the need for further reconstructive procedures. This study retrospectively compares the bony and the cartilaginous acetabular angle of Hilgenreiner (HTE) of 60 paediatric hips on pelvic MRI separated in two groups. Group 1 included 31 hips with RHD defined by a bony HTE > 20°. Group 2 included 27 hips with a HTE < 20°. They were compared by introducing a new ratio calculated from the square of cartilaginous HTE above the bony HTE on frontal MRI. The normal upper limit for this acetabular angle ratio was extrapolated from the published normal values of cartilaginous HTE and bony HTE in children. The acetabular angle ratio was statistically significantly increased in the hips with RHD with a mean value of 7.1 ± 4.7 compared to the hips in the control group presenting a mean value of 2.1 ± 1.9 (p < 0.00001). This newly introduced ratio seems to be a helpful tool to orientate the further treatment in children presenting borderline RHD

Paediatric musculoskeletal infections with Panton-Valentine leucocidin.

Paediatric musculoskeletal infections by Panton-Valentine leucocidin (PVL)-producing Staphylococcus aureus constitute a rare, but highly critical event. They are characterised by a rapid course of marked inflammation, worsening under conservative therapy and a high rate of recurrence. This study aimed to illustrate the importance of paediatric PVL-producing S. aureus musculoskeletal infections in western Switzerland. Case records, clinical parameters and biological assessments of children with musculoskeletal infections due to PVL-producing S. aureus who attended the University Hospitals of Lausanne and Geneva from 2008 to 2016 were studied retrospectively. Of the nine cases (seven male), four presented with haematogenous acute osteomyelitis, two with septic arthritis, and three with skin and soft tissue infections. Laboratory analysis revealed mean values for white blood cell count of 12,700/mm3, C-reactive protein (CRP) 171mg/l, erythrocyte sedimentation rate (ESR) 62 mm/h and platelet count 241,000/mm3. Notably, fever and laboratory values were higher for osteoarticular infections. PVL was produced by methicillin-sensitive S. aureus (MSSA) in eight cases and by community-acquired methicillin-resistant S. aureus (CA-MRSA) in one case. PVL was identified in blood cultures (six cases), operative samples (seven cases) and an oral swab (one case). Treatment relied on surgical procedures, endorsed by two-agent antimicrobial therapy for up to 9 weeks. Complications included recurrent infections (five cases), pathological fracture (one case) and growth arrest (two cases), as well as an important psychological impact (one case). The results of this study highlight the low prevalence of PVL-producing S. aureus musculoskeletal infections in the paediatric population in our region. Nevertheless, given the importance of complications, the recurrence rate and the duration of treatment, clinicians caring for children need to be especially well versed with the peculiarity of this entity. Retrospective case series. IV

Obturator externus abscess in a 9-year-old child: A case report and literature review.

Obturator pyomyositis is a rare condition in children. Diagnosis is often delayed because of its rarity, and the vagaries of its presentation cause it to be easily be missed. Physicians should therefore familiarize themselves with this condition and consider it as a possible differential diagnosis in patients presenting with an acutely painful hip. Inflammatory syndrome is also frequent among sufferers and the MRI is a very sensitive diagnostic tool for obturator pyomyositis. Additionally, joint fluid aspirations and blood cultures are also useful in identifying the pathogen. The appropriate antibiotic therapy provides a rapid regression of symptoms during the early stage of pyomyositis. In cases of MRI-confirmed abscess, surgical treatment is indicated. Our report focuses on a case of obturator pyomyositis in a 9-year-old boy. The child was febrile for 5 days and could only manage to walk a few steps. His hip range of motion was restricted in all directions. In addition, the patient had presented pain and swelling of his right elbow for a day, with a restriction of motion in the joint. There was a clear inflammatory syndrome. A diagnosis of hip and elbow septic arthritis was suspected, and the child underwent joint aspiration of the both cited joints. The aspiration of the elbow returned pus. Conversely, no effusion was found in the hip aspiration. The administration of empiric intravenous antibiotherapy was started. An MRI revealed an osteomyelitis of the ischio-pubic area associated with a subperiosteal abscess. Subsequently, 3 days after elbow arthrotomy, a surgical treatment was performed on the patient's right hip in order to evacuate the subperiosteal abscess and muscular collection because of the persistence of the patient's symptoms and inflammatory syndrome despite susceptible intravenous antibiotics. Postsurgery the patient showed steady improvement. Such cases demonstrate how diagnosis can be difficult because pelvic pyomyositis is often mistaken for more common pathologies such as septic arthritis, osteomyelitis, or appendicitis. This may delay the diagnosis or refer misdiagnosis. We discuss this rare infection in light of the literature with particular reference to its incidence, clinical features, bacteriological etiology, biological, and radiological presentation, and above all, its treatment

Computer-assisted placement technique in hip resurfacing arthroplasty: improvement in accuracy?

Freehand positioning of the femoral drill guide is difficult during hip resurfacing and the surgeon is often unsure of the implant position achieved peroperatively. The purpose of this study was to find out whether, by using a navigation system, acetabular and femoral component positioning could be made easier and more precise. Eighteen patients operated on by the same surgeon were matched by sex, age, BMI, diagnosis and ASA score (nine patients with computer assistance, nine with the regular ancillary). Pre-operative planning was done on standard AP and axial radiographs with CT scan views for the computer-assisted operations. The final position of implants was evaluated by the same radiographs for all patients. The follow-up was at least 1 year. No difference between both groups in terms of femoral component position was observed (p > 0.05). There was also no difference in femoral notching. A trend for a better cup position was observed for the navigated hips, especially for cup anteversion. There was no additional operating time for the navigated hips. Hip navigation for resurfacing surgery may allow improved visualisation and hip implant positioning, but its advantage probably will be more obvious with mini-incisions than with regular incision surgery

Osteogenesis imperfecta: from diagnosis and multidisciplinary treatment to future perspectives.

Osteogenesis imperfecta is an inherited connective tissue disorder with wide phenotypic and molecular heterogeneity. A common issue associated with the molecular abnormality is a disturbance in bone matrix synthesis and homeostasis inducing bone fragility. In very early life, this can lead to multiple fractures and progressive bone deformities, including long bone bowing and scoliosis. Multidisciplinary management improves quality of life for patients with osteogenesis imperfecta. It consists of physical therapy, medical treatment and orthopaedic surgery as necessary. Medical treatment consists of bone-remodelling drug therapy. Bisphosphonates are widely used in the treatment of moderate to severe osteogenesis imperfecta, from infancy to adulthood. Other more recent drug therapies include teriparatide and denosumab. All these therapies target the symptoms and have effects on the mechanical properties of bone due to modification of bone remodelling, therefore influencing skeletal outcome and orthopaedic surgery. Innovative therapies, such as progenitor and mesenchymal stem cell transplantation, targeting the specific altered pathway rather than the symptoms, are in the process of development

Molecular diagnosis and enrichment culture identified a septic pseudoarthrosis due to an infection with Erysipelatoclostridium ramosum.

We describe here a rare case of septic pseudarthrosis due to Erysipelatoclostridium ramosum in a female young patient. The patient, currently in remission from Ewing's sarcoma treated by a bone resection and allograft combined with chemotherapy, suffered from a chronic femoral pseudarthrosis in a context of bone insufficiency and graft resorption. A broad range 16S PCR followed by sequencing, as well as an enrichment culture of a bone biopsy revealed the presence of E. ramosum, an anaerobic firmicute with a low Gram-positive affinity staining and low GC content, that was further characterized by whole genome sequencing (WGS)

Bone tissue engineering using foetal cell therapy.

Different cell sources for bone tissue engineering are reviewed. In particular, adult cell source strategies have been based on the implantation of unfractionated fresh bone marrow; purified, culture expanded mesenchymal stem cells, differentiated osteoblasts, or cells that have been modified genetically to express rhBMP. Several limiting factors are mentioned for these strategies such as low number of available cells or possible immunological reaction of the host. Foetal bone cells are presented as an alternative solution and review of actual treatments using these cells is presented. Finally, foetal cells used specifically for bone tissue engineering are characterised and potentially interesting therapeutic options are proposed

Pédiatrie. Maladie de Perthes : connaissances actuelles et prise en charge [Pediatrics - Perthes disease : current knowledges and treatment]

Perthes's disease corresponds to an interruption of the vascularization of the epiphyseal nucleus of the femoral head followed by avascular necrosis. This necrosis weakens the bone and subchondral fractures associated with a deformation of the femoral head is seen. It is important not to miss an extrusion of the femoral head, which makes surgical treatment unavoidable. The loss of joint congruence causes functional limitations and represents an increased risk for early hip osteoarthritis. Non weight bearing limits the subchondral fractures, but requires an important adaptation from the patient and his entourage