Osseointegration of a hydroxyapatite-coated stem in femoral neck fractures in the over-80 s.

PURPOSE: In the over-80 s, femoral bone is often osteoporotic and unlikely to be conducive to periprosthetic bone rehabitation. This observation often leads to cemented fixation for hemiarthroplasty in femoral neck fracture. Hydroxyapatite is a bioactive coating that has already demonstrated its osteoinductive properties. Our hypothesis is that hydroxyapatite enables prosthetic osseointegration in patients over 80, as well as periprosthetic cortical thickening. The objective was to evaluate the osseointegration of a hydroxyapatite-coated femoral stem in femoral neck fractures in the over-80 s, and the evaluation of the periprosthetic bone regeneration permitted by hydroxyapatite. METHODS: This was a retrospective study. Osseointegration and periprosthetic bone regeneration were assessed on pre-operative, immediate post-operative and last follow-up radiographs with Engh score, O-SS score, cortical index, Canal Bone Ration (CBR) and Canal Fill Ratio (CFR). RESULTS: One hundred and forty-six patients were included. At last follow-up, 99.3% (n = 145) of stems were osseointegrated. The mean Engh score was 19.9 [SD 3.1]. The mean O-SS score was 19.1 [SD 2.4], corresponding to very good osseointegration. The mean CBR at last follow-up was 0.48 [SD 0.07], corresponding to a non-osteoporotic femur. There was a significant difference with pre-operative CBR (p < 0,001). The pre-operative cortical index and the index at the last follow-up were significantly different for all levels of measurement (p < 0,001). The CFR at last follow-up was also significantly different with the post-operative CFR (p < 0,001). CONCLUSION: This study shows the value of using a hydroxyapatite-coated stem on senile, osteoporotic bone to improve cortical thickness along the entire length of femoral bone.

Articulated bipolar vs. non-articulated conventional spacers: A comparative study of results from two-stage treatment of chronic septic arthritis in prosthetic or native hips.

INTRODUCTION: Infection is a serious complication of 0.2-0.7% of primary total hip arthroplasties (THA) and 1-22% of prosthetic revisions. The objective of our study was to compare two types of spacers (unipolar versus bipolar) for two-stage revisions of periprosthetic hip infections. The primary hypothesis was that bipolar spacers have fewer mechanical complications than unipolar spacers. The secondary hypothesis was that bipolar spacers decrease the rate of septic revisions and promote primary prosthesis reimplantation. MATERIAL AND METHOD: This retrospective, monocentric, multi-operator study was carried out between January 2012 and July 2018, including patients operated on for septic arthritis of the native or prosthetic hip (two-stage procedure). The patients were divided into two groups: group A, including the articulated spacers and group B, including the unipolar spacers. We studied the complications of the spacers and the course of the infection over a minimum of two years. Functional status was assessed by the Postel Merle d'Aubigné (PMA) score, the Harris Hip Score (HHS) and pre- and postoperative patient satisfaction scores. RESULTS: We collected data for 39 hips from 37 patients (mean age 63, 22 men and 14 women: 16 patients in group A, 21 in group B). We found no mechanical complications in group A versus 12 (52%) in group B. At 2 years, 93.8% of patients in group A no longer had any signs indicative of an active infection, compared with 71.4% in group B. In group A, the median PMA score increased from 5.5 (4-10.5) to 13.5 (12.5-15.5) and the HHS score from 27.5 (17-41.5) to 79 (64.5-89.5), postoperatively. In the final group B, the PMA score increased from 7 (6-9) to 14 (12-16) and the HHS score from 24 (11-41) to 72 (48-82) postoperatively. CONCLUSION: The use of articulated spacers in THA or septic THA two-stage revision significantly reduces the occurrence of mechanical complications in the short term, as well as the pain between the two procedures. LEVEL OF PROOF: IV.

[TAVI in 2018 : new indications and open questions]. / TAVI en 2018 : nouvelles indications et questions ouvertes.

The last years, various large randomized studies have demonstrated the benefit of TAVI (transcatheter aortic valve implantation) over medical therapy or over conventional surgical treatment in inoperable or very high risk patients with symptomatic severe aortic stenosis. More recently, new data has also shown that among patients at intermediate risk, TAVI is at least as beneficial as surgical valve replacement. In this article, we will focus on the new recommendations of the European society of cardiology but also on issues that remain open.

Ces dernières années, différentes grandes études randomisées ont démontré le bénéfice du TAVI (transcatheter aortic valve implantation) par rapport au traitement médicamenteux ou au traitement chirurgical conventionnel chez les patients avec sténose aortique sévère symptomatique inopérables ou à très haut risque. Plus récemment, de nouvelles données ont également démontré que parmi les patients à risque intermédiaire, le TAVI est au moins aussi bénéfique que le remplacement valvulaire chirurgical. Dans le présent article, nous allons nous intéresser aux nouvelles recommandations de la Société européenne de cardiologie mais également aux questions qui demeurent ouvertes.

Myogenin (Myf4) upregulation in trans-differentiating fibroblasts from a congenital myopathy with arrest of myogenesis and defects of myotube formation.

Congenital myopathies often have an unclear aetiology. Here, we studied a novel case of a severe congenital myopathy with a failure of myotube formation. Polymerase chain reaction-based analysis was performed to characterize the expression patterns of the Desmin, p21, p57, and muscle regulatory factors (MRFs) MyoD, Myf4, Myf5 and Myf6 in differentiating skeletal muscle cells (SkMCs), normal human fibroblasts and patient-derived fibroblasts during trans-differentiation. The temporal and spatial pattern of MRFs was further characterized by immunocyto- and immunohistochemical stainings. In differentiating SkMCs, each MRF showed a characteristic expression pattern. Normal trans-differentiating fibroblasts formed myotubes and expressed all of the MRFs, which were detected. Interestingly, the patient's fibroblasts also showed some fusion events during trans-differentiation with a comparable expression profile for the MRFs, particularly, with increased expression of Myf4 and p21. Immunohistochemical analysis of normal and patient-derived skeletal musculature revealed that Myf4, which is downregulated during normal fetal development, was still present in patient-derived skeletal head muscle, which was also positive for Desmin and sarcomeric actin. The abnormal upregulation of Myf4 and p21 in the patient who suffered from a severe congenital myopathy suggests that the regulation of Myf4 and p21 gene expression during myogenesis might be of interest for further studies.

Platelet activation and aggregation profile in prolonged external ventricular support.

BACKGROUND: Platelet function plays a major role in the understanding of thromboembolic events in prolonged mechanical support. We studied the platelet activation, platelet aggregation profile, and efficacy of aspirin in patients in whom an external ventricular assist device had been implanted. PATIENTS AND METHODS: Fifteen patients were studied prospectively up to 6 weeks after implantation of the same type of ventricular assist device. Platelet function was studied weekly before daily aspirin administration. Aspirin efficacy was tested ex vivo by measuring platelet aggregation triggered by arachidonic acid. Flow cytometry was used to quantify the spontaneous and induced (adenosine diphosphate stimulation) expression of glycoproteins alphaIIbbeta3, Ibalpha, and CD62P on platelet membranes. The plasma levels of von Willebrand factor (von Willebrand factor activity and von Willebrand factor antigen) and fibrinogen were also determined. RESULTS: Six of the 15 patients (26%) maintained an arachidonic acid-induced platelet aggregation despite daily aspirin treatment (250 mg). CD62P values remained increased during a 5-week postoperative period. Spontaneous levels of glycoproteins alphaIIbbeta3 and Ibalpha on platelet membranes remained within a normal range with a preserved reactivity. The plasma levels of fibrinogen and von Willebrand factor remained increased during the entire study period. CONCLUSION: In patients with an implanted external ventricular assist device, the platelet activation profile displays a persistent activation with a preserved reactivity associated with a persistent high inflammatory state and endothelial activation.