Wear debris released by hip prosthesis analysed by microcomputed tomography.

Total hip arthroplasty uses commercial devices that combine different types of biomaterials. Among them, metals, ceramics and metal oxides can be used either in the prosthesis itself or in the cement used to anchor them in the bone. Over time, all of these materials can wear out and release particles that accumulate in the periprosthetic tissues or can migrate away. We used histology blocks from 15 patients (5 titanium metallosis, 5 alumina prostheses, 5 with altered methacrylic cement) to perform a microCT study and compare it with conventional histology data. An EDS-SEM analysis was done to characterise the atomic nature of the materials involved. A morphometric analysis was also performed in 3D to count the particles and assess their density and size. The metallic particles appeared to be the largest and the ceramic particles the finest. However, microCT could not reveal the wear particles of radiolucent biomaterials such as polyethylene and the very fine zirconia particles from cement fragmentation. MicroCT analysis can reveal the extent of the accumulation of these debris in the periprosthetic tissues. LAYOUT DESCRIPTION: Hip prostheses progressively degrade in the body by releasing wear debris. They accumulate in the periprosthetic tissues. Microcomputed tomography was used to image three types of radio-opaque wear debris: metal, ceramic and zirconia used in the bone cements.

Training emotion regulation through real-time fMRI neurofeedback of amygdala activity.

Being in control of one's emotions is not only desirable in many everyday situations but is also a great challenge in a variety of mental disorders. Successful intentional emotion regulation is related to down-regulation of amygdala activity. Training mental interventions supported by neurofeedback of one's own amygdala activity using real-time (rt-)fMRI might be beneficial for mental health and well-being. Rt-fMRI guided amygdala-downregulation using cognitive interventions such as a "reality check", however, have not been well-investigated. Fifteen healthy subjects underwent four rt-fMRI sessions with neurofeedback of their own amygdala activity while applying a reality check as an emotion regulation strategy in order to down-regulate their amygdala signal during a stimulation with emotional pictures. The Control group comprised of eleven subjects also trained emotion regulation but without obtaining feedback. We hypothesized more prominent down-regulation of amygdala activity at the end of the training in the Feedback group. We investigated effects over time and between groups and further task specific connectivity of the amygdala by using psychophysiological interaction analyses. Four weekly amygdala-based feedback sessions resulted in significantly decreased amygdala activity (p = 0.003, d = 0.93), also compared to the Control group (p = 0.014, d = 1.12). Task specific connectivity of the amygdala with the anterior cingulate cortex, hippocampus and distinct prefrontal areas was increased in the Feedback group. Training of emotion regulation supported by rt-fMRI neurofeedback resulted in a prominent amygdala down-regulation compared to training without feedback. The finding implicates successful emotion regulation, compliant with emotion control models, through an easily applicable reality check strategy. Rt-fMRI neurofeedback may support emotion regulation learning and bears clinical potential for psychotherapy.

Clinical and radiological outcomes of a cohort of 9 patients with anatomical fractures of the cuboid treated by locking plate fixation.

INTRODUCTION: Cuboid fractures are very rare. Hence, their treatment has not been standardized. Advances in imaging techniques, particularly three-dimensional computed tomography (3D CT), and the introduction of cuboid-specific plates has improved the care of these injuries. The aim of this study was to determine the radiological and clinical outcomes of anatomical reconstruction of comminuted cuboid fractures with a locking plate. HYPOTHESIS: Fixation of comminuted cuboid fractures with a cuboid-specific locking plate leads to stable anatomical reduction and good functional outcomes. MATERIAL AND METHODS: This was a retrospective study of 9 consecutive cases of comminuted cuboid fracture treated at a single hospital between January 2009 and December 2015. A 3D CT scan was performed preoperatively with subtraction of the posterior tarsal bone to allow the articular facets to be viewed and analyzed. Fracture fixation was done with a Locking Cuboid Plate (DePuy Synthes™). Associated lesions in the foot were treated during the same procedure. The patients were reviewed by an independent observer who performed a clinical examination, and determined the AOFAS and Maryland Foot Score. The success of the reconstruction was determined by comparing the parameters on weight-bearing X-rays views between the fixed and non-operated cuboid. RESULTS: The mean follow-up was 4.1 years (range 1-6). The Maryland Foot Score was 93.1 [86-100] and the AOFAS was 91.9 [82-100]. The reconstruction was anatomical and long lasting in all 9 cases. There was no foot misalignment in the frontal plane, based on the radiographs (hindfoot axis 5.5° [0-9]). The mean Djian-Annonier angle was 123.9° [108-130]. CONCLUSION: Cuboid fractures can be treated effectively through appropriate imaging and with a cuboid-specific locking plate as evidenced by very good midterm clinical and radiological outcomes in this study. LEVEL OF EVIDENCE: IV Retrospective study.

Reconstruction of large diaphyseal bone defect by simplified bone transport over nail technique: A 7-case series.

Reconstruction of large diaphyseal bone defect is complex and the complications rate is high. This study aimed to assess a simplified technique of segmental bone transport by monorail external fixator over an intramedullary nail.A prospective study included 7 patients: 2 femoral and 5 tibial defects. Mean age was 31years (range: 16-61years). Mean follow-up was 62 months (range: 46-84months). Defects were post-traumatic, with a mean length of 7.2cm (range: 4 to 9.5cm). For 3 patients, reconstruction followed primary failure. In 4 cases, a covering flap was necessary. Transport used an external fixator guided by an intramedullary nail, at a rate of 1mm per day. One pin was implanted on either side of the distraction zone. The external fixator was removed 1 month after bone contact at the docking site. Mean bone transport time was 11 weeks (range: 7-15 weeks). Mean external fixation time was 5.1months (range: 3.5 to 8months). Full weight-bearing was allowed 5.7months (range: 3.5-13months) after initiation of transport. In one patient, a pin had to be repositioned. In 3 patients, the transported segment re-ascended after external fixatorablation, requiring repeat external fixation and resumption of transport. There was just 1 case of superficial pin infection. Reconstruction quality was considered "excellent" on the Paley-Marr criteria in 6 cases. The present technique provided excellent reconstruction quality in 6 of the 7 cases. External fixation time was shorter and resumption of weight-bearing earlier than with other reconstruction techniques, notably including bone autograft, vascularized bone graft or the induced membrane technique. Nailing facilitated control of limb axis and length. The complications rate was 50%, comparable to other techniques. This study raises the question of systematic internal fixation of the docking site, to avoid any mobilization of the transported segment. The bone quality, axial control and rapidity shown by the present technique make it well-adapted to reconstruction of diaphyseal bone defect. LEVEL OF EVIDENCE: Four-case series.

Pattern of structural brain changes in social anxiety disorder after cognitive behavioral group therapy: a longitudinal multimodal MRI study.

Social anxiety disorder (SAD) is characterized by fears of social and performance situations. Cognitive behavioral group therapy (CBGT) has in general positive effects on symptoms, distress and avoidance in SAD. Prior studies found increased cortical volumes and decreased fractional anisotropy (FA) in SAD compared with healthy controls (HCs). Thirty-three participants diagnosed with SAD attended in a 10-week CBGT and were scanned before and after therapy. We applied three neuroimaging methods-surface-based morphometry, diffusion tensor imaging and network-based statistics-each with specific longitudinal processing protocols, to investigate CBGT-induced structural brain alterations of the gray and white matter (WM). Surface-based morphometry revealed a significant cortical volume reduction (pre- to post-treatment) in the left inferior parietal cortex, as well as a positive partial correlation between treatment success (indexed by reductions in Liebowitz Social Anxiety Scale) and reductions in cortical volume in bilateral dorsomedial prefrontal cortex. Diffusion tensor imaging analysis revealed a significant increase in FA in bilateral uncinate fasciculus and right inferior longitudinal fasciculus. Network-based statistics revealed a significant increase of structural connectivity in a frontolimbic network. No partial correlations with treatment success have been found in WM analyses. For, we believe, the first time, we present a distinctive pattern of longitudinal structural brain changes after CBGT measured with three established magnetic resonance imaging analyzing techniques. Our findings are in line with previous cross-sectional, unimodal SAD studies and extent them by highlighting anatomical brain alterations that point toward the level of HCs in parallel with a reduction in SAD symptomatology.

An original internal fixation technique by tension band wiring with steel wire in fractures of the coronoid process.

Fractures of the coronoid process, which is a key element in anterior elbow joint stability, represent 14% of proximal ulnar fractures. Optimal treatment should stabilize all fractures associated with elbow instability. Different techniques have been described: suture repair, screws, plates… We propose a series of 5 patients who were treated with an original, easy, tension band wiring fixation technique using steel wire with easy hardware removal.

Is radiographic measurement of distal femoral torsion reliable?

BACKGROUND: Distal femur torsion (DFT) is a crucial parameter in knee replacement surgery. The reference standard for measuring DFT is posterior condylar angle (PCA) measurement using computed tomography (CT). The objective of this study was to assess the feasibility and reliability of a radiographic PCA measurement method. MATERIALS AND METHODS: We studied 125 osteoarthritic knees in 79 patients (42 women and 37 men) with a mean age of 71.6 ± 8.8 years (range 47 to 86 years); 32 knees were aligned, 85 in varus, and eight in valgus. DFT was measured on an antero-posterior (AP) radiograph of the knee in 90° of flexion (known as the seated AP view). The PCA was defined as the angle subtended by the tangent to the posterior condyles and the transepicondylar axis (anatomic PCA [aPCA]) or the line connecting the lateral epicondyle to the medial sulcus (surgical PCA [sPCA]). The PCA was conventionally recorded as positive in the event of external torsion and negative in the event of internal torsion. PCA measurements were performed three times by each of five observers to allow assessments of inter-observer and test-retest reliabilities. RESULTS: aPCA was consistently negative (mean, -6.1 ± 1.6°) (range, 0 to -10°); inter-observer and test-retest reliability were satisfactory (0.54

Internal fixation of complex fractures of the tarsal navicular with locking plates. A report of 10 cases.

INTRODUCTION: Tarsal navicular fractures are rare and treatment of comminuted fractures is especially difficult. Since 2007, the authors have had access to 3D reconstruction from CT scan images and specific locking plates, and they decided to evaluate whether these elements improved management of these severe cases. MATERIALS AND METHODS: Between 2007 and 2011, 10 comminuted tarsal navicular fractures were treated in a prospective study. All of the fractures were evaluated by 3D reconstruction from CT scan images, with suppression of the posterior tarsal bones. The surgical approach was chosen according to the type of lesion. Reduction was achieved with a mini-distractor when necessary, and stabilized by AO locking plate fixation (Synthes™). Patient follow-up included a clinical and radiological evaluation (Maryland Foot score, AOFAS score). Eight patients underwent postoperative CT scan. RESULTS: All patients were followed up after a mean 20.5 months. Union was obtained in all patients and arthrodesis was not necessary in any of them. The mean Maryland Foot score was 92.8/100, and the AOFAS score 90.6/100. One patient with an associated comminuted calcaneal fracture had minimal sequella from a compartment syndrome of the foot. DISCUSSION: The authors did not find any series in the literature that reported evaluating tarsal navicular fractures by 3D reconstruction from CT scan images. The images obtained after suppression of the posterior tarsal bones systematically showed a lateral plantar fragment attached to the plantar calcaneonavicular ligament, which is essential for stability, and which helped determine the reduction technique. Locking plate fixation of these fractures has never been reported. CONCLUSION: Comminuted fractures of the tarsal navicular were successfully treated with specific imaging techniques in particular 3D reconstructions of CT scan images to choose the surgical approach and the reduction technique. Locking plate fixation of the navicular seems to be a satisfactory solution for the treatment of these particularly difficult fractures. LEVEL OF EVIDENCE: Level IV.

Tuberoplasty: minimally invasive osteosynthesis technique for tibial plateau fractures.

Fractures of the tibial plateau are in constant progression. They affect an elderly population suffering from a number of comorbidities, but also a young population increasingly practicing high-risk sports and using two-wheeled vehicles. The objective of this study was therefore to propose a new technique for the treatment of this type of fracture. There are a variety of classical pitfalls of conservative treatment such as defective reduction resulting in early osteoarthritis and alignment defects. Conventional treatments lead to joint stiffness and amyotrophy of the quadriceps, caused by the open technique and late loading. We propose an osteosynthesis technique for tibial plateau fractures with minimally invasive surgery. A minimally invasive technique would be more appropriate to remedy all of the surgical drawbacks resulting from current practices. The surgical technique that we propose uses a balloon allowing progressive and total reduction, associated with percutaneous screw fixation and filling with polymethylmethacrylate (PMMA) cement. The advantages are optimal reduction, minimal devascularization, soft tissues kept intact, as well as early loading and mobilization. This simple technique seems to be a good alternative to conventional treatment. The most comminuted fractures as well as the most posterior compressions can be treated, while causing the least impairment possible. Arthroscopy can be used to verify fracture reduction and cement leakage. At the same time, it can be used to assess the associated meniscal lesions and to repair them if necessary.

Total talar fracture - long-term results of internal fixation of talar fractures. A multicentric study of 114 cases.

INTRODUCTION: Displaced talar neck and body fractures are rare and challenging for the surgeon. Results are often disappointing due to inadequate reduction or internal fixation and high rates of osteoarthritis and osteonecrosis. Very few published series describe the long-term results after internal fixation of talar factures. One of the goals of the 2011 SOO meeting symposium was to specifically evaluate the long-term results after internal fixation of talar fractures. This study included only central fractures. MATERIAL AND METHODS: We reviewed the results of 114 central talar fractures that had been treated by internal fixation between 1982 and 2006 in nine hospitals in the Western part of France. The clinical and radiological follow-up was 111 months on average. All the patients with a radiological assessment had at least 5 years of follow-up. RESULTS: Poor reduction was apparent in 33% of cases. The average Kitaoka score was 70/100, which corresponds to an average functional level. At the last follow-up evaluation, 34% of cases had osteonecrosis and 74% had peritalar osteoarthritis. Secondary fusion was required in 25% of cases with an average follow-up of 24 months. DISCUSSION: The complication rate for talar fractures was high, mostly due to osteonecrosis and osteoarthritis; these conditions had an impact on the final outcome. The outcome could be improved by better evaluating these fractures with a CT scan, developing dual surgical approaches to best preserve the bone vascular supply and achieve better reduction, and improving the internal fixation hardware, especially the use of plates for comminuted fractures.

Total talar fracture - inter- and intra-observer reproducibility of two classification systems (Hawkins and AO) for central talar fractures.

INTRODUCTION: We evaluated the inter- and intra-observer reproducibility of two classification systems for central talar fractures (Hawkins, as modified by Canal and Kelly and then by us; AO/AOT). HYPOTHESIS: The analysis and classification of these fractures will be better with CT scans than with X-rays. MATERIAL AND METHODS: Four observers evaluated 39 X-ray and CT scan files twice in the span of six weeks; each evaluation entailed classifying the fractures and describing their main features. Cohen's Kappa coefficient for inter-rater agreement was calculated and analysed. RESULTS: The inter- and intra-observer reproducibility with CT scans was better with X-rays for most of the parameters evaluated. The modified Hawkins classification provided better reproducibility than the AO/AOT one. However, this classification system was not perfect, even after modifications and use of CT scans. DISCUSSION: CT scans are an essential tool for the analysis of all talar fractures. We modified the Hawkins classification (as modified by Canal and Kelly) to include a Type 0 (no displacement or less than 2mm), include frontal body fractures that are displaced like neck fractures and take into account comminuted fractures and other trauma in the area. LEVEL OF PROOF: IV - retrospective clinical study.

Treatment of complex fractures of the distal radius: a prospective randomised comparison of external fixation 'versus' locked volar plating.

The traditional treatment of severely impacted fractures of the distal radius involves bridging external fixation and maintaining reduction by applying continuous traction. The recent technique using fixed-angle screws within volar plates is reported restore the radial length and the articular profile whilst avoiding joint distraction. It is also believed to produce better and quicker clinical results. To test these claims, we carried out a randomised controlled comparison of the efficiency of external fixation (EF) 'versus' open reduction and internal fixation (ORIF) in treating severely impacted fractures of the distal radius. A total of 39 patients were treated with EF, eventually associated with percutaneous pinning, whereas 36 underwent ORIF with a locked volar plate. There was no significant difference in the two groups with regard to changes in the ulnar variance. Articular reduction was poor in two patients in the EF group with residual step-offs exceeding 2mm; another patient of the EF group suffered a secondary loss of reduction, healing with a severe articular malunion (>2mm). By contrast, articular reduction was satisfactory in all the patients of the ORIF group. The clinical results on the Green and O'Brien rating were significantly better in the ORIF group than in the EF group (p<0.01 at 6 weeks, p<0.05 at 6 months). Nevertheless, open reduction and volar plating did not yield better subjective results than EF. However, although not statistically significant, patients treated by ORIF seemed to resume their usual activities quicker than those treated with EF, suggesting that this technique may be adapted to a greater extent in the case of active, young individuals.

Characterization of glutamic acid uptake by bovine pulmonary arterial endothelial cells.

L-Glutamic acid uptake by bovine pulmonary arterial endothelial cells in culture increased linearly with time up to 30 min and did not show saturation with increased substrate concentration up to 6 X 10(-3) M. The uptake per cell decreased as cell density increased and was lowest when the cells became fully confluent. Most of the uptake was sodium dependent, although the relative contribution of sodium-independent uptake increased with an increase in cell density. Cysteic and aspartic acid strongly inhibited L-glutamic acid uptake, but at higher cell densities this effect was less pronounced than at low densities. Other amino acids, including leucine, glutamine, and serine, exerted a modest inhibitory effect at both high and low cell densities. Thus pulmonary arterial endothelial cells contain similar membrane transport systems for L-glutamic acid as those previously described for fibroblasts, hepatocytes, and nerve cells. However, quantitative properties of the transport systems differ depending on the state of cellular density in monolayers.

Effect of hyperoxia on glutathione levels and glutamic acid uptake in endothelial cells.

Intracellular glutathione was increased by 80% after exposure of bovine pulmonary arterial endothelial cells to 80% O2 (hyperoxia) for 24 h. No change in glutathione occurred in cells exposed to hypoxia (3% O2) for a corresponding period of time. The rate of uptake of [3H]glutamic acid also increased by 35-55% after 24 h of exposure of cells to hyperoxia, whereas exposure to hypoxia had no effect on the [3H]glutamic acid uptake. The increase in glutamic acid uptake reflected a specific effect on amino acid transport systems rather than a change in cell membrane permeability. The major portion of the increased uptake was inhibited by the elimination of sodium and the addition of the competitive inhibitor, cystine, to the incubation medium. Thus increases in glutamic acid uptake parallel increases in cellular glutathione, and glutamic acid may be a regulating factor in the increase in glutathione after exposure to hyperoxia.