A rare case of liner dissociation with ceramic-on-ceramic preassembled acetabular components: a case report.

Liner dissociations are rare but catastrophic complications after THA, requiring revision surgery. Although this complication has been well documented in THA with modular components, it has been rarely described in preassembled designs. In this report we present a rare case of liner dissociation in a ceramic-on-ceramic pre-assembled cup design. A 41-year-old man who received THA seven years ago, presented with sudden pain in the hip. Radiographic examination confirmed a small dissociation of the liner component in the acetabular shell, as well as radiolucency between the acetabular shell and the ceramic liner, and pneumarthrosis. Revision surgery was carried out six weeks following the liner dissociation. To make an accurate diagnosis, orthopaedic surgeons must be aware of the symptoms of liner dissociation.

MRI following primary repair of the anterior cruciate ligament.

Primary repair of the anterior cruciate ligament (ACL) is being performed increasingly in the treatment of acute proximal ACL ruptures. Advantages of ACL repair over surgical reconstruction with a tendon graft include preservation of the anatomy and proprioceptive function of the native ACL, and therefore, faster rehabilitation. The addition of an internal brace protects the repair during ACL healing and can increase the success rate of the procedure. Given this evolution of ACL surgical treatment, radiologists should be familiar with the new repair techniques and their appearances on postoperative imaging. In this article, we describe two different surgical techniques for primary ACL repair, dynamic intraligamentary stabilisation and internal brace ligament augmentation, and provide an overview of the normal and abnormal appearances after this type of repair at magnetic resonance imaging (MRI) follow-up.

Direct comparison of conventional radiography and cone-beam CT in small bone and joint trauma.

OBJECTIVE: To compare the diagnostic value of cone-beam computed tomography (CBCT) and conventional radiography (CR) after acute small bone or joint trauma. MATERIALS AND METHODS: Between March 2013 and January 2014, 231 patients with recent small bone or joint trauma underwent CR and subsequent CBCT. CR and CBCT examinations were independently assessed by two readers, blinded to the result of the other modality. The total number of fractures as well as the number of complex fractures were compared, and inter- and intraobserver agreement for CBCT was calculated. In addition, radiation doses and evaluation times for both modalities were noted and statistically compared. RESULTS: Fracture detection on CBCT increased by 35% and 37% for reader 1 and reader 2, respectively, and identification of complex fractures increased by 236% and 185%. Interobserver agreement for CBCT was almost perfect, as was intraobserver agreement for reader 1. The intraobserver agreement for reader 2 was substantial. Radiation doses and evaluation time were significantly higher for CBCT. CONCLUSION: CBCT detects significantly more small bone and joint fractures, in particular complex fractures, than CR. In the majority of cases, the clinical implication of the additionally detected fractures is limited, but in some patients (e.g., fracture-dislocations), the management is significantly influenced by these findings. As the radiation dose for CBCT substantially exceeds that of CR, we suggest adhering to CR as the first-line examination after small bone and joint trauma and keeping CBCT for patients with clinical-radiographic discordance or suspected complex fractures in need of further (preoperative) assessment.

The role of miR-155 in cigarette smoke-induced pulmonary inflammation and COPD.

Chronic obstructive pulmonary disease (COPD) is a highly prevalent respiratory disease characterized by airflow limitation and chronic inflammation. MiR-155 is described as an ancient regulator of the immune system. Our objective was to establish a role for miR-155 in cigarette smoke (CS)-induced inflammation and COPD. We demonstrate increased miR-155 expression by RT-qPCR in lung tissue of smokers without airflow limitation and patients with COPD compared to never smokers and in lung tissue and alveolar macrophages of CS-exposed mice compared to air-exposed mice. In addition, we exposed wild type and miR-155 deficient mice to CS and show an attenuated inflammatory profile in the latter. Alveolar macrophages were sorted by FACS from the different experimental groups and their gene expression profile was analyzed by RNA sequencing. This analysis revealed increased expression of miR-155 targets and an attenuation of the CS-induced increase in inflammation-related genes in miR-155 deficient mice. Moreover, intranasal instillation of a specific miR-155 inhibitor attenuated the CS-induced pulmonary inflammation in mice. Finally, elastase-induced emphysema and lung functional changes were significantly attenuated in miR-155 deficient mice. In conclusion, we highlight a role for miR-155 in CS-induced inflammation and the pathogenesis of COPD, implicating miR-155 as a new therapeutic target in COPD.

Bone morphogenetic protein 6 (BMP-6) modulates lung function, pulmonary iron levels and cigarette smoke-induced inflammation.

Chronic obstructive pulmonary disease (COPD) is associated with abnormal inflammatory responses and airway wall remodeling, leading to reduced lung function. An association between the bone morphogenetic protein (BMP-6) locus and forced vital capacity has been found in a genome-wide association study. However, the role of BMP-6 in the pathogenesis of COPD remains unknown. The pulmonary expression of BMP-6 was analyzed in patients with COPD and in cigarette smoke (CS)-exposed mice. We evaluated lung function and histology in BMP-6 KO mice at baseline. We exposed BMP-6 KO mice to CS for 4 weeks and measured pulmonary inflammation and iron levels. Pulmonary mRNA levels of BMP-6 were decreased in smokers with and without COPD and in CS-exposed mice. Importantly, BMP-6 expression was lowest in severe COPD. Accordingly, protein levels of BMP-6 were decreased in patients with COPD. Lung function measurements demonstrated a decreased compliance and total lung capacity in BMP-6 KO mice, whereas lung histology was normal. Furthermore, BMP-6 KO mice displayed elevated iron levels and an aggravated CS-induced inflammatory response. These results suggest that BMP-6 is important for normal lung function and that downregulation of BMP-6-as observed in patients with COPD-contributes to pulmonary inflammation after CS exposure.

Resonance frequency analysis of implants in the guinea pig model: influence of boundary conditions and orientation of the transducer.

The goal of this study was to identify the parameters that must be controlled during in vivo resonance frequency measurements with a custom Osstell transducer for custom implants in the guinea pig animal model. A numerical study and in vitro measurements were performed to determine the influence of the boundary conditions as well as the transducer orientation on the resonance frequency measured by the custom Osstell transducer. In the reported guinea pig model, the type of boundary condition, the orientation of the transducer (parallel or perpendicular to the long axis of the bone) and the length of the modelled bone have a large influence on the resonance frequency values. This implies that a follow-up in time of the stability of an implant requires the boundary conditions applied to the bone in which the implant is installed as well as the orientation of the transducer to be highly repeatable. Applying controlled boundary conditions during in vivo measurements had a highly positive influence on the repeatability of the Osstell measurements. This improves the possibility of the technique to measure changes in the implant-bone interface during healing of the implant.

Elevated GDF-15 contributes to pulmonary inflammation upon cigarette smoke exposure.

The molecular mechanisms underlying the pathogenesis of chronic obstructive pulmonary disease (COPD) are still unclear, however signaling pathways associated with lung development, such as the transforming growth factor (TGF)-ß superfamily, could be implicated in COPD. Growth differentiation factor (GDF)-15, a member of the TGF-ß superfamily, is involved in inflammation, mucus secretion, and cachexia. We analyzed the pulmonary expression of GDF-15 in smokers and patients with COPD, in cigarette smoke (CS)-exposed cultures of primary human bronchial epithelial cells (pHBECs), and in CS-exposed mice. Next, we exposed GDF-15 KO and control mice to air or CS and evaluated pulmonary inflammation. GDF-15 levels were higher in sputum supernatant and lung tissue of patients with COPD and smokers without COPD compared with never smokers. Immunohistochemistry revealed GDF-15 staining in the airway epithelium. Increased expression and secretion of GDF-15 was confirmed in vitro in CS-exposed pHBECs compared with air-exposed pHBECs. Similarly, GDF-15 levels were increased in lungs of CS-exposed mice. Importantly, GDF-15 deficiency attenuated the CS-induced pulmonary inflammation. These results suggest that increased GDF-15-as observed in lungs of smokers and patients with COPD-contributes to CS-induced pulmonary inflammation.

Long-term follow up of glatiramer acetate compassionate use in Belgium.

Between June 1995 and November 1998, 228 patients with relapsing-remitting Multiple Sclerosis started treatment with glatiramer acetate (Copaxone) 20 mg once daily in the frame of a "compassionate use" protocol in 15 Belgian centers. Following an average treatment period of 5.8 years, treating neurologists were requested to fill in follow-up forms indicating neurological disability status and side effects during the previous 6 months. These data were available for 134 patients. In this group, the Expanded Disability Status Scale (EDSS) improved in 26.3% of patients. An additional 36.8% of patients remained neurologically stable. The Ambulation Index (AI) showed similar results: 12.5% of patients improved, 50% of patients remained stable, and 37.5% worsened. Only 10% of patients dropped out due to several reasons. The adverse events occurring in the period preceding the follow-up survey were non-serious and consistent with the current product information of glatiramer acetate. Among the 94 patients no longer followed-up in the compassionate program, reasons for lost to follow-up were obtained for 63; most of them (41) had stopped GA treatment or switched to another disease-modifying treatment. Overall these results are very similar to the ones reported in the extension study of the pivotal trial (Johnson et al., 2000), and indicate that patients treated with glatiramer acetate have a better outcome than expected on the basis of the natural course of the disease. Despite limitations of the study design, this report confirms the sustained efficacy of glatiramer acetate in reducing the disease progression in patients with relapsing-remitting multiple sclerosis treated in day-to-day clinical practice.

Acute effects of plant stanol esters on postprandial metabolism and its relation with changes in serum lipids after chronic intake.

BACKGROUND/OBJECTIVES: Plant stanol esters lower serum low-density lipoprotein (LDL)-cholesterol (LDL-C), but responses between individuals vary widely. As the ability of subjects to respond to acute dietary challenges may reflect the flexibility to adapt to changes on the longer term, we related subjects' acute postprandial metabolic changes to changes in serum lipoproteins after chronic intake of plant stanol esters. SUBJECTS/METHODS: In a double-blind crossover design, 20 healthy subjects received in random order a high-fat shake enriched with or without plant stanol esters (4 g). Blood samples were taken during 4 h to examine lipid, glucose and lipoprotein profiles. Two subjects dropped out. For the 3 weeks after this postprandial test, the subjects who received the shake with plant stanol esters continued the consumption of plant stanol-enriched (3g/day) margarine and subjects receiving the control shake in the postprandial test consumed for the next 3 weeks a control margarine. After the washout period, subjects received the other shake and margarines. RESULTS: The margarine enriched with plant stanol esters lowered concentrations of total cholesterol by 7.3% (P<0.01), LDL-C by 9.5% (P<0.01) and apoB100 by 8.6% (P<0.01). Furthermore, particle concentrations of total very low-density lipoprotein (VLDL), small VLDL and large LDL were reduced by 26.6% (P=0.02), 27.6% (P=0.02) and 12.3% (P=0.04), respectively. Plant stanol esters did not affect parameters related to lipid and glucose metabolism during the postprandial phase. However, the incremental area under the curve (iAUC) of the postprandial glucose concentration after consuming the control shake correlated positively with changes in fasting concentrations of total cholesterol, LDL-C, apoB100, total VLDL, small VLDL and intermediate-density lipoprotein after 3 weeks. CONCLUSIONS: A single dose of plant stanol esters does not change postprandial lipid and lipoprotein profiles. However, postprandial glucose responses may predict the effects of chronic plant stanol ester consumption.

Individualised, micro CT-based finite element modelling as a tool for biomechanical analysis related to tissue engineering of bone.

Load-bearing tissues, like bone, can be replaced by engineered tissues or tissue constructs. For the success of this treatment, a profound understanding is needed of the mechanical properties of both the native bone tissue and the construct. Also, the interaction between mechanical loading and bone regeneration and adaptation should be well understood. This paper demonstrates that microfocus computer tomography (microCT) based finite element modelling (FEM) can have an important contribution to the field of functional bone engineering as a biomechanical analysis tool to quantify the stress and strain state in native bone tissue and in tissue constructs. Its value is illustrated by two cases: (1) in vivo microCT-based FEM for the analysis of peri-implant bone adaptation and (2) design of biomechanically optimised bone scaffolds. The first case involves a combined animal experimental and numerical study, in which the peri-implant bone adaptive response is monitored by means of in vivo microCT scanning. In the second case microCT-based finite element models were created of native trabecular bone and bone scaffolds and a mechanical analysis of both structures was performed. Procedures to optimise the mechanical properties of bone scaffolds, in relation to those of native trabecular bone are discussed.

Evaluation of culture media for enrichment and isolation of Shigella sonnei and S. flexneri.

The performance of Gram-negative (GN) broth with (10 microg/ml) and without novobiocin, Shigella broth (SB) with 0.5 and 3.0 microg/ml novobiocin, all incubated at 37 degrees C (SB with 3.0 microg/ml novobiocin also at 42 degrees C) and buffered brilliant green bile glucose (EE) broth with 1.0 microg/ml novobiocin incubated at 37 and 42 degrees C were evaluated for resuscitation and growth of Shigella sonnei and S. flexneri (eight strains; unstressed, chill-stressed and acid-stressed) and non-shigellae (11 strains). GN broth with or without novobiocin supported significantly less growth of Shigella sp. No significant differences in growth of shigellae were obtained between the other culture media. Performance depended more on the Shigella strain used. None of the tested media were significantly superior for suppressing the competitive flora. Electivity and selectivity of MacConkey agar (MAC), tergitol-7 agar (T7), desoxycholate citrate agar (DCA), xylose lysine desoxycholate agar (XLD), Salmonella Shigella agar and Hektoen enteric agar (HEA) were determined by ecometric testing. HEA confirmed to be a high selective medium for both non-shigellae and stressed Shigella sp. Klebsiella sp., Enterobacter sp., Citrobacter sp.. Salmonella sp. and the Escherichia strains can mask the presence of shigellae. In vitro competition experiments and experiments with artificially contaminated foods showed higher resistance of S. sonnei than S. flexneri towards the stress imposed by the food matrix and its indigenous flora. Reliable detection, however, of shigellae in foods with the current enrichment and isolation media was not achieved.

The influence of plaque and/or excessive loading on marginal soft and hard tissue reactions around Brånemark implants: a review of literature and experience.

High implant survival rates are published with more than 15 years of observation time. Failures over time are often caused by ongoing marginal bone loss. Therefore, the need for reliable monitoring of the stability of periimplant attachment and/or bone level is extremely important. Marginal bone loss around osseointegrated implants has often been associated with periimplantitis, but clinical observations cannot prove this relationship. Otherwise, the impact of excessive loading on periimplant bone has been shown in animal studies and has been positively related to implant failure in terms of implant mobility and marginal bone loss. Some clinical observations support this hypothesis.

Peroneal nerve: Normal anatomy and pathologic findings on routine MRI of the knee.

BACKGROUND: Peroneal nerve lesions are not common and are often exclusively assessed clinically and electromyographically. METHODS: On a routine MR examination without dedicated MR-neurography sequences the peroneal nerve can readily be assessed. Axial T1-weighted sequences are especially helpful as they allow a good differentiation between the nerve and the surrounding fat. RESULTS: The purpose of this article is to review the normal anatomy and pathologic conditions of the peroneal nerve around the knee. CONCLUSION: In the first part the variable anatomy of the peroneal nerve around the knee will be emphasized, followed by a discussion of the clinical findings of peroneal neuropathy and general MR signs of denervation. Six anatomical features may predispose to peroneal neuropathy: paucity of epineural tissue, biceps femoris tunnel, bifurcation level, superficial course around the fibula, fibular tunnel and finally the additional nerve branches. In the second part we discuss the different pathologic conditions: accidental and surgical trauma, and intraneural and extraneural compressive lesions. TEACHING POINTS: • Six anatomical features contribute to the vulnerability of the peroneal nerve around the knee. • MR signs of muscle denervation within the anterior compartment are important secondary signs for evaluation of the peroneal nerve. • The most common lesions of the peroneal nerve are traumatic or compressive. • Intraneural ganglia originate from the proximal tibiofibular joint. • Axial T1-weighted images are the best sequence to visualise the peroneal nerve on routine MRI.

Prevalence of work related upper limb disorders in hairdressers: a cross sectional study on the influence of working conditions and psychological, ergonomic and physical factors.

A cross sectional study where 145 hairdressers were interviewed for the occurrence of work related upper limb disorders (WRULD). The interview features for engagement, burnout and workaholism, as well as asks for general health and working conditions. The BMI, the hand size and gripping force of each worker was obtained. WRULD was present in 41%. It was significantly correlated with burnout and workaholism. Surprisingly it was not altered by engagement or by the use of ergonomic equipment. Morphological features (BMI), hand size and gripping force, were not related to the occurrence of WRULD.

Effect of constant strain rate, composed of varying amplitude and frequency, of early loading on peri-implant bone (re)modelling.

AIM: Examine the effect of varying components of strain rate -- amplitude versus frequency -- while maintaining a constant strain rate of early controlled mechanical loading on implant stability, peri-implant bone mass and bone-to-implant contact. MATERIAL AND METHODS: Three groups of guinea-pigs received TiO2 -blasted implants in both tibiae. One week after installation test implants were loaded 5 days/week during 4 weeks. The contra-lateral implants were the unloaded controls. Strain rate was kept constant (1600 micro epsilon/s), while amplitude and frequency were varied per group. Implant stability was followed by resonance frequency analysis. Animals were sacrificed, and ground sections were prepared to rate bone-to-implant contact and bone mass. RESULTS: All implants (n=78) integrated uneventfully. A significant positive effect (p=0.03) of early loading on bone mass was observed in the distal medullar cavity. A significant difference in bone mass between test and control implants was evidenced between the groups (p=0.03 and 0.04). A significant increase in implant stability and bone-to-implant contact could not be shown. CONCLUSIONS: Early controlled stimulation of peri-implant bone is related to amplitude/frequency and not to strain rate as such, considering a constant stimulation time. An increase of bone mass around early-loaded implants was shown. This cortical bone model is most sensitive to low-frequency/high-amplitude stimulation.

The accuracy and reliability of radiographic methods for the assessment of marginal bone level around oral implants.

OBJECTIVES: To determine the accuracy and reliability of radiographic methods for assessment of the marginal bone level around oral implants in human cadavers. METHODS: In three human cadavers two implants were placed according to the Instruction Manual for the Brånemark System. One implant was installed in the canine and one in the premolar region of the left mandible. For each implant, conventional and digital intra-oral paralleling radiography were performed. Digital images were printed with a Kodak 1200 Distributed Medical Imaging printer on blue transparent film, glossy and plain paper. Furthermore, digital scanographic, panoramic and tomographic images were taken with the Cranex Tome multimodal X-ray unit and printed on Agfa Drystar TM 1 B transparent films. All images were evaluated by five dental specialists. Data were statistically compared with real measurements of the marginal bone level on the human cadavers, performed by the same group of observers. Intra- and inter-observer variability were determined. RESULTS: Digital intra-oral images on glossy paper showed the smallest absolute difference between real and measured bone level, followed by digital intra-oral images on film and on plain paper, conventional intra-oral images on analogue film, panoramic, scanographic and tomographic images on film. The difference between real and radiographic measurements was not statistically significant (P>0.05) for all radiographic techniques. Intra- and inter-observer reproducibility was high for all techniques. CONCLUSIONS: The selected imaging techniques showed an acceptable accuracy for peri-implant bone level measurements with an overall error of less than 0.5 mm. Intra-oral images showed the smallest absolute differences.

A comparison of the effective dose from scanography with periapical radiography.

OBJECTIVES: To compare organ and effective doses from analogue scanographic and periapical radiography. METHODS: Thermoluminescent dosimeters (TLD-700) were inserted in the parotid glands (bilateral), submandibular glands (bilateral) and bone marrow (left ascending ramus) of three human cadavers. Dosimeters were also attached to the skin, thyroid gland and lens of both eyes. Central, left lateral and left posterior scanograms were obtained with a Cranex Tome (Soredex, Helsinki, Finland) multimodal imaging system. A similar procedure was applied for periapical radiographs of the midline, left lateral and left molar regions using E-speed film both with and without rectangular collimation. Organ and effective doses were calculated for scanograms and periapical radiographs. RESULTS: The effective doses for the scanograms were 0.001 mSv (central), 0.011 mSv (lateral) and 0.015 mSv (posterior). The effective doses for periapical radiographs were 0.001 mSv (anterior), 0.001 mSv (lateral) and 0.003 mSv (posterior) for rectangular collimation and 0.001 mSv (anterior), 0.002 mSv (lateral) and 0.005 mSv (posterior) for round collimation. CONCLUSIONS: When a larger area of the upper or lower jaw needs to be visualised, scanograms might be considered as an alternative to periapical radiography since the effective dose is lower.

Clinical assessment of pelvic floor dysfunction in multiple sclerosis: urodynamic and neurological correlates.

We present a study on the clinical assessment of pelvic floor dysfunction in 30 female patients with proven multiple sclerosis (MS). A scoring system for pelvic floor muscle testing by digital vaginal palpation is proposed. The concept of pelvic floor spasticity in MS is introduced. The relationship of our findings with the neurological findings and urodynamic data is presented. Pelvic floor spasticity correlates well with the presence of detrusor-external sphincter dyssynergia and with more severe spinal cord disease.