Systematic review of the outcome of cemented versus uncemented total hip arthroplasty following pelvic irradiation.

PURPOSE: The objective of this study is to evaluate the outcomes of total hip arthroplasty (THA) in patients with radiation-related changes to the bone, and specifically whether there is a difference in outcomes between cemented and uncemented acetabular components. METHODS: A database search was performed to identify available studies reporting adults undergoing THA who have previously had pelvic irradiation. Data were extracted and analysed with respect to the use of cemented versus uncemented acetabular components. Statistical analysis was performed using the Chi-square test for independence. RESULTS: The all-cause revision rate was 24% in the cemented THA group (27/111), compared with 15% of uncemented THAs (22/143) (p = 0.073). Revision for acetabular aseptic loosening occurred in 16% of cases (18/111) in the cemented group and 10% (15/143) in the uncemented group (p = 0.178). Acetabular aseptic loosening was reported in 24% of cemented THAs (27/111) and 14% of uncemented THAs (20/143), which was statistically significant (p = 0.035). Not all of these went on to have revision THA. The Incidence of prosthetic joint infection was similar in both groups. CONCLUSION: Overall outcomes appear to be better for uncemented THAs in post-radiotherapy patients, with a significantly lower rate of aseptic loosening and an appreciable (but not statistically significant) reduction in revision rate. The best outcomes seem to be associated with the use of acetabular reinforcement across both cemented and uncemented groups, but further work is needed to evaluate this.

Correction to: A decade of progress in critical care echocardiography: a narrative review.

The original version of this article unfortunately contained a mistake.

A decade of progress in critical care echocardiography: a narrative review.

INTRODUCTION: This narrative review focusing on critical care echocardiography (CCE) has been written by a group of experts in the field, with the aim of outlining the state of the art in CCE in the 10 years after its official recognition and definition. RESULTS: In the last 10 years, CCE has become an essential branch of critical care ultrasonography and has gained general acceptance. Its use, both as a diagnostic tool and for hemodynamic monitoring, has increased markedly, influencing contemporary cardiorespiratory management. Recent studies suggest that the use of CCE may have a positive impact on outcomes. CCE may be used in critically ill patients in many different clinical situations, both in their early evaluation of in the emergency department and during intensive care unit (ICU) admission and stay. CCE has also proven its utility in perioperative settings, as well as in the management of mechanical circulatory support. CCE may be performed with very simple diagnostic objectives. This application, referred to as basic CCE, does not require a high level of training. Advanced CCE, on the other hand, uses ultrasonography for full evaluation of cardiac function and hemodynamics, and requires extensive training, with formal certification now available. Indeed, recent years have seen the creation of worldwide certification in advanced CCE. While transthoracic CCE remains the most commonly used method, the transesophageal route has gained importance, particularly for intubated and ventilated patients. CONCLUSION: CCE is now widely accepted by the critical care community as a valuable tool in the ICU and emergency department, and in perioperative settings.

Clinical, functional and radiological outcomes of extracorporeal irradiation in limb salvage surgery for bone tumours.

AIMS: We present a retrospective review of patients treated with extracorporeally irradiated allografts for primary and secondary bone tumours with the mid- and long-term survivorship and the functional and radiographic outcomes. PATIENTS AND METHODS: A total of 113 of 116 (97.4%) patients who were treated with extracorporeally irradiated allografts between 1996 and 2014 were followed up. Forms of treatment included reconstructions, prostheses and composite reconstructions, both with and without vascularised grafts. Survivorship was determined by the Kaplan-Meier method. Clinical outcomes were assessed using the Musculoskeletal Tumor Society (MSTS) scoring system, the Toronto Extremity Salvage Score (TESS) and Quality of Life-C30 (QLQ-30) measures. Radiographic outcomes were assessed using the International Society of Limb Salvage (ISOLS) radiographic scoring system. RESULTS: There were 61 (54%) men with a mean age of 22 years (6 to 70) and 52 (46%) women with a mean age of 26 years (3 to 85). There were 23 deaths. The five-year patient survivorship was 82.3% and the ten-year patient survivorship was 79.6%. The mean follow-up of the 90 surviving patients was 80.3 months (2 to 207). At the last follow-up, 105 allografts (92.9%) were still in place or had been at the time of death; eight (7%) had failed due to infection, local recurrence or fracture. Outcome scores were comparable with or superior to those in previous studies. The mean outcome scores were: MSTS 79% (sd 8); TESS 83% (sd 19); QLQ 82% (sd 16); ISOLS 80.5% (sd 19). Pearson correlation analysis showed a strong relationship between the MSTS and ISOLS scores (r = 0.71, p < 0.001). CONCLUSION: This study shows that extracorporeal irradiation is a versatile reconstructive technique for dealing with large defects after the resection of bone tumours with good functional and radiographic outcomes. Functional outcomes as measured by MSTS, TESS and QLQ-30 were strongly correlated to radiographic outcomes. Cite this article: Bone Joint J 2017;99-B:1681-8.

A loop-mediated isothermal amplification method for rapid direct detection and differentiation of nonpathogenic and verocytotoxigenic Escherichia coli in beef and bovine faeces.

AIM: To develop a multiplex loop-mediated isothermal amplification (LAMP) assay capable of quantifying Escherichia coli and differentiating verocytotoxigenic E. coli (VTEC). METHODS AND RESULTS: Primer sets were selected to amplify the phoA gene (all E. coli strains) and stx1 and/or stx2 genes (VTEC strains only). LAMP calibration curves demonstrated good quantification capability compared with conventional culture. The limits of detection 50% (LOD50 ) of the multiplex LAMP assay were 2·8 (95% CI 2·4-3·3), 3·2 (95% CI 2·5-3·9) and 2·8-3·2 (95% CI 2·1-3·5) log CFU per g for the phoA, stx1 and stx2 genes, respectively. When validated by testing retail beef and bovine faeces samples, good correlation between E. coli counts indicated by the LAMP assay and culture was observed; however, false-negative LAMP assay results were obtained for 12·5-14·7% of samples. CONCLUSIONS: A rapid, multiplex LAMP assay for direct quantification of E. coli and specific detection of VTEC in beef and faeces was successfully developed. Further optimisation of the assay would be needed to improve detection sensitivity. SIGNIFICANCE AND IMPACT OF THE STUDY: The multiplex LAMP assay represents a rapid alternative to culture for monitoring E. coli levels on beef for hygiene monitoring purposes, and, potentially, a method for detection of VTEC in beef and faeces.

What is the minimum amount of simulated breast movement required for visual detection of blurring? An exploratory investigation.

OBJECTIVE: Image blurring in mammography can cause significant image degradation and interpretational problems. A potential source is due to paddle movement during image formation. Paddle movement has been shown to be as much as 1.5 mm. No study has yet been performed to determine how much motion would be noticeable visually. The aim of this study is to determine the minimum amount of simulated breast movement at which blurring can be detected visually. METHODS: 25 artefact-free mammogram images were selected. Mathematical simulation software was created to mimic the effect of blurring produced by breast movement during exposure. Motion simulation was imposed to 15 levels, from 0.1 to 1.5 mm stepping through 0.1 mm increments. 15 degraded images and 1 without blurring were de-identified, randomized and assessed on a blinded basis by two clinical experts to determine the presence or absence of blurring. Statistical testing was carried out to determine the consistency between the two observers. RESULTS: The probability of simulated blurred image detection is the highest for the gaussian method and the lowest for soft-edged mask estimation. CONCLUSION: The amount of simulated breast movement at which blurring can be detected visually for gaussian blur, hard-edge mask estimation and soft-edge mask estimation is 0.4, 0.8 and 0.7 mm, respectively. Cohen's kappa for all the levels of simulated blurring is 0.689 (p < 0.05). ADVANCES IN KNOWLEDGE: This research establishes the concept of using probability to represent visual detection of blurring rather than defining a hard cut-off level.

Extra patient movement during mammographic imaging: an experimental study.

OBJECTIVE: To determine if movement external to the patient occurring during mammography may be a source of image blur. METHODS: Four mammography machines with eight flexible and eight fixed paddles were evaluated. In the first stage, movement at the paddle was measured mechanically using two calibrated linear potentiometers. A deformable breast phantom was used to mimic a female breast. For each paddle, the movement in millimetres and change in compression force in Newton was recorded at 0.5- and 1-s intervals, respectively, for 40 s with the phantom in an initially compressed state under a load of 80 N. In the second stage, clinical audit on 28 females was conducted on one mammography machine with the 18 × 24- and 24 × 29-cm flexible paddles. RESULTS: Movement at the paddle followed an exponential decay with a settling period of approximately 40 s. The compression force readings for both fixed and flexible paddles decreased exponentially with time, while fixed paddles had a larger drop in compression force than did flexible paddles. There is a linear relationship between movement at the paddle and change in compression force. CONCLUSION: Movement measured at the paddle during an exposure can be represented by a second order system. The amount of extra patient movement during the actual exposure can be estimated using the linear relationship between movement at the paddle and the change in compression force. ADVANCES IN KNOWLEDGE: This research provides a possible explanation to mammography image blurring caused by extra patient movement and proposes a theoretical model to analyse the movement.

Limb preservation surgery with extracorporeal irradiation in the management of malignant bone tumor: the oncological outcomes of 101 patients.

BACKGROUND: En bloc resection, extracorporeal irradiation (ECI) and reimplantation have been used selectively at our centers as part of limb preservation surgery of malignant bone tumors since 1996. We report the long-term oncological outcomes. PATIENTS AND METHODS: One hundred one patients were treated with ECI at two Australian centers between 1996 and 2011. A single dose of 50 Gy was delivered to the resected bone segments. The irradiated bones were reimplanted immediately as a biological graft. Patients were treated with chemotherapy as per standard protocol. The three main histological diagnoses were Ewing's sarcoma (35), osteosarcoma (37) and chondrosarcoma (20). There were nine patients with a range of different histologies. RESULTS: There was one local recurrence (2.86%) in Ewing's sarcoma and the 5-year cumulative overall survival was 81.9%. There was no local recurrence in osteosarcoma and five distant recurrences. The 5-year cumulative overall survival was 85.7%. The local recurrence rate was 20% (4 of 20) in chondrosarcoma, and the 5-year cumulative overall survival was 80.8%. Limb preservation was achieved in 97 patients. For the 64 patients with disease in the pelvis or lower limb, 53 (82.3%) could walk without aids at the time of last follow-up. CONCLUSIONS: This large series of ECI shows an excellent long-term local control. It is a good alternative reconstruction method in selected patients. The overall survival is comparable to other published series.

Quantification of ankle articular cartilage topography and thickness using a high resolution stereophotography system.

OBJECTIVE: To describe the topography and to measure thicknesses, surface areas and volumes in the cartilage layers of the ankle. METHODS: Twelve cadaveric ankle joints were disarticulated and the cartilage surfaces of each bone were imaged with a highly accurate (+/-2 microm) stereophotography system (ATOS). The cartilage was then dissolved and the subchondral bone imaged. The geometric data were then used to measure the quantitative parameters in each cartilage layer. RESULTS: The mean cartilage volume across the 12 specimens ranged from 0.32+/-0.08 ml for the fibula to 2.44+/-0.48 ml for the talus. The mean thickness of both the talar (1.1+/-0.18 mm) and tibial (1.16+/-0.14 mm) cartilage was significantly thicker than the fibula (0.85+/-0.13 mm). The talus had the greatest mean maximum cartilage thickness (2.38+/-0.4 mm). CONCLUSIONS: The reported stereophotographic technique may be used as an independent gold standard for validation of the accuracy of quantitative cartilage measurements made using magnetic resonance imaging. The thickness distribution maps show that the thickest articular cartilage occurs over the talar shoulders where osteochondral lesions commonly occur and not in the centre of the talar dome as commonly believed.

MR imaging of osteochondral grafts and autologous chondrocyte implantation.

Surgical articular cartilage repair therapies for cartilage defects such as osteochondral autograft transfer, autologous chondrocyte implantation (ACI) or matrix associated autologous chondrocyte transplantation (MACT) are becoming more common. MRI has become the method of choice for non-invasive follow-up of patients after cartilage repair surgery. It should be performed with cartilage sensitive sequences, including fat-suppressed proton density-weighted T2 fast spin-echo (PD/T2-FSE) and three-dimensional gradient-echo (3D GRE) sequences, which provide good signal-to-noise and contrast-to-noise ratios. A thorough magnetic resonance (MR)-based assessment of cartilage repair tissue includes evaluations of defect filling, the surface and structure of repair tissue, the signal intensity of repair tissue and the subchondral bone status. Furthermore, in osteochondral autografts surface congruity, osseous incorporation and the donor site should be assessed. High spatial resolution is mandatory and can be achieved either by using a surface coil with a 1.5-T scanner or with a knee coil at 3 T; it is particularly important for assessing graft morphology and integration. Moreover, MR imaging facilitates assessment of complications including periosteal hypertrophy, delamination, adhesions, surface incongruence and reactive changes such as effusions and synovitis. Ongoing developments include isotropic 3D sequences, for improved morphological analysis, and in vivo biochemical imaging such as dGEMRIC, T2 mapping and diffusion-weighted imaging, which make functional analysis of cartilage possible.

Nonlinear viscoelastic behavior of human knee ligaments subjected to complex loading histories.

The nonlinear viscoelastic structural response of the major human knee ligaments when subjected to complex loading histories is investigated, with emphasis on the collateral ligaments. Bone-ligament-bone specimens are tested in knee distraction loading, where the ligaments are in the anatomical position corresponding to a fully extended knee. Temporal nonlinearities for time scales in the range of 1

Matrix-based autologous chondrocyte implantation for cartilage repair with HyalograftC: two-year follow-up by magnetic resonance imaging.

OBJECTIVE: Monitoring of articular cartilage repair after matrix-associated autologous chondrocyte implantation with HyalograftC by a new grading system based on non-invasive high-resolution magnetic resonance imaging. PATIENTS AND METHODS: In 23 patients, postoperative magnetic resonance imaging (MRI) was performed between 76 and 120 weeks. In nine of these patients, five MRI examinations were performed at 4, 12, 24, 52 and 104 weeks after HyalograftC implant. The repair tissue was described with separate variables: degree of defect repair in width and length, signal intensity of the repair tissue and status of the subchondral bone. For these variables a grading system with point scale evaluation was applied. CONCLUSION: High-resolution MRI provides a non-invasive tool for monitoring the development of cartilage repair tissue following HyalograftC technology, shows a good correlation with clinical outcome and may help to differentiate abnormal repair tissue from a normal maturation process.

Pedestrian injuries: viscoelastic properties of human knee ligaments at high loading rates.

OBJECTIVE: Accidents involving pedestrians are very common, and often lead to severe injuries to the lower extremities. In a large portion of pedestrian-automobile collisions, knee ligament injuries are sustained. In this study, the viscoelastic properties of the four major human knee ligaments were investigated at loading rates representative for pedestrian-automobile collisions. METHODS: Bone-ligament-bone specimens were tested in knee distraction loading. The collateral ligaments and the separate functional bundles of the cruciate ligaments were tested in the anatomical position corresponding to a fully extended knee. A series of step-and-hold tests and ramp tests at different rates were conducted to characterize the time-dependent behavior of the knee ligaments for deformation rates associated with the pedestrian impact loading environment. The quasi linear viscoelastic (QLV) theory was used to describe the structural response of the knee ligaments and averaged parameters for this model were determined. RESULTS: The QLV theory was found to be applicable for the time range that is relevant for pedestrian-automobile collisions. The structural behavior of the knee ligaments was found to be particularly rate-sensitive for high elongation rates, as occur during these collisions. The ligament stiffness was found to increase with age for both the collateral ligaments and with weight for the medial collateral ligament. CONCLUSIONS: For the loading conditions that are relevant for pedestrian-automobile collisions, the use of the QLV model for the description of the mechanical behavior of knee ligaments is appropriate. The rate-sensitivity is particularly important for these extreme loading conditions. The relaxation behavior was found to be consistent between different ligament types and samples. Variations due to donor anthropometry were found predominantly for the instantaneous elastic behavior.

Mode of action and application of Scorpion primers to mutation detection.

Scorpion primers can be used to detect PCR products in homogeneous solution. Their structure promotes a unimolecular probing mechanism. We compare their performance with that of the same probe sequence forced to act in a bimolecular manner. The data suggest that Scorpions indeed probe by a unimolecular mechanism which is faster and more efficient than the bimolecular mechanism. This mechanism is not dependent on enzymatic cleavage of the probe. A direct comparison between Scorpions, TaqMan and Molecular Beacons on a Roche LightCycler indicates that Scorpions perform better, particularly under fast cycling conditions. Development of a cystic fibrosis mutation detection assay shows that Scorpion primers are selective enough to detect single base mutations and give good sensitivity in all cases. Simultaneous detection of both normal and mutant alleles in a single reaction is possible by combining two Scorpions in a multiplex reaction. Such favourable properties of Scorpion primers should make the technology ideal in numerous applications.

Arthropod toxins as leads for novel insecticides: an assessment of polyamine amides as glutamate antagonists.

In the search for new toxins, preferably with new sites of action, the polyamine amides represent a new class of compounds with potential as insecticides and as pharmaceutical agents due to their antagonism of ligand-gated cation channels. In particular, they are potent antagonists of the L-glutamate receptors of insect skeletal muscle. In this paper, we report on synthetic studies to produce hybrid analogues based upon the argiotoxin spider toxins and philanthotoxin-433 which is obtained from a solitary, parasitic wasp. We speculate upon possible modes and sites of action for these antagonists and we discuss their potential as insecticides and in the possible treatment of ischaemic damage. The synthesis and characterization of 4-hydroxyphenylpropanoylspermine is reported and the locust muscle biological assay is described. Using this pharmacological screen, structure-activity relationships have been determined in our laboratories. These are reviewed in the light of the current literature. Voltage clamp studies of the synthetic analogue philanthotoxin-343 and the effects of this polyamine amide on glutamate receptors expressed in Xenopus oocytes are outlined. In conclusion, a description of our current ideas and understanding of the many sites and modes of action of the polyamine amides, based both upon our own studies and also upon those recently reported, is presented.

Feeding ecology and territoriality of the Cactus Finch Geospiza scandens on Isla Daphne Major, Galápagos.

In this study we investigated the relationship between food availability, feeding ecology and territoriality in a population of Cactus Finches, Geospiza scandens, on Isla Daphne Major, Galápagos, between 1979 and 1981.We monitored the phenologies of the principal food types on the island and related them to changes in the feeding ecology of G. scandens. Feeding patterns closely tracked the availability of resources, with a similar pattern in each of the three years. Birds relied heavily on Opuntia fruits in the dry season. G. scandens defends year-round territories based on Opuntia. Variation in Opuntia phenologies between individual territories and between years was documented in order to provide a measure of territory quality over the three years. A correlation was demonstrated between the area of cactus within a territory and mating success of the owner. We suggest that territory quality also affects the survival of the owners during periods of food scarcity and that the mating and survival advantage of a high-quality territory occur at different times and to different degrees in different years. Hence the importance of territorial quality can only be judged over a long-term period in these long lived and sedentary birds.