Polyethylene wear and cup migration of cemented total hip arthroplasty with femoral heads made of oxidized zirconium, steel, or cobalt chromium: a 10-year secondary analysis from a randomized trial using radiostereometry.

Background And Purpose: We aimed to evaluate polyethylene (PE) wear, cup migration, and clinical outcome over 10 years in total hip arthroplasties (THA) using different articulations.

Methods:  This is a secondary analysis of 150 patients randomized into 5 groups, using different articulations: Charnley/Charnley Ogee for steel and conventional polyethylene (CPE), or Spectron EF/Reflection with either CPE or highly cross linked polyethylene (XLPE) cups, paired with heads made of either cobalt-chromium (CoCr) or oxidized zirconium (OxZr). All cups were cemented.

Effects of implant precoating and fat contamination on the stability of the tibial baseplate.

Background: Approximately 5% of primary total knee arthroplasty patients require revision within 10 years, often due to distal component loosening. Application of a thin layer of PMMA cement as precoating on the tibial component aims to prevent aseptic loosening. This study investigates the impact of precoating and fat contamination on tibial baseplate stability.

Isolation of TiNbN wear particles from a coated metal-on-metal bearing: Morphological characterization and in vitro evaluation of cytotoxicity in human osteoblasts.

To improve the wear resistance of articulating metallic joint endoprostheses, the surfaces can be coated with titanium niobium nitride (TiNbN). Under poor tribological conditions or malalignment, wear can occur on these implant surfaces in situ. This study investigated the biological response of human osteoblasts to wear particles generated from TiNbN-coated hip implants.

Cementing techniques for total knee arthroplasty in Norwegian hospitals; a questionnaire-based study.

Background: Cementing technique in total knee arthroplasty (TKA) may influence implant survival. There is limited knowledge about the results with clinically used techniques. The aim of this study was to investigate cementing techniques for TKA in Norwegian hospitals, to compare widely used techniques to recommendations from the literature, and to investigate variation within hospitals.

Similarly low blood metal ion levels at 10-years follow-up of total hip arthroplasties with Oxinium, CoCrMo, and stainless steel femoral heads. Data from a randomized clinical trial.

The use of inert head materials such as ceramic heads has been proposed as a method of reducing wear and corrosion products from the articulating surfaces in total hip arthroplasty, as well as from the stem-head taper connection. The aim of the present study was to compare the blood metal ion levels in patients with Oxinium and CoCrMo modular femoral heads, as well as monoblock stainless steel Charnley prostheses at 10 years postoperatively. The 150 patients with osteoarthritis of the hip joint included in a randomized clinical trial were grouped according to femoral head material.

Polycrystalline Diamond Coating on Orthopedic Implants: Realization and Role of Surface Topology and Chemistry in Adsorption of Proteins and Cell Proliferation.

Polycrystalline diamond has the potential to improve the osseointegration of orthopedic implants compared to conventional materials such as titanium. However, despite the excellent biocompatibility and superior mechanical properties, the major challenge of using diamond for implants, such as those used for hip arthroplasty, is the limitation of microwave plasma chemical vapor deposition (CVD) techniques to synthesize diamond on complex-shaped objects. Here, for the first time, we demonstrate diamond growth on titanium acetabular shells using the surface wave plasma CVD method.

Inflammatory tissue reactions around aseptically loose cemented hip prostheses: A retrieval study of the Spectron EF stem with Reflection All-Poly acetabular cup.

The cemented Spectron EF stem in combination with the cemented non-crosslinked Reflection All-Poly cup showed a high rate of mid-term aseptic loosening. However, the failure mechanisms are not fully known. We assessed the inflammatory tissue reactions and wear particles in periprosthetic tissues, implant wear and blood metal ion levels in 28 patients with failed implants.

Metal ion levels in the blood of patients with metal-on-metal hip prostheses.

Background: A BHR (Birmingham hip resurfacing) prosthesis was implanted in 445 people in Norway. Adverse reactions can arise as a result of the release of metal ions from metal-on-metal joint surfaces made from cobalt-chromium alloy. The aim of the study was to analyse the release of metal ions during the first five years after surgery in patients with a BHR prosthesis and to investigate whether this was linked to clinical complications.

Strength of side-to-side and step-cut repairs in tendon transfers: biomechanical testing of porcine flexor tendons.

The aim of the study was to compare side-to-side with step-cut repairs to determine how much of the width it is possible to remove and still keep the repair strong enough to start active mobilization. Porcine flexor tendons were used to create side-to-side, one-third step-cut and half step-cut repairs. There were 15 repairs in each group.

Effect of Drinking Oxygenated Water Assessed by in vivo MRI Relaxometry.

Grant Support: This project was funded by the Research Council of Norway.

Background: Oxygen uptake through the gastrointestinal tract after oral administration of oxygenated water in humans is not well studied and is debated in the literature. Due to the paramagnetic properties of oxygen and deoxyhemoglobin, MRI as a technique might be able to detect changes in relaxometry values caused by increased oxygen levels in the blood.

Determination of oxygen r at 3 Tesla using samples with a concentration range of dissolved oxygen.

Objective: To investigate the sensitivity of modified Look-Locker inversion recovery (MOLLI) to measure changes in dissolved oxygen (DO) concentrations in water samples and to calculate sequence-specific relaxivity (r) and limit of detection (LOD).

Materials And Methods: Ten water samples with a range of DO concentrations were scanned at 3 T using two variations of MOLLI schemes. Using linear regression the r of DO was estimated from the measured DO concentrations and T relaxation rates (R).

Cementing technique for primary knee arthroplasty: a scoping review.

Background and purpose - The optimal cementing technique for primary total knee arthroplasty (TKA) remains unclear. We therefore performed a scoping review based on available studies regarding cementation technique in primary TKA and unicondylar knee arthroplasty (UKA).Patients and methods - A search in 3 databases identified 1,554 studies.

Needle tip tracking for ultrasound-guided peripheral nerve block procedures-An observer blinded, randomised, controlled, crossover study on a phantom model.

Background: The Onvision needle tip tracking (NTT) is a new technology consisting of a needle with an ultrasound sensor close to the needle tip and a console for computerised signal processing. The aim of the study was to evaluate NTT technology during ultrasound-guided simulated peripheral nerve block procedures in a porcine phantom model.

Methods: Forty anaesthesiologists performed in-plane and out-of-plane simulated nerve blocks with and without NTT guidance.

Strength of Pulvertaft modifications: tensile testing of porcine flexor tendons.

The aim of the study was to present two new modifications of the Pulvertaft weave, allowing a higher number of weaves without the need for a longer overlap. The mechanical properties were measured and compared with the traditional technique. Forty-five pairs of porcine flexor tendons were randomized to a Pulvertaft repair with three weaves, a Double Pulvertaft and Locking Pulvertaft repairs.

Corrosion and metal release from overlapping arterial stents under mechanical and electrochemical stress - An experimental study.

Intra-arterial stenosis due to atherosclerosis is often treated with endovascular balloon dilatation with a metal stent. Restenosis is common and is frequently treated with a new stent placed inside the existing one or the stents are placed with overlap to cover a larger area of the vessels. Observations of stent fractures, stent compression, accumulation of immunocompetent cells around stents have suggested the possibility of immunologic reactions to substances released from stents.

Can we ablate liver lesions close to large portal and hepatic veins with MR-guided HIFU? An experimental study in a porcine model.

Objectives: Invasive treatment of tumors adjacent to large hepatic vessels is a continuous clinical challenge. The primary aim of this study was to examine the feasibility of ablating liver tissue adjacent to large hepatic and portal veins with magnetic resonance imaging-guided high-intensity focused ultrasound (MRgHIFU). The secondary aim was to compare sonication data for ablations performed adjacent to hepatic veins (HV) versus portal veins (PV).

Precision of T1-relaxation time measurements in the hepatic portal vein: influence of measurement technique and sequence parameters.

Objective: To investigate the effects of a range of parameter settings on T measurement stability in the portal vein using the T1-mapping sequences Look-Locker (LL) and Modified Look-Locker inversion recovery (MOLLI).

Materials And Methods: Ten different versions of LL and MOLLI sequences were tested and compared to a reference sequence provided by the MR manufacturer. Ten healthy volunteers were imaged multiple times on two separate scan days at 3T.

Patterns of altered regional brain glucose metabolism in borderline personality disorder and bipolar II disorder.

Objective: The relationship between borderline personality disorder (BPD) and bipolar II disorder (BIP-II) is disputed but understudied. Here, we investigated brain glucose metabolism in these patient groups and healthy control subjects (HCs).

Methods: Sixty-five subjects, 22 BPD (19 females), 22 BIP-II (17 females), and 21 HC (14 females), were examined using 2-deoxy-2[18F]-fluoro-d-glucose positron-emission tomography (PET) scanning.

Label-Free Monitoring of Uptake and Toxicity of Endoprosthetic Wear Particles in Human Cell Cultures.

The evaluation of the biological effects of endoprosthetic wear particles on cells in vitro relies on a variety of test assays. However, most of these methods are susceptible to particle-induced interferences; therefore, label-free testing approaches emerge as more reliable alternatives. In this study, impedance-based real-time monitoring of cellular viability and metabolic activity were performed following exposure to metallic and ceramic wear particles.

An Individual Patient Outcome Tool for Joint Replacement Patients.

Patient specific forecasting tools are an area of active research and very much seen as a necessary tool for future improvements in healthcare. In order to succeed with decision making tools, fine-grained data are required to build models relevant and valid at an individual level. Location and assemble of data to build such tools is not trivial.

Novel Nanoparticulate and Ionic Titanium Antigens for Hypersensitivity Testing.

Titanium is used in a wide variety of materials ranging from medical devices to materials used in everyday life. Adverse biological reactions that could occur in patients, consumers, and workers should be monitored and prevented. There is a lack of available agents to test and predict titanium-related hypersensitivity.

Early aseptic loosening of a mobile-bearing total knee replacement.

Background and purpose - Registry-based studies have reported an increased risk of aseptic tibial loosening for the cemented Low Contact Stress (LCS) total knee replacement compared with other cemented designs; however, the reasons for this have not been established. We made a retrieval analysis with the aim of identifying the failure mechanism. Patients and methods - We collected implants, cement, tissue, blood, and radiographs from 32 failed LCS Complete cases.

Signal Enhancement of the Dentate Nucleus at Unenhanced MR Imaging after Very High Cumulative Doses of the Macrocyclic Gadolinium-based Contrast Agent Gadobutrol: An Observational Study.

Purpose To test for measurable visual enhancement of the dentate nucleus (DN) on unenhanced T1-weighted magnetic resonance (MR) images in a cohort of patients with a primary brain tumor who had not received linear gadolinium-based contrast agents (GBCAs) but had received many injections of macrocyclic GBCAs. Materials and Methods Seventeen patients with high-grade gliomas who had received 10-44 administrations of the macrocyclic GBCA gadobutrol (0.1 mmol/kg of body weight) were retrospectively included in this regional ethics committee-approved study.

The Impact of Metal Ion Exposure on the Cellular Behavior of Human Osteoblasts and PBMCs: In Vitro Analyses of Osteolytic Processes.

Osteolysis in the periprosthetic tissue can be caused by metallic wear particles and ions that can originate from implant surface corrosion. These products influence cellular behavior and stimulate the expression of proinflammatory cytokines. The purpose of this study was to evaluate the impact of CoCr29Mo6 ions on cell survival, differentiation, and cytokine expression in human osteoblasts and peripheral blood mononuclear cells (PBMCs).

Impact of Maternal Selenium Status on Infant Outcome during the First 6 Months of Life.

Pregnant women and infants are at risk for selenium deficiency, which is known to have negative effects on immune and brain function. We have investigated selenium levels in 158 healthy never-pregnant women and in 114 pregnant and lactating women and their infants at age 6 months and related this to clinical outcomes during the first 6 months of life. Neurodevelopment was assessed with the parental questionnaire Ages and Stages (ASQ) at 6 months.