Adverse reactions to metal debris occur with all types of hip replacement not just metal-on-metal hips: a retrospective observational study of 3340 revisions for adverse reactions to metal debris from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man.

BACKGROUND: Adverse reactions to metal debris (ARMD) have resulted in the high short-term failure rates observed with metal-on-metal hip replacements. ARMD has recently been reported in non-metal-on-metal total hip replacements (non-MoM THRs) in a number of small cohort studies. However the true magnitude of this complication in non-MoM THRs remains unknown. We used a nationwide database to determine the risk of ARMD revision in all non-MoM THRs, and compared patient and surgical factors associated with ARMD revision between non-MoM and MoM hips. METHODS: We performed a retrospective observational study using data from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man. All primary hip replacements undergoing revision surgery for ARMD were included (n = 3,340). ARMD revision risk in non-MoM THRs was compared between different commonly implanted bearing surfaces and femoral head sizes (Chi-squared test). Differences in patient and surgical factors between non-MoM hips and MoM hips revised for ARMD were also analysed (Chi-squared test and unpaired t-test). RESULTS: Of all ARMD revisions, 7.5% (n = 249) had non-MoM bearing surfaces. The relative risk of ARMD revision was 2.35 times (95% CI 1.76-3.11) higher in ceramic-on-ceramic bearings compared with hard-on-soft bearings (0.055 vs. 0.024%; p < 0.001), and 2.80 times (95% CI 1.74-4.36) higher in 36 mm metal-on-polyethylene bearings compared to 28 mm and 32 mm metal-on-polyethylene bearings (0.058 vs. 0.021%; p < 0.001). ARMD revisions were performed earlier in non-MoM hips compared to MoM hips (mean 3.6-years vs. 5.6-years; p < 0.0001). Non-MoM hips had more abnormal findings at revision (63.1 vs. 35.7%; p < 0.001), and more intra-operative adverse events (6.4 vs. 1.6%; p < 0.001) compared to MoM hips. CONCLUSIONS: Although the overall risk of ARMD revision surgery in non-MoM THRs appears low, this risk is increasing, and is significantly higher in ceramic-on-ceramic THRs and 36 mm metal-on-polyethylene THRs. ARMD may therefore represent a significant clinical problem in non-MoM THRs

Variations in the pre-operative status of patients coming to primary hip replacement for osteoarthritis in European orthopaedic centres.

addresses: Nuffield Department of Orthopaedic Surgery, University of Oxford, Nuffield Orthopaedic Centre, Headington, Oxford, UK. [email protected]: PMCID: PMC2654855types: Journal Article; Multicenter Study; Research Support, Non-U.S. Gov't© 2009 Dieppe et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Total hip joint replacement (THR) is a high volume, effective intervention for hip osteoarthritis (OA). However, indications and determinants of outcome remain unclear. The 'EUROHIP consortium' has undertaken a cohort study to investigate these questions. This paper describes the variations in disease severity in this cohort and the relationships between clinical and radiographic severity, and explores some of the determinants of variation

Recommendations for a core outcome set for measuring standing balance in adult populations: a consensus-based approach

Standing balance is imperative for mobility and avoiding falls. Use of an excessive number of standing balance measures has limited the synthesis of balance intervention data and hampered consistent clinical practice.To develop recommendations for a core outcome set (COS) of standing balance measures for research and practice among adults.A combination of scoping reviews, literature appraisal, anonymous voting and face-to-face meetings with fourteen invited experts from a range of disciplines with international recognition in balance measurement and falls prevention. Consensus was sought over three rounds using pre-established criteria.The scoping review identified 56 existing standing balance measures validated in adult populations with evidence of use in the past five years, and these were considered for inclusion in the COS.Fifteen measures were excluded after the first round of scoring and a further 36 after round two. Five measures were considered in round three. Two measures reached consensus for recommendation, and the expert panel recommended that at a minimum, either the Berg Balance Scale or Mini Balance Evaluation Systems Test be used when measuring standing balance in adult populations.Inclusion of two measures in the COS may increase the feasibility of potential uptake, but poses challenges for data synthesis. Adoption of the standing balance COS does not constitute a comprehensive balance assessment for any population, and users should include additional validated measures as appropriate.The absence of a gold standard for measuring standing balance has contributed to the proliferation of outcome measures. These recommendations represent an important first step towards greater standardization in the assessment and measurement of this critical skill and will inform clinical research and practice internationally

Diagnostic guidelines for the histological particle algorithm in the periprosthetic neo-synovial tissue

Background The identification of implant wear particles and non-implant related particles and the characterization of the inflammatory responses in the periprosthetic neo-synovial membrane, bone, and the synovial-like interface membrane (SLIM) play an important role for the evaluation of clinical outcome, correlation with radiological and implant retrieval studies, and understanding of the biological pathways contributing to implant failures in joint arthroplasty. The purpose of this study is to present a comprehensive histological particle algorithm (HPA) as a practical guide to particle identification at routine light microscopy examination. Methods The cases used for particle analysis were selected retrospectively from the archives of two institutions and were representative of the implant wear and non-implant related particle spectrum. All particle categories were described according to their size, shape, colour and properties observed at light microscopy, under polarized light, and after histochemical stains when necessary. A unified range of particle size, defined as a measure of length only, is proposed for the wear particles with five classes for polyethylene (PE) particles and four classes for conventional and corrosion metallic particles and ceramic particles. Results All implant wear and non-implant related particles were described and illustrated in detail by category. A particle scoring system for the periprosthetic tissue/SLIM is proposed as follows: 1) Wear particle identification at light microscopy with a two-step analysis at low (× 25, × 40, and × 100) and high magnification (× 200 and × 400); 2) Identification of the predominant wear particle type with size determination; 3) The presence of non-implant related endogenous and/or foreign particles. A guide for a comprehensive pathology report is also provided with sections for macroscopic and microscopic description, and diagnosis. Conclusions The HPA should be considered a standard for the histological analysis of periprosthetic neo-synovial membrane, bone, and SLIM. It provides a basic, standardized tool for the identification of implant wear and non-implant related particles at routine light microscopy examination and aims at reducing intra-observer and inter-observer variability to provide a common platform for multicentric implant retrieval/radiological/histological studies and valuable data for the risk assessment of implant performance for regional and national implant registries and government agencies

High-resolution x-ray spectroscopic study of the electronic structure of the prototypical p-type transparent conducting oxide CuAlO2

The electronic structure of the prototypical p-type transparent conducting oxide CuAlO2 has been studied by O K and Cu L3 shell x-ray absorption and emission and AlKα excited x-ray photoemission spectroscopy. The nonresonant O K shell emission is dominated by the O 2p partial density of states, while the AlKα excited valence photoemission and nonresonant Cu L3 emission spectra are dominated by the Cu 3d partial density of states. All three techniques reveal mixing between O 2p and Cu 3d states. Cu L3 emission spectra excited just above the L3 threshold are dominated by inelastic scattering with 5.5eV energy loss. This energy is shown to correspond to the separation between the dominant peaks in the filled and empty densities of states. © 2005 The American Physical Society

Electronic origins of structural distortions in post-transition metal oxides: experimental and theoretical evidence for a revision of the lone pair model.

Structural distortions in post-transition metal oxides are often explained in terms of the influence of sp hybrid "lone pairs." Evidence is presented here showing that this model must be revised. The electronic structures of prototypically distorted alpha-PbO and alpha-Bi2O3 have been measured by high-resolution x-ray photoemission and soft x-ray emission spectroscopies. In contrast with the expectations of the lone pair model, a high density of metal 6s states is observed at the bottom of the valence band. The measurements are consistent with the results of density functional theory calculations

Electronic structure of the alpha and delta phases of Bi2O3: A combined ab initio and x-ray spectroscopy study

α- Bi2 O3 is the thermodynamically stable phase of Bi2 O3 at room temperature. We have performed a theoretical and experimental investigation of its electronic structure using a combination of gradient corrected density functional theory (DFT), along with x-ray photoemission and O-K shell x-ray absorption and emission spectroscopies. We examine the nature of bonding in α- Bi2 O3 and in particular explore the nature of the stereochemically active Bi electron lone pair. The Bi 6s states are found to be concentrated at the bottom of the valence band but the states contributing to the lone pair on Bi are derived from the top of the valence band. Mixing between O 2p and Bi 6s states is found to be crucial in producing the asymmetric density on Bi. The role of the lone pair in the fast ion conductor δ- Bi2 O3 is also investigated, through calculation of the electronic structure with 100, 110, and 111 alignment of oxygen vacancies. Alignment of the vacancies along 100 results in the most energetically favorable configuration of the δ phase, contrary to previous force field calculations and electrostatic arguments which favor the 111 alignment. © 2006 The American Physical Society

History of cervical disc arthroplasty

Enthusiasm for cervical disc arthroplasty is based on the premise that motion-preserving devices attenuate the progression of adjacent-segment disease (ASD) in the cervical spine. Arthrodesis, on the other hand, results in abnormal load transfer on adjacent segments, leading to the acceleration of ASD. It has taken several decades of pioneering work to produce clinically relevant devices that mimic the kinematics of the intervertebral disc. The goal of this work is to trace the origins of cervical arthroplasty technology and highlight the attributes of devices currently available in the market