Sample records for hip spacer implantation

  1. Complications after spacer implantation in the treatment of hip joint in- fections

    Microsoft Academic Search

    Jochen Jung; Nora Verena Schmid; Jens Kelm; Eduard Schmitt; Konstantinos Anagnostakos

    The aim of this retrospective study was to identify and evaluate complications after hip spacer implantation other than reinfection and\\/or infection persistence. Between 1999 and 2008, 88 hip spacer implantations in 82 patients have been performed. There were 43 male and 39 female patients at a mean age of 70 (43 - 89) years. The mean spacer implantation time was

  2. Two-stage revision surgery with preformed spacers and cementless implants for septic hip arthritis: a prospective, non-randomized cohort study

    Microsoft Academic Search

    Carlo L Romanò; Delia Romanò; Enzo Meani; Nicola Logoluso; Lorenzo Drago

    2011-01-01

    Background  Outcome data on two-stage revision surgery for deep infection after septic hip arthritis are limited and inconsistent. This\\u000a study presents the medium-term results of a new, standardized two-stage arthroplasty with preformed hip spacers and cementless\\u000a implants in a consecutive series of adult patients with septic arthritis of the hip treated according to a same protocol.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Nineteen patients (20 hips) were

  3. Investigations on the wear behaviour of the temporary PMMA-based hip Spacer-G.

    PubMed

    Affatato, S; Mattarozzi, A; Taddei, P; Robotti, P; Soffiatti, R; Sudanese, A; Toni, A

    2003-01-01

    Total hip replacement has become one of the most successful orthopaedic procedures. However, complications due to infections may give serious problems and have devastating consequences for the hip implant. The use of a temporary three-dimensional polymethylmethacrylate (PMMA) cement spacer may be an alternative to solve infections in hip implants, improving the lives of patients awaiting reimplantation. In order to evaluate their wear behaviour, five PMMA Spacer-G femoral heads were tested against five post-mortem pelves in a hip joint simulator with bovine calf serum as lubricant. The surface of the worn spacers was characterized by scanning electron microscopy (SEM) analysis; all the samples revealed a similar morphology, showing areas characterized by different degrees of wear. Particle debris was isolated from the lubricant and PMMA particles and bone fractions were quantified. The amount of debris was found to be higher than where no-temporary prostheses were used. However, this result is acceptable since wear debris is removed by lavage irrigation when the Spacer-G is explanted. On the basis of these data, it is considered that the use of the cement Spacer-G could be a promising approach to the treatment of complicated infections of the hip joint. Therefore, Spacer-G is worthy of further research. PMID:12578213

  4. Burnishing Techniques Strengthen Hip Implants

    NASA Technical Reports Server (NTRS)

    2010-01-01

    In the late 1990s, Lambda Research Inc., of Cincinnati, Ohio, received Small Business Innovation Research (SBIR) awards from Glenn Research Center to demonstrate low plasticity burnishing (LPB) on metal engine components. By producing a thermally stable deep layer of compressive residual stress, LPB significantly strengthened turbine alloys. After Lambda patented the process, the Federal Aviation Administration accepted LPB for repair and alteration of commercial aircraft components, the U.S. Department of Energy found LPB suitable for treating nuclear waste containers at Yucca Mountain. Data from the U.S. Food and Drug Administration confirmed LPB to completely eliminate the occurrence of fretting fatigue failures in modular hip implants.

  5. A Hip Implant Energy Harvester

    NASA Astrophysics Data System (ADS)

    Pancharoen, K.; Zhu, D.; Beeby, S. P.

    2014-11-01

    This paper presents a kinetic energy harvester designed to be embedded in a hip implant which aims to operate at a low frequency associated with body motion of patients. The prototype is designed based on the constrained volume available in a hip prosthesis and the challenge is to harvest energy from low frequency movements (< 1 Hz) which is an average frequency during free walking of a patient. The concept of magnetic-force-driven energy harvesting is applied to this prototype considering the hip movements during routine activities of patients. The magnetic field within the harvester was simulated using COMSOL. The simulated resonant frequency was around 30 Hz and the voltage induced in a coil was predicted to be 47.8 mV. A prototype of the energy harvester was fabricated and tested. A maximum open circuit voltage of 39.43 mV was obtained and the resonant frequency of 28 Hz was observed. Moreover, the power output of 0.96 ?W was achieved with an optimum resistive load of 250?.

  6. Instrumented hip implants: electric supply systems.

    PubMed

    Soares dos Santos, Marco P; Ferreira, Jorge A F; Ramos, A; Simões, José A O; Morais, Raul; Silva, Nuno M; Santos, Paulo M; Reis, M J C S; Oliveira, T

    2013-10-18

    Instrumented hip implants were proposed as a method to monitor and predict the biomechanical and thermal environment surrounding such implants. Nowadays, they are being developed as active implants with the ability to prevent failures by loosening. The generation of electric energy to power active mechanisms of instrumented hip implants remains a question. Instrumented implants cannot be implemented without effective electric power systems. This paper surveys the power supply systems of seventeen implant architectures already implanted in-vivo, namely from instrumented hip joint replacements and instrumented fracture stabilizers. Only inductive power links and batteries were used in-vivo to power the implants. The energy harvesting systems, which were already designed to power instrumented hip implants, were also analyzed focusing their potential to overcome the disadvantages of both inductive-based and battery-based power supply systems. From comparative and critical analyses of the methods to power instrumented implants, one can conclude that: inductive powering and batteries constrain the full operation of instrumented implants; motion-driven electromagnetic energy harvesting is a promising method to power instrumented passive and active hip implants. PMID:24050511

  7. MR imaging of hip arthroplasty implants.

    PubMed

    Fritz, Jan; Lurie, Brett; Miller, Theodore T; Potter, Hollis G

    2014-01-01

    Hip arthroplasty has become the standard treatment for end-stage hip disease, allowing pain relief and restoration of mobility in large numbers of patients; however, pain after hip arthroplasty occurs in as many as 40% of cases, and despite improved longevity, all implants eventually fail with time. Owing to the increasing numbers of hip arthroplasty procedures performed, the demographic factors, and the metal-on-metal arthroplasty systems with their associated risk for the development of adverse local tissue reactions to metal products, there is a growing demand for an accurate diagnosis of symptoms related to hip arthroplasty implants and for a way to monitor patients at risk. Magnetic resonance (MR) imaging has evolved into a powerful diagnostic tool for the evaluation of hip arthroplasty implants. Optimized conventional pulse sequences and metal artifact reduction techniques afford improved depiction of bone, implant-tissue interfaces, and periprosthetic soft tissue for the diagnosis of arthroplasty-related complications. Strategies for MR imaging of hip arthroplasty implants are presented, as well as the imaging appearances of common causes of painful and dysfunctional hip arthroplasty systems, including stress reactions and fractures; bone resorption and aseptic loosening; polyethylene wear-induced synovitis and osteolysis; adverse local tissue reactions to metal products; infection; heterotopic ossification; tendinopathy; neuropathy; and periprosthetic neoplasms. A checklist is provided for systematic evaluation of MR images of hip arthroplasty implants. MR imaging with optimized conventional pulse sequences and metal artifact reduction techniques is a comprehensive imaging modality for the evaluation of the hip after arthroplasty, contributing important information for diagnosis, prognosis, risk stratification, and surgical planning. PMID:25019450

  8. Release of gentamicin and vancomycin from preformed spacers in infected total hip arthroplasties: measurement of concentrations and inhibitory activity in patients' drainage fluids and serum.

    PubMed

    Regis, Dario; Sandri, Andrea; Samaila, Elena; Benini, Anna; Bondi, Manuel; Magnan, Bruno

    2013-01-01

    Gentamicin (G) and vancomycin (V) concentrations in drainage fluids obtained from patients during the first 24 hours after implantation of antibiotic-loaded polymethylmethacrylate (PMMA) spacers in two-stage revision of infected total hip arthroplasty were studied. The inhibitory activity of drainage fluids against different multiresistant clinical isolates was investigated as well. Seven hips were treated by implantation of industrial G-loaded spacers. Vancomycin was added by manually mixing with PMMA bone cement. Serum and drainage fluid samples were collected 1, 4, and 24 hours after spacer implantation. Antibiotics concentrations and drains bactericidal titer of combination were determined against multiresistant staphylococcal strains. The release of G and V from PMMA cement at the site of infection was prompt and effective. Serum levels were below the limit of detection. The local release kinetics of G and V from PMMA cement was similar, exerting a pronounced, combined inhibitory effect in the implant site. The inhibitory activity of drainage fluids showed substantial intersubject variability related to antibiotic concentrations and differed according to the pathogens tested. Gentamicin and vancomycin were released from temporary hip spacers at bactericidal concentrations, and their use in combination exerted strong inhibition against methicillin-resistant S. aureus and Coagulase Negative Staphylococci strains. PMID:24174916

  9. Information for Patients Who Have Metal-on-Metal Hip Implants

    MedlinePLUS

    ... Medical Devices Products and Medical Procedures Implants and Prosthetics Metal-on-Metal Hip Implants Section Contents Menu Products and Medical Procedures Implants and Prosthetics Metal-on-Metal Hip Implants The Hip Joint ...

  10. Hip Implant Modified To Increase Probability Of Retention

    NASA Technical Reports Server (NTRS)

    Canabal, Francisco, III

    1995-01-01

    Modification in design of hip implant proposed to increase likelihood of retention of implant in femur after hip-repair surgery. Decreases likelihood of patient distress and expense associated with repetition of surgery after failed implant procedure. Intended to provide more favorable flow of cement used to bind implant in proximal extreme end of femur, reducing structural flaws causing early failure of implant/femur joint.

  11. Current status of noncemented hip implants.

    PubMed

    Harris, W H

    1987-01-01

    Recently the operative techniques, instrumentation, design, and material properties of bony ingrowth total hip replacement have been greatly improved. I prefer a hemispherical acetabular component fixed with screws going through the metal shell. The titanium mesh allows microinterlock with new bone, and macrointerlock is obtained by adding bone graft into the unused screw holes. The femoral component, made of Tivanium with titanium mesh attached to it by a new process called diffusion bonding, retains superalloy fatigue strength characteristics. An intimate press fit is assured by the specific operative technique, and both the fiber mesh and the collar provide proximal stress transfer. The design affords a nondestructive method for removal if necessary. The short-term clinical results are promising; most patients function as well as with cemented total hip replacement. The incidence of thigh pain has been significantly reduced since prior reports of cementless total hip replacement; however, a few patients still have thigh pain. The results in revision surgery are also promising, but as in cemented total hip replacement, the functional capacity of revision cases is usually lower than primary cases. There is an increased capacity to correct complex and difficult acetabular problems with this acetabular component. Obviously, long-term data are needed to establish the behavior of these implants over the immediate and long term. PMID:3818349

  12. [Implant fractures in ceramic hip endoprostheses].

    PubMed

    Heisel, J; Schmitt, E

    1987-01-01

    Between 1974 and 1987, a total of 2356 ceramic hip endoprostheses, both primary and secondary, were implanted at the Orthopedic University Clinic in Homburg/Saar. Strem fractures occurred in three of these patients only, which corresponds to a relative frequency of 0.13%. In two instances, these were fatigue fractures of the AUTOPHOR I (WISIL) prosthesis stem, while in the third instance the fracture, of stem type 2 (ENDOCAST), was the result of a fault during casting. Fractures of ceramic components as a result of a direct trauma of sufficient force were observed in six cases (relative frequency of 0.25%). Persistent fractures only occurred where there was recurrent knocking of a long ceramic collar against the rim of the acetabulum (eight cases, relative frequency of 0.34%), mainly as a result of primary or secondary false positioning of the acetabulum (surgical error, aseptic loosening). Ceramic fractures when using the ceramics/polyethylene combination for joints have yet to be recorded. Given the authors' 12 years of experience, and considering the large number of patients treated fractures of high quality BIOLOX ceramics are a rarity. Both persistent fractures and exaggerated ceramic abrasion were almost always the result of false positioning of the acetabulum, with the recurrent knocking of the hip head ceramic collar playing a significant role. It is evident that the extent of tolerance of ceramics as regards undue strain with a subsequent danger of fracture is lower than that of the metal-polyethylene combination. PMID:3433902

  13. A preliminary biomechanical study of a novel carbon-fibre hip implant versus standard metallic hip implants.

    PubMed

    Bougherara, Habiba; Zdero, Rad; Dubov, Anton; Shah, Suraj; Khurshid, Shaheen; Schemitsch, Emil H

    2011-01-01

    Total hip arthroplasty is a widespread surgical approach for treating severe osteoarthritis of the human hip. Aseptic loosening of standard metallic hip implants due to stress shielding and bone loss has motivated the development of new materials for hip prostheses. Numerically, a three-dimensional finite element (FE) model that mimicked hip implants was used to compare a new hip stem to two commercially available implants. The hip implants simulated were a novel CF/PA12 carbon-fibre polyamide-based composite hip stem, the Exeter hip stem (Stryker, Mahwah, NJ, USA), and the Omnifit Eon (Stryker, Mahwah, NJ, USA). A virtual axial load of 3 kN was applied to the FE model. Strain and stress distributions were computed. Experimentally, the three hip stems had their distal portions rigidly mounted and had strain gauges placed along the surface at 3 medial and 3 lateral locations. Axial loads of 3 kN were applied. Measurements of axial stiffness and strain were taken and compared to FE analysis. The overall linear correlation between FE model versus experimental strains showed reasonable results for the lines-of-best-fit for the Composite (Pearson R(2)=0.69, slope=0.82), Exeter (Pearson R(2)=0.78, slope=0.59), and Omnifit (Pearson R(2)=0.66, slope=0.45), with some divergence for the most distal strain locations. From FE analysis, the von Mises stress range for the Composite stem was much lower than that in the Omnifit and Exeter implants by 200% and 45%, respectively. The preliminary experiments showed that the Composite stem stiffness (1982 N/mm) was lower than the metallic hip stem stiffnesses (Exeter, 2460 N/mm; Omnifit, 2543 N/mm). This is the first assessment of stress, strain, and stiffness of the CF/PA12 carbon-fibre hip stem compared to standard commercially-available devices. PMID:20952241

  14. A spacer that facilitates construction of implant-supported prostheses frameworks.

    PubMed

    Huband, M L; Hochstedler, J L; Salinas, T J

    1996-01-01

    This article describes a technique that uses polyvinlysiloxane (PVS) putty impression material to create adequate space between the tissue and inferior margin of a framework in pattern construction for implant supported hybrid dentures. This spacer is easily retrieved from the cast, so the dental technician can evaluate and adjust the spacer to a standardized thickness and shape it to form the framework's underside. Basic framework construction for implant hybrid dentures is also reviewed, including specific dimensions, acrylic retentive features and passive construction. PVS putty impression material is easy to obtain, maintains dimensions well and is easy to shape, making it an excellent choice for use as a spacer and a matrix to preserve the position of denture teeth during fabrication. PMID:9516261

  15. Optimal design of composite hip implants using NASA technology

    NASA Technical Reports Server (NTRS)

    Blake, T. A.; Saravanos, D. A.; Davy, D. T.; Waters, S. A.; Hopkins, D. A.

    1993-01-01

    Using an adaptation of NASA software, we have investigated the use of numerical optimization techniques for the shape and material optimization of fiber composite hip implants. The original NASA inhouse codes, were originally developed for the optimization of aerospace structures. The adapted code, which was called OPORIM, couples numerical optimization algorithms with finite element analysis and composite laminate theory to perform design optimization using both shape and material design variables. The external and internal geometry of the implant and the surrounding bone is described with quintic spline curves. This geometric representation is then used to create an equivalent 2-D finite element model of the structure. Using laminate theory and the 3-D geometric information, equivalent stiffnesses are generated for each element of the 2-D finite element model, so that the 3-D stiffness of the structure can be approximated. The geometric information to construct the model of the femur was obtained from a CT scan. A variety of test cases were examined, incorporating several implant constructions and design variable sets. Typically the code was able to produce optimized shape and/or material parameters which substantially reduced stress concentrations in the bone adjacent of the implant. The results indicate that this technology can provide meaningful insight into the design of fiber composite hip implants.

  16. Management of periprosthetic joint infection after total hip arthroplasty using a custom made articulating spacer (CUMARS); the Exeter experience.

    PubMed

    Tsung, Jason D; Rohrsheim, James A L; Whitehouse, Sarah L; Wilson, Matthew J; Howell, Jonathan R

    2014-09-01

    Periprosthetic joint infection (PJI) after THA is a major complication with an incidence of 1%-3%. We report our experiences with a technique using a custom-made articulating spacer (CUMARS) at the first of two-stage treatment for PJI. This technique uses widely available all-polyethylene acetabular components and the Exeter Universal stem, fixed using antibiotic loaded acrylic cement. Seventy-six hips were treated for PJI using this technique. Performed as the first of a two-stage procedure, good functional results were commonly seen, leading to postponing second stage indefinitely with retention of the CUMARS prosthesis in 34 patients. The CUMARS technique presents an alternative to conventional spacers, using readily available components that are well tolerated, allowing weight bearing and mobility, and achieving comparable eradication rates. PMID:24851790

  17. Modular hip implant fracture at the stem-sleeve interface.

    PubMed

    Parisi, Thomas; Burroughs, Brian; Kwon, Young-Min

    2015-03-01

    The use of modular implants in femoral stem design has grown increasingly popular over the last decade because of the theoretical advantage of more flexibility and optimization of femoral anteversion, limb length, and femoral component offset. With the benefit of increased surgical flexibility, however, modularity also carries the theoretical risks of fretting at the modular surfaces, sequelae of wear debris, and possible failure and fracture of the stem at the modular junction. Indeed, there have been an increasing number of reports of modular implants failing due to fracture at modular junctions. The S-ROM prosthesis (DePuy Orthopaedics, Inc, Warsaw, Indiana), however, has a stellar clinical record and has been used with good results in both primary and revision total hip arthroplasty. Only a single case of S-ROM failure at the stem-sleeve interface has been reported in the orthopedic literature. The aim of this case report was to present a succinct history of proximal modularity in total hip arthroplasty and to describe the only known case of this type of catastrophic failure in an S-ROM prosthesis with a metal-on-metal bearing. Despite a low level of serum metal ions on presentation, scanning electron microscopy showed findings consistent with corrosive processes and pseudotumor was seen at revision surgery. [Orthopedics. 2015; 38(3):e234-e239.]. PMID:25760513

  18. [Cobalt poisoning due to metal-on-metal hip implants].

    PubMed

    Dijkman, Marieke A; de Vries, Irma; Mulder-Spijkerboer, Henneke; Meulenbelt, Jan

    2012-01-01

    Since 2011, cobalt and chromium blood levels are measured in patients with a metal-on-metal hip implant (MoM prosthesis). In this article we discuss the health risks that are related to chronically elevated blood cobalt concentrations induced by abnormal wear and corrosion of the MoM prosthesis. Only a few patients who have systemic symptoms of poisoning, besides local symptoms around the failing MoM prosthesis, have been described in the literature. Toxic blood cobalt concentrations may be accompanied by hypothyroidism, polyneuropathy, impairment of cranial nerves II and VIII and cardiomyopathy. Treatment consists of removal of the prosthesis. In patients with a normal kidney function, the cobalt blood levels rapidly decrease and symptoms of cobalt intoxication subside. Chelation therapy should be restricted to those patients who are unable to undergo removal of the prosthesis immediately due to their medical condition. This can for example be because of a severe cobalt-induced cardiomyopathy. PMID:23075776

  19. Effect of ion implantation on the tribology of metal-on-metal hip prostheses.

    PubMed

    Bowsher, John G; Hussain, Azad; Williams, Paul; Nevelos, Jim; Shelton, Julia C

    2004-12-01

    Nitrogen ion implantation (which considerably hardens the surface of the bearing) may represent one possible method of reducing the wear of metal-on-metal (MOM) hip bearings. Currently there are no ion-implanted MOM bearings used clinically. Therefore a physiological hip simulator test was undertaken using standard test conditions, and the results compared to previous studies using the same methods. N2-ion implantation of high carbon cast Co-Cr-Mo-on-Co-Cr-Mo hip prostheses increased wear by 2-fold during the aggressive running-in phase compared to untreated bearing surfaces, plus showing no wear reductions during steady-state conditions. Although 2 specimens were considered in the current study, it would appear that ion implantation has no clinical benefit for MOM. PMID:15578563

  20. High-Tech Hip Implant for Wireless Temperature Measurements In Vivo

    PubMed Central

    Bergmann, Georg; Graichen, Friedmar; Dymke, Jörn; Rohlmann, Antonius; Duda, Georg N.; Damm, Philipp

    2012-01-01

    When walking long distances, hip prostheses heat up due to friction. The influence of articulating materials and lubricating properties of synovia on the final temperatures, as well as any potential biological consequences, are unknown. Such knowledge is essential for optimizing implant materials, identifying patients who are possibly at risk of implant loosening, and proving the concepts of current joint simulators. An instrumented hip implant with telemetric data transfer was developed to measure the implant temperatures in vivo. A clinical study with 100 patients is planned to measure the implant temperatures for different combinations of head and cup materials during walking. This study will answer the question of whether patients with synovia with poor lubricating properties may be at risk for thermally induced bone necrosis and subsequent implant failure. The study will also deliver the different friction properties of various implant materials and prove the significance of wear simulator tests. A clinically successful titanium hip endoprosthesis was modified to house the electronics inside its hollow neck. The electronics are powered by an external induction coil fixed around the joint. A temperature sensor inside the implant triggers a timer circuit, which produces an inductive pulse train with temperature-dependent intervals. This signal is detected by a giant magnetoresistive sensor fixed near the external energy coil. The implant temperature is measured with an accuracy of 0.1°C in a range between 20°C and 58°C and at a sampling rate of 2–10 Hz. This rate could be considerably increased for measuring other data, such as implant strain or vibration. The employed technique of transmitting data from inside of a closed titanium implant by low frequency magnetic pulses eliminates the need to use an electrical feedthrough and an antenna outside of the implant. It enables the design of mechanically safe and simple instrumented implants. PMID:22927973

  1. Investigation of Wear and Corrosion of a High-Carbon Stellite Alloy for Hip Implants

    NASA Astrophysics Data System (ADS)

    Hu, P. S.; Liu, R.; Liu, J.; McRae, G.

    2014-04-01

    Low-carbon Stellite 21 has been used as hip implant material for a number of decades; however, its limited metal-on-metal bearing has resulted in loosening between the femoral head and the acetabular cup of hip implants. In order to improve the metal-on-metal bearing, it is proposed that a high-carbon alloy, Stellite 720, surface coating be applied on Stellite 21 hip implants to improve mechanical and tribological performance. For this coating to be practical, it must also meet the requirements of corrosion resistance for orthopedic implant materials. In this research, Stellite 720 is investigated with pin-on-disk wear tests, and electrochemical and immersion corrosion tests in simulated human body fluid (Hank's solution; pH 7.4 at temperature of 37°C). The experimental results demonstrate that Stellite 720 exhibits much better wear resistance than Stellite 21, and has the potential for better corrosion resistance as well. The applicability of coating Stellite 21 hip implants with Stellite 720 is discussed.

  2. Mechanical properties of human bone-implant interface tissue in aseptically loose hip implants.

    PubMed

    Kraaij, Gert; Zadpoor, Amir A; Tuijthof, Gabrielle J M; Dankelman, Jenny; Nelissen, Rob G H H; Valstar, Edward R

    2014-10-01

    The main cause of failure in total hip replacement is aseptic loosening which is associated with the formation of a periprosthetic fibrous (interface) tissue. Despite important applications for finite element modeling of loose implants, the mechanical properties of the bone-implant interface tissue have never been measured in humans. In this study, we performed unconfined compression tests to characterize the mechanical properties of the interface tissue and to determine the parameters of various hyperelastic material models which were fitted to the measurements. Human interface tissues were retrieved during 21 elective revision surgeries from aseptically loosened cemented (N=10) and uncemented hip implants (N=11). Specimens were tested at a fixed deformation rate of 0.1mm/min up to a maximum force of 10N. Elastic moduli for low and high strain regions of the stress-strain curves were determined. Interface tissue from aseptically loose cemented prostheses shows higher elastic moduli (mean=1.85MPa, 95% C.I.=1.76-1.95MPa) in the high strain region as compared to that of the interface tissue from the cementless group (mean=1.65MPa, 95% C.I.=1.43-1.88MPa). The 5-terms Mooney-Rivlin model ( [Formula: see text] ) described the stress-strain behavior the best. Large variations in the mechanical behavior were observed both between specimens from the same patient as between those of different patients. The material model parameters were therefore estimated for the mean data as well as for the curves with the highest and lowest strain at the maximum load. The model parameters found for the mean data were C1=-0.0074MPa, C2=0.0019MPa, C3=0MPa, C4=-0.0032MPa and C5=0MPa in the cemented group and C1=-0.0137MPa, C2=0.0069MPa, C3=0.0026MPa, C4=-0.0094MPa and C5=0MPa in the cementless group. The results of this study can be used in finite element computer. PMID:25023868

  3. Mechanical strength of sliding crew-plate hip implants. A biomechanical study of unstable trochanteric fractures. VI.

    PubMed

    Jensen, J S

    1980-08-01

    Static load testing of sliding screw-plate hip implants manufactured from Cobalt-Chromium-Molybdenum alloy or 316 LVM stainless steel was performed. Implant angles of 135 degrees and 150 degrees were applied and the telescoping ability eliminated by gluing the screw to the barrel of the implant. In comparison with the results obtained in tests of McLaughlin and Jewett hip implants superior yield loads were determined for both implant angles. Calculations were made of the improvement of implant strength due to telescoping. Implants with a 135 degree angle are recommended for the fixation of unstable trochanteric fractures, as the hip joint load during normal level walking does not exceed the yield load of these implants. PMID:7446052

  4. Measuring the 3D-Position of Cementless Hip Implants using Pre and Postoperative CT Images

    Microsoft Academic Search

    G. Yamako; T. Hiura; K. Nakata; G. Omori; Y. Dohmae; M. Oda; T. Hara

    Quantitative measurement of the location of cementless hip implants postoperatively not only explains subsequent common complications,\\u000a such as impingement and loosening, but can also predict postoperative subject-specific primary stability, if combined with\\u000a the finite element method. However, the metal artifacts on the postoperative computed tomography (CT) image make it difficult\\u000a to estimate the threedimensional (3D) alignment, implant shape, bone geometry,

  5. A biomechanical assessment of modular and monoblock revision hip implants using FE analysis and strain gage measurements

    PubMed Central

    2010-01-01

    Background The bone loss associated with revision surgery or pathology has been the impetus for developing modular revision total hip prostheses. Few studies have assessed these modular implants quantitatively from a mechanical standpoint. Methods Three-dimensional finite element (FE) models were developed to mimic a hip implant alone (Construct A) and a hip implant-femur configuration (Construct B). Bonded contact was assumed for all interfaces to simulate long-term bony ongrowth and stability. The hip implants modeled were a Modular stem having two interlocking parts (Zimmer Modular Revision Hip System, Zimmer, Warsaw, IN, USA) and a Monoblock stem made from a single piece of material (Stryker Restoration HA Hip System, Stryker, Mahwah, NJ, USA). Axial loads of 700 and 2000 N were applied to Construct A and 2000 N to Construct B models. Stiffness, strain, and stress were computed. Mechanical tests using axial loads were used for Construct A to validate the FE model. Strain gages were placed along the medial and lateral side of the hip implants at 8 locations to measure axial strain distribution. Results There was approximately a 3% average difference between FE and experimental strains for Construct A at all locations for the Modular implant and in the proximal region for the Monoblock implant. FE results for Construct B showed that both implants carried the majority (Modular, 76%; Monoblock, 66%) of the 2000 N load relative to the femur. FE analysis and experiments demonstrated that the Modular implant was 3 to 4.5 times mechanically stiffer than the Monoblock due primarily to geometric differences. Conclusions This study provides mechanical characteristics of revision hip implants at sub-clinical axial loads as an initial predictor of potential failure. PMID:20462448

  6. Fluoroscopy-guided implantation of subacromial "biodegradable spacer" using local anesthesia in patients with irreparable rotator cuff tear.

    PubMed

    Gervasi, Enrico; Cautero, Enrico; Dekel, Assaf

    2014-08-01

    Treatment of massive rotator cuff tears can be challenging, especially when tears are considered irreparable or, when repaired, at significant risk of retear. A surgical technique is described using a biodegradable subacromial balloon-shaped spacer (InSpace; Ortho-Space, Caesarea, Israel) that, when implanted between the humeral head and acromion, permits smooth, frictionless gliding, supporting shoulder biomechanics. The specific insertion technique described herein is a simple procedure that can be performed in a day-care or outpatient setting with patients under local anesthesia, thus providing a treatment option for patients with multiple comorbidities complicating or contraindicating surgery, such as reverse arthroplasty under general anesthesia. PMID:25264508

  7. Do gait adaptations during stair climbing result in changes in implant forces in subjects with total hip replacements compared to normal subjects?

    Microsoft Academic Search

    Kharma C. Foucher; Debra E. Hurwitz; Markus A. Wimmer

    2008-01-01

    BackgroundThe study objective was to identify gait abnormalities and their relationships to hip loading during stair climbing after total hip replacement. Hypotheses: (1) total hip replacement subjects would have significantly lower dynamic hip range of motion and peak external moments during stair climbing compared to normal subjects and (2) the peak twisting moment about the long axis of the implant

  8. The influence of the centre of rotation on implant survival using a modular stem hip prosthesis

    PubMed Central

    De Fine, Marcello; Biondi, Federico; Tassinari, Enrico; Galvani, Andrea; Toni, Aldo

    2008-01-01

    The restoration of the hip centre of rotation in an anatomical position is considered to be relevant for total hip prosthesis survival. When the cup is implanted with a high centre of rotation, the lever arm of the abductor muscles is decreased, causing higher joint-reaction forces. Modular stems with varying lengths and geometries can be used to balance soft tissues, and ceramic bearing surfaces can be used to reduce the wear rate. Forty-four hip replacements performed with a high hip centre of rotation were matched with 44 performed with an anatomical centre of rotation. In all cases the preoperative diagnosis was dysplasia of the hip (DDH) and cementless modular neck prostheses with ceramic bearing surfaces were used. At nine years follow-up the mean Harris hip and WOMAC scores were not statistically different. All stems and cups were stable; the femoral offset was no different between the two groups (p?=?0.4) as leg-length discrepancy (p?=?0.25). PMID:19099304

  9. Larger diameter bearings reduce wear in metal-on-metal hip implants.

    PubMed

    Affatato, S; Leardini, W; Jedenmalm, A; Ruggeri, O; Toni, A

    2007-03-01

    Metal-on-metal hip arthroplasty has the longest clinical history of all total arthroplasties. We asked whether large diameter femoral heads would result in less wear than those with small diameters. We also asked if there is a threshold diameter that ensures good wear behavior. We tested three batches of cast high-carbon cobalt-chromium-molybdenum hip implants (28 mm, 36 mm, and 54 mm diameters) in a hip simulator for 5 million cycles. We used bovine serum as lubricant and weighed the samples at regular intervals during testing. The 28-mm configuration had almost twice the wear of the 54-mm configuration, but we observed no difference between the 36-mm and the 54-mm configurations. The similarity in the wear performances of the larger configurations supports the presence of a threshold diameter that ensures good wear behavior. PMID:17065844

  10. Optical measurement system for preparation and after-OP-check of a hip joint endoprothetic implantation

    NASA Astrophysics Data System (ADS)

    Maschke, R.; Lempe, B.; Taudt, Ch.; Rudek, F.; Baselt, T.; Basan, F.; Grunert, R.; Hartmann, P.

    2014-02-01

    With 332,000 operations carried out every year, the implantation of an artificial hip joint is one of the most common surgical operations performed in the US. According to prognosis which takes the demographical change into account, the number of these operations will increase in the coming years. One of the essential requirements is the perfect reconstruction of the biomechanical functions, especially the knowledge about the center of the hip rotation and the length of the leg. Based on this information it is possible to ensure the right position of the newly set leg during surgery. The aim of this work is to present and evaluate an optical measurement method in order to gather information about the center of the hip joint and the leg length. An appropriate laboratory setup has been designed and implemented in order to evaluate two different approaches: a structured light-method consisting of a DLP-Beamer or a laser source which projects defined patterns onto the patient and a marker-based system. Together with this both methods are combined with custom software to determine the hip joint center and the leg length with an accuracy of around +/- 0.2 inches. The clinical use of the tested approaches would give the surgeon the opportunity to reset the implant-parameters in the course of the surgery. In this way subsequent illnesses such as scoliotic pelvis can be prevented.

  11. Comparative surface examinations on corund blasted titanium implants and explants in total hip arthroplasty

    Microsoft Academic Search

    Alexander Schuh; Wolfgang Uter; Werner Kachler; Jürgen Göske; Günther Zeiler; Christoph Lill

    2005-01-01

    Introduction: Blasting techniques using corundum to create rough surfaces are used in many different processes for the surface treatment\\u000a of hip implants. Recent evidence points an association between residual particles and early loosenings in the sense of third-body\\u000a wear. Materials and method: The surfaces of five unused, original-packaged CLS stems and ARR-Titan supporting rings, respectively, were compared with\\u000a five explanted

  12. Good short-term outcome of primary total hip arthroplasty with cementless bioactive glass ceramic bottom-coated implants

    PubMed Central

    2012-01-01

    Background and purpose Cementless total hip arthroplasty is currently favored by many orthopedic surgeons. The design of the porous surface is critically important for long-term fixation. We examined the clinical and radiographic outcome of the cementless titanium hip implant with a bottom coating of apatite-wollastonite containing bioactive glass ceramic. Methods We retrospectively reviewed 109 hips (92 patients) that had undergone primary cementless total hip arthroplasty with bioactive glass ceramic bottom-coated implants. The mean follow-up period was 7 (3–9) years. Hip joint function was evaluated with the Merle d’Aubigné and Postel hip score, and radiographic changes were determined from anteroposterior radiographs. Results The mean hip score improved from 9.7 preoperatively to 17 at the final follow-up. The overall survival rate was 100% at 9 years, when radiographic loosening or revision for any reason was used as the endpoint. 3 stems in 2 patients subsided more than 3 mm vertically within 1 year after implantation. Radiographs of the interface of the stem and femur were all classified as bone ingrowth fixation. Conclusions The short-term results of this study show good outcome for cementless implants with a bottom coating of apatite-wollastonite containing bioactive glass ceramic. PMID:23043270

  13. In vivo implant fixation of carbon fiber-reinforced PEEK hip prostheses in an ovine model.

    PubMed

    Nakahara, Ichiro; Takao, Masaki; Bandoh, Shunichi; Bertollo, Nicky; Walsh, William R; Sugano, Nobuhiko

    2013-03-01

    Carbon fiber-reinforced polyetheretherketone (CFR/PEEK) is theoretically suitable as a material for use in hip prostheses, offering excellent biocompatibility, mechanical properties, and the absence of metal ions. To evaluate in vivo fixation methods of CFR/PEEK hip prostheses in bone, we examined radiographic and histological results for cementless or cemented CFR/PEEK hip prostheses in an ovine model with implantation up to 52 weeks. CFR/PEEK cups and stems with rough-textured surfaces plus hydroxyapatite (HA) coatings for cementless fixation and CFR/PEEK cups and stems without HA coating for cement fixation were manufactured based on ovine computed tomography (CT) data. Unilateral total hip arthroplasty was performed using cementless or cemented CFR/PEEK hip prostheses. Five cementless cups and stems and six cemented cups and stems were evaluated. On the femoral side, all cementless stems demonstrated bony ongrowth fixation and all cemented stems demonstrated stable fixation without any gaps at both the bone-cement and cement-stem interfaces. All cementless cases and four of the six cemented cases showed minimal stress shielding. On the acetabular side, two of the five cementless cups demonstrated bony ongrowth fixation. Our results suggest that both cementless and cemented CFR/PEEK stems work well for fixation. Cup fixation may be difficult for both cementless and cemented types in this ovine model, but bone ongrowth fixation on the cup was first seen in two cementless cases. Cementless fixation can be achieved using HA-coated CFR/PEEK implants, even under load-bearing conditions. PMID:23097319

  14. Revision total hip and knee arthroplasty implant identification: implications for use of Unique Device Identification 2012 AAHKS member survey results.

    PubMed

    Wilson, Natalia A; Jehn, Megan; York, Sally; Davis, Charles M

    2014-02-01

    FDA's Unique Device Identification (UDI) Rule will mandate manufacturers to assign unique identifiers to their marketed devices. UDI use is expected to improve implant documentation and identification. A 2012 American Association of Hip and Knee Surgeons membership survey explored revision total hip and knee arthroplasty implant identification processes. 87% of surgeons reported regularly using at least 3 methods to identify failed implants pre-operatively. Median surgeon identification time was 20 min; median staff time was 30 min. 10% of implants could not be identified pre-operatively. 2% could not be identified intra-operatively. UDI in TJA registry and UDI in EMR were indicated practices to best support implant identification and save time. FDA's UDI rule sets the foundation for UDI use in patient care settings as standard practice for implant documentation. PMID:23890830

  15. [15-year results following implantation of a stem type AML hip prosthesis].

    PubMed

    Schwerter, K; Meyenberg, A; Sander, K; Layher, F; Roth, A

    2013-06-01

    The trend in arthroplasty of the hip joint to implement new models is partly based on theoretical considerations. In order to verify to which extent the philosophy of individual models is ultimately successful, the presentation of long-term results is required. In the years 1991 and 1992, 433 patients with primary implantation of an uncemented total hip replacement in primary coxarthrosis with a stem type AML (anatomic medullary locking) were treated surgically. 283 of them got a cementless cup type Duraloc. In 311 (71.8 %) patients the mean survival rate of the prosthesis could be determined at a mean follow-up of 15.5 years. 145 (33.5 %) patients were followed up completely both clinically and radiologically. Radiographically, the stem position, changes of the periprosthetic bone of the stem and the cup, as well as the wear of the cups were examined. The cumulative survival rate of the AML stem after 15.5 years was 97.5 %, of the Duraloc cup 88.2 %. The clinical results of the hip scores according to Harris and Merle d'Aubigné were good and excellent and patient satisfaction was very high. There was no relationship between stem position, stress shielding and surrounding lyses at the femur and the acetabulum and survival of stem or cup. There was no correlation between inlay wear and survival of the Duraloc cup. A subsiding of the stem in 2 cases had no effect on the clinical symptoms and quality of life. The press-fit implanted AML stem and the Duraloc cup revealed very good results during the investigation period. Like other implants, the survival rate is limited at the presented implant mainly by the cup. PMID:23696163

  16. Hip

    Microsoft Academic Search

    Cheryl A. Petersilge; Carlos A. Guanche

    As magnetic resonance (MR) has become increasingly more popular for assessment of hip and groin pain, our knowledge of the\\u000a many pathologic conditions affecting the hip and pelvis has grown. Magnetic resonance has contributed significantly to our\\u000a understanding of sports-related injuries as well as to underlying conditions such as femoroacetabular impingement, which can\\u000a lead to pain and limited range of

  17. Hip-inspired implant for revision of failed reverse shoulder arthroplasty with severe glenoid bone loss

    PubMed Central

    2014-01-01

    Background and purpose Glenoid reconstruction and inverted glenoid re-implantation is strongly advocated in revisions of failed reverse shoulder arthroplasty (RSA). Nevertheless, severe glenoid deficiency may preclude glenoid reconstruction and may dictate less favorable solutions, such as conversion to hemiarthropasty or resection arthropasty. The CAD/CAM shoulder (Stanmore Implants, Elstree, UK), a hip arthroplasty-inspired implant, may facilitate glenoid component fixation in these challenging revisions where glenoid reconstruction is not feasible. We questioned (1) whether revision arthroplasty with the CAD/CAM shoulder would alleviate pain and improve shoulder function in patients with failed RSA, not amenable to glenoid reconstruction, (2) whether the CAD/CAM hip-inspired glenoid shell would enable secure and durable glenoid component fixation in these challenging revisions. Patients and methods 11 patients with failed RSAs and unreconstructable glenoids underwent revision with the CAD/CAM shoulder and were followed-up for mean 35 (28–42) months. Clinical outcomes included the Oxford shoulder score, subjective shoulder value, pain rating, physical examination, and shoulder radiographs. Results The average Oxford shoulder score and subjective shoulder value improved statistically significantly after the revision from 50 to 33 points and from 17% to 48% respectively. Pain rating at rest and during activity improved significantly from 5.3 to 2.3 and from 8.1 to 3.8 respectively. Active forward flexion increased from 25 to 54 degrees and external rotation increased from 9 to 21 degrees. 4 patients required reoperation for postoperative complications. No cases of glenoid loosening occurred. Interpretation The CAD/CAM shoulder offers an alternative solution for the treatment of failed RSA that is not amenable to glenoid reconstruction. PMID:24650026

  18. Modular titanium alloy neck adapter failures in hip replacement - failure mode analysis and influence of implant material

    Microsoft Academic Search

    Thomas M Grupp; Thomas Weik; Wilhelm Bloemer; Hanns-Peter Knaebel

    2010-01-01

    BACKGROUND: Modular neck adapters for hip arthroplasty stems allow the surgeon to modify CCD angle, offset and femoral anteversion intraoperatively. Fretting or crevice corrosion may lead to failure of such a modular device due to high loads or surface contamination inside the modular coupling. Unfortunately we have experienced such a failure of implants and now report our clinical experience with

  19. Implant based differences in adverse local tissue reaction in failed total hip arthroplasties: a morphological and immunohistochemical study

    PubMed Central

    2014-01-01

    Background Adverse local tissue reaction (ALTR) is characterized by periprosthetic soft tissue inflammation composed of a mixed inflammatory cell infiltrate, extensive soft tissue necrosis, and vascular changes. Multiple hip implant classes have been reported to result in ALTR, and clinical differences may represent variation in the soft tissue response at the cellular and tissue levels. The purpose of this study was to describe similarities and differences in periprosthetic tissue structure, organization, and cellular composition by conventional histology and immunohistochemistry in ALTR resulting from two common total hip arthroplasty (THA) implant classes. Methods Consecutive patients presenting with ALTR from two major hip implant classes (N?=?54 patients with Dual-Modular Neck implant; N?=?14 patients with Metal-on-Metal implant) were identified from our prospective Osteolysis Tissue Database and Repository. Clinical characteristics including age, sex, BMI, length of implantation, and serum metal ion levels were recorded. Retrieved synovial tissue morphology was graded using light microscopy and cellular composition was assessed using immunohistochemistry. Results Length of implantation was shorter in the DMN group versus MoM THA group (21.3 [8.4] months versus 43.6 [13.8] months respectively; p?implant performance. Morphologic examination revealed a common spectrum of neo-synovial proliferation and necrosis in both groups. Macrophages were more commonly present in diffuse sheets (Grade 3) in the MoM relative to DMN group (p?=?0.016). Perivascular lymphocytes with germinal centers (Grade 4) were more common in the DMN group, which trended towards significance (p?=?0.066). Qualitative differences in corrosion product morphology were seen between the two groups. Immunohistochemistry showed features of a CD4 and GATA-3 rich lymphocyte reaction in both implants, with increased ratios of perivascular T-cell relative to B-cell markers in the DMN relative to the MoM group (p?=?0.032). Conclusion Our results demonstrate that both implant classes display common features of neo-synovial proliferation and necrosis with a CD4 and GATA-3 rich inflammatory infiltrate. Qualitative differences in corrosion product appearance, macrophage morphology, and lymphocyte distributions were seen between the two implant types. Our data suggests that ALTR represents a histological spectrum with implant-based features. PMID:25242891

  20. In vivo severe corrosion and hydrogen embrittlement of retrieved modular body titanium alloy hip-implants.

    PubMed

    Rodrigues, Danieli C; Urban, Robert M; Jacobs, Joshua J; Gilbert, Jeremy L

    2009-01-01

    Titanium alloys are widely used in total-joint replacements due to a combination of outstanding mechanical properties, biocompatibility, passivity, and corrosion resistance. Nevertheless, retrieval studies have pointed out that these materials can be subjected to localized or general corrosion in modular interfaces when mechanical abrasion of the oxide film (fretting) occurs. Modularity adds large crevice environments, which are subject to micromotion between contacting interfaces and differential aeration of the surface. Titanium alloys are also known to be susceptible to hydrogen absorption, which can induce precipitation of hydrides and subsequent brittle failure. In this work, the surface of three designs of retrieved hip-implants with Ti-6Al-4V/Ti-6Al-4V modular taper interfaces in the stem were investigated for evidence of severe corrosion and precipitation of brittle hydrides during fretting-crevice corrosion in the modular connections. The devices were retrieved from patients and studied by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), and chemical analysis. The surface qualitative investigation revealed severe corrosion attack in the mating interfaces with evidence of etching, pitting, delamination, and surface cracking. In vivo hydrogen embrittlement was shown to be a mechanism of degradation in modular connections resulting from electrochemical reactions induced in the crevice environment of the tapers during fretting-crevice corrosion. PMID:18683224

  1. A comparative FEA of the debonding process in different concepts of cemented hip implants.

    PubMed

    Pérez, M A; García-Aznar, J M; Doblaré, M; Seral, B; Seral, F

    2006-07-01

    Debonding of the stem-cement interface and damage accumulation in the cement mantle are basic events that contribute to the long-term failure of cemented hip reconstructions. In this work, a numerical study with these two processes coupled is presented. On the one hand, debonding of the stem-cement interface was simulated by means of a cohesive surface theory that was implemented into an interface finite element. This interface model includes a tensile-shear behavior law, the fatigue failure of the interface, and the friction evolution between both surfaces. On the other hand, damage accumulation in the cement was formulated through the theory of continuum damage mechanics, considering cement damage due to tension, creep under compression, crack closure effects, non-linear damage accumulation and cement residual stresses appearing during polymerisation. This methodology was applied to simulate and compare the degradation process of the cement and stem-cement interface in four different concepts of design: Exeter, Charnley, Elite Plus and ABG II stems. As the actual mechanical properties of the surface of each specific prosthesis are not known, we assumed the same for all of them, distinguishing between polished and matt surfaces. With this assumption, the predicted results showed that the debonding process is very different for each implant depending on the stem geometry. Lower cement deterioration was obtained for the Exeter and ABG II stems, while the lowest stem-cement interface debonding was produced in the Exeter and the Elite Plus stems. PMID:16257253

  2. IN VIVO SEVERE CORROSION AND HYDROGEN EMBRITTLEMENT OF RETRIEVED MODULAR BODY TITANIUM ALLOY HIP-IMPLANTS

    PubMed Central

    Rodrigues, Danieli C.; Urban, Robert M.; Jacobs, Joshua J.; Gilbert, Jeremy L.

    2009-01-01

    Titanium alloys are widely used in total-joint replacements due to a combination of outstanding mechanical properties, biocompatibility, passivity and corrosion resistance. Nevertheless, retrieval studies have pointed out that these materials can be subjected to localized or general corrosion in modular interfaces when mechanical abrasion of the oxide film (fretting) occurs. Modularity adds large crevice environments, which are subject to micromotion between contacting interfaces and differential aeration of the surface. Titanium alloys are also known to be susceptible to hydrogen absorption, which can induce precipitation of hydrides and subsequent brittle failure. In this work, the surface of three designs of retrieved hip-implants with Ti-6Al-4V/Ti-6Al-4V modular taper interfaces in the stem were investigated for evidence of severe corrosion and precipitation of brittle hydrides during fretting-crevice corrosion in the modular connections. The devices were retrieved from patients and studied by means of scanning electron microscopy (SEM), x-ray diffraction (XRD) and chemical analysis. The surface qualitative investigation revealed severe corrosion attack in the mating interfaces with evidence of etching, pitting, delamination and surface cracking. In vivo hydrogen embrittlement was shown to be a mechanism of degradation in modular connections resulting from electrochemical reactions induced in the crevice environment of the tapers during fretting-crevice corrosion. PMID:18683224

  3. Clinical and radiological results after implantation of the femoral neck preserving Delfi M hip prosthesis: a case series.

    PubMed

    Budde, Stefan; Windhagen, Henning; Lerch, Matthias; Broese, Maximilian; Götze, Patricc; Thorey, Fritz

    2012-01-01

    Various types of bone preserving total hip prostheses with a proximal force transmission concept have been developed for younger adults, one of these being the implant "Delfi M®", produced by ESKA until 2009. Since the demand could not meet the expectations, the production was stopped due to economic reasons so that only 31 implants of this type were sold and even less actually implanted. This study followed up 15 Delfi M® prostheses in 12 patients for 3.1 years and represents the only existing valid data about this implant.Demographical, preoperative and postoperative data including clinical scores (HOOS and mHHS) were collected retrospectively. Postoperative X-rays were analyzed by an independent radiologist. One implant had to be exchanged due to an infection and another one due to excessive implant migration. The mHHS and the HOOS scores showed a significant improvement after surgery. In the radiological analysis, there were no signs of radiolucent lines or osteolyses.This trial demonstrates good clinical and radiological midterm results for the Delfi M prosthesis. Limitations of this study are a small sample size and a follow-up time of 3 years at only one timepoint. PMID:22508021

  4. Wear behaviour of cobalt-chromium-molybdenum alloys used in metal-on-metal hip implants

    NASA Astrophysics Data System (ADS)

    Varano, Rocco

    The influence of carbon (C) content, microstructure, crystallography and mechanical properties on the wear behaviour of metal-on-metal (MM) hip implants made from commercially available cobalt-chromium-molybdenum (CoCrMo) alloys designated as American Society of Testing and Materials (ASTM) grade F1537, F75 and as-cast were studied in this work. The as-received bars of wrought CoCrMo alloys (ASTM F1537 of either about 0.05% or 0.26% C) were each subjected to various heat treatments to develop different microstructures. Pin and plate specimens were fabricated from each bar and were tested against each other using a linear reciprocating pin-on-plate apparatus in 25% by volume bovine serum solution. The applied normal load was 9.81 N and the reciprocating plate had a sinusoidal velocity with an average speed of 26 mm/s. The wear was measured gravimetrically and it was found to be most strongly affected by alloy C content, irrespective of grain size or carbide morphology. More precisely, the wear behaviour was directly correlated to the dissolved C content of the alloys. Increased C in solid-solution coincided with lower volumetric wear since C helps to stabilize the face-centred cubic (FCC) crystal structure thus limiting the amount of strain induced transformation (SIT) to the hexagonal close-packed crystal structure (HCP). Based on the observed surface twinning in and around the contact zone and the potentially detrimental effect of the HCP phase, it was postulated that the MM wear behaviour of CoCrMo alloys in the present study was controlled by a deformation mechanism, rather than corrosion or tribochemical reactions.

  5. No association between serum metal ions and implant fixation in large-head metal-on-metal total hip arthroplasty

    PubMed Central

    Søballe, Kjeld; Jakobsen, Stig Storgaard; Lorenzen, Nina Dyrberg; Mechlenburg, Inger; Stilling, Maiken

    2014-01-01

    Background The mechanism of failure of metal-on-metal (MoM) total hip arthroplasty (THA) has been related to a high rate of metal wear debris, which is partly generated from the head-trunnion interface. However, it is not known whether implant fixation is affected by metal wear debris. Patients and methods 49 cases of MoM THA in 41 patients (10 women) with a mean age of 52 (28–68) years were followed with stereoradiographs after surgery and at 1, 2, and 5 years to analyze implant migration by radiostereometric analysis (RSA). Patients also participated in a 5- to 7-year follow-up with measurement of serum metal ions, questionnaires (Oxford hip score (OHS) and Harris hip score (HHS)), and measurement of cup and stem positions and systemic bone mineral density. Results At 1–2 years, mean total translation (TT) was 0.04 mm (95% CI: –0.07 to 0.14; p = 0.5) for the stems; at 2–5 years, mean TT was 0.13 mm (95% CI: –0.25 to –0.01; p = 0.03), but within the precision limit of the method. For the cups, there was no statistically significant TT or total rotation (TR) at 1–2 and 2–5 years. At 2–5 years, we found 4 cups and 5 stems with TT migrations exceeding the precision limit of the method. There was an association between cup migration and total OHS < 40 (4 patients, 4 hips; p = 0.04), but there were no statistically significant associations between cup or stem migration and T-scores < –1 (n = 10), cup and stem positions, or elevated serum metal ion levels (> 7µg/L (4 patients, 6 hips)). Interpretation Most cups and stems were well-fixed at 1–5 years. However, at 2–5 years, 4 cups and 5 stems had TT migrations above the precision limits, but these patients had serum metal ion levels similar to those of patients without measurable migrations, and they were pain-free. Patients with serum metal ion levels > 7 µg/L had migrations similar to those in patients with serum metal ion levels < 7 µg/L. Metal wear debris does not appear to influence the fixation of hip components in large-head MoM articulations at medium-term follow-up. PMID:24847790

  6. Superelastic Orthopedic Implant Coatings

    NASA Astrophysics Data System (ADS)

    Fournier, Eric; Devaney, Robert; Palmer, Matthew; Kramer, Joshua; El Khaja, Ragheb; Fonte, Matthew

    2014-07-01

    The demand for hip and knee replacement surgery is substantial and growing. Unfortunately, most joint replacement surgeries will fail within 10-25 years, thereby requiring an arduous, painful, and expensive revision surgery. To address this issue, a novel orthopedic implant coating material ("eXalt") has been developed. eXalt is comprised of super elastic nitinol wire that is knit into a three-dimensional spacer fabric structure. eXalt expands in vivo to conform to the implantation site and is porous to allow for bone ingrowth. The safety and efficacy of eXalt were evaluated through structural analysis, mechanical testing, and a rabbit implantation model. The results demonstrate that eXalt meets or exceeds the performance of current coating technologies with reduced micromotion, improved osseointegration, and stronger implant fixation in vivo.

  7. One-Stage Revision Arthroplasty for Infected Hip Replacements

    PubMed Central

    Muñoz-Mahamud, Ernesto; Gallart, Xavier; Soriano, Alejandro

    2013-01-01

    Infection remains a serious complication after total hip arthroplasty (THA) and is a leading cause of hip revision surgery. It is currently accepted that removal of the prosthesis is essential to curing an infection when facing chronic PJIs with prosthesis loosening. In order to avoid the disadvantages of a two-stage approach, some authors have proposed a one-stage hip revision for the treatment of hip prosthesis infection in selected patients using not only antibiotic-loaded cemented components but also cementless implant. In the case of a one-stage procedure, the patient is exposed to a single major procedure and therefore lower cumulative perioperative risk. A functional prosthesis replacement is completed without exposure to the complications associated with spacers. In addition, there are also benefits both financially and in terms of resource allocation. PMID:23898350

  8. Toxicology-based cancer causation analysis of CoCr-containing hip implants: a quantitative assessment of genotoxicity and tumorigenicity studies.

    PubMed

    Christian, Whitney V; Oliver, Lindsay D; Paustenbach, Dennis J; Kreider, Marisa L; Finley, Brent L

    2014-09-01

    In this paper, quantitative methods were used to evaluate the weight of evidence regarding a causative relationship between cobalt-chromium (CoCr)-containing hip implants and increased cancer risk. We reviewed approximately 80 published papers and identified no-observed-adverse-effect level (NOAEL) and/or lowest-observed-adverse-effect level (LOAEL) values for specific endpoints of interest: genotoxic effects from in vitro studies with human cell lines as well as genotoxicity and tumor formation in animal bioassays. Test articles included Co particles and ions, Cr particles and ions, and CoCr alloy particles as well as CoCr alloy implants. The NOAEL/LOAEL values were compared with body burdens of Co/Cr particles and ions we calculated to exist in systemic tissues of hip implant patients under normal and excessive wear conditions. We found that approximately 40 tumor bioassays have been conducted with CoCr alloy implants or Co/Cr particles and ions at levels hundreds to thousands of times higher than those present in hip implant patients, and none reported a statistically significant increased incidence of systemic tumors. Results from in vitro and in vivo genotoxicity assays, which are relatively less informative owing to false positives and other factors, also indicated that DNA effects would be highly unlikely to occur as a result of wear debris from a CoCr implant. Hence, the toxicological weight of evidence suggests that CoCr-containing hip implants are unlikely to be associated with an increased risk of systemic cancers, which is consistent with published and ongoing cancer epidemiology studies involving patients with CoCr hip implants. PMID:25080401

  9. Multi-scalar analysis of hip implant components using modal decomposition

    NASA Astrophysics Data System (ADS)

    Grandjean, J.; Le Goic, G.; Favreliere, H.; Ledoux, Y.; Samper, S.; Formosa, F.; Devun, L.; Gradel, T.

    2012-12-01

    This paper presents a metrological analysis of hip prosthesis components. When changing ceramic prostheses, the surgeon sometimes finds traces of alloy lying in the insert or the femoral head. These traces can be thin and accurate or as a wide band. From the measurements made on the contact areas of hip prosthesis components, we analyse these phenomena by highlighting the defects of form, waviness and roughness of these surfaces using a novel geometric parameterization (namely modal parameterization). The aim of this work is to isolate these defects to characterize the prostheses components. We show that this parameterization allows a multi-scale analysis of surfaces regardless of the type of wear of the prosthesis, and that the results offer some relevant explanations to the analysis of visible damage on the prostheses. In a later study, we are going to analyse the defects influence on the alteration of the performance of hip prostheses.

  10. Microseparation and stripe wear in alumina-on-alumina hip implants.

    PubMed

    Affatato, Saverio; Traina, Francesco; Toni, Aldo

    2011-06-01

    The combination of materials that still has highest wear resistance for total hip replacement is ceramic-on-ceramic. However, brittleness is a major concern for ceramics: in vivo and in vitro studies on ceramic hip prostheses correlate microseparation with hip noise, ceramic wear, or ceramic liner damage. Ceramic microseparation can lead to edge load, ceramic head wear, and squeaking. The aim of this in vitro study was to investigate whether different angles of inclination influence the wear pattern of alumina-on-alumina hip joints with micro-separation during the swing phase. We also evaluated the wear rate obtained from this in vitro investigation with retrieval specimens obtained at 13 years' mean follow-up. The study was performed using a 12-station hip joint wear simulator (Shore Western, Monrovia, CA, USA) under bovine calf serum used as lubricant. Wear was evaluated by the gravimetric method and the test length was set at two million cycles. After two million cycles, a volumetric loss of 0.11 ±0.03 mm3 and 0.12 ±0.06 mm3 was observed, respectively, for 23° and 63° angles of inclination. In particular, the results obtained in this work revealed an increase of about 12-fold compared to previous results without microseparation conditions. No significant differences were observed between the two different inclinations on the wear patterns of the acetabular cups with a level of significance of a = 0.5. The location and general shape of the stripes wear were similar for the retrieved and simulator balls. PMID:21725932

  11. Modular titanium alloy neck adapter failures in hip replacement - failure mode analysis and influence of implant material

    PubMed Central

    2010-01-01

    Background Modular neck adapters for hip arthroplasty stems allow the surgeon to modify CCD angle, offset and femoral anteversion intraoperatively. Fretting or crevice corrosion may lead to failure of such a modular device due to high loads or surface contamination inside the modular coupling. Unfortunately we have experienced such a failure of implants and now report our clinical experience with the failures in order to advance orthopaedic material research and joint replacement surgery. The failed neck adapters were implanted between August 2004 and November 2006 a total of about 5000 devices. After this period, the titanium neck adapters were replaced by adapters out of cobalt-chromium. Until the end of 2008 in total 1.4% (n = 68) of the implanted titanium alloy neck adapters failed with an average time of 2.0 years (0.7 to 4.0 years) postoperatively. All, but one, patients were male, their average age being 57.4 years (36 to 75 years) and the average weight 102.3 kg (75 to 130 kg). The failures of neck adapters were divided into 66% with small CCD of 130° and 60% with head lengths of L or larger. Assuming an average time to failure of 2.8 years, the cumulative failure rate was calculated with 2.4%. Methods A series of adapter failures of titanium alloy modular neck adapters in combination with a titanium alloy modular short hip stem was investigated. For patients having received this particular implant combination risk factors were identified which were associated with the occurence of implant failure. A Kaplan-Meier survival-failure-analysis was conducted. The retrieved implants were analysed using microscopic and chemical methods. Modes of failure were simulated in biomechanical tests. Comparative tests included modular neck adapters made of titanium alloy and cobalt chrome alloy material. Results Retrieval examinations and biomechanical simulation revealed that primary micromotions initiated fretting within the modular tapered neck connection. A continuous abrasion and repassivation process with a subsequent cold welding at the titanium alloy modular interface. Surface layers of 10 - 30 ?m titanium oxide were observed. Surface cracks caused by fretting or fretting corrosion finally lead to fatigue fracture of the titanium alloy modular neck adapters. Neck adapters made of cobalt chrome alloy show significantly reduced micromotions especially in case of contaminated cone connection. With a cobalt-chromium neck the micromotions can be reduced by a factor of 3 compared to the titanium neck. The incidence of fretting corrosion was also substantially lower with the cobalt-chromium neck configuration. Conclusions Failure of modular titanium alloy neck adapters can be initiated by surface micromotions due to surface contamination or highly loaded implant components. In the present study, the patients at risk were men with an average weight over 100 kg. Modular cobalt chrome neck adapters provide higher safety compared to titanium alloy material. PMID:20047653

  12. A Randomised Multi-centre Study to Compare the Long-term Performance of the Future Hip to 3 Other Implants in Primary Total Hip Replacement

    ClinicalTrials.gov

    2011-09-01

    Osteoarthritis; Post-traumatic Arthritis; Collagen Disorders; Avascular Necrosis; Traumatic Femoral Fractures; Nonunion of Femoral Fractures; Congenital Hip Dysplasia; Slipped Capital Femoral Epiphysis; Perthes Disease

  13. Finite element analysis of a subtrochanteric fractured femur with dynamic hip screw, dynamic condylar screw, and proximal femur nail implants--a comparative study.

    PubMed

    Sowmianarayanan, S; Chandrasekaran, A; Kumar, R Krishna

    2008-01-01

    Selection of the correct type of implant for fracture fixation has become a very interesting problem in the orthopaedic community. The present work studies the biomechanical behaviour of the femur with three different implant configurations for simple transverse subtrochanteric fracture and the intact femur using finite element analysis. The implants considered in this study are as follows: dynamic hip screw (DHS), dynamic condylar screw (DCS), and proximal femur nail (PFN). The modelling software Unigraphics and finite element simulation software ANSYS are used for the present analysis. The three implants are compared for deflection, stress, and strains. The simulation also includes modelling of the cortical defect near the fracture. An estimation of the critical depth of the cortical defect based on the von Mises stress is obtained using this study on the DHS implant. The displacement and principal stress on the proximal femur have been compared for all the implant models. The stresses on the cortical screws for DCS and DHS implants have also been compared. The result shows that the DHS and DCS implants behave in a similar way to the intact femur compared with the PFN implant. PMID:18335723

  14. Appraisal of evidence base for introduction of new implants in hip and knee replacement: a systematic review of five widely used device technologies

    PubMed Central

    Nieuwenhuijse, Marc J; Nelissen, R G H H; Schoones, J W

    2014-01-01

    Objective To determine the evidence of effectiveness and safety for introduction of five recent and ostensibly high value implantable devices in major joint replacement to illustrate the need for change and inform guidance on evidence based introduction of new implants into healthcare. Design Systematic review of clinical trials, comparative observational studies, and registries for comparative effectiveness and safety of five implantable device innovations. Data sources PubMed (Medline), Embase, Web of Science, Cochrane, CINAHL, reference lists of articles, annual reports of major registries, summaries of safety and effectiveness for pre-market application and mandated post-market studies at the US Food and Drug Administration. Study selection The five selected innovations comprised three in total hip replacement (ceramic-on-ceramic bearings, modular femoral necks, and uncemented monoblock cups) and two in total knee replacement (high flexion knee replacement and gender specific knee replacement). All clinical studies of primary total hip or knee replacement for symptomatic osteoarthritis in adults that compared at least one of the clinical outcomes of interest (patient centred outcomes or complications, or both) in the new implant group and control implant group were considered. Data searching, abstraction, and analysis were independently performed and confirmed by at least two authors. Quantitative data syntheses were performed when feasible. Results After assessment of 10?557 search hits, 118 studies (94 unique study cohorts) met the inclusion criteria and reported data related to 15?384 implants in 13?164 patients. Comparative evidence per device innovation varied from four low to moderate quality retrospective studies (modular femoral necks) to 56 studies of varying quality including seven high quality (randomised) studies (high flexion knee replacement). None of the five device innovations was found to improve functional or patient reported outcomes. National registries reported two to 12 year follow-up for revision occurrence related to more than 200?000 of these implants. Reported comparative data with well established alternative devices (over 1?200?000 implants) did not show improved device survival. Moreover, we found higher revision occurrence associated with modular femoral necks (hazard ratio 1.9) and ceramic-on-ceramic bearings (hazard ratio 1.0-1.6) in hip replacement and with high flexion knee implants (hazard ratio 1.0-1.8). Conclusion We did not find convincing high quality evidence supporting the use of five substantial, well known, and already implemented device innovations in orthopaedics. Moreover, existing devices may be safer to use in total hip or knee replacement. Improved regulation and professional society oversight are necessary to prevent patients from being further exposed to these and future innovations introduced without proper evidence of improved clinical efficacy and safety. PMID:25208953

  15. Long-term implant fixation and stress-shielding in total hip replacement.

    PubMed

    Sumner, D R

    2015-03-18

    Implant fixation implies a strong and durable mechanical bond between the prosthetic component and host skeleton. Assuming the short-term impediments to implant fixation are successfully addressed and that longer-term issues such as late infection and mechanical failure of the components are avoided, the biological response of the host tissue to the presence of the implant is critical to long-term success. In particular, maintenance of adequate peri-prosthetic bone stock is a key factor. Two major causes of bone loss in the supporting bone are adverse bone remodeling in response to debris shed from the implant and stress-shielding. Here, I review some of the major lessons learned from studying stress-shielding-induced bone loss. It is well known that stress-shielding can be manipulated by altering implant design, but less well appreciated that the development of bone anabolic agents may make it possible to reduce the severity of stress-shielding and the associated bone loss by augmenting the host skeleton through the use of locally or systemically delivered agents. In most cases, mechanical, material and biological factors do not act in isolation, emphasizing that it is often not possible to optimize all boundary conditions. PMID:25579990

  16. Sensitivity analysis of a cemented hip stem to implant position and cement mantle thickness.

    PubMed

    Shi, J; Browne, M; Strickland, M; Flivik, G; Taylor, M

    2014-11-01

    Patient-specific finite element models of the implanted proximal femur can be built from pre-operative computed tomography scans and post-operative X-rays. However, estimating three-dimensional positioning from two-dimensional radiographs introduces uncertainty in the implant position. Further, accurately measuring the thin cement mantle and the degree of cement-bone interdigitation from imaging data is challenging. To quantify the effect of these uncertainties in stem position and cement thickness, a sensitivity study was performed. A design-of-experiment study was implemented, simulating both gait and stair ascent. Cement mantle stresses and bone-implant interface strains were monitored. The results show that small variations in alignment affect the implant biomechanics, especially around the most proximal and most distal ends of the stem. The results suggest that implant position is more influential than cement thickness. Rotation around the medial-lateral axis is the dominant factor in the proximal zones and stem translations are the dominant factors around the distal tip. PMID:23405986

  17. Stronger Implant Does Not Cause Stress-Shielding in the Fixation of Hip Fractures – Validated Finite Element Analysis and Cadaver Tests

    Microsoft Academic Search

    S. Eberle; C. Gerber; G. Oldenburg; P. Augat

    \\u000a Background: A stable fixation by osteosynthesis is essential to allow an early mobilization of patients with hip fractures.\\u000a When stronger implants are employed to prevent potential complications, it is feared that stress-shielding occurs. The hypothesis\\u000a of this study was that a stronger intramedullary nail becomes less stressed during loading. It was specifically investigated\\u000a if this would lead to more load

  18. Effects of CoCr metal wear debris generated from metal-on-metal hip implants and Co ions on human monocyte-like U937 cells.

    PubMed

    Posada, Olga M; Tate, Rothwelle J; Grant, M Helen

    2015-03-01

    Hip resurfacing with cobalt-chromium (CoCr) alloy was developed as a surgical alternative to total hip replacement. However, the biological effects of nanoparticles generated by wear at the metal-on-metal articulating surfaces has limited the success of such implants. The aim of this study was to investigate the effects of the combined exposure to CoCr nanoparticles and cobalt ions released from a resurfacing implant on monocytes (U937 cells) and whether these resulted in morphology changes, proliferation alterations, toxicity and cytokine release. The interaction between prior exposure to Co ions and the cellular response to nanoparticulate debris was determined to simulate the situation in patients with metal-on-metal implants receiving a second implant. Effects on U937 cells were mainly seen after 120h of treatment. Prior exposure to Co ions increased the toxic effects induced by the debris, and by Co ions themselves, suggesting the potential for interaction in vivo. Increased TNF-? secretion by resting cells exposed to nanoparticles could contribute to osteolysis processes in vivo, while increased IFN-? production by activated cells could represent cellular protection against tissue damage. Data suggest that interactions between Co ions and CoCr nanoparticles would occur in vivo, and could threaten the survival of a CoCr metal implant. PMID:25433333

  19. Alumina-on-alumina hip implants: A wear study of retrieved components.

    PubMed

    Affatato, S; Traina, F; De Fine, M; Carmignato, S; Toni, A

    2012-01-01

    Alumina-alumina bearings are among the most resistant to wear in total hip replacement. Examination of their surfaces is one way of comparing damage caused by wear of hip joints simulated in vitro to that seen in explanted bearings. The aim of this study was to determine whether second-generation ceramic bearings exhibited a better pattern of wear than those reported in the literature for first-generation bearings. We considered both macro- and microscopic findings. We found that long-term alumina wear in association with a loose acetabular component could be categorised into three groups. Of 20 specimens, four had 'low wear', eight 'crescent wear' and eight 'severe wear', which was characterised by a change in the physical shape of the bearing and a loss of volume. This suggests that the wear in alumina-alumina bearings in association with a loose acetabular component may be variable in pattern, and may explain, in part, why the wear of a ceramic head in vivo may be greater than that seen after in vitro testing. PMID:22219245

  20. Internal Fixation of Intertrochanteric Hip Fractures: A Clinical Comparison of Two Implant Designs

    PubMed Central

    Tao, Ran; Lu, Yue; Xu, Hua; Zhou, Zhen-Yu; Wang, You-Hua; Liu, Fan

    2013-01-01

    Objective. To compare two internal fixation devices clinically in stabilisation of intertrochanteric femur fractures. Methods. Eighty-seven patients were randomised upon their admission to the hospital using a sealed envelope method. Forty-five were treated with proximal femur nail antirotation (PFNA) and 42 with reverse less invasive stabilisation system (LISS). The perioperative data were recorded and compared in relation to fracture type. Results. In each type of fractures, no significant differences were found with respect to the blood loss, the quality of reduction, the time to bony healing, and the Harris hip score between the 2 groups. The mean duration of surgery was significantly longer in reverse LISS group than in PFNA group. Conclusion. Both the PFNA and the reversed LISS are effective in the treatment of different types of intertrochanteric femur fractures. PFNA is superior to reverse LISS in terms of surgical time, weight-bearing, and perhaps fluoroscopy time. PMID:23476148

  1. Failure analysis of a total hip prosthesis implanted in active patient.

    PubMed

    Hernandez-Rodriguez, M A L; Ortega-Saenz, J A; Contreras-Hernandez, Geo R

    2010-11-01

    This work presents an analysis of a total hip prosthesis that failed in service prematurely within 5 years. The prosthesis presented a fractured stem that was extracted from a 46 year old male patient, 75 kg weight and 1.76 m height. In order to determine the origin of the failure, the femoral stem component was analyzed by means of visual inspection; optical microscope (OM), scanning electronic microscopy (SEM) and energy disperse spectroscopy (EDS). The investigation showed that the crack had originated due to a high stress concentration on the anterolateral corner section of the stem. Any discontinuity or defect on the prosthesis surface in this location acted as preferential site to nucleate a crack which propagated by fatigue until the cross section was not able to sustain an eventual high load produced for the active patient. PMID:20826368

  2. Pore Geometry Optimization of Titanium (Ti6Al4V) Alloy, for Its Application in the Fabrication of Customized Hip Implants

    PubMed Central

    Roy, Sandipan; Panda, Debojyoti; Khutia, Niloy; Chowdhury, Amit Roy

    2014-01-01

    The present study investigates the mechanical response of representative volume elements of porous Ti-6Al-4V alloy, to arrive at a desired range of pore geometries that would optimize the reduction in stiffness necessary for biocompatibility with the stress concentration arising around the pore periphery, under physiological loading conditions with respect to orthopedic hip implants. A comparative study of the two is performed with the aid of a newly defined optimizing parameter called pore efficiency that takes into consideration both the stiffness quantity and the stress localization around pores. To perform a detailed analysis of the response of the porous structure over the entire spectrum of loading conditions that a hip implant is subjected to in vivo, the mechanical responses of 3D finite element models of cubic and rectangular parallelepiped geometries, with porosities varying over a range of 10% to 60%, are simulated under representative compressive, flexural as well as combined loading conditions. The results that are obtained are used to suggest a range of pore diameters that lower the effective stiffness and modulus of the implant to around 60% of the stiffness and modulus of dense solid implants while keeping the stress levels within permissible limits. PMID:25400663

  3. Pore Geometry Optimization of Titanium (Ti6Al4V) Alloy, for Its Application in the Fabrication of Customized Hip Implants.

    PubMed

    Roy, Sandipan; Panda, Debojyoti; Khutia, Niloy; Chowdhury, Amit Roy

    2014-01-01

    The present study investigates the mechanical response of representative volume elements of porous Ti-6Al-4V alloy, to arrive at a desired range of pore geometries that would optimize the reduction in stiffness necessary for biocompatibility with the stress concentration arising around the pore periphery, under physiological loading conditions with respect to orthopedic hip implants. A comparative study of the two is performed with the aid of a newly defined optimizing parameter called pore efficiency that takes into consideration both the stiffness quantity and the stress localization around pores. To perform a detailed analysis of the response of the porous structure over the entire spectrum of loading conditions that a hip implant is subjected to in vivo, the mechanical responses of 3D finite element models of cubic and rectangular parallelepiped geometries, with porosities varying over a range of 10% to 60%, are simulated under representative compressive, flexural as well as combined loading conditions. The results that are obtained are used to suggest a range of pore diameters that lower the effective stiffness and modulus of the implant to around 60% of the stiffness and modulus of dense solid implants while keeping the stress levels within permissible limits. PMID:25400663

  4. Arthroscopic Fixation of Cell Free Polymer-Based Cartilage Implants with a Bioinspired Polymer Surface on the Hip Joint: A Cadaveric Pilot Study

    PubMed Central

    Lahner, Matthias; Duif, Christian; Ficklscherer, Andreas; Kaps, Christian; Kalwa, Lukas; Seidl, Tobias

    2014-01-01

    This study investigates the adhesion capacity of a polyglycolic acid- (PGA-) hyaluronan scaffold with a structural modification based on a planar polymer (PM) surface in a cadaver cartilage defect model. Two cadaver specimens were used to serially test multiple chondral matrices. In a cadaver hip model, cell free polymer-based cartilage implants with a planar bioinspired PM surface (PGA-PM-scaffolds) were implanted arthroscopically on 10?mm?×?15?mm full-thickness femoral hip cartilage lesions. Unprocessed cartilage implants without a bioinspired PM surface were used as control group. The cartilage implants were fixed without and with the use of fibrin glue on femoral hip cartilage defects. After 50 movement cycles and removal of the distraction, a rearthroscopy was performed to assess the outline attachment and integrity of the scaffold. The fixation techniques without and with fibrin fixation showed marginal differences for outline attachment, area coverage, scaffold integrity, and endpoint fixation after 50 cycles. The PGA-PM-scaffolds with fibrin fixation achieved a higher score in terms of the attachment, integrity, and endpoint fixation than the PGA-scaffold on the cartilage defect. Relating to the outline attachment, area coverage, scaffold integrity, and endpoint fixation, the fixation with PGA-PM-scaffolds accomplished significantly better results compared to the PGA-scaffolds (P = 0.03752, P = 0.03078, P = 0.00512, P = 0.00512). PGA-PM-scaffolds demonstrate increased observed initial fixation strength in cadaver femoral head defects relative to PGA-scaffold, particularly when fibrin glue is used for fixation. PMID:25247185

  5. Two years follow-up study of the pain-relieving effect of gold bead implantation in dogs with hip-joint arthritis

    PubMed Central

    Jæger, Gry T; Larsen, Stig; Søli, Nils; Moe, Lars

    2007-01-01

    Seventy-eight dogs with pain from hip dysplasia participated in a six-month placebo-controlled, double-blinded clinical trial of gold bead implantation. In the present, non-blinded study, 73 of these dogs were followed for an additional 18 months to evaluate the long-term pain-relieving effect of gold bead implantation. The recently-published results of the six month period revealed that 30 of the 36 dogs (83%) in the gold implantation group showed significant improvement (p = 0.02), included improved mobility and reduction in the signs of pain, compared to the placebo group (60% improvement). In the long-term two-year follow-up study, 66 of the 73 dogs had gold implantation and seven dogs continued as a control group. The 32 dogs in the original placebo group had gold beads implanted and were followed for a further 18 months. A certified veterinary acupuncturist used the same procedure to insert the gold beads as in the blinded study, and the owners completed the same type of detailed questionnaires. As in the blinded study, one investigator was responsible for all the assessments of each dog. The present study revealed that the pain-relieving effect of gold bead implantation observed in the blinded study continued throughout the two-year follow-up period. PMID:17381835

  6. Metal Ion Concentrations in Body Fluids after Implantation of Hip Replacements with Metal-on-Metal Bearing – Systematic Review of Clinical and Epidemiological Studies

    PubMed Central

    Hartmann, Albrecht; Hannemann, Franziska; Lützner, Jörg; Seidler, Andreas; Drexler, Hans; Günther, Klaus-Peter; Schmitt, Jochen

    2013-01-01

    Introduction The use of metal-on-metal (MoM) total hip arthroplasty (THA) increased in the last decades. A release of metal products (i.e. particles, ions, metallo-organic compounds) in these implants may cause local and/or systemic adverse reactions. Metal ion concentrations in body fluids are surrogate measures of metal exposure. Objective To systematically summarize and critically appraise published studies concerning metal ion concentrations after MoM THA. Methods Systematic review of clinical trials (RCTs) and epidemiological studies with assessment of metal ion levels (cobalt, chromium, titanium, nickel, molybdenum) in body fluids after implantation of metalliferous hip replacements. Systematic search in PubMed and Embase in January 2012 supplemented by hand search. Standardized abstraction of pre- and postoperative metal ion concentrations stratified by type of bearing (primary explanatory factor), patient characteristics as well as study quality characteristics (secondary explanatory factors). Results Overall, 104 studies (11 RCTs, 93 epidemiological studies) totaling 9.957 patients with measurement of metal ions in body fluids were identified and analyzed. Consistently, median metal ion concentrations were persistently elevated after implantation of MoM-bearings in all investigated mediums (whole blood, serum, plasma, erythrocytes, urine) irrespective of patient characteristics and study characteristics. In several studies very high serum cobalt concentrations above 50 µg/L were measured (detection limit typically 0.3 µg/L). Highest metal ion concentrations were observed after treatment with stemmed large-head MoM-implants and hip resurfacing arthroplasty. Discussion Due to the risk of local and systemic accumulation of metallic products after treatment with MoM-bearing, risk and benefits should be carefully balanced preoperatively. The authors support a proposed „time out“ for stemmed large-head MoM-THA and recommend a restricted indication for hip resurfacing arthroplasty. Patients with implanted MoM-bearing should receive regular and standardized monitoring of metal ion concentrations. Further research is indicated especially with regard to potential systemic reactions due to accumulation of metal products. PMID:23950923

  7. Long-term effectiveness of an ad hoc tailored titanium implant as a spacer for microvascular decompression in the treatment of trigeminal neuralgia caused by megadolichoectatic basilar artery anomaly: 9-year follow-up.

    PubMed

    Banczerowski, Péter; Czigléczki, Gábor; Nyáry, István

    2014-12-01

    An enlarged, elongated, ectatic, and sclerotic aberration of the vertebrobasilar system is known as a megadolichoectatic basilar artery (BA) anomaly. The anomaly is often involved in the pathological process of trigeminal neuralgia by compressing and distorting the trigeminal nerve. First-line medical treatment includes drug therapy, but a second-line surgical procedure could be effective in medication-resistant cases. The authors report the case of a 65-year-old man with a 12-year history of progressing trigeminal neuralgia who underwent microvascular decompression after the first-line drug treatment had failed. This case is unique because an in situ tailored titanium microplate was used as a spacer to alleviate compression by the BA on the trigeminal nerve. The titanium implant provided durable and sufficient retraction for the sclerotic arterial complex when the trigeminal nerve was placed in the tunnel of the implant. The 9-year follow-up examination proves the safety and long-term efficacy of titanium implants in the treatment of trigeminal neuralgia caused by a megadolichoectatic BA anomaly. The method applied in this case was not intended to be and certainly is not an alternative to routine microvascular decompression-this surgical solution may be reserved for some extreme cases. PMID:25259563

  8. Spacer use - series (image)

    MedlinePLUS

    ... and can reduce side effects. Spacers hold the "puff" of medicine between you and the MDI, so ... Spray one puff of medicine into the spacer, and immediately begin to inhale slowly for three to five seconds, taking a ...

  9. Hip Implant Systems

    MedlinePLUS

    ... of metal and the socket is made of plastic (polyethylene) or has a plastic lining. Ceramic-on-Polyethylene: The ball is made of ceramic and the socket is made of plastic (polyethylene) or has a plastic lining. Metal-on- ...

  10. [The alumina oxide ceramic-metal composite endoprosthesis. A new hip endoprosthesis for partially cement free implantation (author's transl)].

    PubMed

    Griss, P; Heimke, G; von Andrian-Werburg, H F

    1975-01-01

    The favorable combination of properties of dense, pure Al2O3-ceramics as a material for endoprostheses of the high load bearing joints have been confirmed in more than 4 years of experimental work with different types of animals. During this period Al2O3-ceramic parts for total hip replacement have already been developed and tested as well as the special instrumentation and the technique of the surgical procedure concerned. Based on these experiences a new total hip endoprostheses together with its complete technique for the operation is presented with which an improved alternative for replacements of Weber-Huggler-prostheses is offered and the application of total hip replacements can be extended to patients below 60 years of age. PMID:1092290

  11. First insight on the impact of an osteoblastic layer on the bio-tribocorrosion performance of Ti6Al4V hip implants.

    PubMed

    Runa, M J; Mathew, M T; Fernandes, M H; Rocha, L A

    2015-01-01

    In uncemented Ti6Al4V hip implants, the bone-stem interface is subjected to cyclic loading motion driven by the daily activities of the patients, which may lead to the complete failure of the implant in the long term. It may also compromise the proliferation and differentiation processes of osteoblastic cells (bone-forming cells). The main objective of this work is to approach for the first time the role of these organic materials on the bio-tribocorrosion mechanisms of cultured Ti6Al4V alloys. The colonized materials with MG63 osteoblastic-like cells were characterized through cell viability/proliferation and enzymatic activity. Tribocorrosion tests were performed under a reciprocating sliding configuration and low contact pressure. Electrochemical techniques were used to measure the corrosion kinetics of the system, under free potential conditions. All tests were performed at a controlled atmosphere. The morphology and topography of the wear scar were evaluated. The results showed that the presence of an osteoblastic cell layer on the implant surface significantly influences the tribocorrosion behavior of Ti6Al4V alloy. It was concluded that the cellular material was able to form an extra protective layer that inhibits further wear degradation of the alloy and decreases its corrosion tendency. PMID:25448346

  12. Metal-on-Metal Hip Prostheses and Systemic Health: A Cross-Sectional Association Study 8 Years after Implantation

    PubMed Central

    Prentice, Jennifer R.; Clark, Matthew J.; Hoggard, Nigel; Morton, Allison C.; Tooth, Claire; Paley, Martyn N.; Stockley, Ian; Hadjivassiliou, Marios; Wilkinson, J. Mark

    2013-01-01

    There is public concern over the long term systemic health effects of metal released from hip replacement prostheses that use large-diameter metal-on-metal bearings. However, to date there has been no systematic study to determine which organs may be at risk, or the magnitude of any effect. We undertook a detailed cross-sectional health screen at a mean of 8 years after surgery in 35 asymptomatic patients who had previously received a metal-on-metal hip resurfacing (MoMHR) versus 35 individually age and sex matched asymptomatic patients who had received a conventional hip replacement. Total body bone mineral density was 5% higher (mean difference 0.05 g/cm2, P?=?0.02) and bone turnover was 14% lower (TRAP 5b, mean difference ?0.56IU/L, P?=?0.006; osteocalcin, mean difference ?3.08 ng/mL, P?=?0.03) in the hip resurfacing versus conventional hip replacement group. Cardiac ejection fraction was 7% lower (mean absolute difference ?5%, P?=?0.04) and left ventricular end-diastolic diameter was 6% larger (mean difference 2.7 mm, P?=?0.007) in the hip resurfacing group versus those patients who received a conventional hip replacement. The urinary fractional excretion of metal was low (cobalt 5%, chromium 1.5%) in patients with MoMHR, but creatinine clearance was normal. Diuretic prescription was associated with a 40% increase in the fractional excretion of chromium (mean difference 0.5%, P?=?0.03). There was no evidence of difference in neuropsychological, renal tubular, hepatic or endocrine function between groups (P>0.05). Our findings of differences in bone and cardiac function between patient groups suggest that chronic exposure to low elevated metal concentrations in patients with well-functioning MoMHR prostheses may have systemic effects. Long-term epidemiological studies in patients with well-functioning metal on metal hip prostheses should include musculoskeletal and cardiac endpoints to quantitate the risk of clinical disease. PMID:23762480

  13. Two-year results of interspinous spacer (X-Stop) implantation in 175 patients with neurologic intermittent claudication due to lumbar spinal stenosis

    Microsoft Academic Search

    Johannes Kuchta; Rolf Sobottke; Peer Eysel; Patrick Simons

    2009-01-01

    The clinical outcome of patients with symptomatic lumbar spinal stenosis (LSS) was assessed during a follow-up period of 2 years\\u000a after X-Stop implantation. The X-Stop is the most commonly used interspinous distraction device in patients with neurogenic\\u000a intermittent claudication due to LSS. Between 2003 and 2007, more than 1,000 patients were examined in our centre with symptoms\\u000a of intermittent claudication due

  14. Infectious prosthetic hip joint loosening: bacterial species involved in its aetiology and their antibiotic resistance profiles against antibiotics recommended for the therapy of implant-associated infections.

    PubMed

    Bogut, Agnieszka; Nied?wiadek, Justyna; Strzelec-Nowak, Dagmara; Blacha, Jan; Mazurkiewicz, Tomasz; Marczy?ski, Wojciech; Kozio?-Montewka, Maria

    2014-04-01

    Reliable microbiological diagnosis along with surgery and prolonged antibiotic therapy are key elements in the management of prosthetic-joint infections (PJIs). The purpose of this study was to characterize antibiotic resistance profiles of bacteria involved in the aetiology of PJIs. A total of 33 bacterial isolates cultured from 31 patients undergoing exchange of total hip prostheses were analyzed. The diagnostic approach toward isolation of prosthesis- associated microorganisms included sonication of retrieved implants and conventional cultures of periprosthetic tissues and synovial fluid. The in vitro resistance profiles of bacterial isolates were determined in relation to antibiotics recommended for the therapy of PJIs using the disc diffusion method, E-tests(®) and broth microdilution system. Coagulase-negative staphylococci (CNS) were predominant microorganisms followed by Staphylococcus aureus, Enterobacter cloacae, Streptococcus mitis, and Propionibacterium acnes. Twenty out of 30 and 12 out of 30 staphylococcal isolates were methicillin- and multi-drug resistant, respectively. Only two isolates were rifampicinresistant. All staphylococci were susceptible to glycopeptides and linezolid. This paper stresses the pathogenic role of staphylococci in patients suffering from implant loosening and reports high methicillin- and multidrug-resistance rates in these bacteria. Hence, antimicrobial susceptibility tests of individual bacterial isolates must always be performed to guide selection of the optimal therapeutic option. PMID:24858648

  15. Hip contact forces and gait patterns from routine activities

    Microsoft Academic Search

    G Bergmann; G Deuretzbacher; M Heller; F Graichen; A Rohlmann; J Strauss; G. N Duda

    2001-01-01

    In vivo loads acting at the hip joint have so far only been measured in few patients and without detailed documentation of gait data. Such information is required to test and improve wear, strength and fixation stability of hip implants. Measurements of hip contact forces with instrumented implants and synchronous analyses of gait patterns and ground reaction forces were performed

  16. Aberrant pelvis and hip kinematics impair hip loading before and after total hip replacement.

    PubMed

    Lenaerts, G; Mulier, M; Spaepen, A; Van der Perre, G; Jonkers, I

    2009-10-01

    Musculoskeletal loading is an important factor affecting the development of osteoarthritis, bone remodelling and primary fixation of total hip replacement (THR). In this study, we analyzed the relation between muscular force, gait kinematics and kinetics and hip loading in 20 patients before and six weeks after THR. Hip contact forces were calculated from gait analysis data using musculoskeletal modelling, inverse dynamics and static optimization. We found aberrant pelvis and hip kinematics and kinetics before and six weeks after surgery, confirming previous findings in literature. Furthermore, we found a decrease in the total contact force and its vertical component. These changes result in a decrease of the associated inclination angles of the total hip contact force in the sagittal and transverse planes, changing the orientation towards more vertical implant loading after THR. These changes in hip loading were related to observed gait kinematics and kinetics. Most importantly, excessive pelvic obliquity and associated hip adduction related to impaired implant loading. We concluded, therefore, that physical therapy in the early post-operative phase should primarily focus on stretching of anterior and medial structures and strengthening of hip flexors and abductors to achieve normalization of the hip and pelvis kinematics and consequently normalize hip loading. PMID:19560359

  17. Cementless hydroxyapatite coated hip prostheses.

    PubMed

    Herrera, Antonio; Mateo, Jesús; Gil-Albarova, Jorge; Lobo-Escolar, Antonio; Ibarz, Elena; Gabarre, Sergio; Más, Yolanda; Gracia, Luis

    2015-01-01

    More than twenty years ago, hydroxyapatite (HA), calcium phosphate ceramics, was introduced as a coating for cementless hip prostheses. The choice of this ceramic is due to its composition being similar to organic apatite bone crystals. This ceramic is biocompatible, bioactive, and osteoconductive. These qualities facilitate the primary stability and osseointegration of implants. Our surgical experience includes the implantation of more than 4,000 cementless hydroxyapatite coated hip prostheses since 1990. The models implanted are coated with HA in the acetabulum and in the metaphyseal area of the stem. The results corresponding to survival and stability of implants were very satisfactory in the long-term. From our experience, HA-coated hip implants are a reliable alternative which can achieve long term survival, provided that certain requirements are met: good design selection, sound choice of bearing surfaces based on patient life expectancy, meticulous surgical technique, and indications based on adequate bone quality. PMID:25802848

  18. Cementless Hydroxyapatite Coated Hip Prostheses

    PubMed Central

    Herrera, Antonio; Mateo, Jesús; Gil-Albarova, Jorge; Lobo-Escolar, Antonio; Ibarz, Elena; Gabarre, Sergio; Más, Yolanda

    2015-01-01

    More than twenty years ago, hydroxyapatite (HA), calcium phosphate ceramics, was introduced as a coating for cementless hip prostheses. The choice of this ceramic is due to its composition being similar to organic apatite bone crystals. This ceramic is biocompatible, bioactive, and osteoconductive. These qualities facilitate the primary stability and osseointegration of implants. Our surgical experience includes the implantation of more than 4,000 cementless hydroxyapatite coated hip prostheses since 1990. The models implanted are coated with HA in the acetabulum and in the metaphyseal area of the stem. The results corresponding to survival and stability of implants were very satisfactory in the long-term. From our experience, HA-coated hip implants are a reliable alternative which can achieve long term survival, provided that certain requirements are met: good design selection, sound choice of bearing surfaces based on patient life expectancy, meticulous surgical technique, and indications based on adequate bone quality. PMID:25802848

  19. Hip arthrography, aspiration, block, and bursography.

    PubMed

    Aliabadi, P; Baker, N D; Jaramillo, D

    1998-07-01

    Hip arthrography in children with Legg-Calvé-Perthes disease is used to determine the optimal position of the femoral head for immobilization during the process of epiphyseal healing and in developmental dysplasia of the hip as a guide to operative treatment. In adult hips, arthrography and aspiration are useful techniques for demonstration of prosthetic implant loosening and infection. Aspiration of the hip joint and culture of aspirated fluid helps to diagnose septic arthritis. Anesthetic hip arthrography helps to distinguish between pain originating from the hip and radicular pain from the spine. Iliopsoas bursography may be used to diagnose bursal enlargement and its cause. PMID:9673646

  20. In vivo corrosion of 316L stainless-steel hip implants: morphology and elemental compositions of corrosion products.

    PubMed

    Walczak, J; Shahgaldi, F; Heatley, F

    1998-01-01

    Eleven surgically retrieved stainless steel implants showing varying degrees of surface corrosion were examined to characterize the morphology and composition of corrosion products. The implants were fabricated to the specification AISI316L (Muller) and BS 3531 pt 1 1971-78 (Charnley). They had been in place for 9-21 y (Mean :13 y) and failures were due to aseptic loosening. The morphology and chemical compositions of corrosion products were recorded using scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). Nine implants had areas of corrosion covering 1-5 cm of the stem, partially or all round. Corrosion existed in layers. The layers consisted either of chromium in association with sulfur, or iron in association with phosphorus. Variable amounts of calcium and chlorine were also present in all layers. Nickel, which makes up 13% of the alloy, was persistently absent. The presence and extent of corrosion was independent of the alloy composition and could not be related to the duration of implantation. PMID:9678872

  1. Implants

    MedlinePLUS

    ... palate, which can reduce your sense of taste. Self-esteem — Because implants are so much like your natural teeth, you will think about them less. Your self-esteem and confidence will be improved because you will ...

  2. Spacer-related problems in two-stage revision knee arthroplasty.

    PubMed

    Struelens, Bernard; Claes, Steven; Bellemans, Johan

    2013-08-01

    Although articulated cement spacers are frequently used in a staged approach of an infected total knee arthroplasty (TKA), no data are available on the incidence and type of spacer-related problems in these patients. A retrospective analysis of 154 patients who underwent a two-stage revision procedure for an infected TKA was performed. All patients received an articulating cement spacer at the implant removal procedure; their radiographs were analyzed for spacer-related issues such as spacer dislocation, fracture, tilting or translation, and knee subluxation. In 43% of the patients, the spacer was considered as optimal. The main finding of this study is the large incidence (57%) of spacer-specific problems in two-stage revision knee arthroplasty for infected TKA. Spacer tilting and mediolateral translation were found to be the most frequent spacer-specific problems, in 24% and 21% of the cases respectively. These were considered as minor problems. Major problems were seen in 12 % : in 3% of the knees the spacer had dislocated, in 5% the spacer fractured and in 4%, although the spacer seemed to be adequately positioned relative to the femoral and tibial bone, frank knee subluxation could be noted. The impact of spacer-specific problems with articulating cement spacers on final outcome in two-stage revision knee surgery will be further investigated. PMID:24205773

  3. [Designing special prosthesis "spacer"].

    PubMed

    Gruji?, Jovan; Tabakovi?, Slobodan; Zeljkovi?, Milan; Zivkovi?, Aleksandar; Vucini?, Zoran; Djordjevi?, Aca; Mandi?, Nikica; Luji?, Nenad; Sekuli?, Jovan

    2013-01-01

    Malignant diseases of the medial part of the femur, humerus and tibia, treated with surgical removal of the affected part of the bone and prosthesis fitting special "Spacer". This type of prosthesis is made in the form of the proximal and distal components that connect by screws. The design of endoprosthesis provides without possible rotation linear relationship and allows the transfer of load from the proximal to the distal bone, but the screws that provide connection are not exposed to stress. For pro-per sizing and implementation of a special prosthesis is necessary to determine the geometric parameters of bone mass and disease and then develop a computer model of the prosthesis. Designing a special prosthesis "spacer" is a complex procedure based on the processing of diagnostic images (X-ray, CT or MRI) with the use of specialized software digitized picture elements pixels translate into voxels. In this way a geometric model contains a form of external (KORTEX), and the internal geometry of the bone (medullary canal). On the basis of such a developed computer models is possible accurately determine the part of the bone that is necessary to remove, and the size of medullary canal space that is built into proximal or distal component of special endoprosthesis "Spacer". PMID:24298748

  4. Total hip arthroplasty for surgical management of advanced tuberculous hip arthritis: Case report.

    PubMed

    Tan, Shi Ming; Chin, Pak Lin

    2015-03-18

    Tuberculosis (TB) arthritis of the hip is a debilitating disease that often results in severe cartilage destruction and degeneration of the hip. In advanced cases, arthrodesis of the hip confers benefits to the young, high-demand and active patient. However, many of these patients go on to develop degenerative arthritis of the spine, ipsilateral knee and contralateral hip, necessitating the need for a conversion to total hip arthroplasty. Conversion of a previously fused hip to a total hip arthroplasty presents as a surgical challenge due to altered anatomy, muscle atrophy, previous surgery and implants, neighbouring joint arthritis and limb length discrepancy. We report a case of advanced TB arthritis of the hip joint in a middle-aged Singaporean Chinese gentleman with a significant past medical history of miliary tuberculosis and previous hip arthrodesis. Considerations in pre-operative planning, surgical approaches and potential pitfalls are discussed and the operative technique utilized and post-operative rehabilitative regime of this patient is described. This case highlights the necessity of pre-operative planning and the operative technique used in the conversion of a previous hip arthrodesis to a total hip arthroplasty in a case of TB hip arthritis. PMID:25793173

  5. Total hip arthroplasty for surgical management of advanced tuberculous hip arthritis: Case report

    PubMed Central

    Tan, Shi Ming; Chin, Pak Lin

    2015-01-01

    Tuberculosis (TB) arthritis of the hip is a debilitating disease that often results in severe cartilage destruction and degeneration of the hip. In advanced cases, arthrodesis of the hip confers benefits to the young, high-demand and active patient. However, many of these patients go on to develop degenerative arthritis of the spine, ipsilateral knee and contralateral hip, necessitating the need for a conversion to total hip arthroplasty. Conversion of a previously fused hip to a total hip arthroplasty presents as a surgical challenge due to altered anatomy, muscle atrophy, previous surgery and implants, neighbouring joint arthritis and limb length discrepancy. We report a case of advanced TB arthritis of the hip joint in a middle-aged Singaporean Chinese gentleman with a significant past medical history of miliary tuberculosis and previous hip arthrodesis. Considerations in pre-operative planning, surgical approaches and potential pitfalls are discussed and the operative technique utilized and post-operative rehabilitative regime of this patient is described. This case highlights the necessity of pre-operative planning and the operative technique used in the conversion of a previous hip arthrodesis to a total hip arthroplasty in a case of TB hip arthritis. PMID:25793173

  6. Recent patents and designs on hip replacement prostheses.

    PubMed

    Derar, H; Shahinpoor, M

    2015-01-01

    Hip replacement surgery has gone through tremendous evolution since the first procedure in 1840. In the past five decades the advances that have been made in technology, advanced and smart materials innovations, surgical techniques, robotic surgery and methods of fixations and sterilization, facilitated hip implants that undergo multiple design revolutions seeking the least problematic implants and a longer survivorship. Hip surgery has become a solution for many in need of hip joint remedy and replacement across the globe. Nevertheless, there are still long-term problems that are essential to search and resolve to find the optimum implant. This paper reviews several recent patents on hip replacement surgery. The patents present various designs of prostheses, different materials as well as methods of fixation. Each of the patents presents a new design as a solution to different issues ranging from the longevity of the hip prostheses to discomfort and inconvenience experienced by patients in the long-term. PMID:25893020

  7. Recent Patents and Designs on Hip Replacement Prostheses

    PubMed Central

    Derar, H; Shahinpoor, M

    2015-01-01

    Hip replacement surgery has gone through tremendous evolution since the first procedure in 1840. In the past five decades the advances that have been made in technology, advanced and smart materials innovations, surgical techniques, robotic surgery and methods of fixations and sterilization, facilitated hip implants that undergo multiple design revolutions seeking the least problematic implants and a longer survivorship. Hip surgery has become a solution for many in need of hip joint remedy and replacement across the globe. Nevertheless, there are still long-term problems that are essential to search and resolve to find the optimum implant. This paper reviews several recent patents on hip replacement surgery. The patents present various designs of prostheses, different materials as well as methods of fixation. Each of the patents presents a new design as a solution to different issues ranging from the longevity of the hip prostheses to discomfort and inconvenience experienced by patients in the long-term.

  8. PacerSpacer

    NSDL National Science Digital Library

    In this resource provided by DeafTEC, the PacerSpacer resource is described in detail and recommended to instructors with deaf and hard of hearing students in their classrooms. The purpose of the software is to allow adequate time for students for students to read the slides before the instructor begins speaking in order to minimize distraction and allow for more process time. The software itself is described here as , "a small square of color, which begins as red, then changes to yellow briefly, and finally to green – like a traffic light with one square bulb. Place it in an out of the way spot on the background – the slide master(s) – of your presentation; then as each new slide comes up, wait to begin speaking until the PacerSpacer changes from red to yellow to green. It’s a way to hold you back from the urge to start speaking ‘too soon.’" Instructors will also find a download option for the software depending on their OS, as well as install instructions and a FAQ.

  9. Subacromial Spacer Placement for Protection of Rotator Cuff Repair

    PubMed Central

    Szöllösy, Gregor; Rosso, Claudio; Fogerty, Simon; Petkin, Kalojan; Lafosse, Laurent

    2014-01-01

    Rotator cuff repairs have a high failure rate proportional to the tear size. Various techniques have been described to improve the repair strength and failure rate. The described surgical technique uses a biodegradable subacromial balloon-shaped spacer (InSpace; OrthoSpace, Caesarea, Israel) that is implanted arthroscopically to protect our tendon repair. We describe the introduction technique and suggest some hints and tricks. The spacer is placed under direct vision in the subacromial space after the rotator cuff repair is finished. Correct placement is verified by moving the arm freely. The subacromial spacer may help to protect the rotator cuff repair by centering the humeral head and reducing friction between suture knots and the acromion. It may also help to flatten dog-ear formations. PMID:25473615

  10. Subacromial spacer placement for protection of rotator cuff repair.

    PubMed

    Szöllösy, Gregor; Rosso, Claudio; Fogerty, Simon; Petkin, Kalojan; Lafosse, Laurent

    2014-10-01

    Rotator cuff repairs have a high failure rate proportional to the tear size. Various techniques have been described to improve the repair strength and failure rate. The described surgical technique uses a biodegradable subacromial balloon-shaped spacer (InSpace; OrthoSpace, Caesarea, Israel) that is implanted arthroscopically to protect our tendon repair. We describe the introduction technique and suggest some hints and tricks. The spacer is placed under direct vision in the subacromial space after the rotator cuff repair is finished. Correct placement is verified by moving the arm freely. The subacromial spacer may help to protect the rotator cuff repair by centering the humeral head and reducing friction between suture knots and the acromion. It may also help to flatten dog-ear formations. PMID:25473615

  11. Biotribology of artificial hip joints.

    PubMed

    Di Puccio, Francesca; Mattei, Lorenza

    2015-01-18

    Hip arthroplasty can be considered one of the major successes of orthopedic surgery, with more than 350000 replacements performed every year in the United States with a constantly increasing rate. The main limitations to the lifespan of these devices are due to tribological aspects, in particular the wear of mating surfaces, which implies a loss of matter and modification of surface geometry. However, wear is a complex phenomenon, also involving lubrication and friction. The present paper deals with the tribological performance of hip implants and is organized in to three main sections. Firstly, the basic elements of tribology are presented, from contact mechanics of ball-in-socket joints to ultra high molecular weight polyethylene wear laws. Some fundamental equations are also reported, with the aim of providing the reader with some simple tools for tribological investigations. In the second section, the focus moves to artificial hip joints, defining materials and geometrical properties and discussing their friction, lubrication and wear characteristics. In particular, the features of different couplings, from metal-on-plastic to metal-on-metal and ceramic-on-ceramic, are discussed as well as the role of the head radius and clearance. How friction, lubrication and wear are interconnected and most of all how they are specific for each loading and kinematic condition is highlighted. Thus, the significant differences in patients and their lifestyles account for the high dispersion of clinical data. Furthermore, such consideration has raised a new discussion on the most suitable in vitro tests for hip implants as simplified gait cycles can be too far from effective implant working conditions. In the third section, the trends of hip implants in the years from 2003 to 2012 provided by the National Joint Registry of England, Wales and Northern Ireland are summarized and commented on in a discussion. PMID:25621213

  12. Biotribology of artificial hip joints

    PubMed Central

    Di Puccio, Francesca; Mattei, Lorenza

    2015-01-01

    Hip arthroplasty can be considered one of the major successes of orthopedic surgery, with more than 350000 replacements performed every year in the United States with a constantly increasing rate. The main limitations to the lifespan of these devices are due to tribological aspects, in particular the wear of mating surfaces, which implies a loss of matter and modification of surface geometry. However, wear is a complex phenomenon, also involving lubrication and friction. The present paper deals with the tribological performance of hip implants and is organized in to three main sections. Firstly, the basic elements of tribology are presented, from contact mechanics of ball-in-socket joints to ultra high molecular weight polyethylene wear laws. Some fundamental equations are also reported, with the aim of providing the reader with some simple tools for tribological investigations. In the second section, the focus moves to artificial hip joints, defining materials and geometrical properties and discussing their friction, lubrication and wear characteristics. In particular, the features of different couplings, from metal-on-plastic to metal-on-metal and ceramic-on-ceramic, are discussed as well as the role of the head radius and clearance. How friction, lubrication and wear are interconnected and most of all how they are specific for each loading and kinematic condition is highlighted. Thus, the significant differences in patients and their lifestyles account for the high dispersion of clinical data. Furthermore, such consideration has raised a new discussion on the most suitable in vitro tests for hip implants as simplified gait cycles can be too far from effective implant working conditions. In the third section, the trends of hip implants in the years from 2003 to 2012 provided by the National Joint Registry of England, Wales and Northern Ireland are summarized and commented on in a discussion. PMID:25621213

  13. Fungal Periprosthetic Joint Infection of the Hip: A Systematic Review

    PubMed Central

    Schoof, Benjamin; Jakobs, Oliver; Schmidl, Stefan; Klatte, Till Orla; Frommelt, Lars; Gehrke, Thorsten; Gebauer, Matthias

    2015-01-01

    Periprosthetic joint infection (PJI) is a severe complication of total joint arthroplasty with an incidence of approximately 1%. Due to the high risk of persisting infection, successful treatment of fungal PJI is challenging. The purpose of this study was to gain insight into the current management of fungal PJI of the hip and, by systematically reviewing the cases published so far, to further improve the medical treatment of this serious complication of total hip arthroplasty. Thus, we conducted a systematic review of the available literature concerning fungal PJI in total hip arthroplasty, including 45 cases of fungal PJI. At the moment a two-stage revision procedure is favorable and there is an ongoing discussion on the therapeutic effect of antifungal drug loaded cement spacers on fungal periprosthetic infections of the hip. Due to the fact that there is rare experience with it, there is urgent need to establish guidelines for the treatment of fungal infections of total hip arthroplasty. PMID:25874063

  14. Hip joints

    NSDL National Science Digital Library

    Connie Raab (National Institutes of Health; )

    2006-05-17

    The human hips are an example of a ball-and-socket joint. Ball-and-socket joints have the ability to rotate in a circular motion. The joint where the arm connects to the shoulder is also a type of ball-and-socket joint.

  15. Hip Replacement

    MedlinePLUS

    ... some people more likely to have successful surgery. Studies are exploring the use of various agents to minimize bone loss around the implant. Strategies to prevent blood clots and implant-related infection are also being investigated. Other areas of research address issues of recovery ...

  16. Radiographic assessment of the cement mantle thickness of the femoral stem in total hip replacement: a case study of 112 consecutive implants.

    PubMed

    Isaac, G H; Busch, C A; Shetty, V; Drabu, K J

    2000-01-01

    The results are reported of a radiographic study of cement mantle thickness in 112 consecutive primary hip replacements. Measurements were made by three observers of the apparent cement thickness medially and laterally using standard anterior-posterior radiographs. The average cement thickness was 3.2 mm, which is 1.2 mm greater than the size difference between the broach and the prosthesis, and was in the range 2-5 mm in 67 per cent of all measurement points. This has significance for the design of instrumentation to prepare the femoral cavity to give a defined cement mantle thickness. There was a greater cement mantle thickness proximally than distally. In 95 cases it was possible to determine the orientation of the stem within the cement mantle, which showed an even distribution between varus and valgus orientation; 49 per cent were within 1 degree of neutral and only one case was more than 5 degrees from neutral. PMID:11109854

  17. Metal-on-Metal Total Hip Resurfacing Arthroplasty

    PubMed Central

    2006-01-01

    Executive Summary Objective The objective of this review was to assess the safety and effectiveness of metal on metal (MOM) hip resurfacing arthroplasty for young patients compared with that of total hip replacement (THR) in the same population. Clinical Need Total hip replacement has proved to be very effective for late middle-aged and elderly patients with severe degenerative diseases of the hips. As indications for THR began to include younger patients and those with a more active life style, the longevity of the implant became a concern. Evidence suggests that these patients experience relatively higher rates of early implant failure and the need for revision. The Swedish hip registry, for example, has demonstrated a survival rate in excess of 80% at 20 years for those aged over 65 years, whereas this figure was 33% by 16 years in those aged under 55 years. Hip resurfacing arthroplasty is a bone-conserving alternative to THR that restores normal joint biomechanics and load transfer. The technique has been used around the world for more than 10 years, specifically in the United Kingdom and other European countries. The Technology Metal-on-metal hip resurfacing arthroplasty is an alternative procedure to conventional THR in younger patients. Hip resurfacing arthroplasty is less invasive than THR and addresses the problem of preserving femoral bone stock at the initial operation. This means that future hip revisions are possible with THR if the initial MOM arthroplasty becomes less effective with time in these younger patients. The procedure involves the removal and replacement of the surface of the femoral head with a hollow metal hemisphere, which fits into a metal acetabular cup. Hip resurfacing arthroplasty is a technically more demanding procedure than is conventional THR. In hip resurfacing, the femoral head is retained, which makes it much more difficult to access the acetabular cup. However, hip resurfacing arthroplasty has several advantages over a conventional THR with a small (28 mm) ball. First, the large femoral head reduces the chance of dislocation, so that rates of dislocation are less than those with conventional THR. Second, the range of motion with hip resurfacing arthroplasty is higher than that achieved with conventional THR. A variety of MOM hip resurfacing implants are used in clinical practice. Six MOM hip resurfacing implants have been issued licences in Canada. Review Strategy A search of electronic bibliographies (OVID Medline, Medline In-Process and Other Non-Indexed Citations, Embase, Cochrane CENTRAL and DSR, INAHTA) was undertaken to identify evidence published from Jan 1, 1997 to October 27, 2005. The search was limited to English-language articles and human studies. The literature search yielded 245 citations. Of these, 11 met inclusion criteria (9 for effectiveness, 2 for safety). The result of the only reported randomized controlled trial on MOM hip resurfacing arthroplasty could not be included in this assessment, because it used a cemented acetabular component, whereas in the new generation of implants, a cementless acetabular component is used. After omitting this publication, only case series remained. Summary of Findings   Health Outcomes The Harris hip score and SF-12 are 2 measures commonly used to report health outcomes in MOM hip resurfacing arthroplasty studies. Other scales used are the Oxford hip score and the University of California Los Angeles hip score. The case series showed that the mean revision rate of MOM hip resurfacing arthroplasty is 1.5% and the incidence of femoral neck fracture is 0.67%. Across all studies, 2 cases of osteonecrosis were reported. Four studies reported improvement in Harris hip scores. However, only 1 study reported a statistically significant improvement. Three studies reported improvement in SF-12 scores, of which 2 reported a significant improvement. One study reported significant improvement in UCLA hip score. Two studies reported postoperative Oxford hip scores, but no preoperative values were reported. None of the reviewed studies r

  18. Results of total hip arthroplasty in patients who have rapidly progressive hip disease: a systematic review of the literature.

    PubMed

    Pivec, Robert; Johnson, Aaron J; Mont, Michael A

    2012-05-01

    Rapidly progressive hip disease is a rare condition characterized by rapid joint space narrowing (>2 mm in 1 year), chondrolysis and destruction of the femoral head. Although the etiology and pathogenetic mechanism is unclear, subchondral insufficiency fractures in the setting of physiologically weakened bone has recently been implicated as the primary insult. The standard of care has been total hip arthroplasty; however, there is a theoretical risk that the disease process may continue, placing the prosthesis at risk. In order to determine the clinical outcomes and implant survivorship in this population, a systematic search of the literature was conducted. Midterm (mean: 5 years) results following total hip arthroplasty demonstrated mean good-to-excellent clinical results (clinical hip scores >80 points) and a 3% revision rate, making this a valuable treatment option for patients who have rapidly progressive hip disease. The underlying disease process does not appear to compromise implant longevity. PMID:22702256

  19. Grid-spacer removal model. [PWR; BWR

    SciTech Connect

    Berna, G.A.

    1982-03-01

    A model has been developed for SCDAP to treat the effect of grid spacer removal. The model simply tests the grid temperature against the melting temperature of the grid spacer material. If the grid spacer temperature is equal to or above its melting temperature, the grid is removed as an obstruction.

  20. Articulating vs. Static antibiotic impregnated spacers in revision total knee arthroplasty for sepsis. A systematic review.

    PubMed

    Guild, George N; Wu, Baohua; Scuderi, Giles R

    2014-03-01

    Periprosthetic infection after total knee arthroplasty is a devastating complication, and two-stage exchange is the standard of care in North America. Articulating and static spacers have been developed to treat these infections but controversy exists over which method is superior. We performed a systematic review using MEDLINE and other literature search engines identifying 47 articles meeting inclusion criteria producing 2011 spacers for comparison. Articulating spacers had increased range of motion 100.1° vs. 82.9° (P<0.003), lower re-infection rate 7.5% (P<0.0031), facilitated re-implantation (P<0.0011), and developed less bone loss (P<.0001) than did static spacers. This study answers several clinically relevant questions and provides useful information in guiding clinical decision making in treating periprosthetic infection. PMID:24268975

  1. Hip Replacement

    NSDL National Science Digital Library

    Patient Education Institute

    This patient education program explains the benefits and risks of hip replacement surgery for treatment of osteoarthritis or injury. This is a MedlinePlus Interactive Health Tutorial from the National Library of Medicine, designed and developed by the Patient Education Institute. NOTE: The tutorial requires a special Flash plug-in, version 4 or above. If you do not have Flash, you will be prompted to obtain a free download of the software before you start the tutorial. You will also need an Acrobat Reader, available as a free download, in order to view the Reference Summary.

  2. Generator stator core vent duct spacer posts

    DOEpatents

    Griffith, John Wesley (Schenectady, NY); Tong, Wei (Clifton Park, NY)

    2003-06-24

    Generator stator cores are constructed by stacking many layers of magnetic laminations. Ventilation ducts may be inserted between these layers by inserting spacers into the core stack. The ventilation ducts allow for the passage of cooling gas through the core during operation. The spacers or spacer posts are positioned between groups of the magnetic laminations to define the ventilation ducts. The spacer posts are secured with longitudinal axes thereof substantially parallel to the core axis. With this structure, core tightness can be assured while maximizing ventilation duct cross section for gas flow and minimizing magnetic loss in the spacers.

  3. Spacer grid assembly and locking mechanism

    DOEpatents

    Snyder, Jr., Harold J. (Rancho Santa Fe, CA); Veca, Anthony R. (San Diego, CA); Donck, Harry A. (San Diego, CA)

    1982-01-01

    A spacer grid assembly is disclosed for retaining a plurality of fuel rods in substantially parallel spaced relation, the spacer grids being formed with rhombic openings defining contact means for engaging from one to four fuel rods arranged in each opening, the spacer grids being of symmetric configuration with their rhombic openings being asymmetrically offset to permit inversion and relative rotation of the similar spacer grids for improved support of the fuel rods. An improved locking mechanism includes tie bars having chordal surfaces to facilitate their installation in slotted circular openings of the spacer grids, the tie rods being rotatable into locking engagement with the slotted openings.

  4. Chondrolysis after hip arthroscopy.

    PubMed

    Más Martínez, Jesús; Sanz Reig, Javier; Morales Santias, Manuel; Bustamante Suarez de Puga, David

    2015-01-01

    We report the case of a 58-year-old woman who presented with left hip pain and was diagnosed with femoroacetabular impingement. She underwent hip arthroscopy to repair a degenerative labral tear, as well as radiofrequency debridement and microfracture of the exposed chondral defect, and femoral osteoplasty. Two months after hip arthroscopy, hip pain and limping began. Hip radiography showed a concentric decrease of joint space and no signs of joint incongruity or osteophytosis. Revision surgery 4 months after hip arthroscopy showed that the cartilage of the femoral head was soft and separated from the subchondral bone. PMID:25218006

  5. CRISPR Interference Directs Strand Specific Spacer Acquisition

    PubMed Central

    Swarts, Daan C.; Mosterd, Cas; van Passel, Mark W. J.; Brouns, Stan J. J.

    2012-01-01

    Background CRISPR/Cas is a widespread adaptive immune system in prokaryotes. This system integrates short stretches of DNA derived from invading nucleic acids into genomic CRISPR loci, which function as memory of previously encountered invaders. In Escherichia coli, transcripts of these loci are cleaved into small RNAs and utilized by the Cascade complex to bind invader DNA, which is then likely degraded by Cas3 during CRISPR interference. Results We describe how a CRISPR-activated E. coli K12 is cured from a high copy number plasmid under non-selective conditions in a CRISPR-mediated way. Cured clones integrated at least one up to five anti-plasmid spacers in genomic CRISPR loci. New spacers are integrated directly downstream of the leader sequence. The spacers are non-randomly selected to target protospacers with an AAG protospacer adjacent motif, which is located directly upstream of the protospacer. A co-occurrence of PAM deviations and CRISPR repeat mutations was observed, indicating that one nucleotide from the PAM is incorporated as the last nucleotide of the repeat during integration of a new spacer. When multiple spacers were integrated in a single clone, all spacer targeted the same strand of the plasmid, implying that CRISPR interference caused by the first integrated spacer directs subsequent spacer acquisition events in a strand specific manner. Conclusions The E. coli Type I-E CRISPR/Cas system provides resistance against bacteriophage infection, but also enables removal of residing plasmids. We established that there is a positive feedback loop between active spacers in a cluster – in our case the first acquired spacer - and spacers acquired thereafter, possibly through the use of specific DNA degradation products of the CRISPR interference machinery by the CRISPR adaptation machinery. This loop enables a rapid expansion of the spacer repertoire against an actively present DNA element that is already targeted, amplifying the CRISPR interference effect. PMID:22558257

  6. Hip Injuries and Disorders

    MedlinePLUS

    ... or falling can all sometimes lead to hip injuries. These include Strains Bursitis Dislocations Fractures Certain diseases also lead to hip injuries or problems. Osteoarthritis can cause pain and limited ...

  7. Total Hip Replacement

    MedlinePLUS

    ... ankle pump exercises, and early mobilization. Leg-length Inequality Sometimes a er a hip replacement, one leg ... Surgeons (AAOS). To learn more about your orthopaedic health, please visit orthoinfo.org. Total Hip Replacement cont.

  8. Cochlear Implants

    MedlinePLUS

    ... Medical Devices Products and Medical Procedures Implants and Prosthetics Cochlear Implants Cochlear Implants View movie of the ... More in Products and Medical Procedures Implants and Prosthetics Cochlear Implants What is a Cochlear Implant? Benefits ...

  9. How to measure wear following total hip arthroplasty.

    PubMed

    Grillini, Laura; Affatato, Saverio

    2013-01-01

    Total hip arthroplasty has yielded excellent results in decreasing pain and enhancing function in patients with hip degenerative disease. However, the problems associated with prosthetic failure and the consequent need for revision surgery still represent a major clinical issue. The most common reasons for revision surgery include implant loosening, periprosthetic osteolysis, infection, malalignment, stiffness, implant failure or fracture, and wear. The need for eliminating or reducing wear plays a crucial role in refining prosthesis composition and design. In this regard, it is important to develop new techniques for more accurate and reproducible measurement of wear. This should allow earlier detection of increased wear and thus permit earlier identification of patients who are at risk, and also help to identify faulty implant designs.?This work is aimed at discussing the most common in vivo and in vitro methods used for evaluating the wear of hip prosthesis components. PMID:23760744

  10. Cardiovascular Effects of Implanted Acrylic Bone Cement

    Microsoft Academic Search

    Hugh Phillips; Peter V. Cole; Alan W. F. Lettin

    1971-01-01

    A pilot study has shown that there is usually but not invariably a fall in systemic arterial blood pressure within 90 seconds of implanting acrylic cement into the femoral shaft during hip arthroplasty. There is usually no change in arterial blood pressure on implanting acrylic cement into the acetabulum. The observed hypotension may be due to absorption of monomer or

  11. How to use an inhaler - with spacer

    MedlinePLUS

    ... empty your lungs Breathe in slowly Put the spacer between your teeth and close your lips tightly around it. Keep your chin up. Start breathing in slowly through your mouth. Spray 1 puff into the spacer by pressing down on the inhaler. Keep breathing ...

  12. Total Hip Joint Replacement Biotelemetry System

    NASA Technical Reports Server (NTRS)

    Boreham, J. F.; Postal, R. B.; Luntz, R. A.

    1981-01-01

    The development of a biotelemetry system that is hermetically sealed within a total hip replacement implant is reported. The telemetry system transmits six channels of stress data to reconstruct the major forces acting on the neck of the prosthesis and uses an induction power coupling technique to eliminate the need for internal batteries. The activities associated with the telemetry microminiaturization, data recovery console, hardware fabrications, power induction systems, electrical and mechanical testing and hermetic sealing test results are discussed.

  13. Monte Carlo calculations of the impact of a hip prosthesis on the dose distribution

    Microsoft Academic Search

    Edwige Buffard; Régine Gschwind; Libor Makovicka; Céline David

    2006-01-01

    Because of the ageing of the population, an increasing number of patients with hip prostheses are undergoing pelvic irradiation. Treatment planning systems (TPS) currently available are not always able to accurately predict the dose distribution around such implants. In fact, only Monte Carlo simulation has the ability to precisely calculate the impact of a hip prosthesis during radiotherapeutic treatment. Monte

  14. Metal-on-Metal Hip Resurfacing Arthroplasty

    PubMed Central

    Sehatzadeh, S; Kaulback, K; Levin, L

    2012-01-01

    Background Metal-on-metal (MOM) hip resurfacing arthroplasty (HRA) is in clinical use as an appropriate alternative to total hip arthroplasty in young patients. In this technique, a metal cap is placed on the femoral head to cover the damaged surface of the bone and a metal cup is placed in the acetabulum. Objectives The primary objective of this analysis was to compare the revision rates of MOM HRA using different implants with the benchmark set by the National Institute of Clinical Excellence (NICE). The secondary objective of this analysis was to review the literature regarding adverse biological effects associated with implant material. Review Methods A literature search was performed on February 13, 2012, to identify studies published from January 1, 2009, to February 13, 2012. Results The revision rates for MOM HRA using 6 different implants were reviewed. The revision rates for MOM HRA with 3 implants met the NICE criteria, i.e., a revision rate of 10% or less at 10 years. Two implants had short-term follow-ups and MOM HRA with one of the implants failed to meet the NICE criteria. Adverse tissue reactions resulting in failure of the implants have been reported by several studies. With a better understanding of the factors that influence the wear rate of the implants, adverse tissue reactions and subsequent implant failure can be minimized. Many authors have suggested that patient selection and surgical technique affect the wear rate and the risk of tissue reactions. The biological effects of high metal ion levels in the blood and urine of patients with MOM HRA implants are not known. Studies have shown an increase in chromosomal aberrations in patients with MOM articulations, but the clinical implications and long-term consequences of this increase are still unknown. Epidemiological studies have shown that patients with MOM HRA implants did not have an overall increase in mortality or risk of cancer. There is insufficient clinical data to confirm the teratogenicity of MOM implants in humans. Conclusions Metal-on-metal HRA can be beneficial for appropriately selected patients, provided the surgeon has the surgical skills required for performing this procedure. Plain Language Summary There are many young patients with hip diseases who need to have hip replacement surgery. Although a traditional hip replacement is an acceptable procedure for these patients, some surgeons prefer using a newer technique in young patients called hip resurfacing. In this technique, instead of removing the head of the femoral bone, a metal cap is placed on the femoral head to cover the damaged surface of the bone and a metal cup is placed in the hip socket, similar to the cups used in traditional hip replacement. The analysis of the revision rates (i.e., how soon and in how many patients the surgery needs to be redone) and safety of resurfacing implants showed that generally these implants can last 10 years or more for the majority of young people. Good outcomes can be expected when skilled surgeons perform the surgery in properly selected patients. However, since these implants are made of metal (cobalt and chromium alloy), there is concern about excess metal debris production due to friction between the 2 metal components leading to high levels of metal ions in the blood and urine of patients. The production of metal debris may result in inflammation in the joint or development of a benign soft tissue mass leading to implant failure. However, it has been shown that this risk can be reduced by proper positioning of the implant and the careful selection of patients for this procedure. Little is known about the long-term biological effects of high levels of metal ions in the blood and urine of patients who have received metal implants. There is concern about potential increases in the risk of cancer and the risk of fetal abnormalities, but these effects have not been established yet. However, since cobalt and chromium can pass the placental barrier, implants that are not metal-on-metal are recommended for women at childbearing ages if they

  15. Pyrocarbon spacer as a trapezium replacement for arthritis of the trapeziometacarpal joint; a follow-up study of 60 cases.

    PubMed

    Szalay, Gabor; Meyer, Christof; Scheufens, Tanja; Schnettler, Reinhard; Christ, Ralph; Schleicher, Iris

    2013-12-01

    Rhizarthrosis is the most common degenerative joint disease of the hand, affecting about 10% of the population. We report our results with trapezium replacement using a pyrocarbon spacer. Between January 2005 and April 2010, 70 patients underwent trapeziectomy with interposition of a pyrocarbon spacer. Sixty patients were examined at an average follow-up of 23.6 (5-64) months after the operation. Six (8.6%) of the 70 implanted pyrocarbon spacers dislocated. Based on the assessment scale devised by Buck-Gramcko, 19 patients achieved a very good outcome (31.6%), 31 patients (51.6%) had a good outcome, six results were satisfactory (10%) and four patients (6.6%) had a poor result. In this study, trapeziectomy and implantation of a pyrocarbon spacer achieved good or very good results in 83.2% of cases. The high cost of the implant and the observed rate of spacer dislocation should however be considered critically. While the short-term results of this method are encouraging, long-term outcomes will show whether this technique can keep up with the good results of suspension arthroplasty. PMID:24563969

  16. LISA telescope spacer design investigations

    NASA Astrophysics Data System (ADS)

    Sanjuan, Josep; Mueller, Guido; Livas, Jeffrey; Preston, Alix; Arsenovic, Petar; Castellucci, Kevin; Generie, Joseph; Howard, Joseph; Stebbins, Robin

    The Laser Interferometer Space Antenna (LISA) is a space-based gravitational wave observa-tory with the goal of observing Gravitational Waves (GWs) from astronomical sources in a frequency range from 30 µHz to 0.1 Hz. The detection of GWs at such low frequency requires measurements of distances at the pico-meter level between bodies separated by 5 million kilo-meters. The LISA mission consists of three identical spacecraft (SC) separated by 5 × 106 km forming an equilateral triangle. Each SC contains two optical assemblies and two vacuum en-closures housing one proof mass (PM) in geodesic (free fall) motion each. The two assemblies on one SC are each pointing towards an identical assembly on each of the other two SC to form a non-equal arm interferometer. The measurement of the GW strain is done by measuring the change in the length of the optical path between the PMs of one arm relative to the other arms caused by the pass of a GW. An important element of the Interferometric Measurement System (IMS) is the telescope which, on one hand, gathers the light coming from the far SC (˜100 pW) and, on the other hand, expands and collimates the small outgoing beam ( 1 W) and sends it to the far SC. Due to the very demanding sensitivity requirements care must be taken in the design and validation of the telescope not to degrade the IMS performance. For instance, the diameter of the telescope sets the the shot noise of the IMS and depends critically on the diameter of the primary and the divergence angle of the outgoing beam. As the telescope is rather fast telescope, the divergence angle is a critical function of the overall separation between the primary and secondary. Any long term changes of the distance of more than a a few micro-meter would be detrimental to the LISA mission. Similarly challenging are the requirements on the in-band path-length noise for the telescope which has to be kept below 1 pm Hz-1/2 in the LISA band. Different configurations (on-axis/off axis) and materials such as Silicon Carbide (SiC) and Carbon Fiber Reinforced Plastic (CFRP) are considered to be used in the telescope spacer structure. We will describe our experimental efforts to understand and quantify the behavior of different materials and also discuss a first investigation of a specific on-axis SiC telescope spacer for LISA. This work is supported by NASA contract 00069955.

  17. 21 CFR 888.3370 - Hip joint (hemi-hip) acetabular metal cemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...false Hip joint (hemi-hip) acetabular metal cemented prosthesis. 888.3370 Section...3370 Hip joint (hemi-hip) acetabular metal cemented prosthesis. (a) Identification. A hip joint (hemi-hip) acetabular metal cemented prosthesis is a device...

  18. 21 CFR 888.3370 - Hip joint (hemi-hip) acetabular metal cemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...false Hip joint (hemi-hip) acetabular metal cemented prosthesis. 888.3370 Section...3370 Hip joint (hemi-hip) acetabular metal cemented prosthesis. (a) Identification. A hip joint (hemi-hip) acetabular metal cemented prosthesis is a device...

  19. 21 CFR 888.3370 - Hip joint (hemi-hip) acetabular metal cemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...false Hip joint (hemi-hip) acetabular metal cemented prosthesis. 888.3370 Section...3370 Hip joint (hemi-hip) acetabular metal cemented prosthesis. (a) Identification. A hip joint (hemi-hip) acetabular metal cemented prosthesis is a device...

  20. Ceramic-on-Ceramic Total Hip Arthroplasty: Minimum of Six-Year Follow-up Study

    PubMed Central

    Choy, Won-Sik; Lee, Sang Ki; Bae, Kyoung Wan; Hwang, Yoon Sub; Park, Chang Kyu

    2013-01-01

    Background This study examines the clinical and radiologic results of ceramic-on-ceramic total hip arthroplasties with regard to wear, osteolysis, and fracture of the ceramic after a minimum follow-up of six years. Methods We evaluated the results of a consecutive series of 148 primary ceramic-on-ceramic total hip arthroplasties that had been performed between May 2001 and October 2005 in 142 patients. The mean age was 57.2 years (range, 23 to 81 years). The mean follow-up period was 7.8 years (range, 6.1 to 10.1 years). Preoperative diagnosis was avascular necrosis in 77 hips (52%), degenerative arthritis in 36 hips (24.3%), femur neck fracture in 18 hips (12.2%), rheumatoid arthritis in 15 hips (10.1%), and septic hip sequelae in 2 hips (1.4%). Clinical results were evaluated with the Harris hip score, and the presence of postoperative groin or thigh pain. Radiologic analysis was done with special attention in terms of wear, periprosthetic osteolysis, and ceramic failures. Results The mean Harris hip score improved from 58.3 (range, 10 to 73) to 92.5 (range, 79 to 100) on the latest follow-up evaluation. At final follow-up, groin pain was found in 4 hips (2.7%), and thigh pain was found in 6 hips (4.1%). Radiologically, all femoral stems demonstrated stable fixations without loosening. Radiolucent lines were observed around the stem in 25 hips (16.9%), and around the cup in 4 hips (2.7%). Endosteal new bone formation was observed around the stem in 95 hips (64.2%) and around the cup in 88 hips (59.5%). No osteolysis was observed around the stem and cup. There were 2 hips (1.4%) of inclination changes of acetabular cup, 2 hips (1.4%) of hip dislocation, 1 hip (0.7%) of ceramic head fracture, and 1 hip (0.7%) of squeaking. The Kaplan-Meier survival rate of the prostheses was 98.1% at postoperative 7.8 years. Conclusions The ceramic-on-ceramic total hip arthroplasty produced excellent clinical results and implant survival rates with no detectable osteolysis on a minimum six-year follow-up study. The ceramic-on-ceramic couplings could be a reasonable option of primary total hip arthroplasty for variable indications. PMID:24009902

  1. Cochlear Implants

    MedlinePLUS

    Cochlear Implants Cochlear Implants Patient Health Information News media interested in covering the latest from AAO-HNS/F can ... only with a cochlear implant. How do cochlear implants work? Cochlear implants bypass damaged hair cells and ...

  2. Breast Implants

    MedlinePLUS

    ... in women with breast implants. Outline the regulatory history of breast implants in the United States. Encourage reporting ... Medical Procedures Implants and Prosthetics Breast Implants Regulatory History of Breast Implants in the U.S. Saline-Filled Breast ...

  3. Hip injuries in athletes.

    PubMed

    Blankenbaker, Donna G; De Smet, Arthur A

    2010-11-01

    Hip injuries are common in athletes, and there is an extensive differential diagnosis of potential causes. This article reviews the anatomy of the hip, and discusses the imaging findings of hip pathology in athletes including skeletal, intraarticular, and extra-articular abnormalities. The role of radiography, computed tomography (CT), magnetic resonance (MR) imaging, MR arthrography, CT arthrography, and sonography in evaluating each condition is discussed. PMID:21094404

  4. Inflammatory Pseudotumor Complicated by Recurrent Dislocations after Revision Total Hip Arthroplasty

    PubMed Central

    Lee, Jason; Schwarzkopf, Ran

    2014-01-01

    A 71-year-old female with a history of right total hip arthroplasty presented with an enlarging pseudotumor. Pseudotumor is a known complication following metal-on-metal and metal-on-conventional polyethylene and metal-on-highly cross-linked polyethylene implants. Revision total hip arthroplasty following resection of pseudotumor has resulted in an increase in incidence of postoperative complications. Despite stable implants, these complications arise from the amount of soft tissue damage combined with the loss of tissue support around the resected hip. Our case is a clear example of a major complication, recurrent dislocation, following resection and revision surgery. PMID:25161791

  5. Hip joint replacement

    MedlinePLUS

    ... made joint. The artificial joint is called a prosthesis . ... thromboembolic disease in patients undergoing elective hip and ... joint arthroplasties: current concepts of patient outcomes after ...

  6. Hip fracture - discharge

    MedlinePLUS

    Inter-trochanteric fracture repair - discharge; Subtrochanteric fracture repair - discharge; Femoral neck fracture repair - discharge; Trochanteric fracture repair - discharge; Hip pinning surgery - ...

  7. Hip fracture surgery

    MedlinePLUS

    ... neck fracture repair; Trochanteric fracture repair; Hip pinning surgery ... You may receive general anesthesia before this surgery. This means ... spinal anesthesia. With this kind of anesthesia, medicine is ...

  8. Uncemented custom femoral components in hip arthroplasty

    PubMed Central

    2010-01-01

    Background and purpose We have developed an individually designed, uncemented femoral component for achievement of improved strain distribution and fixation to the bone, to make uncemented stems more applicable in femurs of abnormal size and shape, and to improve the joint mechanics. Here we describe the design of the implant and present the results of a prospective clinical study with at least 7 years of follow-up. Patients and methods The prostheses are produced by CAD-CAM technique. The design of the stem is based on CT information, and the neck design is based on the surgeon's planning of the center of rotation, femoral head offset, and leg length correction. The first-generation stem produced before 2001 had a proximal HA coating and a sand-blasted distal part that was down-scaled to avoid contact with compact bone. The second-generation stem had a porous coating beneath the HA layer and the distal part of the stem was polished. The implant was used in 762 hips (614 patients) from 1995 until 2009. 191 of these hips were followed for 7 years and 83 others were followed for 10 years, and these hips are included in the present study. Mean age at surgery was 48 (20–65) years. Congenital dysplasia of the hip was the reason for osteoarthritis in 46% and 57% of the hips in respective groups. Merle d'Aubigné score was recorded in 152 and 75 hips in the two groups. Prostheses followed for 10 years, and almost all in the 7-year group, were first-generation stems. Results The 7- and 10-year cumulative revision rates were 1.1% and 2.4%, respectively, with stem revision for any reason as endpoint. The clinical results were similar at 7 and 10 years, with Merle d'Aubigné scores of 17. Intraoperative trochanteric fissures occurred in 2 of the 191 operations (1.0%); both healed after wiring. In hips followed for 7 years, 2 periprosthetic fractures occurred; exchange of the stem was necessary in both. One additional fracture occurred between 7 and 10 years, and it was treated successfully with osteosynthesis. The rate of dislocation was 1.6% and 2.4%, respectively. There was no radiographic loosening at follow-up. Interpretation Use of a custom femoral stem gives a reliable fixation and promising medium-term clinical results in femurs of normal and abnormal shape and dimension. The individual design, which enables optimized joint mechanics, gives a low risk of mechanical complications. PMID:20809741

  9. A finite element analysis of hollow stemmed hip prostheses as a means of reducing stress shielding of the femur

    Microsoft Academic Search

    S Gross; E. W Abel

    2001-01-01

    Stress shielding of the femur is known to be a principal factor in aseptic loosening of hip replacements. This paper considers the use of a hollow stemmed hip implant for reducing the effects of stress shielding, while maintaining acceptably low levels of stress in the cement. Using finite element modelling, the stresses in the proximal femur using different shapes of

  10. More ribosomal spacer sequences from Xenopus laevis.

    PubMed Central

    Moss, T; Boseley, P G; Birnstiel, M L

    1980-01-01

    The base sequence analysis of a Xenopus laevis ribosomal DNA repeat (7) has been extended to cover almost the entire non-transcribed and external transcribed spacer. A compilation of these sequences is presented. All the repetitive and non-repetitive sequence elements of the spacer are identified and their evolution discussed. Comparison of the X.laevis and S.cerevisiae (25,26) ribosomal DNAs shows about 80% sequence conservation in the 18S gene but no sequence conservation, from the available data, in the external transcribed spacer. The sequence coding for the 3' terminus of the X.laevis 40S ribosomal precursor RNA is presented and its structural features analyzed. Images PMID:7003549

  11. Sunspots and hip fractures.

    PubMed

    Caniggia, M; Scala, C

    1991-01-01

    In this paper a remarkable statistical link between sunspot cycles and prevalence of hip fractures in the elderly is shown. Hip fractures in old people are due to: 1. increased bone fragility for metabolic bone disease; 2. increased propension to fall. Though it is obvious that a correlation does not imply any causal relationship, reasonable conjectures can be allowed. The hypothesis of an 11-year cyclic variation of ultraviolet radiation as a cause of hip fractures is untenable; one may better assume that solar flares can negatively influence the nervous postural regulation leading to a greater propensity to accidental falls. PMID:1935412

  12. The Result of Revision Total Hip Arthroplasty in Patients with Metallosis Following a Catastrophic Failure of a Polyethylene Liner

    PubMed Central

    Kwak, Hong Suk; Lee, Young-Kyun; Koo, Kyung-Hoi; Yoon, Kang Sup; Kim, Hee Joong

    2015-01-01

    Background Wear cannot be completely prevented after total hip arthroplasty. If severe polyethylene (PE) liner wear develops, the so-called catastrophic failure occurs and metallosis develops. We postulated that longevity of the new implant may be affected after revision surgery for metallosis following a catastrophic failure of a PE liner due to the substantial amount of PE wear particles and infiltration of the metal particles in this catastrophic condition. Methods Twenty-three hips of 23 patients were identified because they showed metallosis during revision total hip arthroplasties performed in Seoul National University Hospital between January 1996 and August 2004. They were followed for at least 6.5 years after the index revision total hip arthroplasty. The clinical and radiological results of revision total hip arthroplasties in these patients were evaluated. Results The median Harris hip score increased from 60 points before revision total hip arthroplasties to 90 points at the final follow-up. Osteolysis was detected at an average of 9.3 years after revision total hip arthroplasties in 13 hips and acetabular cup loosening at average 9.8 years after revision total hip arthroplasties in 9 hips. With radiographic evidence of osteolysis and loosening as the end points, the 15-year survival rates were 28.2% and 56.0%, respectively. Conclusions The survival rate of revision total hip arthroplasty in patients with metallosis following a catastrophic failure of a PE liner was low. PMID:25729518

  13. Ultrasound: Infant Hip

    MedlinePLUS

    ... hip area, and images are recorded on a computer. The black-and-white images show the internal ... the images can be seen clearly on the computer screen. A technician (sonographer) trained in ultrasound imaging ...

  14. Arthroscopic Hip Labral Repair

    PubMed Central

    Philippon, Marc J.; Faucet, Scott C.; Briggs, Karen K.

    2013-01-01

    Labral tears in the hip may cause painful clicking or locking of the hip, reduced range of motion, and disruption to sports and daily activities. The acetabular labrum aids stabilization of the hip joint, particularly during hip motion. The fibrocartilaginous structure extends the acetabular rim and provides a suction seal around the femoroacetabular interface. Treatment options for labral tears include debridement, repair, and reconstruction. Repair of the labrum has been shown to have better results than debridement. Labral refixation is achieved with sutures anchored into the acetabular rim. The acetabular rim is trimmed either to correct pincer impingement or to provide a bleeding bed to improve healing. Labral repair has shown excellent short-term to midterm outcomes and allows patients to return to activities and sports. Arthroscopic rim trimming and labral refixation comprise an effective treatment for labral tears with an underlying diagnosis of femoroacetabular impingement and are supported by the peer-reviewed literature. PMID:23875153

  15. Hip Conditioning Program

    MedlinePLUS

    ... sequence 4 times. Hip Conditioning Program Stretching exerciSeS Repetitions 2 sets of 4 Days per week Daily ... other side. Repeat the entire sequence 4 times. Repetitions 2 sets of 4 Days per week Daily ...

  16. Bone cement implantation syndrome.

    PubMed

    Razuin, R; Effat, O; Shahidan, M N; Shama, D V; Miswan, M F M

    2013-06-01

    Bone cement implantation syndrome (BCIS) is characterized by hypoxia, hypotension, cardiac arrhythmias, increased pulmonary vascular resistance and cardiac arrest. It is a known cause of morbidity and mortality in patients undergoing cemented orthopaedic surgeries. The rarity of the condition as well as absence of a proper definition has contributed to under-reporting of cases. We report a 59-year-old woman who sustained fracture of the neck of her left femur and underwent an elective hybrid total hip replacement surgery. She collapsed during surgery and was revived only to succumb to death twelve hours later. Post mortem findings showed multiorgan disseminated microembolization of bone marrow and amorphous cement material. PMID:23817399

  17. Small Stem Total Hip Arthroplasty in Hypoplasia of the Femur

    PubMed Central

    Haverkamp, Daniel; Van der Vis, Harm M.; Besselaar, Philip P.; Marti, René K.

    2008-01-01

    Total hip arthroplasty in hypoplastic femurs is technically difficult and the incidence of complications and aseptic loosening is relatively high. Cemented, uncemented, off-the-shelf, and custom-made stems all have been advocated in these cases. From 1978 to 1997, we performed 86 total hip arthroplasties in 77 patients with a hypoplastic femur using a cemented, off-the-shelf, small, curved, cobalt-chromium stem. We hypothesized results equaled those of the identical but larger-sized stems in normal-sized femora which were used as comparisons. Clinical and radiographic evaluations were performed. Minimum followup was 4.2 years (mean, 12 years; range, 4.2–20.3 years); mean Harris hip score was 88, and mean hip flexion was 104°. Six stems were revised: four because of aseptic loosening, one after a femoral fracture, and one because of malpositioning. Complications included one perforation and one fracture of the femur, one fracture, one nonunion of the greater trochanter, and one deep infection. Implant survivorship for all hips at 15 years with aseptic revision of the stem as the end point was 90% (confidence interval, 82–99) which equaled results of the larger stems. The small off-the-shelf cemented Weber stem has a high long-term survival and a low complication rate. Survival compares favorably with other small-sized total hip systems. Level of Evidence: Level III, therapeutic study, case-control. PMID:18343979

  18. [Fretting in modular design implant systems].

    PubMed

    Willmann, G

    1993-03-01

    Fretting is a problem of load-bearing implants (hip, knee) especially when modular in design and employing different materials. In contrast, fretting has not yet been observed in dental implants. In the case of ceramic femoral heads and cups (e.g. BIOLOX) no problems with fretting have so far been reported. The state-of-the-art is discussed and assessed. PMID:8490086

  19. Idiopathic chondrolysis of the hip.

    PubMed

    Daluga, D J; Millar, E A

    1989-01-01

    Fourteen patients (16 hips) with idiopathic chondrolysis of the hip were retrospectively studied at the Shriners Hospital from 1973 to 1986. Follow up averaged 84 months (range 13-180 months). All 14 patients were female. All but one were premenstrual. Each patient presented with an insidious onset of pain in the hip, thigh, or knee and radiographic symmetrical joint space narrowing. Three of the 16 hips required fusions, and only five regained a full range of motion. Partial restoration of the joint space occurred in eight hips. Essential treatment consists of unloading the hip joint while maintaining motion. PMID:2732319

  20. Cementless two-stage exchange arthroplasty for infection after total hip arthroplasty.

    PubMed

    Masri, Bassam A; Panagiotopoulos, Kostas P; Greidanus, Nelson V; Garbuz, Donald S; Duncan, Clive P

    2007-01-01

    We retrospectively reviewed all patients at one center with an infected total hip arthroplasty treated with 2-stage revision using cementless components for the second stage and the PROSTALAC articulated spacer at the first stage. Twenty-nine patients were reviewed and followed for at least 2 years postoperatively. An isolated Staphylococcus species was cultured in 76% (22/29) of patients. Three (10.3%) of 29 patients had recurrent infection at the site of the prosthesis. One of the 3 patients ultimately underwent a Girdlestone arthroplasty. Another patient was managed with irrigation and debridement, whereas the final patient was treated with intravenous antibiotics alone. Treatment of infection at the site of a hip arthroplasty with 2-stage revision using cementless components and an articulated spacer yields recurrence rates similar to revisions where at least one of the components at the second stage is fixed with antibiotic-loaded cement. PMID:17197311

  1. Nitriding of titanium disks and industrial dental implants using hollow cathode discharge

    Microsoft Academic Search

    C ALVESJR; C. L. B. Guerra Neto; G. H. S. Morais; C. F. da Silva; V. Hajek

    2005-01-01

    Standard plasma nitriding of commercially pure Ti or various Ti alloys for human body implants (e.g., hip, knee, shoulder and ankle implants) has already proven useful. However, its use in dental implantology is rather limited due to high nitriding temperatures. The small dental implants of complex geometries are frequently distorted. To solve this problem and benefit from the ability of

  2. ROUGH SURFACES OF TITANIUM AND TITANIUM ALLOYS FOR IMPLANTS AND PROSTHESES

    E-print Network

    Boyer, Edmond

    . Abstract Titanium and titanium alloys for dental implants and hip prostheses were surface-treated and of an acid (HCl/H2SO4 hot solution) etching performed on Ti dental implants after the sandROUGH SURFACES OF TITANIUM AND TITANIUM ALLOYS FOR IMPLANTS AND PROSTHESES 1 E. Conforto, 2 B

  3. Preclinical investigations towards the first spacer gel application in prostate cancer treatment during particle therapy at HIT

    PubMed Central

    2013-01-01

    Background The application of spacer gel represents a promising approach to reliably spare the rectal frontal wall during particle therapy (IJROBP 76:1251-1258, 2010). In order to qualify the spacer gel for the clinical use in particle therapy, a variety of measurements were performed in order to ensure the biological compatibility of the gel, its physical stability during and after the irradiation, and a proper definition of the gel in terms of the Hounsfield Unit (HU) values for the treatment planning system. The potential for the use of the spacer gel for particle therapy monitoring with off-line Positron Emission Tomography (PET) was also investigated. Results The spacer gel implanted to the prostate patient in direct neighbourhood to the clinical target volume does not interfere with the particle therapy treatment planning procedure applied at Heidelberg Ion Beam Therapy Centre (HIT). The performed measurements show that Bragg-peak position of the particles can be properly predicted on the basis of computed tomography imaging with the treatment planning system used at HIT (measured water equivalent path length of 1.011 ±0.011 (2?), measured Hounsfield Unit of 28.9 ±6.1 (2?)). The spacer gel samples remain physically unchanged after irradiation with a dose exceeding the therapeutic dose level. The independently measured Bragg-Peak position does not change within the time interval of 10 weeks. Conclusions As a result of the presented experiments, the first clinical application of spacer gel implant during prostate cancer treatment with carbon ions and protons was possible at HIT in 2012. The reported pre-clinical investigations demonstrate that use of spacer gel is safe in particle therapy in presence of therapy target motion and patient positioning induced particle range variations. The spacer gel injected between prostate and rectum enlarge the distance between both organs, which is expected to clinically significantly decrease the undesirable exposure of the most critical organ at risk, i.e. rectal frontal wall. Further research on the composition of spacer gel material might lead to additional clinical benefits by validation of particle therapy of prostate via post-therapeutic PET-imaging or by patient positioning based on the gel as a radio-opaque marker. PMID:23742233

  4. Cochlear Implants.

    ERIC Educational Resources Information Center

    Clark, Catherine; Scott, Larry

    This brochure explains what a cochlear implant is, lists the types of individuals with deafness who may be helped by a cochlear implant, describes the process of evaluating people for cochlear implants, discusses the surgical process for implanting the aid, traces the path of sound through the cochlear implant to the brain, notes the costs of…

  5. Fixation using alternative implants for the treatment of hip fractures (FAITH): design and rationale for a multi-centre randomized trial comparing sliding hip screws and cancellous screws on revision surgery rates and quality of life in the treatment of femoral neck fractures

    PubMed Central

    2014-01-01

    Background Hip fractures are a common type of fragility fracture that afflict 293,000 Americans (over 5,000 per week) and 35,000 Canadians (over 670 per week) annually. Despite the large population impact the optimal fixation technique for low energy femoral neck fractures remains controversial. The primary objective of the FAITH study is to assess the impact of cancellous screw fixation versus sliding hip screws on rates of revision surgery at 24 months in individuals with femoral neck fractures. The secondary objective is to determine the impact on health-related quality of life, functional outcomes, health state utilities, fracture healing, mortality and fracture-related adverse events. Methods/Design FAITH is a multi-centre, multi-national randomized controlled trial utilizing minimization to determine patient allocation. Surgeons in North America, Europe, Australia, and Asia will recruit a total of at least 1,000 patients with low-energy femoral neck fractures. Using central randomization, patients will be allocated to receive surgical treatment with cancellous screws or a sliding hip screw. Patient outcomes will be assessed at one week (baseline), 10 weeks, 6, 12, 18, and 24 months post initial fixation. We will independently adjudicate revision surgery and complications within 24 months of the initial fixation. Outcome analysis will be performed using a Cox proportional hazards model and likelihood ratio test. Discussion This study represents major international efforts to definitively resolve the treatment of low-energy femoral neck fractures. This trial will not only change current Orthopaedic practice, but will also set a benchmark for the conduct of future Orthopaedic trials. Trial registration The FAITH trial is registered at ClinicalTrials.gov (Identifier NCT00761813). PMID:24965132

  6. Wear of the epiphysis-acetabulum in total hip arthroplasty: a review of the literature.

    PubMed

    Affatato, S; Cianci, R; Terzi, S; Toni, A; Giunti, A

    1996-01-01

    Problems related to the use of total hip arthroplasty and the properties of the materials used to make prostheses have encouraged wear phenomena of the epiphysis-acetabulum combination of international importance and acknowledgement. Based on a review of the literature, the authors analyze the most recent years of study of wear phenomena and discuss the choice of materials to be used in total hip arthroplasty implant, with particular interest in any potential defects. PMID:8968115

  7. Pattern Alteration: Protruding Hip Bone

    E-print Network

    2006-08-04

    People with very thin figures typically have to alter their clothing for protruding hip bones. This is because diagonal wrinkles radiate from the hip bones. This well-illustrated publication shows how to correct this problem in pants and skirts....

  8. Hip joint replacement - series (image)

    MedlinePLUS

    ... hip socket. The socket is usually made of metal. A liner that fits inside the socket. It ... usually plastic, but some surgeons use ceramic and metal. The liner allows the hip to move smoothly. ...

  9. Extra-articular hip endoscopy

    PubMed Central

    Verhelst, L.; Guevara, V.; De Schepper, J.; Van Melkebeek, J.; Pattyn, C.; Audenaert, E. A.

    2012-01-01

    The aim of this review is to evaluate the current available literature evidencing on peri-articular hip endoscopy (the third compartment). A comprehensive approach has been set on reports dealing with endoscopic surgery for recalcitrant trochanteric bursitis, snapping hip (or coxa-saltans; external and internal), gluteus medius and minimus tears and endoscopy (or arthroscopy) after total hip arthroplasty. This information can be used to trigger further research, innovation and education in extra-articular hip endoscopy. PMID:23610664

  10. Dual mobility cups in total hip arthroplasty

    PubMed Central

    De Martino, Ivan; Triantafyllopoulos, Georgios Konstantinos; Sculco, Peter Keyes; Sculco, Thomas Peter

    2014-01-01

    Total hip arthroplasty (THA) is considered one of the most successful surgical procedures in orthopaedics. With the increase in the number of THAs performed in the world in the next decades, reducing or preventing medical and mechanical complications such as post-operative THA instability will be of paramount importance, particularly in an emerging health care environment based on quality control and patient outcome. Dual mobility acetabular component (also known as unconstrained tripolar implant) was introduced in France at the end of the 1970s as an alternative to standard sockets, to reduce the risk of THA dislocation in patients undergoing primary THA in France. Dual mobility cups have recently gained wider attention in the United States as an alternative option in the prevention and treatment of instability in both primary and revision THA and offer the benefit of increased stability without compromising clinical outcomes and implant longevity. In this article, we review the use of dual mobility cup in total hip arthroplasty in terms of its history, biomechanics, outcomes and complications based on more than 20 years of medical literature. PMID:25035820

  11. Modular noncemented total hip arthroplasty for congenital dislocation of the hip. Case report and design rationale.

    PubMed

    Gorski, J M

    1988-03-01

    The highest rate of failure and the greatest technical difficulty in total hip arthroplasty occurs with congenital dislocation of the hip (CDH). Predisposing factors are failure to secure special femoral components to fit an extremely narrow and straight medullary cavity with space for only a very thin mantle of cement. The acetabulum is usually atrophic, and bone grafts are commonly required to support a small-diameter cup. The young age of the average patient and high levels of activity contribute to cement failure. A new modular cementless prosthesis provides excellent immediate skeletal fixation and pain relief in CDH patients. Five modular components are screwed or press-fit into bone. The modular approach facilitates implantation, reduces inventory, and is adaptable to unforeseen problems. These advantages are ordinarily absent with standard or custom cemented components. Modular components may also permit easier revision. The prosthesis is made of titanium alloy for its superalloy strength, elastic modulus, and bioinertness. By omitting the cement mantle, press-fit is obtained with the largest possible implant. The large size minimizes stem breakage in these young, small bones. Excellent short-term results suggest that modular cementless implants are indicated in some patients with CDH. PMID:3342552

  12. Tube support grid and spacer therefor

    DOEpatents

    Ringsmuth, Richard J. (Solano Beach, CA); Kaufman, Jay S. (Del Mar, CA)

    1986-01-01

    A tube support grid and spacers therefor provide radially inward preloading of heat exchange tubes to minimize stress upon base welds due to differential thermal expansion. The grid comprises a concentric series of rings and spacers with opposing concave sides for conforming to the tubes and V-shaped ends to provide resilient flexibility. The flexibility aids in assembly and in transmitting seismic vibrations from the tubes to a shroud. The tube support grid may be assembled in place to achieve the desired inwardly radial preloading of the heat exchange tubes. Tab and slot assembly further minimizes stresses in the system. The radii of the grid rings may be preselected to effect the desired radially inward preloading.

  13. The painful hip: new concepts

    Microsoft Academic Search

    Donna G. Blankenbaker; Michael J. Tuite

    2006-01-01

    Hip pain is a common condition, and the work-up often includes imaging. This article reviews the normal MR anatomy of the hip and the imaging findings of internal derangements, snapping hip, and femoral acetabular impingement. We will describe the role of MR arthrography in evaluating the patient with suspected labral and articular cartilage abnormalities, as well as the pitfalls in

  14. Aseptic loosening of total hip replacement presenting as an anterior thigh mass.

    PubMed

    Gudena, Ravindra; Kuna, Suma; Pradhan, Nikhil

    2013-12-01

    Aseptic loosening is one of the commonest complications of total hip replacement that can cause pain and instability. The chronic inflammatory response to the wear debris from the polyethylene or metal can cause osteolysis and implant failure. We report a case of aseptic loosening of the hip, presented with a swelling over the anterior thigh without any pain or instability in the joint. This mass was a foreign body granuloma formed secondary to the polyethylene wear debris due to the instability of the polyethylene in the metal shell. The patient underwent successful revision hip arthroplasty after the removal of the foreign body granuloma. PMID:21984313

  15. Investigations on a LISA Telescope Spacer

    NASA Astrophysics Data System (ADS)

    Spector, Aaron; Sanjuan, Josep; Preston, Alix

    2010-10-01

    The Laser Interferometer Space Antenna (LISA) is a space-based mission designed to observe gravitational waves from 0.1 mHz to 1 Hz. Using a triangular constellation of three spacecraft separated by 5x10^6 km, LISA will be able to detect the length changes between the spacecraft induced by gravitational waves. These length changes can be detected with pm/rtHz sensitivity using laser interferometry. Each spacecraft must contain two telescopes that can transmit and receive light between spacecraft. To expand and collimate the beam, a two-mirror system was designed with a primary and secondary mirror separated by a spacer. The noise requirements for LISA demand that the telescope spacer must be extremely stable. Two designs, on-axis and off-axis, are being considered for the telescope spacer. Various materials are also being examined. An on-axis silicon carbide telescope test structure was built to assess the stability of this configuration. A Michelson Interferometer was used to monitor length changes of the test structure while being cooled to space-like temperatures. Stability measurements are currently being made by locking the telescope laser to a cavity mounted on the test structure and then the beat note between the telescope laser and another cavity-locked laser is observed. A beat note between another laser locked to the Doppler-free spectral lines of iodine and the telescope laser will be used to determine the long term stability of the test structure.

  16. Greater trochanteric hip pain.

    PubMed

    Kimpel, Diane M; Garner, Chadwick C; Magone, Kevin M; May, Jedediah H; Lawless, Matthew W

    2014-01-01

    In the patient with lateral hip pain, there is a broad differential diagnosis, making appropriate evaluation and management challenging. Greater trochanteric pain syndrome is a term used to denote chronic lateral hip pain and encompasses several painful soft tissue diagnoses including coxa saltans, trochanteric bursitis, and gluteus minimus and medius tendon tears. An overview of these common causes is presented through a series of cases that encompass the anatomic associations, classic presentations, diagnostic tests, and management strategies unique to each disorder. By reviewing this information, we hope to provide clinicians with the tools to evaluate greater trochanteric pain syndrome efficiently and effectively. PMID:24651142

  17. Impingement in Total Hip Replacement: Mechanisms and Consequences

    PubMed Central

    Brown, Thomas D.; Callaghan, John J.

    2009-01-01

    The occurrence of total hip impingement, whether or not accompanied by frank dislocation, holds substantial untoward clinical consequences, especially as less-forgiving advanced bearing implant designs come into ever more widespread use. Biomechanical aspects of impingement and dislocation have historically received relatively little scientific attention, although that situation is now rapidly changing. The present article reviews contemporary laboratory and clinical research on the impingement/dislocation phenomena, focusing particularly on how implant design variables, surgical implantation factors and patient activity each act individually and in concert to pose impingement and dislocation challenges. In recent years, several powerful new research methodologies have emerged that have greatly expanded the scope for clinical translation of systematic laboratory study. Transferring the findings from such research into yet better implant designs, and even better surgical procedures, offers encouragement that the clinical impact of this troublesome complication can be further reduced. PMID:19956356

  18. Contralateral hip and knee gait biomechanics are unchanged by total hip replacement for unilateral hip osteoarthritis

    Microsoft Academic Search

    Kharma C. Foucher; Markus A. Wimmer

    Both the hip and knee contralateral to a total hip replacement (THR) have an increased risk of osteoarthritis (OA) progression, and ultimate joint replacement. It is also known that abnormal gait contributes to OA progression. For these reasons, we conducted a longitudinal analysis of contralateral hip and knee gait during the first year after unilateral THR to determine whether abnormal

  19. Vibroacoustography for the assessment of total hip arthroplasty

    PubMed Central

    Kamimura, Hermes A. S.; Wang, Liao; Carneiro, Antonio A. O.; Kinnick, Randall R.; An, Kai-Nan; Fatemi, Mostafa

    2013-01-01

    OBJECTIVES: This paper proposes imaging with 3-dimensional vibroacoustography for postoperatively assessing the uncovered cup area after total hip arthroplasty as a quantitative criterion to evaluate implant fixation. METHODS: A phantom with a bone-like structure covered by a tissue-mimicking material was used to simulate a total hip arthroplasty case. Vibroacoustography images of the uncovered cup region were generated using a two-element confocal ultrasound transducer and a hydrophone inside a water tank. Topological correction based on the geometry of the implant was performed to generate a 3-dimensional representation of the vibroacoustography image and to accurately evaluate the surface. The 3-dimensional area obtained by the vibroacoustography approach was compared to the area evaluated by a 3-dimensional motion capture system. RESULTS: The vibroacoustography technique provided high-resolution, high-contrast, and speckle-free images with less sensitivity to the beam incidence. Using a 3-dimensional-topology correction of the image, we accurately estimated the uncovered area of the implant with a relative error of 8.1% in comparison with the motion capture system measurements. CONCLUSION: Measurement of the cup coverage after total hip arthroplasty has not been well established; however, the covered surface area of the acetabular component is one of the most important prognostic factors. The preliminary results of this study show that vibroacoustography is a 3-dimensional approach that can be used to postoperatively evaluate total hip arthroplasty. The favorable results also provide an impetus for exploring vibroacoustography in other bone or implant surface imaging applications. PMID:23778334

  20. Diamond Coating of Hip Joint Replacement: Improvement of Durability

    Microsoft Academic Search

    Z. Nibennaoune; D. George; S. Ahzi; Y. Remond; J. Gracio; D. Ruch

    \\u000a Despite the success of surgical implants such as artificial hip, materials used in these procedures still do not satisfy the\\u000a demands of human life time functioning. Currently used materials such as titanium alloys, ceramics and polymers are degraded\\u000a after about a dozen years of use. Diamond coating technology has proven to be efficient in the performance of human joints.\\u000a In

  1. The athlete's hip and groin.

    PubMed

    Tammareddi, Kumar; Morelli, Vincent; Reyes, Miguel

    2013-06-01

    Groin and hip injuries are seen in athletes who perform quick directional changes and cutting movements. Because forces generated through athletic performance are transferred through the hip, injuries to these areas may limit athletes with mild pain or lead to career-ending injuries. The anatomy of the hip and groin is complex and symptoms often overlap. This article discusses some athletic causes, but other medical conditions may be associated with hip and groin pain as well. Updates in evaluation and treatment are discussed for adductor strains, hip osteoarthritis, femoroacetabular impingement, sports hernia, osteitis pubis, and obturator nerve entrapment. PMID:23668647

  2. Revision in Cemented and Cementless Infected Hip Arthroplasty

    PubMed Central

    Cherubino, Paolo; Puricelli, Marco; D’Angelo, Fabio

    2013-01-01

    Infection is a frequent cause of failure after joint replacement surgery. The infection rate after total hip arthroplasty (THA) has been reduced to 1-2% in the last years. However, it still represents a challenging problem for the orthopedic surgeon. Difficulty of therapeutic approach, and poor functional outcomes together with length of treatment and overall cost are the main burden of this issue. Even the diagnosis of an infected hip could be challenging although it is the first step of an accurate treatment. At the end, many cases require removing the implants. Afterwards, the treatment strategy varies according to authors with three different procedures: no re-implantation, immediate placement of new implants or a two-stage surgery re-implantation. Based on the most recently systematic review there is no suggestion that one- or two-stage revision methods have different re-infection outcomes. The two-stage implant-exchange protocol remains the gold standard. It is considered as the most efficacious clinical approach for the treatment of periprosthetic infection, especially in patients with sinus tracts, swelling, extended abscess formation in depth and infection of Methicillin Resistant Staphylococcus Aureus (MRSA), and other multidrug-resistant bacteria as reported in recent consensus documents. PMID:23898351

  3. 21 CFR 888.3400 - Hip joint femoral (hemi-hip) metallic resurfacing prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...femoral (hemi-hip) metallic resurfacing prosthesis. 888.3400 Section 888.3400...femoral (hemi-hip) metallic resurfacing prosthesis. (a) Identification. A hip...femoral (hemi-hip) metallic resurfacing prosthesis is a device intended to be...

  4. 21 CFR 888.3400 - Hip joint femoral (hemi-hip) metallic resurfacing prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...femoral (hemi-hip) metallic resurfacing prosthesis. 888.3400 Section 888.3400...femoral (hemi-hip) metallic resurfacing prosthesis. (a) Identification. A hip...femoral (hemi-hip) metallic resurfacing prosthesis is a device intended to be...

  5. 21 CFR 888.3400 - Hip joint femoral (hemi-hip) metallic resurfacing prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...femoral (hemi-hip) metallic resurfacing prosthesis. 888.3400 Section 888.3400...femoral (hemi-hip) metallic resurfacing prosthesis. (a) Identification. A hip...femoral (hemi-hip) metallic resurfacing prosthesis is a device intended to be...

  6. 21 CFR 888.3400 - Hip joint femoral (hemi-hip) metallic resurfacing prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...femoral (hemi-hip) metallic resurfacing prosthesis. 888.3400 Section 888.3400...femoral (hemi-hip) metallic resurfacing prosthesis. (a) Identification. A hip...femoral (hemi-hip) metallic resurfacing prosthesis is a device intended to be...

  7. Clinical Outcomes Assessment of Three Similar Hip Arthroplasty Bearing Surfaces

    PubMed Central

    Parsons, Christopher; Batson, Ryan; Reighard, Shane; Tanner, Stephanie; Snider, Becky; Pace, Thomas B.

    2014-01-01

    This report examines the clinical performance of three very similar total hip arthroplasty designs with distinctly different bearing surfaces used over the course 10-17 years. Clinical outcomes assessments for each group are compared in the context of varying implant related costs related to the latest technology at the time of surgery. Eighty-one surgeries were studied and differ by bearing surface. In this study, 36 hips are ceramic on polyethylene, 27 are metal on polyethylene and 18 are metal on metal. All polyethylene components are nonhighly cross-linked. The ceramic on polyethylene group has younger patients, on average, and higher percentage of patients with significant polyethylene wear. These groups have an average follow-up time of 8.6 years when assessing functional hip scores, thigh pain, groin pain, revision surgeries and radiographic osteolysis. The implant purchasing cost at the time of surgery was assessed to determine if a correlation exists between outcomes and the more technologically advanced implants use at the time of surgery. Based on midterm clinical outcome assessment, no correlation between initial hospital cost and clinical outcomes of one bearing surface over another can be found. PMID:25002938

  8. Total Hip Replacement for the Treatment of End Stage Arthritis of the Hip: A Systematic Review and Meta-Analysis

    PubMed Central

    Tsertsvadze, Alexander; Grove, Amy; Freeman, Karoline; Court, Rachel; Johnson, Samantha; Connock, Martin; Clarke, Aileen; Sutcliffe, Paul

    2014-01-01

    Background Evolvements in the design, fixation methods, size, and bearing surface of implants for total hip replacement (THR) have led to a variety of options for healthcare professionals to consider. The need to determine the most optimal combinations of THR implant is warranted. This systematic review evaluated the clinical effectiveness of different types of THR used for the treatment of end stage arthritis of the hip. Methods A comprehensive literature search was undertaken in major health databases. Randomised controlled trials (RCTs) and systematic reviews published from 2008 onwards comparing different types of primary THR in patients with end stage arthritis of the hip were included. Results Fourteen RCTs and five systematic reviews were included. Patients experienced significant post-THR improvements in Harris Hip scores, but this did not differ between impact types. There was a reduced risk of implant dislocation after receiving a larger femoral head size (36 mm vs. 28 mm; RR?=?0.17, 95% CI: 0.04, 0.78) or cemented cup (vs. cementless cup; pooled odds ratio: 0.34, 95% CI: 0.13, 0.89). Recipients of cross-linked vs. conventional polyethylene cup liners experienced reduced femoral head penetration and revision. There was no impact of femoral stem fixation and cup shell design on implant survival rates. Evidence on mortality and complications (aseptic loosening, femoral fracture) was inconclusive. Conclusions The majority of evidence was inconclusive due to poor reporting, missing data, or uncertainty in treatment estimates. The findings warrant cautious interpretation given the risk of bias (blinding, attrition), methodological limitations (small sample size, low event counts, short follow-up), and poor reporting. Long-term pragmatic RCTs are needed to allow for more definitive conclusions. Authors are encouraged to specify the minimal clinically important difference and power calculation for their primary outcome(s) as well CONSORT, PRISMA and STROBE guidelines to ensure better reporting and more reliable production and assessment of evidence. PMID:25003202

  9. Pain after hip arthroplasty managed by Brennan Healing Science.

    PubMed

    Namavar, Roxanna

    2014-01-01

    A case is presented illustrating the potential effect of Brennan Healing Science on pain following hip arthroplasty for avascular necrosis. A 54-year-old woman experienced anterior groin pain, numbness at the bottom of her foot, and occasional grinding at her hip 22 years after right total hip arthroplasty secondary to avascular necrosis. X-ray films showed signs of osteolysis behind the acetabular cup and asymmetric decreased polyethylene thickness of the acetabular prosthetic. Her orthopedic surgeon advised the patient to follow up every 6-9 months to avoid catastrophic failure of the implant, with plans for surgical revision to be scheduled at the next appointment. The patient sought alternative treatment to avoid an invasive procedure. On presentation, the patient had difficulty walking up the stairs into the treatment room due to pain which she rated a 9/10. She found it painful to rotate, flex, extend her hip, or to sit. Hands-on healing techniques based on the Brennan Healing Science method were initiated, starting at the feet, balancing the energy, and working the way up the joints. Once the work at the hip was completed, the hands-on techniques continued up the centerline of the body and the healing was brought to a close. On completion of a 60-minute healing, the patient was able to stand freely and rated her pain as a 4/10. Flexion, extension, and rotation at the hip were no longer distressing. She was able to walk up and down stairs without distress and denied instability, bursitis, or trochanteric or iliopsoas pain or swelling. Repeat X-rays showed decrease in bone spurs and no hardware problem, and her orthopedic surgeon recommended follow-up after 2 years. It is suggested that Brennan Healing Science techniques could play an effective and cost-efficient role in the treatment of pain following hip arthroplasty. PMID:24439097

  10. INL HIP Plate Fabrication

    SciTech Connect

    B. H. Park; C. R. Clark; J. F. Jue

    2010-02-01

    This document outlines the process used to bond monolithic fuel plates by Hot Isostatic Pressing (HIP). This method was developed at Idaho National Laboratory (INL) for the Reduced Enrichment for Research and Test Reactors (RERTR) program. These foils have been used in a number of irradiation experiments in support of the United States Global Threat Reduction Initiative (GTRI) program.

  11. Treatment of hip instability.

    PubMed

    Robbins, G M; Masri, B A; Garbuz, D S; Greidanus, N; Duncan, C P

    2001-10-01

    Instability after total hip arthroplasty is a major source of patient morbidity, second only to aseptic loosening. Certain patient groups have been identified as having a greater risk of instability, including patients undergoing revision arthroplasty as early or late treatment for proximal femoral fractures. PMID:11689373

  12. Idiopathic chondrolysis of hip.

    PubMed

    Sureka, Jyoti; Jakkani, Ravi Kanth; Inbaraj, Alfred; Panwar, Sanuj

    2011-05-01

    An uncommon case of idiopathic chondrolysis of the hip in an 11-year-old girl is reported. It was characterized by clinical presentation, laboratory tests, and imaging techniques. A differential diagnosis is discussed highlighting the radiological features for quick diagnosis. PMID:21607844

  13. HIP quench technology

    SciTech Connect

    Bergman, C.; Westerlund, J. [ABB Pressure Systems AB, Vaesteraas (Sweden); Zimmerman, F.X. [ABB Autoclave Systems AB, Erie, PA (United States)

    1996-12-31

    Hot Isostatic Pressing (HIP) is a viable production process today for densifying metals, ceramics, and composites to achieve fully dense parts. One major drawback for conventional HIPing is the long ten to twelve hour cycle time resulting in low productivity and high processing cost. Drastic furnace improvements have been made in the late 1980`s with the advent of Uniform Rapid Cooling (URC) called HIP Quenching. This innovation allows floor/floor cycles as short as four to five hours with one hour soak depending on the material to be HIPed. A flow device such as a fan is utilized at the base of the furnace for forced gas convection in promoting main features to: (1) accelerate time for heating, soaking and cooling; (2) add combined solution heat treating; and (3) reduce thermal distortion of parts with varying cross-sections. All three points promise to positively effect better economy with improved property and quality to promote the HIP process further. This paper describes the URC technology and illustrates a couple of HIP Quench studies made for a turbine disc and efficient High Speed Steel powder consolidation.

  14. Aseptic hip pneumarthrosis following modular total hip arthroplasty: a potential mimic of hip infection.

    PubMed

    Morag, Yoav; Yablon, Corrie M; Weber, Alexander E; Brandon, Catherine; Blaha, David J

    2015-04-01

    Pneumarthrosis following total hip arthroplasty accompanied by acute hip symptoms is a potentially ominous finding suggesting infection with gas-forming bacteria, a medical emergency. We describe a case of a 61-year-old male presenting to the Emergency Department 43 months following a titanium/titanium (Ti/Ti) modular neck-stem total hip arthroplasty (MTHA) (Wright Medical Systems, Arlington, Tennessee) with acute presentation of hip symptoms and joint gas on radiographs proven to be aseptic hip pneumarthrosis. We review the imaging features of aseptic hip pneumarthrosis following MTHA which have not been elaborated on previously and suggest a less aggressive workup in select cases. We believe emergency radiologists should be aware of this unusual complication as it may mimic a septic hip which may entail an unnecessarily aggressive workup. PMID:25491939

  15. Extra-articular Snapping Hip

    PubMed Central

    2010-01-01

    Context: Snapping hip, or coxa saltans, is a vague term used to describe palpable or auditory snapping with hip movements. As increasing attention is paid to intra-articular hip pathologies such as acetabular labral tears, it is important to be able to identify and understand the extra-articular causes of snapping hip. Evidence Acquisition: The search terms snapping hip and coxa sultans were used in PubMed to locate suitable studies of any publication date (ending date, November 2008). Results: Extra-articular snapping may be caused laterally by the iliotibial band or anteriorly by the iliopsoas tendon. Snapping of the iliopsoas tendon usually requires contraction of the hip flexors and may be difficult to differentiate from intra-articular causes of snapping. Dynamic ultrasound can help detect abrupt tendon translation during movement, noninvasively supporting the diagnosis of extra-articular snapping hip. The majority of cases of snapping hip resolve with conservative treatment, which includes avoidance of aggravating activities, stretching, and anti-inflammatory medication. In recalcitrant cases, surgery to lengthen the iliotibial band or the iliopsoas tendon has produced symptom relief but may result in prolonged weakness. Conclusions: In treating active patients with snapping soft tissues around the hip, clinicians should recognize that the majority of cases resolve without surgical intervention, while being mindful of the potential for concomitant intra-articular and internal snapping hips. PMID:23015936

  16. Inheritance of the rDNA spacer in D. melanogaster

    Microsoft Academic Search

    E. Boncinelli; A. Borghese; F. Graziani; G. la Mantia; A. Manzi; C. Mariani; A. Simeone

    1983-01-01

    We studied the organization of rDNA spacer sequences within several rDNA loci in D. melanogaster. Every locus showed many discrete length classes of rDNA spacer, ranging from 2.4 kb to about 20 kb. Different loci show characteristic distributions of spacers within the various length classes. Using this molecular characteristic as a genetic marker, segregation, recombination and occurrence of unequal crossing-over

  17. Wear of metal-on-metal hip bearings: metallurgical considerations after hip simulator studies.

    PubMed

    Affatato, Saverio; Traina, Francesco; Ruggeri, Oddone; Toni, Aldo

    2011-12-01

    Metal-on-metal hip-bearing components with different percentages of carbon content (low and high carbon) were tested in 6 different configurations using a hip joint simulator. The aim of this study was to characterize metallurgical and tribological events occurring at the articulating surfaces of these articulations. Also, ion release was evaluated and correlated with wear. After the test, for the high-carbon components, carbides were observed below the matrix surface. In the low-carbon content components, most carbides were "carbide-free", while a minority were worn below the matrix surface with increased test cycles. In the cast alloy components, some carbides were pulled out resulting in micropits. Scanning microscope electron characterization of the tested specimens showed scratches and holes. The surface showed a dominant severe wear mechanism due to third-body particles. A greater amount of ions was released in the lubricant used during the wear test for the smaller diameter compared with the bigger one. This study showed that the metallurgical and tribological events taking place at the articulating surfaces of metal-metal hip implants are numerous and complex. The surface morphology after the test showed the effect of more critical working conditions with smaller diameters. PMID:22198601

  18. Properties of cellulase immobilized on agarose gel with spacer

    SciTech Connect

    Chim-anage, P.; Kashiwagi, Y.; Magae, Y.; Ohta, T.; Sasaki, T.

    1986-12-01

    Cellulase produced by fungus Trichoderma viride was immobilized on agarose beads (Sepharose 4B) activated by cyanogen bromide and also on activated agarose beads that contained spacer arm (activated Ch-Sepharose 4B and Affi-Gel 15). The CMCase activity retained by immobilized cellulase on activated Sepharose containing the spacer tended to be higher than that immobilized without spacer, although the extent of protein immobilization was lower. Also, the higher substrate specificity for cellulase immobilized on beads with spacer was obtained for cellobiose, acid-swollen cellulose, or cellulose powder. The hydrolysis product from their substrates was mainly glucose. 10 references.

  19. Grid welding fixture for a spacer grid

    SciTech Connect

    Anderson, M.W.; Whitt, J.S.

    1995-03-14

    A modular grid welding fixture for a spacer grid that facilitates full grid laser welding of a spacer grid in one setup is disclosed. The modular design allows for partial implementation of each weld type. A base plate is used for mounting to the positioning/rotational plate of the welding system. A removable sub-plate received in the base plate is used to position the grid strips for proper location for welding. A top fixture plate is aligned with the base plate and provides for mounting of a second sub-plate if required. Side plates with spring loaded pressure pads that are hinged to the top fixture plate apply uniform pressure to the outer grid strips during processing. The base plate, top plate, side plate, and pressure pads are provided with a plurality of through holes to allow access of the laser beam for welding. Corner clips are used to insure contact of the overlapping sections of the outer grid strips for proper corner welding. 4 figs.

  20. The output of budesonide from spacer devices assessed under simulated breathing conditions

    Microsoft Academic Search

    Peter W. Barry; Chris O’Callaghan

    1999-01-01

    Background: Spacer devices are increasingly used to aid inhalational therapy, and many different devices are available. Patient and spacer size and spacer static charge may affect drug delivery, but the optimum spacer size and method of reducing static charge is not certain. Objective: We sought to determine the output of budesonide from 3 different spacer devices when assessed by using

  1. Cochlear Implants

    MedlinePLUS

    A cochlear implant is a small, complex electronic device that can help to provide a sense of sound. People who are ... of-hearing can get help from them. The implant consists of two parts. One part sits on ...

  2. Carmustine Implant

    MedlinePLUS

    Carmustine implant is used along with surgery and sometimes radiation therapy to treat malignant glioma (a certain type of ... Carmustine implant comes as a small wafer that is placed in the brain by a doctor during surgery to ...

  3. Cochlear Implants

    MedlinePLUS

    ... the process Understand (when able), along with their parents, their role in the successful use of cochlear implants Have (when able), along with their parents, realistic expectations for cochlear implant use Are willing ...

  4. Cochlear implant

    MedlinePLUS

    ... antenna. This part of the implant receives the sound, converts the sound into an electrical signal, and sends it to ... implants allow deaf people to receive and process sounds and speech. However, it is important to understand ...

  5. Goserelin Implant

    MedlinePLUS

    Goserelin implant is used in combination with radiation therapy and other medications to treat localized prostate cancer ... the treatment of abnormal bleeding of the uterus. Goserelin implant is in a class of medications called ...

  6. Evidence of MRSE on a gentamicin and vancomycin impregnated polymethyl-methacrylate (PMMA) bone cement spacer after two-stage exchange arthroplasty due to periprosthetic joint infection of the knee

    PubMed Central

    2014-01-01

    Background Periprosthetic joint infections (PJI) are often treated by two stage exchange with the use of an antibiotic impregnated spacer. Most of the two-stage exchange algorithms recommend the implantation of an antibiotic-impregnated spacer during the first stage for a period of 2–24 weeks before reimplantation of the new prosthesis. For the spacer to have a therapeutic effect, the local antibiotic concentration must be greater than the minimal inhibition concentration (MIC) against the pathogens causing the PJI. It must remain so for the entire spacer period, otherwise recurrence of infection or resistances might occur. The question as to whether a sufficient concentration of antibiotics in vivo is reached for the entire spacer period has not been answered satisfactorily. Case presentation We here present a case of a histologically confirmed chronic PJI 20 month after primary arthroplasty. The primary knee arthroplasty was performed due to osteoarthritis of the joint. Initial assessment did not detect a causative pathogen, and two stage exchange with a vancomycin-gentamycin impregnated spacer was performed. At the time of reimplantation, sonication of the explanted spacer revealed a multi-resistant strain of staphylococcus epidermidis on the device and in the joint. Adaption of the therapy and prolonged treatment successfully eradicated the infection. Conclusion According to the authors’ knowledge, the case presented here confirms for the first time the surface contamination (proven through sonication) of a vancomycin-/gentamicin- impregnated Vancogenx®-spacer with a MRSE after ten weeks of implantation. This case study demonstrates the difficulties still associated with the diagnostics of PJI and the published different two stage treatment regimes with the use of antibiotic impregnated spacers. PMID:24641471

  7. Oral implants.

    PubMed

    van Steenberghe, D

    1991-04-01

    Today, more and more evidence suggests that even small changes in hardware for oral implants may jeopardize its biocompatibility. Even the manner in which the hardware is sterilized can influence cellular adhesion. This review discusses the surface characteristics, configuration, and success rates of various oral implants, as well as the complications that can result following implantation. PMID:1777657

  8. Comparison of total hip arthroplasty in osteoarthritis of mechanical and rheumatologic causes

    PubMed Central

    Ejnisman, Leandro; Leonhardt, Nathalia Zalc; Fernandes, Laura Fillipini Lorimier; Leonhardt, Marcos de Camargo; Vicente, José Ricardo Negreiros; Croci, Alberto Tesconi

    2014-01-01

    Objective: To compare the use of uncemented implants in total hip arthroplasty in patients with rheumathologic diseases and mechanical osteoarthrosis. Methods: We retrospectively evaluated 196 patients who were operated by the Hip and Arthroplasty Surgery Group of the IOT-HCFMUSP between 2005 and 2009. Patients were divided into two groups: mechanical causes (165 patients) and rheumathologic causes (31 patients). Groups were compared between each other in age, gender and follow-up time. Osseointegration rate and percentage of failure in arthroplasty were evaluated. Results: No statistically significant difference was found in osseointegration rates (in both femoral and acetabular components) in both groups. The rates of revision surgery and implant survival also did not show statistically significant differences. Conclusion: The use of uncemented total hip arthroplasty did not show worse results in rheumathologic patients. Level of Evidence III, Retrospective Case Control Study. PMID:24644419

  9. Material optimization of femoral component of total hip prosthesis using fiber reinforced polymeric composites.

    PubMed

    Katoozian, H; Davy, D T; Arshi, A; Saadati, U

    2001-09-01

    In this report an integrated approach to the three-dimensional material optimization of femoral components of hip prostheses is described. The effectiveness of using reinforced fiber composites for the material optimization of hip implants has been demonstrated and general guidelines on some material design aspects of total hip replacement (THR), in terms of fiber volume fraction and fiber orientation angles, are provided. A modular program was developed to interface the optimization routine with the finite element code. In this study two cases of cemented and non-cemented THR were investigated. In both cases perfectly bonded interfaces were assumed. Two objective functions were defined based on interface failure criteria and bone adaptive remodeling to avoid interface disruption and to reduce the risk of bone loss. The overall results demonstrated the effectiveness of the technique, which can provide meaningful insights into the fiber-reinforced composite material design of orthopaedic implants. PMID:11574257

  10. Isolated fracture of the hip stem prosthesis made of austenitic steel - a literature review.

    PubMed

    Mierzejewska, ?aneta Anna; Oksiut, Zbigniew

    2014-01-01

    Proper design and functioning of the hip joint ensure smooth motion over the full range in multiple planes. Any change in this arrangement may lead to joint damage, causing deformation, pain and loss of functionality. Hip replacement is a procedure intended to replace the damaged articular surfaces and replacing them with artificial components. However, as any surgical intervention, it carries the risk of serious complications. One of them are isolated stem fractures, consisting of breaking the implant inside the intramedullary canal without damaging the surrounding tissue. This article contains a review of the literature data concerning the clinical cases of isolated fractures of hip endoprosthesis stems made of austenitic stainless steel. Although stem fractures are one of the rarest complications of implantation, the lack of clear description of the causes of this phenomenon in the literature makes it worthwhile to take up on the subject. PMID:25133797

  11. Primary hip arthroplasty costs are greater in low-volume than in high-volume Canadian hospitals.

    PubMed

    Martineau, Paul; Filion, Kristian B; Huk, Olga L; Zukor, David J; Eisenberg, Mark J; Antoniou, John

    2005-08-01

    Despite the widespread success of total hip arthroplasties for treatment of arthritis of the hip, the procedure continues to be targeted for cost control. Our objective was to compare the total in-hospital cost of primary total hip arthroplasties in high-volume and low-volume hospitals. Data concerning the patient-level in-hospital costs of 940 consecutive primary total hip arthroplasties were extracted from the cost accounting system of three Canadian hospitals. Mean in-hospital costs for patients having total hip arthroplasties in a high-volume institution (> or = 300 total hip arthroplasties/year) compared with two low-volume Canadian institutions (< 300 total hip arthroplasties/year) were: overhead costs 1380 US dollars +/- 35 US dollars versus 2432 US dollars +/- 49 US dollars; direct costs 3023 US dollars +/- 93 US dollars versus 4952 US dollars +/- 91 US dollars and total costs 4403 US dollars +/- 117 US dollars versus 7385 US dollars +/- 1 US dollar 38, respectively (all comparisons in US dollars). Lower overhead and direct and total costs were found for primary total hip arthroplasties done in a high-volume Canadian hospital compared with the low-volume centers. Differences in direct costs, made up in large part by the implant cost, accounted for most of the disparity. As total hip arthroplasties continue to be scrutinized for cost containment, doing the procedure in a high-volume center seems to be an effective method of controlling costs. PMID:16056043

  12. Analysis of a femoral hip prosthesis designed to reduce stress shielding

    Microsoft Academic Search

    Makarand G Joshi; Suresh G Advani; Freeman Miller; Michael H Santare

    2000-01-01

    The natural stress distribution in the femur is significantly altered after total hip arthroplasty (THA). When an implant is introduced, it will carry a portion of the load, causing a reduction of stress in some regions of the remaining bone. This phenomenon is commonly known as stress shielding. In response to the changed mechanical environment the shielded bone will remodel

  13. Towards Verified and Validated FE Simulations of a Femur with a Cemented Hip Prosthesis

    E-print Network

    Yosibash, Zohar

    Towards Verified and Validated FE Simulations of a Femur with a Cemented Hip Prosthesis Zohar at the neck. The head and neck were removed and the femur was implanted with a cemented prosthesis. The fixed femur was CT-scanned and loaded through the prosthesis so that strains and displacements were measured

  14. Compliant positioning of total hip components for optimal range of motion

    Microsoft Academic Search

    K.-H. Widmer; B. Zurfluh

    2004-01-01

    Impingement between femoral neck and endoprosthetic cup is one of the causes for dislocation in total hip arthroplasty (THA). Choosing a correct combined orientation of both components, the acetabular cup and femoral stem, in manual or computer-assisted implantation will yield a maximized, stable range of motion (ROM) and will reduce the risk for dislocation. A mathematical model of a THA

  15. 21 CFR 888.3350 - Hip joint metal/polymer semi-constrained cemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...device intended to be implanted to replace a hip joint. The device limits translation and rotation in one or more planes via the geometry of its articulating surfaces. It has no linkage across-the-joint. This generic type of device includes...

  16. 21 CFR 888.3350 - Hip joint metal/polymer semi-constrained cemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...device intended to be implanted to replace a hip joint. The device limits translation and rotation in one or more planes via the geometry of its articulating surfaces. It has no linkage across-the-joint. This generic type of device includes...

  17. 21 CFR 888.3350 - Hip joint metal/polymer semi-constrained cemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...device intended to be implanted to replace a hip joint. The device limits translation and rotation in one or more planes via the geometry of its articulating surfaces. It has no linkage across-the-joint. This generic type of device includes...

  18. 21 CFR 888.3340 - Hip joint metal/composite semi-constrained cemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...device intended to be implanted to replace a hip joint. The device limits translation and rotation in one or more planes via the geometry of its articulating surfaces. It has no linkage across-the-joint. This generic type of device includes...

  19. Orthognathic model surgery with LEGO key-spacer.

    PubMed

    Tsang, Alfred Chee-Ching; Lee, Alfred Siu Hong; Li, Wai Keung

    2013-12-01

    A new technique of model surgery using LEGO plates as key-spacers is described. This technique requires less time to set up compared with the conventional plaster model method. It also retains the preoperative setup with the same set of models. Movement of the segments can be measured and examined in detail with LEGO key-spacers. PMID:24045189

  20. Pathogenic organisms in hip joint infections

    PubMed Central

    Geipel, Udo

    2009-01-01

    Infections of the hip joint are usually of bacterial etiology. Only rarely, an infectious arthritis is caused in this localization by viruses or fungi. Native joint infections of the hip are less common than infections after implantation of prosthetic devices. Difficulties in prosthetic joint infections are, (I) a higher age of patients, and, thus an associated presence of other medical risk factors, (II) often long courses of treatment regimes depending on the bacterium and its antibiotic resistance, (III) an increased mortality, and (IV) a high economic burden for removal and reimplantation of an infected prosthetic device. The pathogenic mechanisms responsible for articular infections are well studied only for some bacteria, e.g. Staphylococcus aureus, while others are only partially understood. Important known bacterial properties and microbiological characteristics of infection are the bacterial adhesion on the native joint or prosthetic material, the bacterial biofilm formation, the development of small colony variants (SCV) as sessile bacterial types and the increasing resistance to antibiotics. PMID:19834588

  1. Graphitic Tribological Layers in Metal-on-Metal Hip Replacements

    NASA Astrophysics Data System (ADS)

    Liao, Y.; Pourzal, R.; Wimmer, M. A.; Jacobs, J. J.; Fischer, A.; Marks, L. D.

    2011-12-01

    Arthritis is a leading cause of disability, and when nonoperative methods have failed, a prosthetic implant is a cost-effective and clinically successful treatment. Metal-on-metal replacements are an attractive implant technology, a lower-wear alternative to metal-on-polyethylene devices. Relatively little is known about how sliding occurs in these implants, except that proteins play a critical role and that there is a tribological layer on the metal surface. We report evidence for graphitic material in the tribological layer in metal-on-metal hip replacements retrieved from patients. As graphite is a solid lubricant, its presence helps to explain why these components exhibit low wear and suggests methods of improving their performance; simultaneously, this raises the issue of the physiological effects of graphitic wear debris.

  2. Extensively coated cementless femoral components in revision hip arthroplasty.

    PubMed

    Greidanus, N; Antoniou, J; Paprosky, W

    2000-01-01

    A septic loosening and osteolysis can compromise the available host bone in patients requiring revision hip arthroplasty. Secure fixation of revision femoral components may not be possible if reliant only on proximal femoral bone for biologic fixation or cement interdigitation. The challenge for the revision arthroplasty surgeon is to find the best method to secure the implant in a femur with deficient bone proximally that will provide stability for load bearing and motion. In addition to providing stability, the implant must be durable and maintain long-term fixation. With over 16 years of experience with fully porous coated femoral revision implants, we have found that maximizing prosthetic-bone fit in the proximal femoral diaphyseal bone provides reliable long-term fixation in the majority of femoral revision cases. PMID:21136415

  3. Extensively Coated Cementless Femoral Components in Revision Hip Arthroplasty.

    PubMed

    Greidanus, Nelson; Antoniou, John; Paprosky, Wayne

    2000-10-01

    A septic loosening and osteolysis can compromise the available host bone in patients requiring revision hip arthroplasty. Secure fixation of revision femoral components may not be possible if reliant only on proximal femoral bone for biologic fixation or cement interdigitation. The challenge for the revision arthroplasty surgeon is to find the best method to secure the implant in a femur with deficient bone proximally that will provide stability for load bearing and motion. In addition to providing stability, the implant must be durable and maintain long-term fixation. With over 16 years of experience with fully porous coated femoral revision implants, we have found that maximizing prosthetic-bone fit in the proximal femoral diaphyseal bone provides reliable long-term fixation in the majority of femoral revision cases. PMID:12219307

  4. Graphitic tribological layers in metal-on-metal hip replacements.

    PubMed

    Liao, Y; Pourzal, R; Wimmer, M A; Jacobs, J J; Fischer, A; Marks, L D

    2011-12-23

    Arthritis is a leading cause of disability, and when nonoperative methods have failed, a prosthetic implant is a cost-effective and clinically successful treatment. Metal-on-metal replacements are an attractive implant technology, a lower-wear alternative to metal-on-polyethylene devices. Relatively little is known about how sliding occurs in these implants, except that proteins play a critical role and that there is a tribological layer on the metal surface. We report evidence for graphitic material in the tribological layer in metal-on-metal hip replacements retrieved from patients. As graphite is a solid lubricant, its presence helps to explain why these components exhibit low wear and suggests methods of improving their performance; simultaneously, this raises the issue of the physiological effects of graphitic wear debris. PMID:22194573

  5. The Furlong hydroxyapatite-coated total hip replacement in patients under age 51. A 6-year follow-up study.

    PubMed

    Loupasis, G; Morris, E W; Hyde, I D

    1998-03-01

    Forty-five Furlong hydroxyapatite-coated total hip replacements were reviewed at an average of 71 months (46-89) after surgery. Patient's average age at surgery was 46 years (31-50). The average Harris hip score at the time of final review was 89, and 38 hips (84%) had no pain (28) or only slight pain (10). Three hips were revised, none for aseptic loosening. Two cups were loose. The remainder of the cups and all the stems were radiographically stable with positive evidence of bone ingrowth and no signs of impending failure. One cup showed definite wear of the polyethylene liner. Focal progressive osteolytic lesions occurred in the calcar region in 3 stable hips (7%). To date the Furlong hydroxyapatite-coated implant has produced encouraging results in this group of young patients, although longer follow-up is needed to determine its durability. PMID:9586246

  6. Computed tomography in evaluation of revision hip arthroplasty outcomes.

    PubMed

    Kochman, Andrzej; Morawska-Kochman, Monika; Guzi?ski, Maciej; Drobniewski, Marek; Sibi?ski, Marcin; Synder, Marek

    2014-01-01

    Background. This study aimed to assess contact between Recon Shell reinforcement cages used in revision hip arthroplasty and the bony base. Radiographic examinations were performed with the use of multi-energy computed tomography. Material and methods. We tentatively assess the fixation of Burch-Schneider reinforcement cages (Recon Shell made by Aesculap company) implanted in 10 patients, using two methods of evaluation. An analysis of dual energy CT scans enabled us to assess contact between the reinforcement cages and the bony base. Results. The two methods of evaluation produced different results. The evaluation method based on the division of the acetabular component into a weight-bearing zone and a non-weight-bearing zone (accounting for screw fixation) showed lack of support in the weight-bearing zone in 6 out of 10 cases and direct contact with the implant bed in only one case. The assessment of contact at anchorage holes of reinforcement cages fixed at primary procedures revealed no such support in only one case and the presence of direct contact in 5 cases. There was no correlation between the radiological outcomes and clinical results based on the Harris Hip Score. Conclusions. 1. Multi-energy computed tomography (MARS) is useful in evaluating results of revision hip allo-plasty. 2. The introduction of new imaging techniques for the evaluation of revision procedures demonstrates a need for new, unified methods of outcome assessment adjusted to the characteristics of a particular procedure. PMID:25406920

  7. In vitro friction and lubrication of large bearing hip prostheses.

    PubMed

    Flanagan, S; Jones, E; Birkinshaw, C

    2010-01-01

    New material combinations and designs of artificial hip implants are being introduced in an effort to improve proprioception and functional longevity. Larger joints in particular are being developed to improve joint stability, and it is thought that these larger implants will be more satisfactory for younger and more physically active patients. The study detailed here used a hip friction simulator to assess the friction and lubrication properties of large-diameter hip bearings of metal-on-metal and ceramic-on-reinforced-polymer couplings. Joints of different diameters were evaluated to determine what effect, if any, bearing diameter had on lubrication. In addition, the effects of lubricant type are considered, using carboxymethyl cellulose and bovine calf serum, and the physiological lubricant is shown to be considerably more effective at reducing friction. The frictional studies showed that the metal-on-metal joints worked under a mixed lubrication regime, producing similar friction factor values to each other. The addition of bovine calf serum (BCS) reduced the friction. The ceramic-on-reinforced-polymer samples were shown to operate with high friction factors and mixed lubrication. When tested with BCS, the larger-diameter bearings showed a decrease in friction compared with the smaller-size bearings, and the addition of BCS resulted in an increase in friction, unlike the metal-on-metal system. The study demonstrated that the component's diameter had little or no influence on the lubrication and friction of the large bearing combinations tested. PMID:20839653

  8. [Bilateral avascular necrosis after resurfacing hip arthroplasty. A case report].

    PubMed

    Sanz-Ruiz, P; Chana-Rodríguez, F; Villanueva-Martínez, M; Vaquero-Martín, J

    2011-01-01

    Resurfacing hip arthroplasty is an alternative to conventional arthroplasty and it is indicated in young and active patients. Good results and the prevention of complications stem from a meticulous surgical technique and proper patient selection. We present herein the case of a 43 year-old patient who, after undergoing bilateral hip replacement with resurfacing prostheses, sustained a non-simultaneous fracture of both femoral necks due to avascular necrosis. He was treated by placing a metaphyseal anchoring stem. Postoperative X-rays showed proper implant placement without femoral notching, with a discrete 7 degrees valgus alignment of the femoral component. Both passive and active mobility was painful. X-rays showed cervical fracture of the right femur. The femoral head was attached to the implant, with no metallosis nor loosening of the femoral or acetabular components, but the bone had a fragmented and friable appearance that histopathologically was defined as avascular necrosis. Femoral neck fracture is the main complication after resurfacing hip arthroplasty. The effect of other factors like bone necrosis due to cement is unknown. PMID:22512114

  9. The Concept of LDSI (Locally-Differentiated-Scanning Ion Implantation) for the Fine Threshold Voltage Control in Nano-Scale FETs

    Microsoft Academic Search

    Min-Yong Lee; S. W. Jin; Y. S. Sohn; S. K. Na; K. B. Rouh; Y. S. Joung; Y. J. Ki; I. K. Han; Y. W. Song; S. W. Park

    2006-01-01

    New Concept of ion implantation technology, namely Locally-Differentiated-Scanning Ion Implantation (LDSI), is suggested for the first time in this report. The Vth variation caused by process non-uniformity in each process variables such as gate Critical Dimension (CD), spacer deposition Uniformity and spacer etch CD, etc, becomes big huddle in scale down and larger diameter wafer. This LDSI technology has been

  10. The impact of proximal femoral morphology on failure strength with a mid-head resection short-stem hip arthroplasty.

    PubMed

    Olsen, Michael; Al Saied, Mohamed; Morison, Zachary; Sellan, Michael; Waddell, James P; Schemitsch, Emil H

    2014-12-01

    Mid-head resection short-stem hip arthroplasty is a conservative alternative to conventional total hip replacement and addresses proximal fixation challenges in patients not suitable for hip resurfacing. It is unclear whether proximal femoral morphology impacts the ultimate failure load of mid-head resection implanted femurs, thus the aim of this study was to investigate the effect of native neck-shaft angle (NSA) and coronal implant alignment on proximal femoral strength. In total, 36 synthetic femurs with two different proximal femoral morphologies were utilized in this study. Of them, 18 femurs with a varus NSA of 120° and 18 femurs with a valgus NSA of 135° were each implanted with a mid-head resection prosthesis. Femurs within the two different femoral morphology groups were divided into three equal coronal implant alignment groups: 10° valgus, 10° varus or neutral alignment. Prepared femurs were tested for stiffness and to failure in axial compression. There was no significant difference in stiffness nor failure load between femurs implanted with valgus-, varus- or neutrally aligned implants in femurs with a NSA of 120° (p = 0.396, p = 0.111, respectively). Femurs implanted in valgus orientation were significantly stiffer and failed at significantly higher loads than those implanted in varus alignment in femurs with a NSA of 135° (p = 0.001, p = 0.007, respectively). A mid-head resection short-stem hip arthroplasty seems less sensitive to clinically relevant variations of coronal implant alignment and may be more forgiving upon implantation in some femoral morphologies, however, a relative valgus component alignment is recommended. PMID:25515228

  11. Sodium--sulfur electric batteries with ceramic spacer in sulfur compartment. [spacer placed adjacent materials subject to electrochemical attack

    Microsoft Academic Search

    L. S. Evans; J. R. Harbar

    1977-01-01

    A sodium-sulfur cell is provided having a ceramic spacer means disposed in the liquid sulfur compartment to provide a region substantially free from cathodic reactions. The spacer means is disposed adjacent to materials likely to be adversely affected by the cathodic reactions, such as glass seals used to join the solid electrolyte to a ceramic support member, or a metallic

  12. CoCrMo Metal-on-Metal Hip Replacements

    PubMed Central

    Liao, Yifeng; Hoffman, Emily; Wimmer, Markus; Fischer, Alfons; Jacobs, Joshua; Marks, Laurence

    2012-01-01

    After the rapid growth in the use of CoCrMo metal-on-metal hip replacements since the second generation was introduced circa 1990, metal-on-metal hip replacements have experienced a sharp decline in the last two years due to biocompatibility issues related to wear and corrosion products. Despite some excellent clinical results, the release of wear and corrosion debris and the adverse response of local tissues have been of great concern. There are many unknowns regarding how CoCrMo metal bearings interact with the human body. This perspective article is intended to outline some recent progresses in understanding wear and corrosion of metal-on-metal hip replacement both in-vivo and in-vitro. The materials, mechanical deformation, corrosion, wear-assisted corrosion, and wear products will be discussed. Possible adverse health effects caused by wear products will be briefly addressed, as well as some of the many open questions such as the detailed chemistry of corrosion, tribochemical reactions and the formation of graphitic layers. Nowadays we design almost routinely for high performance materials and lubricants for automobiles; humans are at least as important. It is worth remembering that a hip implant is often the difference between walking and leading a relatively normal life, and a wheelchair. PMID:23196425

  13. Developmental dysplasia of the hip

    MedlinePLUS

    ... of the hip joint that is present at birth. The condition is found in babies or young children. ... of the hip joint may help diagnose the condition in older infants ... be detected at birth, but some cases are mild and symptoms may ...

  14. Racial differences in hip axis lengths might explain racial differences in rates of hip fracture

    Microsoft Academic Search

    S. R. Cummings; J. A. Cauley; L. Palermo; P. D. Ross; R. D. Wasnich; D. Black; K. G. Faulkner

    1994-01-01

    Compared with white women, Asian women have about a 40%–50% and blacks a 50%–60% lower risk of hip fracture, but the reason for this racial difference is not known. Women with a shorter hip axis have a lower risk of hip fracture. To test the hypothesis that a shorter hip axis length could account for the lower risk of hip

  15. Hip Abduction Can Prevent Posterior Edge Loading of Hip Replacements

    PubMed Central

    van Arkel, Richard J; Modenese, Luca; Phillips, Andrew TM; Jeffers, Jonathan RT

    2013-01-01

    Edge loading causes clinical problems for hard-on-hard hip replacements, and edge loading wear scars are present on the majority of retrieved components. We asked the question: are the lines of action of hip joint muscles such that edge loading can occur in a well-designed, well-positioned acetabular cup? A musculoskeletal model, based on cadaveric lower limb geometry, was used to calculate for each muscle, in every position within the complete range of motion, whether its contraction would safely pull the femoral head into the cup or contribute to edge loading. The results show that all the muscles that insert into the distal femur, patella, or tibia could cause edge loading of a well-positioned cup when the hip is in deep flexion. Patients frequently use distally inserting muscles for movements requiring deep hip flexion, such as sit-to-stand. Importantly, the results, which are supported by in vivo data and clinical findings, also show that risk of edge loading is dramatically reduced by combining deep hip flexion with hip abduction. Patients, including those with sub-optimally positioned cups, may be able to reduce the prevalence of edge loading by rising from chairs or stooping with the hip abducted. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1172–1179, 2013. PMID:23575923

  16. Designing human friendly human interaction proofs (HIPs)

    Microsoft Academic Search

    Kumar Chellapilla; Kevin Larson; Patrice Y. Simard; Mary Czerwinski

    2005-01-01

    HIPs, or Human Interactive Proofs, are challenges meant to be easily solved by humans, while remaining too hard to be economically solved by computers. HIPs are increasingly used to protect services against automatic script attacks. To be effective, a HIP must be difficult enough to discourage script attacks by raising the computation and\\/or development cost of breaking the HIP to

  17. Large head metal-on-metal cementless total hip arthroplasty versus 28mm metal-on-polyethylene cementless total hip arthroplasty: design of a randomized controlled trial

    PubMed Central

    Zijlstra, Wierd P; Bos, Nanne; van Raaij, Jos JAM

    2008-01-01

    Background Osteoarthritis of the hip is successfully treated by total hip arthroplasty with metal-on-polyethylene articulation. Polyethylene wear debris can however lead to osteolysis, aseptic loosening and failure of the implant. Large head metal-on-metal total hip arthroplasty may overcome polyethylene wear induced prosthetic failure, but can increase systemic cobalt and chromium ion concentrations. The objective of this study is to compare two cementless total hip arthroplasties: a conventional 28 mm metal-on-polyethylene articulation and a large head metal-on-metal articulation. We hypothesize that the latter arthroplasties show less bone density loss and higher serum metal ion concentrations. We expect equal functional scores, greater range of motion, fewer dislocations, fewer periprosthetic radiolucencies and increased prosthetic survival with the metal-on-metal articulation. Methods A randomized controlled trial will be conducted. Patients to be included suffer from non-inflammatory degenerative joint disease of the hip, are aged between 18 and 80 and are admitted for primary cementless unilateral total hip arthroplasty. Patients in the metal-on-metal group will receive a cementless titanium alloy acetabular component with a cobalt-chromium liner and a cobalt-chromium femoral head varying from 38 to 60 mm. Patients in the metal-on-polyethylene group will receive a cementless titanium alloy acetabular component with a polyethylene liner and a 28 mm cobalt-chromium femoral head. We will assess acetabular bone mineral density by dual energy x-ray absorptiometry (DEXA), serum ion concentrations of cobalt, chromium and titanium, self reported functional status (Oxford hip score), physician reported functional status and range of motion (Harris hip score), number of dislocations and prosthetic survival. Measurements will take place preoperatively, perioperatively, and postoperatively (6 weeks, 1 year, 5 years and 10 years). Discussion Superior results of large head metal-on-metal total hip arthroplasty over conventional hip arthroplasty have been put forward by experts, case series and the industry, but to our knowledge there is no randomized controlled evidence. Conclusion This randomized controlled study has been designed to test whether large head metal-on-metal cementless total hip arthroplasty leads to less periprosthetic bone density loss and higher serum metal ion concentrations compared to 28 mm metal-on-polyethylene cementless total hip arthroplasty. Trial registration Netherlands Trial Registry NTR1399 PMID:18842151

  18. Pervasive generation of oppositely oriented spacers during CRISPR adaptation

    PubMed Central

    Shmakov, Sergey; Savitskaya, Ekaterina; Semenova, Ekaterina; Logacheva, Maria D.; Datsenko, Kirill A.; Severinov, Konstantin

    2014-01-01

    During the process of prokaryotic CRISPR adaptation, a copy of a segment of foreign deoxyribonucleic acid referred to as protospacer is added to the CRISPR cassette and becomes a spacer. When a protospacer contains a neighboring target interference motif, the specific small CRISPR ribonucleic acid (crRNA) transcribed from expanded CRISPR cassette can protect a prokaryotic cell from virus infection or plasmid transformation and conjugation. We show that in Escherichia coli, a vast majority of plasmid protospacers generate spacers integrated in CRISPR cassette in two opposing orientations, leading to frequent appearance of complementary spacer pairs in a population of cells that underwent CRISPR adaptation. When a protospacer contains a spacer acquisition motif AAG, spacer orientation that generates functional protective crRNA is strongly preferred. All other protospacers give rise to spacers oriented in both ways at comparable frequencies. This phenomenon increases the repertoire of available spacers and should make it more likely that a protective crRNA is formed as a result of CRISPR adaptation. PMID:24728991

  19. A computerized system for radiographical evaluation in total hip arthroplasty.

    PubMed

    Cianci, R; Baruffaldi, F; Fabbri, F; Affatato, S; Toni, A; Giunti, A

    1995-04-01

    In the field of orthopaedic surgery radiographical image evaluation is frequently used to determine possible pathological processes. For total hip arthroplasty in particular, it is important to evaluate both preoperative femoral morphology and post-operative prosthesis performance in terms of bone adhesion to the implant and, consequently, loosening or stability of prosthesis components. References to a method called Roentgen stereophotogrammetric analysis (RSA) exist in the literature; however, the authors note that this method is expensive and requires the insertion of markers during the operation. Here we present an alternative computerized method for radiographical evaluation which we call radiographical evaluation system in total hip arthroplasty (RESTHA). The accuracy and the repeatability of the method have been evaluated using a medium-sized pelvis-femur system made of composite material. A mean error of +/- 2 mm has been associated to each experimental point. A post-operative inquiry case study is presented to indicate the applicability of the method. PMID:7656557

  20. Inhalational drug delivery from seven different spacer devices.

    PubMed Central

    Barry, P. W.; O'Callaghan, C.

    1996-01-01

    BACKGROUND: A study was performed to determine in vitro the difference in drug output of seven currently available spacer devices when used with different inhaled medications. METHODS: A glass multistage liquid impinger (MSLI) was used to determine the amount of disodium cromoglycate (DSCG, 5 mg), salbutamol (100 micrograms), or budesonide (200 micrograms) obtained in various particle size ranges from metered dose inhalers (MDIs) actuated directly into the MSLI or via one of seven different spacer devices; the Fisonair, Nebuhaler, Volumatic, Inspirease, Aerochamber, Aerosol Cloud Enhancer, and Dynahaler. RESULTS: In particles smaller than 5 microns in diameter the dose of DSCG recovered from the Fisonair and Nebuhaler was 118% and 124%, respectively, of that recovered using the MDI alone. The dose recovered from the smaller volume spacers was 90% (Inspirease), 36% (Aerochamber), 33% (Aerosol Cloud Enhancer), and 21% (Dynahaler) of that from the MDI alone. The Volumatic increased the amount of salbutamol in particles smaller than 5 microns to 117% of that from the MDI, and the Inspirease and Aerochamber spacers decreased it by nearly 50%. The amount of budesonide in small particles recovered after use of the Nebuhaler, Inspirease, and the Aerochamber was 92%, 101%, and 78%, respectively, of that from the MDI alone. CONCLUSIONS: Under the test conditions used, large volume spacers such as the Fisonair, Nebuhaler, and Volumatic delivered significantly more DSCG and salbutamol than the smaller spacers tested. The differences between spacers were less for budesonide than the other medications studied. This study shows that there are significant differences in the amount of drug available for inhalation when different spacers are used as inhalational aids with different drugs. Spacer devices need to be fully evaluated for each drug prescribed for them. Images PMID:8795674

  1. Cobalt-Alloy Implant Debris Induce HIF-1? Hypoxia Associated Responses: A Mechanism for Metal-Specific Orthopedic Implant Failure

    PubMed Central

    Samelko, Lauryn; Caicedo, Marco S.; Lim, Seung-Jae; Della-Valle, Craig; Jacobs, Joshua; Hallab, Nadim J.

    2013-01-01

    The historical success of orthopedic implants has been recently tempered by unexpected pathologies and early failures of some types of Cobalt-Chromium-Molybdenum alloy containing artificial hip implants. Hypoxia-associated responses to Cobalt-alloy metal debris were suspected as mediating this untoward reactivity at least in part. Hypoxia Inducible Factor-1? is a major transcription factor involved in hypoxia, and is a potent coping mechanism for cells to rapidly respond to changing metabolic demands. We measured signature hypoxia associated responses (i.e. HIF-1?, VEGF and TNF-?) to Cobalt-alloy implant debris both in vitro (using a human THP-1 macrophage cell line and primary human monocytes/macrophages) and in vivo. HIF-1? in peri-implant tissues of failed metal-on-metal implants were compared to similar tissues from people with metal-on-polymer hip arthroplasties, immunohistochemically. Increasing concentrations of cobalt ions significantly up-regulated HIF-1? with a maximal response at 0.3 mM. Cobalt-alloy particles (1 um-diameter, 10 particles/cell) induced significantly elevated HIF-1?, VEGF, TNF-? and ROS expression in human primary macrophages whereas Titanium-alloy particles did not. Elevated expression of HIF-1? was found in peri-implant tissues and synovial fluid of people with failing Metal-on-Metal hips (n?=?5) compared to failed Metal-on-Polymer articulating hip arthroplasties (n?=?10). This evidence suggests that Cobalt-alloy, more than other metal implant debris (e.g. Titanium alloy), can elicit hypoxia-like responses that if unchecked can lead to unusual peri-implant pathologies, such as lymphocyte infiltration, necrosis and excessive fibrous tissue growths. PMID:23840602

  2. Implantable Microimagers

    PubMed Central

    Ng, David C.; Tokuda, Takashi; Shiosaka, Sadao; Tano, Yasuo; Ohta, Jun

    2008-01-01

    Implantable devices such as cardiac pacemakers, drug-delivery systems, and defibrillators have had a tremendous impact on the quality of live for many disabled people. To date, many devices have been developed for implantation into various parts of the human body. In this paper, we focus on devices implanted in the head. In particular, we describe the technologies necessary to create implantable microimagers. Design, fabrication, and implementation issues are discussed vis-à-vis two examples of implantable microimagers; the retinal prosthesis and in vivo neuro-microimager. Testing of these devices in animals verify the use of the microimagers in the implanted state. We believe that further advancement of these devices will lead to the development of a new method for medical and scientific applications.

  3. The Canadian Arthroplasty Society's experience with hip resurfacing arthroplasty. An analysis of 2773 hips.

    PubMed

    2013-08-01

    The purpose of this study was twofold: first, to determine whether the five-year results of hip resurfacing arthroplasty (HRA) in Canada justified the continued use of HRA; and second, to identify whether greater refinement of patient selection was warranted. This was a retrospective cohort study that involved a review of 2773 HRAs performed between January 2001 and December 2008 at 11 Canadian centres. Cox's proportional hazards models were used to analyse the predictors of failure of HRA. Kaplan-Meier survival analysis was performed to predict the cumulative survival rate at five years. The factors analysed included age, gender, body mass index, pre-operative hip pathology, surgeon's experience, surgical approach, implant sizes and implant types. The most common modes of failure were also analysed. The 2773 HRAs were undertaken in 2450 patients: 2127 in men and 646 in women. The mean age at operation was 50.5 years (sd 8.72; 18 to 82) and mean follow-up was 3.4 years (sd 2.1; 2.0 to 10.1). At the last follow-up a total of 101 HRAs (3.6%) required revision. Using revision for all causes of failure as the endpoint, Kaplan-Meier survival analysis showed a cumulative survival of 96.4% (95% confidence interval (CI) 96.1 to 96.9) at five years. With regard to gender, the five-year overall survival was 97.4% in men (95% CI 97.1 to 97.7) and 93.6% in women (95% CI 92.6 to 94.6). Female gender, smaller femoral components, specific implant types and a diagnosis of childhood hip problems were associated with higher rates of failure. The most common cause of failure was fracture of the femoral neck, followed by loosening of the femoral component. The failure rates of HRA at five years justify the ongoing use of this technique in men. Female gender is an independent predictor of failure, and a higher failure rate at five years in women leads the authors to recommend this technique only in exceptional circumstances for women. PMID:23908418

  4. [Sport activity after hip and knee arthroplasty].

    PubMed

    Keren, Amit; Berkovich, Yaron; Berkovitch, Yaron; Soudry, Michael

    2013-11-01

    Joint arthroplasty is one of the commonest surgical procedures in orthopedic surgery. In recent years there was an increase in the number of procedures, patient satisfaction and implant survival. Originally, these operations were designed for old patients in order to relieve pain and to enable ambulation. Over the past few years, these operations have become common in younger patients which desire to return to activity, including sports activities. The importance of physical activity is a well known fact. In recent years it became clear that with the proper physical activity the outcomes of the operations are better. There are several types of arthroplasty. Many factors influence the outcome of the operation apart from the post-surgery physical activity. These factors include patient factors, surgical technique and type of arthroplasty. This review summarizes the recommendations for sports activities after hip and knee arthroplasties. These activities are evaluated according to surgeons' recommendations, stress applied on the implant and long term outcomes. The recommended sports activities after joint arthroplasties are walking, swimming and cycling. Soccer, basketball and jogging are not advised. Tennis, downhill skiing and horse riding are recommended with previous experience. There are many more sports activities that patients can participate in, and it is important that the patient discuss the different options prior to the operation. Since these operations are so common, many non-orthopedic physicians encounter these patients in their practice. They should be acquainted with the recommendations for sports activities and encourage them. PMID:24416822

  5. Drug-Eluting Nasal Implants: Formulation, Characterization, Clinical Applications and Challenges

    PubMed Central

    Parikh, Ankit; Anand, Utkarshini; Ugwu, Malachy C.; Feridooni, Tiam; Massoud, Emad; Agu, Remigius U.

    2014-01-01

    Chronic inflammation and infection of the nasal sinuses, also referred to as Chronic Rhinosinusitis (CRS), severely affects patients’ quality of life. Adhesions, ostial stenosis, infection and inflammation relapses complicate chronic sinusitis treatment strategies. Drug-eluting stents, packings or implants have been suggested as reasonable alternatives for addressing these concerns. This article reviewed potential drug candidates for nasal implants, formulation methods/optimization and characterization methods. Clinical applications and important considerations were also addressed. Clinically-approved implants (Propel™ implant, the Relieva stratus™ MicroFlow spacer, and the Sinu-Foam™ spacer) for CRS treatment was an important focus. The advantages and limitations, as well as future considerations, challenges and the need for additional research in the field of nasal drug implant development, were discussed. PMID:24871904

  6. Impingement and Dislocation in Total HIP Arthroplasty: Mechanisms and Consequences

    PubMed Central

    Brown, Thomas D; Elkins, Jacob M; Pedersen, Douglas R; Callaghan, John J

    2014-01-01

    In contemporary total hip arthroplasty, instability has been a complication in approximately 2% to 5% of primary surgeries and 5% to 10% of revisions. Due to the reduction in the incidence of wear-induced osteolysis that has been achieved over the last decade, instability now stands as the single most common reason for revision surgery. Moreover, even without frank dislocation, impingement and subluxation are implicated in a set of new concerns arising with advanced bearings, associated with the relatively unforgiving nature of many of those designs. Against that backdrop, the biomechanical factors responsible for impingement, subluxation, and dislocation remain under-investigated relative to their burden of morbidity. This manuscript outlines a 15-year program of laboratory and clinical research undertaken to improve the scientific basis for understanding total hip impingement and dislocation. The broad theme has been to systematically evaluate the role of surgical factors, implant design factors, and patient factors in predisposing total hip constructs to impinge, sublux, and/or dislocate. Because this class of adverse biomechanical events had not lent itself well to study with existing approaches, it was necessary to develop (and validate) a series of new research methodologies, relying heavily on advanced finite element formulations. Specific areas of focus have included identifying the biomechanical challenges posed by dislocation-prone patient activities, quantifying design parameter effects and component surgical positioning effects for conventional metal-on-polyethylene implant constructs, and the impingement/dislocation behavior of non-conventional constructs, quantifying the stabilizing role of the hip capsule (and of surgical repairs of capsule defects), and systematically studying impingement and edge loading of hard-on-hard bearings, fracture of ceramic liners, confounding effects of patient obesity, and subluxation-mediated worsening of third body particle challenge. PMID:25328453

  7. "In vivo" determination of hip joint separation and the forces generated due to impact loading conditions.

    PubMed

    Dennis, D A; Komistek, R D; Northcut, E J; Ochoa, J A; Ritchie, A

    2001-05-01

    Numerous supporting structures assist in the retention of the femoral head within the acetabulum of the normal hip joint including the capsule, labrum, and ligament of the femoral head (LHF). During total hip arthroplasty (THA), the LHF is often disrupted or degenerative and is surgically removed. In addition, a portion of the remaining supporting structures is transected or resected to facilitate surgical exposure. The present study analyzes the effects of LHF absence and surgical dissection in THA patients. Twenty subjects (5 normal hip joints, 10 nonconstrained THA, and 5 constrained THA) were evaluated using fluoroscopy while performing active hip abduction. All THA subjects were considered clinically successful. Fluoroscopic videos of the normal hips were analyzed using digitization, while those with THA were assessed using a computerized interactive model-fitting technique. The distance between the femoral head and acetabulum was measured to determine if femoral head separation occurred. Error analysis revealed measurements to be accurate within 0.75mm. No separation was observed in normal hips or those subjects implanted with constrained THA, while all 10 (100%) with unconstrained THA demonstrated femoral head separation, averaging 3.3mm (range 1.9-5.2mm). This study has shown that separation of the prosthetic femoral head from the acetabular component can occur. The normal hip joint has surrounding capsuloligamentous structures and a ligament attaching the femoral head to the acetabulum. We hypothesize that these soft tissue supports create a passive, resistant force at the hip, preventing femoral head separation. The absence of these supporting structures after THA may allow increased hip joint forces, which may play a role in premature polyethylene wear or prosthetic loosening. PMID:11311703

  8. Endodontic implants.

    PubMed

    Yadav, Rakesh K; Tikku, A P; Chandra, Anil; Wadhwani, K K; Ashutosh Kr; Singh, Mayank

    2014-01-01

    Endodontic implants were introduced back in 1960. Endodontic implants enjoyed few successes and many failures. Various reasons for failures include improper case selection, improper use of materials and sealers and poor preparation for implants. Proper case selection had given remarkable long-term success. Two different cases are being presented here, which have been treated successfully with endodontic implants and mineral trioxide aggregate Fillapex (Andreaus, Brazil), an MTA based sealer. We suggest that carefully selected cases can give a higher success rate and this method should be considered as one of the treatment modalities. PMID:25298723

  9. Endodontic implants

    PubMed Central

    Yadav, Rakesh K.; Tikku, A. P.; Chandra, Anil; Wadhwani, K. K.; Ashutosh kr; Singh, Mayank

    2014-01-01

    Endodontic implants were introduced back in 1960. Endodontic implants enjoyed few successes and many failures. Various reasons for failures include improper case selection, improper use of materials and sealers and poor preparation for implants. Proper case selection had given remarkable long-term success. Two different cases are being presented here, which have been treated successfully with endodontic implants and mineral trioxide aggregate Fillapex (Andreaus, Brazil), an MTA based sealer. We suggest that carefully selected cases can give a higher success rate and this method should be considered as one of the treatment modalities. PMID:25298723

  10. Lifestyle and health-related quality of life in Asian patients with total hip arthroplasties.

    PubMed

    Fujita, Kimie; Xia, Zhenlan; Liu, Xueqin; Mawatari, Masaaki; Makimoto, Kiyoko

    2014-09-01

    Total hip arthroplasty reduces pain and restores physical function in patients with hip joint problems. This study examined lifestyle and health-related quality of life before and after total hip arthroplasty in Japanese and Chinese patients. Two hospitals in China recruited 120 patients and 120 Japanese patients matched by age and operative status were drawn from a prospective cohort database. Oxford Hip Score, EuroQol, and characteristics of Asian lifestyle and attitudes toward the operation were assessed. There were no differences between patients from the two countries in quality-of-life-scale scores: postoperative patients had significantly better quality-of-life scores than preoperative patients in both countries. In China, patients who reported that living at home was inconvenient had significantly worse Oxford Hip Scores than those who did not. Mean scores for anxiety items concerning possible dislocation and durability of the implant were significantly higher in Japanese than in Chinese subjects. Our findings suggest that providing information about housing conditions and lifestyles would result in improved quality of life and reduced anxiety in patients with implanted joints. PMID:24845456

  11. Ultrasound-Assisted Hip Arthroscopy

    PubMed Central

    Weinrauch, Patrick; Kermeci, Sharon

    2014-01-01

    We describe the use of intraoperative ultrasound for the safe development of arthroscopic portals during hip arthroscopy without the requirement for fluoroscopy. We find this technique consistently accurate, allowing the safe introduction of arthroscopic instruments into the hip with a very low rate of iatrogenic injury. We have further developed the technique for application to both central- and peripheral-compartment procedures. We now have a total experience of more than 700 procedures to date. With the described technique of ultrasound guidance for portal placement, fluoroscopy is required in fewer than 2% of hip arthroscopy procedures at our institution. PMID:24904772

  12. Revision rate after short-stem total hip arthroplasty

    PubMed Central

    van Oldenrijk, Jakob; Molleman, Jeroen; Klaver, Michel; Poolman, Rudolf W; Haverkamp, Daniel

    2014-01-01

    Background and purpose The aim of short-stem total hip arthroplasty is to preserve proximal bone stock for future revisions, to improve biomechanical reconstruction, and to make minimally invasive approaches easier. It is therefore being increasingly considered to be a sound alternative to conventional total hip arthroplasty, especially for young and active patients. However, it is still unknown whether survival rates of short-stem hips match current standards. We made a systematic summary of reported overall survival after short-stem total hip arthroplasty. Materials and methods We conducted a systematic review of English, French, German, and Dutch literature. 2 assessors independently identified clinical studies on short-stem hip arthroplasty. After recalculating reported revision rates, we determined whether each implant had a projected revision rate of 10% or less at 10 years of follow-up or a revision rate per 100 observed component years of 1 or less. Stems were classified as “collum”, “partial collum”, or “trochanter-sparing”. Results and Interpretation We found 49 studies, or 51 cohorts, involving 19 different stems. There was a large increase in recent publications. The majority of studies included had a follow-up of less than 5 years. We found a large number of observational studies on “partial collum” and “trochanter-sparing” stems, demonstrating adequate survival rates at medium-term follow-up. Clinical evidence from “collum stem” studies was limited to a small number of studies with a medium-term follow-up period. These studies did not show a satisfactory overall survival rate. PMID:24694271

  13. Surface-Tethered Iterative Carbohydrate Synthesis (STICS): A spacer study

    PubMed Central

    Ganesh, N. Vijaya; Fujikawa, Kohki; Tan, Yih Horng; Nigudkar, Swati S.

    2013-01-01

    Comparative study of STICS using HPLC-assisted experimental set-up clearly demonstrated benefits of using longer spacer-anchoring systems. The use of mixed self-assembled monolayers helps to provide the required space for glycosylation reaction around the immobilized glycosyl acceptor. Both extension of the spacer length and using mixed self-assembled monolayers help to promote reaction and the beneficial effects may include moving the glycosyl acceptor further out into solution and providing additional conformational flexibility. It is possible that surface-immobilized glycosyl acceptors with a longer spacer (C8-O-C8)-lipoic acid have a higher tendency to mimic a solution-phase reaction environment than that of acceptors with shorter spacers. PMID:23822088

  14. Future Bearing Surfaces in Total Hip Arthroplasty

    PubMed Central

    2014-01-01

    One of the most important issues in the modern total hip arthroplasty (THA) is the bearing surface. Extensive research on bearing surfaces is being conducted to seek an ideal bearing surface for THA. The ideal bearing surface for THA should have superior wear characteristics and should be durable, bio-inert, cost-effective, and easy to implant. However, bearing surfaces that are currently being implemented do not completely fulfill these requirements, especially for young individuals for whom implant longevity is paramount. Even though various new bearing surfaces have been investigated, research is still ongoing, and only short-term results have been reported from clinical trials. Future bearing surfaces can be developed in the following ways: (1) change in design, (2) further improvement of polyethylene, (3) surface modification of the metal, (4) improvement in the ceramic, and (5) use of alternative, new materials. One way to reduce wear and impingement in THA is to make changes in its design by using a large femoral head, a monobloc metal shell with preassembled ceramic liner, dual mobility cups, a combination of different bearing surfaces, etc. Polyethylene has improved over time with the development of highly crosslinked polyethylene. Further improvements can be made by reinforcing it with vitamin E or multiwalled carbon nanotubes and by performing a surface modification with a biomembrane. Surface modifications with titanium nitride or titanium niobium nitride are implemented to try to improve the metal bearings. The advance to the fourth generation ceramics has shown relatively promising results, even in young patients. Nevertheless, further improvement is required to reduce fragility and squeaking. Alternative materials like diamond coatings on surfaces, carbon based composite materials, oxidized zirconium, silicon nitride, and sapphire are being sought. However, long-term studies are necessary to confirm the efficacy of these surfaces after enhancements have been made with regard to fixation technique and implant quality. PMID:24605198

  15. New Solution for Massive, Irreparable Rotator Cuff Tears: The Subacromial “Biodegradable Spacer

    PubMed Central

    Savarese, Eugenio; Romeo, Rocco

    2012-01-01

    Massive, irreparable rotator cuff tears are a source of pain and disability. Although most rotator cuff tears can be completely repaired, a significant number are considered massive and irreparable. Numerous operative techniques have been described for the treatment of these kinds of tears including arthroscopic debridement, biceps tenotomy, tendon transfer, grafting, and reverse arthroplasty. We describe a surgical technique using a biodegradable subacromial balloon spacer (InSpace; OrthoSpace, Kfar Saba, Israel) implanted between the humeral head and acromion that permits smooth, frictionless gliding, restoring the shoulder biomechanics. The technique is easy to perform and is less invasive than the conventional surgical techniques available, and it may potentially serve as a bridging option in patients with massive, irreparable tears who are normally candidates for reverse arthroplasty. PMID:23766979

  16. Improvement of pressurised aerosol deposition with Nebuhaler spacer device.

    PubMed Central

    Newman, S P; Millar, A B; Lennard-Jones, T R; Morén, F; Clarke, S W

    1984-01-01

    The effect on aerosol deposition from a pressurised metered dose inhaler of a 750 cm3 spacer device with a one way inhalation valve (Nebuhaler, Astra Pharmaceuticals) was assessed by means of an in vivo radiotracer technique. Nine patients with obstructive lung disease took part in the study. The pattern of deposition associated with use of a metered dose inhaler alone was compared with that achieved with the spacer used both for inhalation of single puffs of aerosol and for inhalation of four puffs actuated in rapid succession and then inhaled simultaneously. On each occasion there was a delay of 1 s between aerosol release and inhalation, simulating poor inhaler technique. With the metered dose inhaler alone, a mean (SEM) 8.7 (1.8)% of the dose reached the lungs and 80.9 (1.9)% was deposited in the oropharynx. With single puffs from the spacer 20.9 (1.6)% of the dose (p less than 0.01) reached the lungs, only 16.5 (2.3)% (p less than 0.01) was deposited in the oropharynx, and 55.8 (3.1)% was retained within the spacer itself. With four puffs from the spacer 15.2 (1.5)% reached the lungs (p = 0.02 compared with the metered dose inhaler alone, p less than 0.01 compared with single puffs from the spacer), 11.4 (1.2)% was deposited in the oropharynx, and 67.5 (1.8)% in the device itself. It is concluded that the spacer device gives lung deposition of metered dose aerosols comparable to or greater than a correctly used inhaler and oropharyngeal deposition is greatly reduced. The spacer should be used preferably for the inhalation of single puffs of aerosol but may also be used for the inhalation of up to four puffs actuated in rapid succession and then inhaled simultaneously. Images PMID:6440305

  17. Rehabilitation after hip fracture.

    PubMed

    Pils, Katharina; Müller, Walter; Likar, Rudolf; Gosch, Markus; Iglseder, Bernhard; Müller, Ernst J; Thaler, Heinrich; Gerstorfer, Inge; Zmaritz, Michaela; Weissenberger-Leduc, Monique; Mikosch, Peter; Pinter, Georg

    2013-10-01

    Low-trauma hip fracture in old age leads to impairment, increased need of care and mortality. Rehabilitation should start in the department for traumatology and accompany the patient through different settings until the pretraumatic status is reached. Besides the surgical procedure and the medical management of an aged person with complex disease and polypharmacy, the multidisciplinary rehabilitation process is an important factor for regaining ability for self-care and autonomous decisions. Pain management supports the process. The ideal setting is not clear yet. Besides established rehabilitation facilities for elderly people, including the departments for 'Akutgeriatrie/Remobilisation', the 'Outreach Geriatric Remobilisation' project offers new perspectives. It was designed to remobilise patients with multimorbidity in their own homes. PMID:24154800

  18. Fracture of the ceramic epiphysis in hip arthroplasty.

    PubMed

    Toni, A; Terzi, S; Sudanese, A; Zappoli, F A; Giunti, A

    1996-01-01

    Between November 1985 and October 1993, a total of 694 ceramic-ceramic hip arthroplasties were implanted; up until 1987 the alumina used in the first 82 cases was Ostalox, produced by IMEC of Caravaggio, characterized by poor control of the size of the crystals; after 1987 Biolox alumina of the Feldmhule company was used in 612 cases. Fracture of the ceramic head occurred in 2 cases; in both patients ceramic was of the Ostalox type, meaning a 2.4% incidence of fracture; up until the present none of the 612 Biolox heads has presented this complication. PMID:8791872

  19. Selecting the surgical approach for revision total hip arthroplasty.

    PubMed

    Kerboull, L

    2015-02-01

    Selecting the approach for revision total hip arthroplasty is a crucial step in pre-operative planning. Whether the surgical objectives can be reached via a conventional approach or require a specific approach must be determined. The best approach depends on multiple factors including the reason for revision, patient's characteristics, implants requiring removal, previous approach, soft tissue and bone lesions, and surgeon's level of experience. These factors are discussed herein, as well as the potential and limitations of conventional approaches and the indications for specific approaches. PMID:25553602

  20. A concept for hip prosthesis identification using ultra wideband radar.

    PubMed

    Lui, Hoi-Shun; Shuley, Nicholas; Crozier, Stuart

    2004-01-01

    Ultra wideband (UWB) radar has been extensively investigated both theoretically and practically for the identification buried artifacts. Ground probe radar (GPR) concentrates on the identification of lightly buried land mines, unexploded ordnance (UXO) and archeological targets. The same technology is proposed in a similar context for the rapid identification of in vivo implanted metallic prostheses. The technique is based on resonance based target identification and the paper investigates UWB scattering from a metallic hip prosthesis in free space as a first step in the identification process. PMID:17271965

  1. Urogynecologic Surgical Mesh Implants

    MedlinePLUS

    ... Medical Devices Products and Medical Procedures Implants and Prosthetics Urogynecologic Surgical Mesh Implants Urogynecologic Surgical Mesh Implants ... More in Products and Medical Procedures Implants and Prosthetics Urogynecologic Surgical Mesh Implants Pelvic Organ Prolapse (POP) ...

  2. Nuclear reactor spacer grid and ductless core component

    DOEpatents

    Christiansen, David W. (Kennewick, WA); Karnesky, Richard A. (Richland, WA)

    1989-01-01

    The invention relates to a nuclear reactor spacer grid member for use in a liquid cooled nuclear reactor and to a ductless core component employing a plurality of these spacer grid members. The spacer grid member is of the egg-shell type and is constructed so that the walls of the cell members of the grid member are formed of a single thickness of metal to avoid tolerance problems. Within each cell member is a hydraulic spring which laterally constrains the nuclear material bearing rod which passes through each cell member against a hardstop in response to coolant flow through the cell member. This hydraulic spring is also suitable for use in a water cooled nuclear reactor. A core component constructed of, among other components, a plurality of these spacer grid members, avoids the use of a full length duct by providing spacer sleeves about the sodium tubes passing through the spacer grid members at locations between the grid members, thereby maintaining a predetermined space between adjacent grid members.

  3. Control Sidewall Spacer Geometry with Next-Generation In-Line 3D-AFM

    Microsoft Academic Search

    Tianming Bao; Vladimir Ukraintsev

    INtroDu Ct IoN Gate spacer engineering has become one of the primary concerns in dimension metrology. This application note discusses recent advances in 3D atomic force microscopy (3D-AFM) that solve the specialized characterization needs for critical sidewall spacer geometry controls, including multiple spacer thickness and nitride spacer pulldown.

  4. Small Incision Total Hip Arthroplasty

    MedlinePLUS Videos and Cool Tools

    ... outcomes, primarily because of recent advances in surgical instrumentation and techniques. In addition to the live hip ... the surgery, but with this newer, you know, instrumentation, the availability of centers and surgeons has really ...

  5. Idiopathic chondrolysis of the hip.

    PubMed

    Duncan, J W; Nasca, R; Schrantz, J

    1979-10-01

    Eight patients were seen with idiopathic chondrolysis in nine hips, with from one to eight years' follow-up. The adolescent patients showed characteristic diagnostic patterns--patients in the hip and a limp. The disease occurs most frequently in black girls and in them it tends to be more severe. Threre is progressive loss of articular cartilage, frequently progressing to flexion-adduction contracture and fibrous ankylosis. The pathological process in our patients mainly consisted of chronic synovitis and loss of articular cartilate in the weight-bearing surface of the femoral head. The patients with mild cases were satisfactorily treated with physical therapy, non-weight-bearing, and analgesics. The other hips, however, did best when allowed to undergo fibrous ankylosis with the hip in a functional position. PMID:489643

  6. Developmental Dysplasia of the Hip

    MedlinePLUS

    ... treatment is usually preferred in children younger than 18 months. or open reduction , in which the hip is ... the procedure of choice for kids older than 18 months. After reaching age 2 or 3, a child ...

  7. Hip Fractures among Older Adults

    MedlinePLUS

    ... MMWR 1996;45(41):877–83. Deprey SM, Descriptive analysis of fatal falls of older adults in ... for persons with and without hip fracture: a population-based study. Journal of the American Geriatrics Society ...

  8. Monoarticular Hip Involvement in Pseudogout

    PubMed Central

    Kocyigit, Figen; Kuyucu, Ersin; Kocyigit, Ali

    2015-01-01

    Pseudogout is the acutest form of arthritis in the elderly. Although clinical manifestations vary widely, polyarticular involvement is typical mimicking osteoarthritis or rheumatoid arthritis. Monoarticular involvement is relatively rare and is generally provoked by another medical condition. There are reported cases of hip involvement by pseudogout in monoarticular form. However, all of the cases were presented as septic arthritis. In this report, we present a case of monoarticular hip involvement mimicking soft tissue abscess. We confirmed the pseudogout diagnosis after ultrasonographic evaluation of the involved hip joint and pathological and biochemical analysis of synovial fluid analysis. Diagnosis is important to avoid unnecessary medical and surgical treatment in cases of the bizarre involvement of hip in pseudogout.

  9. Initial results with a mini-posterior approach for total hip arthroplasty

    PubMed Central

    2007-01-01

    Implantation of the total hip prosthesis should always be as atraumatic as possible. The principle underlying this technique is to visualise the working area while keeping the aperture to a minimum, with a resulting reduction in trauma to the soft tissue. We present a new, improved single-incision approach in total hip arthroplasty: the mini-posterior approach. Preliminary results from 60 patients operated using this approach indicate rapid functional recovery, minimal postoperative pain, a reduced duration of hospitalisation, few complications, and optimal component positioning. Further follow-up is warranted. PMID:17668205

  10. Outcome after total hip arthroplasty

    Microsoft Academic Search

    Jay R. Lieberman; Frederick Dorey; Paul Shekelle; Lana Schumacher; Douglas J. Kilgus; Bert J. Thomas; Gerald A. Finerman

    1997-01-01

    The purpose of this study was to examine the relationship between the Harris Hip Score (HHS), a traditional method of patient assessment of a total hip arthroplasty (THA), and the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), a commonly used health-related quality-of-life survey. One hundred forty patients returning for routine clinical follow-up evaluation of a primary THA were asked

  11. Patient satisfaction and functional status after aseptic versus septic revision total knee arthroplasty using the PROSTALAC articulating spacer.

    PubMed

    Meek, R M Dominic; Dunlop, David; Garbuz, Donald S; McGraw, Robert; Greidanus, Nelson V; Masri, Bassam A

    2004-10-01

    This study compared the functional results of an articulating antibiotic spacer for 2-stage revision knee arthroplasty for infection, to the functional results of aseptic revision. One hundred twenty-five patients who underwent revision of total knee arthroplasty for infection and aseptic loosening were identified. All of the patients with infection were treated with the PROSTALAC system (DePuy). At a minimum 2-year follow-up, WOMAC, Oxford-12, SF-12, patient satisfaction data, Harris Hip Score knee scores, and range of motion were assessed. The 2 cohorts (4 deaths in total, leaving 54 septic, 57 aseptic) were equivalent for age, gender, and comorbidity scores. At a mean of 41 months, none of the outcomes were significantly worse for the septic group, which had 2 recurrences of infection (4%). The satisfactory functional results of the PROSTALAC system may be related to the design features. PMID:15483804

  12. Hip Resurfacing Arthroplasty in Treatment of Avascular Necrosis of the Femoral Head

    PubMed Central

    Pyda, Micha?; Koczy, Bogdan; Widuchowski, Wojciech; Widuchowska, Ma?gorzata; Sto?tny, Tomasz; Mielnik, Micha?; Hermanson, Jacek

    2015-01-01

    Background Hip resurfacing is a conservative type of total hip arthroplasty but its use is controversial, especially in patients with osteonecrosis. The aim of this study was analysis of the clinical and radiographic outcomes of hip resurfacing in patients with osteonecrosis. Material/Methods Between 2007 and 2008, 30 hip resurfacing arthroplasties were performed due to osteoarthritis secondary to avascular necrosis of femoral head staged as Ficat III and IV. Patients were qualified to resurfacing arthroplasty when the extent of avascular necrosis using Kerboul’s method was <200° and the angle between avascular necrosis and head-neck junction was >20°. All patients were evaluated clinically and radiologically before and 60 months after the operation. Results The mean Harris Hip Score (HHS) score increased from 47.8 to 94.25 (p<0.05). Physical activity level (University of California, Los Angeles activity score – UCLA activity score) improved from 3.7 to 7.55 (p<0.05). No implant migration was observed. Conclusions Management of osteonecrosis of the hip with resurfacing arthroplasty seems to be effective in strictly-selected patients. PMID:25618763

  13. Hematogenous infection of total hip arthroplasty with Actinomyces following a noninvasive dental procedure.

    PubMed

    Brown, Matthew L; Drinkwater, Christopher J

    2012-07-01

    This article describes a case of an infected total hip arthroplasty following a dental procedure. A 59-year-old man underwent total hip arthroplasty for osteoarthritis and had a routine recovery. Approximately 9 months postoperatively, he underwent a dental cleaning without antibiotic prophylaxis. One month later, he reported gradually worsening right hip pain and a purulent discharge. After several unsuccessful interventions, the patient was referred to the authors' facility. The patient's history, draining sinus tract, and radiographic changes were considered diagnostic of a late chronic infection, and the patient underwent 2-stage revision. Intraoperatively, the sinus tract extended directly to the acetabular component. Actinomyces spp were isolated from 3 of 7 intraoperative anaerobic cultures, and the patient received penicillin G for 8 weeks. Two weeks after discontinuing antibiotics, with no clinical manifestation of recurrent infection and a negative hip aspiration, a new hip prosthesis was implanted. The patient was prescribed penicillin for 12 months postoperatively. Harris Hip Score was 100 at 52-month follow-up. The American Dental Association and the American Academy of Orthopaedic Surgeons issued consensus guidelines for chemoprophylaxis in orthopedic patients undergoing dental procedures in 1997 and 2003. Although the American Academy of Orthopaedic Surgeons issued a revised guideline in 2009 recommending more robust antibiotic prophylaxis, significant controversy exists because at least one professional organization representing dentists has repudiated the 2009 American Academy of Orthopaedic Surgeons guideline. The authors describe the implications from their experience and similar cases in the literature with regard to such guidelines. PMID:22784905

  14. [Idiopathic chondrolysis of the hip].

    PubMed

    Lejman, Tadeusz; Sulko, Jerzy

    2005-01-01

    Between 1993-2003 the authors treated 5 girls with idiopathic chondrolysis of the hip joint. Their mean age at first symptoms were 9 years (range 6-11 years). In all initial symptoms were pain and a hip flexion contracture of a mean 33 degrees (range 30-40 degrees). All were treated with multiple stationary rehabilitation including traction, range of motion exercises, analgetic physical therapy and longlasting walking with crutches. At the follow up examination only one hip was I 10 degree. Remaining 4 children were painfree. In 2 of them an acetabular protrusion, hip joint space narrowing and degenerative changes were observed on anteroposterior radiographs and clinically the hips were stiff in functional position. In the remaining 2 children, the hip range of motion was limited, with 30 and 90 degree of flexion, but joint space became wider on radiographs. Results were bad, because we do not know neither effective causative non symptomatic methods of treatment. Maybe the new technics of treatment, like arthrodiastasis, will bring better results. PMID:16158864

  15. Loosening detection of the femoral component of hip prostheses with extracorporeal shockwaves: A pilot study.

    PubMed

    Rieger, Johannes S; Jaeger, Sebastian; Kretzer, Jan Philippe; Rupp, Rüdiger; Bitsch, Rudi G

    2015-02-01

    The diagnosis of aseptic loosening of hip implants is often challenging. A vibrational analysis of the bone-implant interface could be an alternative method to analyze the fixation of endoprostheses. We assessed an innovative and new approach for excitation by using extracorporeal shockwaves in this study. In three cadaver specimens total hip arthroplasty was performed bilaterally. Four different states of implant loosening were simulated. Three accelerometers were fixed at the medial condyle, the greater trochanter, and the crest of the ilium. The bone-implant compound was excited with highly standardized extracorporeal shock waves. Resonance spectra between 100 Hz and 5000 Hz were recorded. This technique permitted a good adaptation to varying soft tissue conditions. The main resonance frequency of the hip joints occurred at about 2000 Hz. The analysis of the measured spectra showed an interrelation between the state of loosening and the frequency values of the resonances. In case of a stem loosening, there were significant shifts of the resonance into the lower frequency area between 386 Hz and 847 Hz. With this novel technique the degree of stem loosening could be assessed in a soft tissue considering configuration. This study forms a first step for future establishment of a non-invasive, non-radiological and fast applicable diagnostic procedure for early detection of endoprostheses loosening before manifest presence of clinical signs. PMID:25553960

  16. A stature-specific concept for uncemented, primary total hip arthroplasty

    PubMed Central

    Omlor, Georg W; Ullrich, Hannah; Krahmer, Knut; Jung, Alexander; Aldinger, Günther

    2010-01-01

    Background and purpose Variations in hip anatomy limit the femoral canal fit of standard uncemented hip stems. In addition, there are still issues with leg length discrepancy and offset reconstruction, potentially resulting in impingement, dislocation, and wear. Modular stems with different shapes for femoral canal fit and multiple neck options may improve the outcome and reduce complications. Patients and methods 173 patients (190 hips) received an uncemented THA with 1 of 2 different stem shapes for canal fit and a modular neck for stature-specific hip reconstruction. Median follow-up time was 9 (7–13) years. During the follow-up period, 20 patients died (22 hips) and 12 patients (13 hips) were lost to follow-up. 155 hips were available for evaluation, including clinical and radiological outcome. Results 1 stem was revised for a periprosthetic fracture following trauma; 10 cups and 2 modular necks were revised (1 for breakage and 1 during cup revision). At 10 years, stem survival was 100%, modular neck survival was 99% (CI: 95–100), and cup survival was 94% (CI: 87–97). No leg length discrepancies were measured in 96% of cases. Offset with anatomic lateralization was achieved in 98%. Median Harris hip score was 94 (47–100) and median Merle d'Aubigné score was 16 (10–18). Relevant radiolucent lines and osteolysis were not found. Interpretation The uncemented modular neck, dual-stem system used in this series allows accurate reconstruction of the joint by adapting the implant to the needs of the patient. This may improve the outcome of primary THA, which is supported by the results of this medium-term follow-up evaluation. PMID:20146639

  17. Alumina hip joints characterized by run-in wear and steady-state wear to 14 million cycles in hip-simulator model.

    PubMed

    Oonishi, Hironobu; Clarke, Ian C; Good, Victoria; Amino, Hirokazu; Ueno, Masuru

    2004-09-15

    The biphasic wear performance (run-in; steady-state phase) of 28-mm alumina-alumina hip implants was studied by hip simulator methods using bovine serum as the lubricant. The Biolox implants were run to 5.7 million cycles and Bioceram implants to 14.4 million cycles (Mc). Wear with all-alumina total hip replacements (THR) first showed a high wear rate of the order 1.2 mm3/Mc, lasting approximately 0.17 Mc. Overall to 0.7 Mc, the run-in phase appeared curvilinear but could be described by a linear phase averaging 0.3 mm3/Mc. From 0.7 to 1 Mc duration, the wear trend transitioned into a steady-state phase. Wear rates from 1 to 14 Mc were of the order 0.02 mm3/Mc. Surface contamination from the serum lubricant resulted in cyclic weight fluctuations of the order 0.2 mg. The transition from average run-in to steady-state phase represented a wear reduction of 13-fold. Comparing the steady-state wear value to that in standard 28-mm UHMWPE CUPS approaching 75 mm3/year, there was clearly a three-orders-of-magnitude wear superiority in favor of ceramic cups. PMID:15307156

  18. Metal ion levels decrease after revision for metallosis arising from large-diameter metal-on-metal hip arthroplasty.

    PubMed

    Ebreo, Darren; Khan, Abdul; El-Meligy, Mohammed; Armstrong, Catherine; Peter, Viju

    2011-12-01

    Concerns have been renewed regarding the possible long-term effects of elevated circulating levels of cobalt and chromium as a direct result of implantation of large femoral head diameter metal-on-metal bearings. In order to establish whether metal ion levels remain persistently elevated, we compared metal ion levels before and after revision surgery in patients with large head diameter (greater than 38 mm) metal-on-metal total hip arthroplasty or hip resurfacing arthroplasty. At greater than one year post removal of a large-diameter metal-on-metal hip implant for the indication of symptomatic metallosis, metal ion levels were found to fall to almost normal levels. PMID:22308623

  19. [Total hip replacement with isoelastic prosthesis in animals (author's transl)].

    PubMed

    Muhr, O; Stockhusen, H; Müller, O

    1976-10-01

    Uncemented fixation and low-fraction materials are the basis of this experiment. Plastics with an elasticity similar to the bone ("isoelasticity") show very propitious material qualities. The direct cementless incorporation of test bodies must be checked. In 63 sheep isoelastic total hip joints were implanted. After 2 till 51 weeks the animals were sacrificed and 44 specimen of hips and organs were explored macroscopically, radiologically, spherimetrically and histologically. The result was: 1. Plastic hip prosthesis are incorporated in the bone, but the boundary layer is built by a collagenous fiber tissue. 2. Loosening brings resoption of the bone and expansion of the structural changed soft tissue. 3. The transformation of the femoral cortex to osteoporosis is considered possibly as the consequence of an insufficient biological transfer of the weight. 4. Fractures of the femoral prosthesis-stem could not be observed. 5. The radiology allows at the pelvis prosthesis a concret statement concerning stability, on the femoral part a probable one. 6. The abrasion is minimal, the tissue reaction to abrasion products is unessential. 7. Small abrasion particles are carried of by the lymph tract and stored in the first regional gland. A more distant spreading is not demonstrable. PMID:985179

  20. Hip Replacement - Multiple Languages: MedlinePlus

    MedlinePLUS

    ... JavaScript. Hip Replacement - Multiple Languages Arabic (???????) Bosnian (Bosanski) Chinese - Simplified (????) Chinese - Traditional (????) French (français) ... Arabic) ??????? Bilingual PDF Health Information Translations Bosnian (Bosanski) Total Hip Replacement Potpuna zamjena kuka - Bosanski (Bosnian) ...

  1. 21M.775 Hip Hop, Spring 2003

    E-print Network

    DeFrantz, Thomas

    Subject explores the political and aesthetic foundations of hip hop. Students trace the musical, corporeal, visual, spoken word, and literary manifestations of hip hop over its thirty year presence in the American cultural ...

  2. Tribological investigations of the wear couple alumina-CFRP for total hip replacement.

    PubMed

    Früh, H J; Willmann, G

    1998-07-01

    Wear debris is the main reason for aseptic loosening in total hip. Most troublesome is the wear of polyethylene cups. Ceramic femoral heads were introduced about 20 years ago. The combination ceramic-on-polyethylene reduces the wear rate and the loosening rate. But cups of polyethylene are still the weakest link in a hip prosthesis. Carbon fibre reinforced plastic (CFRP) was proposed as an alternative for polyethylene. Various test were performed to study the combination metal-on-CFRP, zirconia-on-CFRP, and alumina-on-CFRP. The simulator tests showed that the wear rate of alumina-on-CFRP is in the order of 1-3 microm per year. Based on investigation of retrieved implants the wear rate is 6.3 microm per year. Based on these results the combination alumina femoral heads (Biolox-forte) and CFRP cups (Caproman) could be approved for total hip replacement. PMID:9720898

  3. Failure of a Novel Ceramic-on-Ceramic Hip Resurfacing Prosthesis.

    PubMed

    Matharu, Gulraj S; Daniel, Joseph; Ziaee, Hena; McMinn, Derek J W

    2014-10-22

    We report the early failure of five ceramic-on-ceramic hip resurfacings (CoCHRs). The ceramic used for the acetabular liner was a novel ceramic-composite (two thirds polyurethane and one third alumina ceramic). All cases were revised for increasing metal ion levels (blood cobalt 3.93-208.0?g/l and chromium 1.57-17.5?g/l) due to ceramic liner fracture and/or accelerated wear of the ceramic femoral head coating. Patients underwent bearing exchange and revision using primary hip arthroplasty implants at a mean of 3.0years following CoCHR. Intraoperatively all patients had metallosis. At 1 to 2years of follow-up blood metal ions normalized with no complications. We do not recommend this particular type of ceramic-on-ceramic bearing for hip resurfacing. PMID:25453631

  4. Revision Total Hip Arthroplasty Combined with Subtrochanteric Shortening Osteotomy: Case Report

    PubMed Central

    Sonohata, Motoki; Kitajima, Masaru; Kawano, Syunsuke; Honke, Hidefumi; Hotokebuchi, Takao; Mawatari, Masaaki

    2014-01-01

    Revision surgery is one of the most difficult reconstructive challenges facing orthopaedic surgeons; therefore, many new techniques and implants are needed to ensure that such patient can be successfully treated. We report a 66-year old female with a chronic dislocated bipolar hip prosthesis. She underwent a revision total hip arthroplasty combined with V-shaped subtrochanteric shortening osteotomy. This report demonstrates that V-shaped subtrochanteric shortening osteotomy can be used for revision surgery. Nevertheless, this technique is not suitable for all hip revisions, and the indications and various possible procedures and devices should be carefully considered to select the best treatment for each patient. We believe that the current report provides evidence supporting a new technical option for complex cases during revision THA. PMID:24683429

  5. Have cementless and resurfacing components improved the medium-term results of hip replacement for patients under 60 years of age?

    PubMed Central

    Mason, James; Baker, Paul; Gregg, Paul J; Porter, Martyn; Deehan, David J; Reed, Mike R

    2015-01-01

    Background and purpose The optimal hip replacement for young patients remains unknown. We compared patient-reported outcome measures (PROMs), revision risk, and implant costs over a range of hip replacements. Methods We included hip replacements for osteoarthritis in patients under 60 years of age performed between 2003 and 2010 using the commonest brand of cemented, cementless, hybrid, or resurfacing prosthesis (11,622 women and 13,087 men). The reference implant comprised a cemented stem with a conventional polyethylene cemented cup and a standard-sized head (28- or 32-mm). Differences in implant survival were assessed using competing-risks models, adjusted for known prognostic influences. Analysis of covariance was used to assess improvement in PROMs (Oxford hip score (OHS) and EQ5D index) in 2014 linked procedures. Results In males, PROMs and implant survival were similar across all types of implants. In females, revision was statistically significantly higher in hard-bearing and/or small-stem cementless implants (hazard ratio (HR) = 4) and resurfacings (small head sizes (< 48 mm): HR = 6; large head sizes (? 48 mm): HR = 5) when compared to the reference cemented implant. In component combinations with equivalent survival, women reported significantly greater improvements in OHS with hybrid implants (22, p = 0.006) and cementless implants (21, p = 0.03) (reference, 18), but similar EQ5D index. For men and women, National Health Service (NHS) costs were lowest with the reference implant and highest with a hard-bearing cementless replacement. Interpretation In young women, hybrids offer a balance of good early functional improvement and low revision risk. Fully cementless and resurfacing components are more costly and do not provide any additional benefit for younger patients. PMID:25285617

  6. The peritrochanteric space of the hip.

    PubMed

    Voos, James E; Ranawat, Anil S; Kelly, Bryan T

    2009-01-01

    The field of hip arthroscopy continues to grow as surgeons become more familiar with disorders of the intra-articular and extra-articular compartments of the hip. Recent studies have described the endoscopic treatment of injuries to the lateral peritrochanteric compartment of the hip, including recalcitrant trochanteric bursitis, external coxa saltans, and tears of the gluteus medius and minimus tendons. PMID:19385533

  7. Hip-Hop and the Academic Canon

    ERIC Educational Resources Information Center

    Abe, Daudi

    2009-01-01

    Over the last 30 years, the hip-hop movement has risen from the margins to become the preeminent force in US popular culture. In more recent times academics have begun to harness the power of hip-hop culture and use it as a means of infusing transformative knowledge into the mainstream academic discourse. On many college campuses, hip-hop's…

  8. Spontaneous modular femoral head dissociation complicating total hip arthroplasty.

    PubMed

    Talmo, Carl T; Sharp, Kinzie G; Malinowska, Magdalena; Bono, James V; Ward, Daniel M; LaReau, Justin

    2014-06-01

    Modular femoral heads have been used successfully for many years in total hip arthroplasty. Few complications have been reported for the modular Morse taper connection between the femoral head and trunnion of the stem in metal-on-polyethylene bearings. Although there has always been some concern over the potential for fretting, corrosion, and generation of particulate debris at the modular junction, this was not considered a significant clinical problem. More recently, concern has increased because fretting and corrosive debris have resulted in rare cases of pain, adverse local tissue reaction, pseudotumor, and osteolysis. Larger femoral heads, which have gained popularity in total hip arthroplasty, are suspected to increase the potential for local and systemic complications of fretting, corrosion, and generation of metal ions because of greater torque at the modular junction. A less common complication is dissociation of the modular femoral heads. Morse taper dissociation has been reported in the literature, mainly in association with a traumatic event, such as closed reduction of a dislocation or fatigue fracture of the femoral neck of a prosthesis. This report describes 3 cases of spontaneous dissociation of the modular prosthetic femoral head from the trunnion of the same tapered titanium stem because of fretting and wear of the Morse taper in a metal-on-polyethylene bearing. Continued clinical and scientific research on Morse taper junctions is warranted to identify and prioritize implant and surgical factors that lead to this and other types of trunnion failure to minimize complications associated with Morse taper junctions as hip implants and surgical techniques continue to evolve. PMID:24972443

  9. Femoral head diameter considerations for primary total hip arthroplasty.

    PubMed

    Girard, J

    2015-02-01

    The configuration of total hip arthroplasty (THA) implants has constantly evolved since they were first introduced. One of the key components of THA design is the diameter of the prosthetic femoral head. It has been well established that the risk of dislocation is lower as the head diameter increases. But head diameter impacts other variables beyond joint stability: wear, cam-type impingement, range of motion, restoration of biomechanics, proprioception and groin pain. The introduction of highly cross-linked polyethylene and hard-on-hard bearings has allowed surgeons to implant large-diameter heads that almost completely eliminate the risk of dislocation. But as a result, cup liners have become thinner. With femoral head diameters up to 36 mm, the improvement in joint range of motion, delay in cam-type impingement and reduction in dislocation risk have been clearly demonstrated. Conversely, large-diameter heads do not provide any additional improvements. If an "ecologically sound" approach to hip replacement is embraced (e.g. keeping the native femoral head diameter), hip resurfacing with a metal-on-metal bearing must be carried out. The reliability of large-diameter femoral heads in the longer term is questionable. Large-diameter ceramic-on-ceramic bearings may be plagued by the same problems as metal-on-metal bearings: groin pain, squeaking, increased stiffness, irregular lubrication, acetabular loosening and notable friction at the Morse taper. These possibilities require us to be extra careful when using femoral heads with a diameter greater than 36 mm. PMID:25596984

  10. Clinical Results of the Metha Short Hip Stem: A Perspective for Younger Patients?

    PubMed Central

    Thorey, Fritz; Hoefer, Claudia; Abdi-Tabari, Nima; Lerch, Matthias; Budde, Stefan; Windhagen, Henning

    2013-01-01

    In recent years, various uncemented proximal metaphyseal hip stems were introduced for younger patients as a bone preserving strategy. Initial osteodensitometric analyses of the surrounding bone of short stems indicate an increase of bone mass with secondary bone ingrowth fixation as a predictor of long-term survival of these types of implants. We report the outcome of 151 modular Metha short hip stem implants in 148 patients between March 2005 and October 2007. The mean follow-up was 5.8±0.7 years and the mean age of the patients was 55.7±9.8 years. Along with demographic data and co-morbidities, the Harris Hip Score (HHS), the Hip dysfunction and Osteoarthritis Outcome Score (HOOS), and also the results of a patient-administered questionnaire were recorded pre-operatively and at follow-up. The mean HHS increased from 46±17 pre-operatively to 90±5 the HOOS improved from 55±16 pre-operatively to 89±10 at the final follow-up. A total of three patients have been revised, two for subsidence with femoral revision and one for infection without femoral revision (Kaplan Meier survival estimate 98%). The radiological findings showed no radiolucent lines in any of the patients. The modular Metha short hip stem was implanted in younger patients, who reported an overall high level of satisfaction. The clinical and radiographic results give support to the principle of using short stems with metaphyseal anchorage. However, long-term results are necessary to confirm the success of this concept in the years to come. PMID:24416478

  11. Clinical results of the metha short hip stem: a perspective for younger patients?

    PubMed

    Thorey, Fritz; Hoefer, Claudia; Abdi-Tabari, Nima; Lerch, Matthias; Budde, Stefan; Windhagen, Henning

    2013-01-01

    In recent years, various uncemented proximal metaphyseal hip stems were introduced for younger patients as a bone preserving strategy. Initial osteodensitometric analyses of the surrounding bone of short stems indicate an increase of bone mass with secondary bone ingrowth fixation as a predictor of long-term survival of these types of implants. We report the outcome of 151 modular Metha short hip stem implants in 148 patients between March 2005 and October 2007. The mean follow-up was 5.8±0.7 years and the mean age of the patients was 55.7±9.8 years. Along with demographic data and co-morbidities, the Harris Hip Score (HHS), the Hip dysfunction and Osteoarthritis Outcome Score (HOOS), and also the results of a patient-administered questionnaire were recorded pre-operatively and at follow-up. The mean HHS increased from 46±17 pre-operatively to 90±5 the HOOS improved from 55±16 pre-operatively to 89±10 at the final follow-up. A total of three patients have been revised, two for subsidence with femoral revision and one for infection without femoral revision (Kaplan Meier survival estimate 98%). The radiological findings showed no radiolucent lines in any of the patients. The modular Metha short hip stem was implanted in younger patients, who reported an overall high level of satisfaction. The clinical and radiographic results give support to the principle of using short stems with metaphyseal anchorage. However, long-term results are necessary to confirm the success of this concept in the years to come. PMID:24416478

  12. Total hip arthroplasty in the young: special emphasis on post-SCFE patients.

    PubMed

    Nelms, Nathaniel J; Lewallen, Laura W; McIntosh, Amy L; Sierra, Rafael J

    2013-01-01

    Slipped capital femoral epiphysis (SCFE) is a hip disorder of adolescence, which has the potential for profound implications into adulthood. SCFE patients are at risk of early joint degeneration and subsequent need for arthroplasty. The rate at which arthroplasty is required is not precisely known, but is estimated to be approximately 45% by 50 years after a slip. The femoral neck and shaft displace anteriorly and rotate externally relative to the femoral epiphysis, which remains fixed in the acetabulum. Stabilization of the physis is the goal of acute management. Despite such efforts, accelerated joint degeneration may occur over time. This progression is due to avascular necrosis, chondrolysis, or following years of femoroacetabular impingement. Total hip arthroplasty (THA) and total hip resurfacing (THR) are options for end-stage hip arthritis due to SCFE. THR is technically more challenging, with very limited ability to address deformity-related issues of impingement, decreased hip offset, and trochanteric malposition. THR, as in any metal on metal arthroplasty, may be associated with local metal sensitivity or systemic metal toxicity. Given the limited utility and potential risks, THR is currently not recommended in the majority of cases. THA, although historically demonstrating poor long-term implant performance in the young patient, has become a more reliable option recently. The potential benefits of THA are considerable, even for the young patient with end-stage hip degeneration. Certain cemented and many cementless stem designs show good long-term survival, as do current cementless cups. Advances in bearing surfaces promise to minimize wear and extend implant longevity. Ceramic on ceramic, metal on highly cross-linked polyethylene, and ceramic on highly cross-linked polyethylene bearing couples offer promise. PMID:23764787

  13. Idiopathic chondrolysis of the hip.

    PubMed

    Mounach, Aziza; Nouijai, Abderrazak; Ghozlani, Imad; Ghazi, Miriam; Bezza, Ahmed; Achemlal, Lahcen; El Maghraoui, Abdellah

    2007-12-01

    Idiopathic chondrolysis of the hip is a rare disease in which gradual necrosis of the hyaline cartilage covering the femoral head and acetabulum leads to joint space narrowing and motion restriction. Pain, motion range limitation, and radiographic joint space narrowing are the main manifestations. We report 2 cases in 15-year-old girls, one black and the other Caucasian. Unexplained pain and motion restriction in the left hip were the presenting manifestations. Narrowing of the hip joint space was noted on standard radiographs. Magnetic resonance imaging showed a joint effusion in 1 patient and unevenness of the femoral head contour in the other. Laboratory tests including microbiological studies were normal or negative. Nonspecific synovitis was found in biopsy specimens. Immobilization and traction were the main components of the treatment strategy. PMID:17892963

  14. Acetabular distraction: an alternative approach to pelvic discontinuity in failed total hip replacement.

    PubMed

    Brown, N M; Hellman, M; Haughom, B H; Shah, R P; Sporer, S M; Paprosky, W G

    2014-11-01

    A pelvic discontinuity occurs when the superior and inferior parts of the hemi-pelvis are no longer connected, which is difficult to manage when associated with a failed total hip replacement. Chronic pelvic discontinuity is found in 0.9% to 2.1% of hip revision cases with risk factors including severe pelvic bone loss, female gender, prior pelvic radiation and rheumatoid arthritis. Common treatment options include: pelvic plating with allograft, cage reconstruction, custom triflange implants, and porous tantalum implants with modular augments. The optimal technique is dependent upon the degree of the discontinuity, the amount of available bone stock and the likelihood of achieving stable healing between the two segments. A method of treating pelvic discontinuity using porous tantalum components with a distraction technique that achieves both initial stability and subsequent long-term biological fixation is described. PMID:25381413

  15. Image-guided, navigation-assisted Relieva Stratus MicroFlow Spacer insertion into the ethmoid sinus.

    PubMed

    Taulu, Rami; Numminen, Jura; Bizaki, Argyro; Rautiainen, Markus

    2014-10-18

    Anatomical complexity presents the main challenge in the administration of topical corticosteroid therapy to the paranasal sinus mucosa. This often leads to suboptimal drug delivery due to low concentrations of the therapeutic agent to the intended target area. The Relieva Stratus™ MicroFlow Spacer (Relieva Stratus) is a drug-eluting stent that is temporarily implanted into the ethmoid sinus. The reservoir of the stent is filled with triamcinolone acetonide, which is then slowly released from the device into the ethmoid sinus mucosa. The Relieva Stratus provides local and targeted delivery of the anti-inflammatory agent to the diseased mucosa. This minimally invasive implant is an option when treating ethmoid sinusitis. From January 2011 to November 2013, a total of 52 Relieva Stratus implantations into the ethmoidal cells were performed at the Department of Ear and Oral Diseases at Tampere University Hospital, Finland. C-arm fluoroscopy guidance was employed for 26 sinuses (13 patients) and optical image-guided surgery (IGS)-assisted insertions were performed on another 26 sinuses (13 patients). The accuracy of fluoroscopic insertion is not optimal, but this method is accurate enough to prevent the violation of the skull base and lamina papyracea. IGS enables the precise treatment of the diseased cells. From a technical perspective, IGS-guided insertion is a faster, safer and more exact procedure that guarantees the optimal positioning and efficacy of the implant. Moreover, IGS guidance does not entail the use of ionizing radiation. PMID:25325931

  16. [Ceramic-on-Ceramic Bearings in Total Hip Arthroplasty (THA)].

    PubMed

    Sentürk, U; Perka, C

    2015-04-01

    The main reason for total hip arthroplasty (THA) revision is the wear-related aseptic loosening. Younger and active patients after total joint replacement create high demands, in particular, on the bearings. The progress, especially for alumina ceramic-on-ceramic bearings and mixed ceramics have solved many problems of the past and lead to good in vitro results. Modern ceramics (alumina or mixed ceramics containing alumina) are extremely hard, scratch-resistant, biocompatible, offer a low coefficient of friction, superior lubrication and have the lowest wear rates in comparison to all other bearings in THA. The disadvantage of ceramic is the risk of material failure, i.e., of ceramic fracture. The new generation of mixed ceramics (delta ceramic), has reduced the risk of head fractures to 0.03-0.05?%, but the risk for liner fractures remains unchanged at about 0.02?%. Assuming a non-impinging component implantation, ceramic-on-ceramic bearings have substantial advantages over all other bearings in THA. Due to the superior hardness, ceramic bearings produce less third body wear and are virtually impervious to damage from instruments during the implantation process. A specific complication for ceramic-on-ceramic bearings is "squeaking". The high rate of reported squeaking (0.45 to 10.7?%) highlights the importance of precise implant positioning and the stem and patient selection. With precise implant positioning this problem is rare with many implant designs and without clinical relevance. The improved tribology and the presumable resulting implant longevity make ceramic-on-ceramic the bearing of choice for young and active patients. PMID:25874400

  17. Use of mesenchymal stem cells to enhance bone formation around revision hip replacements.

    PubMed

    Korda, Michelle; Blunn, Gordon; Goodship, Allen; Hua, Jia

    2008-06-01

    Tissue engineering approaches to regenerate bone stock in revision total hip replacements could enhance the longevity of the implant and benefit the quality of the patient's life. This study investigated the impaction of allograft with mesenchymal stem cells in an ovine hip hemiarthroplasty model. In total, 10 sheep were divided into two groups with 5 sheep in each group. The groups were: 1) mesenchymal stem cells mixed with allograft; 2) allograft only as a control. Ground reaction force was assessed for limb function and showed that there was no significant difference in the recovery for animals in different groups. The amount of bone regenerated around the hip replacement was assessed using un-decalcified histology. The results showed that the stem cell group generated significantly more new bone at the implant-allograft interface and within the graft than the control group. The results from this study indicate that the use of stem cells on an allograft scaffold increases bone formation indicating that the use of stem cells for revision hip arthroplasty may be beneficial for patients undergoing revision surgery where the bone stock is compromised. PMID:18271017

  18. How Do Metal Ion Levels Change over Time in Hip Resurfacing Patients? A Cohort Study

    PubMed Central

    Savarino, Lucia; Cadossi, Matteo; Chiarello, Eugenio; Fotia, Caterina; Greco, Michelina; Baldini, Nicola; Giannini, Sandro

    2014-01-01

    Metal-on-metal hip resurfacing (MOM-HR) is offered as an alternative to traditional hip arthroplasty for young, active adults with advanced osteoarthritis. Nevertheless, concerns remain regarding wear and corrosion of the bearing surfaces and the resulting increase in metal ion levels. We evaluated three cohorts of patients with Birmingham hip resurfacing (BHR) at an average follow-up of 2, 5, and 9 years. We asked whether there would be differences in ion levels between the cohorts and inside the gender. Nineteen patients were prospectively analyzed. The correlation with clinical-radiographic data was also performed. Chromium, cobalt, nickel, and molybdenum concentrations were measured by atomic absorption spectrophotometry. Chromium and cobalt levels demonstrated a tendency to decrease over time. Such tendency was present only in females. An inverse correlation between chromium, implant size, and Harris hip score was present at short term; it disappeared over time together with the decreased ion levels. The prospective analysis showed that, although metal ion levels remained fairly constant within each patient, there was a relatively large variation between subjects, so mean data in this scenario must be interpreted with caution. The chronic high exposure should be carefully considered during implant selection, particularly in young subjects, and a stricter monitoring is mandatory. PMID:25580456

  19. Mechanical failure of metal-polyethylene sandwich liner in metal-on-metal total hip replacement.

    PubMed

    Oshima, Yasushi; Fetto, Joseph F

    2015-01-01

    Metal-on-metal had been proposed as an optimal articulation in THRs, however, many monoblock prostheses have been recalled in the USA because of significant high rates of early failure. Metal-on-metal prostheses had been implanted in our institution, and this is a case history of a single patient, in whom metal-on-metal THRs with different femoral sizes of heads were implanted. A 57-year-old female patient underwent bilateral total hip replacements with metal-on-metal prostheses using metal-polyethylene "sandwich" liners 9 years ago on the right side and 7 years ago on the left side respectively. The only difference in both sides was the femoral head diameter of 28 mm in right and 34 mm in left. Seven years after the left surgery, the acetabular liner was dissociated, however, metallosis was not detected. Although the larger femoral head was thought to increase hip joint stability, it dictated a reduction in polyethylene thickness in this prosthesis design, and it was 4 mm in the left hip. Recently, metal-on-metal articulations are thought not to be optimal for hip joint bearing surface, however, this clinical failure was due to the polyethylene thickness and quality. PMID:25601670

  20. A novel murine model of established Staphylococcal bone infection in the presence of a fracture fixation plate to study therapies utilizing antibiotic-laden spacers after revision surgery.

    PubMed

    Inzana, Jason A; Schwarz, Edward M; Kates, Stephen L; Awad, Hani A

    2015-03-01

    Mice are the small animal model of choice in biomedical research due to the low cost and availability of genetically engineered lines. However, the devices utilized in current mouse models of implant-associated bone infection have been limited to intramedullary or trans-cortical pins, which are not amenable to treatments involving extensive debridement of a full-thickness bone loss and placement of a segmental antibiotic spacer. To overcome these limitations, we developed a clinically faithful model that utilizes a locking fracture fixation plate to enable debridement of an infected segmental bone defect (full-thickness osteotomy) during a revision surgery, and investigated the therapeutic effects of placing an antibiotic-laden spacer in the segmental bone defect. To first determine the ideal time point for revision following infection, a 0.7 mm osteotomy in the femoral mid-shaft was stabilized with a radiolucent PEEK fixation plate. The defect was inoculated with bioluminescent Staphylococcus aureus, and the infection was monitored over 14 days by bioluminescent imaging (BLI). Osteolysis and reactive bone formation were assessed by X-ray and micro-computed tomography (micro-CT). The active bacterial infection peaked by 5 days post-inoculation, however the stability of the implant fixation became compromised by 10-14 days post-inoculation due to osteolysis around the screws. Thus, day 7 was defined as the ideal time point to perform the revision surgery. During the revision surgery, the infected tissue was debrided and the osteotomy was widened to 3mm to place a poly-methyl methacrylate spacer, with or without vancomycin. Half of the groups also received systemic vancomycin for the remaining 21 days of the study. The viable bacteria remaining at the end of the study were measured using colony forming unit assays. Volumetric bone changes (osteolysis and reactive bone formation) were directly measured using micro-CT image analysis. Mice that were treated with local or systemic vancomycin did not display gross pathology at the end of the study. While localized vancomycin delivery alone tended to decrease the bacterial burden and osteolysis, these effects were only significant when combined with systemic antibiotic therapy. This novel mouse model replicates key features of implant-associated osteomyelitis that make treatment extremely difficult, such as biofilm formation and osteolysis, and imitates the clinical practice of placing an antibiotic-laden spacer after infected tissue debridement. In addition, the model demonstrates the limitations of current PMMA spacers and could be an invaluable tool for evaluating alternative antimicrobial treatments for implant-associated bone infection. PMID:25459073

  1. Process optimized minimally invasive total hip replacement.

    PubMed

    Gebel, Philipp; Oszwald, Markus; Ishaque, Bernd; Ahmed, Gaffar; Blessing, Recha; Thorey, Fritz; Ottersbach, Andreas

    2012-01-01

    The purpose of this study was to analyse a new concept of using the the minimally invasive direct anterior approach (DAA) in total hip replacement (THR) in combination with the leg positioner (Rotex- Table) and a modified retractor system (Condor). We evaluated retrospectively the first 100 primary THR operated with the new concept between 2009 and 2010, regarding operation data, radiological and clinical outcome (HOOS). All surgeries were perfomed in a standardized operation technique including navigation. The average age of the patients was 68 years (37 to 92 years), with a mean BMI of 26.5 (17 to 43). The mean time of surgery was 80 min. (55 to 130 min). The blood loss showed an average of 511.5 mL (200 to 1000 mL). No intra-operative complications occurred. The postoperative complication rate was 6%. The HOOS increased from 43 points pre-operatively to 90 (max 100 points) 3 months after surgery. The radiological analysis showed an average cup inclination of 43° and a leg length discrepancy in a range of +/- 5 mm in 99%. The presented technique led to excellent clinic results, showed low complication rates and allowed correct implant positions although manpower was saved. PMID:22577504

  2. The clinical and radiological outcomes of hip resurfacing versus total hip arthroplasty: a meta-analysis and systematic review

    PubMed Central

    2010-01-01

    Background and purpose Hip resurfacing (HRS) procedures have gained increasing popularity for younger, higher-demand patients with degenerative hip pathologies. However, with concerns regarding revision rates and possible adverse metal hypersensitivity reactions with metal-on-metal articulations, some authors have questioned the hypothesized superiority of hip resurfacing over total hip arthroplasty (THA). In this meta-analysis, we compared the clinical and radiological outcomes and complication rates of these 2 procedures. Methods A systematic review was undertaken of all published (Medline, CINAHL, AMED, EMBASE) and unpublished or gray literature research databases up to January 2010. Clinical and radiological outcomes as well as complications of HRS were compared to those of THA using risk ratio, mean difference, and standardized mean difference statistics. Studies were critically appraised using the CASP appraisal tool. Results 46 studies were identified from 1,124 citations. These included 3,799 HRSs and 3,282 THAs. On meta-analysis, functional outcomes for subjects following HRS were better than or the same as for subjects with a THA, but there were statistically significantly greater incidences of heterotopic ossification, aseptic loosening, and revision surgery with HRS compared to THA. The evidence base showed a number of methodological inadequacies such as the limited use of power calculations and poor or absent blinding of both patients and assessors, possibly giving rise to assessor bias. Interpretation On the basis of the current evidence base, HRS may have better functional outcomes than THA, but the increased risks of heterotopic ossification, aseptic loosening, and revision surgery following HRS indicate that THA is superior in terms of implant survival. PMID:21067432

  3. Prediction of post-operative urinary retention in hip and knee arthroplasty in a male population

    Microsoft Academic Search

    J. J. Cronin; F. J. Shannon; E. Bale; W. Quinlan

    2007-01-01

    Urinary retention is an important complication of hip and knee arthroplasty. The insertion of a urinary catheter has been\\u000a associated with an increased incidence of implant infection in previous studies (David and Vrahas in J Am Acad Orthop Surg\\u000a 8(1):66–74, 2000; Haase and Harding in Compan Surg 1(4):1–6, 1984). The purpose of this study was to assess the rates of

  4. Wear and corrosion of sliding counterparts of stainless-steel hip screw-plates

    Microsoft Academic Search

    B. F Shahgaldi; J Compson

    2000-01-01

    Wear of the lag screw and barrel of stainless-steel sliding hip screw-plates (SHSP) produces particles and corrosion that jam the sliding screw. This alters the mechanics of the SHSP causing failure and difficulty in removal. We examined 15 surgically-removed SHSP for the extent of wear and corrosion of metal, and damage to the surrounding tissue. SHSP implants were in place

  5. Sports hip injuries: assessment and management.

    PubMed

    Kelly, Bryan T; Maak, Travis G; Larson, Christopher M; Bedi, Asheesh; Zaltz, Ira

    2013-01-01

    Over the past 10 years, the understanding, assessment, and management of hip pain and injuries in the athlete have improved. Traditionally, the evaluation of hip pain and injuries was limited to obvious disorders, such as hip arthritis and fractures, or disorders that were previously considered to be simply soft-tissue strains and contusions, such as groin pulls, hip pointers, and bursitis. Two parallel tracks of progress have improved understanding of the complexities of hip joint athletic injuries and the biomechanical basis of early hip disease. In the field of sports medicine, improved diagnostic skills now allow better interpretation of debilitating intra-articular hip disorders and their effects on core performance. In the field of hip preservation, there has been an evolution in understanding the effects of biomechanical mismatches between the femoral head and the acetabulum on the development of early hip damage, injury, and arthritis. The integration of these two parallel fields has accelerated the understanding of the importance of hip biomechanics and early hip injury in human performance and function. PMID:23395055

  6. The Exeter™ Universal Hip in Patients 50 Years or Younger at 10–17 Years’ Followup

    PubMed Central

    Squires, Ben; Gie, Graham A.; Timperley, Andrew J.; Ling, Robin S. M.

    2008-01-01

    The Exeter™ Universal hip (Stryker Inc., Newbury, UK) has reported survival rates of 91.74% at 12 years in all patients with reoperation as an endpoint. However, its performance in younger patients has not been fully established. We reviewed survivorship and the clinical and radiographic outcomes of this hip system implanted in 107 patients (130 hips) 50 years old or younger at the time of surgery. The mean age at surgery was 42 years. The minimum followup was 10 years (mean, 12.5 years; range, 10–17 years) with no patients lost to followup. Twelve hips had been revised. Of these, nine had aseptic loosening of the acetabular component and one cup was revised for focal lysis and pain. One hip was revised for recurrent dislocation and one joint underwent revision for infection. Radiographs demonstrated 14 (12.8%) of the remaining acetabular prostheses were loose but no femoral components were loose. Survivorship of both stem and cup from all causes was 92.6% at an average of 12.5 years. Survivorship of the stem from all causes was 99% and no stem was revised for aseptic loosening. The Exeter™ Universal stem performed well, even in the young, high-demand patient. Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18196413

  7. Long-term results of the threaded Weill cup in primary total hip arthroplasty

    PubMed Central

    Clarius, Michael; Jung, Alexander W.; Raiss, Patric; Streit, Marcus R.; Merle, Christian

    2009-01-01

    Uncemented, threaded acetabular components with smooth surface treatment were widely used in continental Europe in the 1970s and 1980s for primary total hip arthroplasty (THA). Previously published studies showed high failure rates in the mid-term. In a consecutive series of 116 patients, 127 threaded cups with smooth surface treatment (Weill cup; Zimmer, Winterthur, Switzerland) were implanted in combination with one type of uncemented stem. Patients were followed up clinically and radiographically. Mean time of follow-up was 17 years (range 15–20). At the time of follow-up, the acetabular component had been revised or was awaiting revision in 30 hips (24%). Two hips were revised for infection and 23 for aseptic loosening. Four polyethylene liners were exchanged because of excessive wear. One hip was awaiting revision. The survival rate for all acetabular revisions including one hip awaiting revision was 75% (95%CI: 65–85%) at 17 years. These results support the view that smooth, threaded acetabular components do not provide satisfactory long-term fixation and should be abandoned. It is important to closely monitor patients with these components as the failure rate remains high in the long-term. PMID:19629480

  8. Long-term results of the threaded Mecron cup in primary total hip arthroplasty

    PubMed Central

    Clarius, Michael; Jung, Alexander W.; Streit, Marcus R.; Merle, Christian; Raiss, Patric

    2009-01-01

    In the 1970s, high failure rates of cemented acetabular components, especially in young patients, in the middle- and long-term prompted a search for alternatives. The Mecring was one of the most popular first generation uncemented, threaded cups widely used in the 1980s for arthroplasty of the hip. First generation threaded cups commonly had smooth surface treatment and showed unacceptably high failure rates in the mid-term. In a consecutive series of 209 patients, 221 threaded uncemented acetabular cups with smooth surface treatment (Mecring) had been implanted in combination with one type of uncemented stem. Patients were followed up clinically and radiographically. The mean time of follow-up was 17 (range 15–20) years. In 91 (41%) hips the acetabular component had been revised or was awaiting revision: two hips for infection and 84 (38%) for aseptic loosening. Five hips were awaiting revision. The survival rate for all revisions including hips awaiting revision was 49% (95% CI: 41–57%) at 17 years. These results support the view that smooth, threaded acetabular components do not provide satisfactory long-term fixation and should be abandoned. Patients with these components must be closely monitored as the failure rate remains high in the long-term. PMID:19629481

  9. Ion Implant

    NSDL National Science Digital Library

    This website includes an animation which illustrates the ion implant process. Objective: Name the three common dopants used in implantation processes and explain the process of generating an ion beam from source to wafer. You can find this animation under the heading "Process & Equipment III." This simulation is from Module 026 of the Process & Equipment III Cluster of the MATEC Module Library (MML). To view other clusters or for more information about the MML visit http://matec.org/ps/library3/process_I.shtmlKey

  10. Innovation and regulation in human implant technologies: developing comparative approaches.

    PubMed

    Faulkner, A; Kent, J

    2001-10-01

    Human implant technologies are subject to continual innovation and proliferation, raising important issues for technology testing, healthcare sciences, clinical performance and risk assessment, and regulation. The regulatory environment of medical devices is being shaped by harmonisation of standards in the European Union. The aim of this paper is to compare the histories and current regulatory environment of two technologies, breast implants and artificial hips, and to consider the implications of this comparison for a sociological healthcare research agenda to investigate the issues raised. The main focus is upon developments in the United Kingdom. Major points of contrast between the two technologies include the institutional contexts in which clinical evidence has been marshalled for government attention; the relative importance of strategic alliances between clinicians and manufacturers in the innovation process; the degree of public controversy evident; the varying definitions of an 'adverse incident' within medical device vigilance systems; and in the UK the presence of a national register for breast implants but not for hip implants. Inter-national contrasts in these dimensions are noted. The analysis suggests that improved understanding is required of the institutional, organisational and professional processes involved in implant technology innovation and regulation. A comparative research agenda is proposed, focusing upon: innovativeness and proliferation; safety and technological standards; clinical and social outcomes; and consumer/user information and choice. It is concluded that research in these areas will enhance the 'evidence-base' for the evaluation of human implant technologies in the context of their innovatory and regulatory environments. PMID:11522136

  11. Bone remodeling in a new biomimetic polymer-composite hip stem.

    PubMed

    Bougherara, Habiba; Bureau, Martin N; Yahia, L'Hocine

    2010-01-01

    Adaptive bone remodeling is an important factor that leads to bone resorption in the surrounding femoral bone and implant loosening. Taking into account this factor in the design of hip implants is of clinical importance, because it allows the prediction of the bone-density redistribution and enables the monitoring of bone adaptation after prosthetic implantation. In this article, adaptive bone remodeling around a new biomimetic polymer-composite-based (CF/PA12) hip prosthesis is investigated to evaluate the amount of stress shielding and bone resorption. The design concept of this new prosthesis is based on a hollow substructure made of hydroxyapatite-coated, continuous carbon fiber (CF)-reinforced polyamide 12 (PA12) composite with an internal soft polymer-based core. Strain energy density theory coupled with 3D Finite Element models is used to predict bone density redistributions in the femoral bone before and after total hip replacement (THR) using both polymer-composite and titanium (Ti) stems. The result of numerical simulations of bone remodeling revealed that the CF/PA12 composite stem generates a better bone density pattern compared with the Ti-based stem, indicating the effectiveness of the composite stem to reduce bone resorption caused by stress-shielding phenomenon. This may result in an extended lifetime of THR. PMID:19165787

  12. Surface micro-analyses of long-term worn retrieved "Osteal" alumina ceramic total hip replacement.

    PubMed

    Tateiwa, Toshiyuki; Clarke, Ian C; Pezzotti, Giuseppe; Sedel, Laurent; Kumakura, Tsuyoshi; Shishido, Takaaki; Yamamoto, Kengo

    2007-11-01

    We analyzed wear pattern of long-term retrieved alumina-alumina hip prostheses from Osteal, which were implanted for 15-19 years. A comparison was carried out with our previous study of 17-year Biolox alumina-on-alumina hip prostheses, (Shishido et al., J Biomed Mater Res B 2003;67:638-647) and all-alumina total hip replacement run under microseparation simulator tests. Of particular interest was the occurrence of stripe wear in these first generation alumina ceramic bearings. Two balls of Osteal revealed only one stripe wear as did the respective liners on their rim areas. In these latter balls, the stripes were shallower than those previously observed in Biolox implants. A microscopic analysis of the bearing surface was carried out using scanning electron microscopy and fluorescence microprobe spectroscopy. On average, the Osteal retrievals had one grade lower wear than Biolox retrievals. Fluorescence microprobe maps showed that Biolox ball surfaces had higher compressive stress than the Osteal likely due to severe impingement and microseparation promoted by the bulky implant design. PMID:17455269

  13. Ribosomal DNA Intergenic Spacer of the Swimming Crab, Charybdis japonica

    Microsoft Academic Search

    Seong Ho Ryu; Yoon Kyung Do; Ui Wook Hwang; Chong Pyo Choe; Won Kim

    1999-01-01

    .   We have determined the full sequence of the ribosomal DNA intergenic spacer (IGS) of the swimming crab, Charybdis japonica, by long PCR for the first time in crustacean decapods. The IGS is 5376 bp long and contains two nonrepetitive regions separated\\u000a by one long repetitive region, which is composed mainly of four subrepeats (subrepeats I, II, III, and IV).

  14. Design Features of Intersaw Spacers for Ultrasonic Gang Saw

    Microsoft Academic Search

    S. G. Adikov; O. V. Kretinin; V. F. Gordeev

    2007-01-01

    This article is devoted to analysis of different variants intersaw spacers for the ultrasonic gang saw. The influence on longitudinal and bending oscillations of saw blades is shown. The optimum design which secures saw blades resistance to fractures and necessary amplitude of oscillations is offered.

  15. Filter holder assembly having extended collar spacer ring

    DOEpatents

    Alvin, Mary Anne (Pittsburgh, PA); Bruck, Gerald J. (Murrysville, PA)

    2002-01-01

    A filter holder assembly is provided that utilizes a fail-safe regenerator unit with an annular spacer ring having an extended metal collar for containment and positioning of a compliant ceramic gasket used in the assembly. The filter holder assembly is disclosed for use with advanced composite, filament wound, and metal candle filters.

  16. Characterization of wear in composite material orthopaedic implants. Part II: The implant/bone interface.

    PubMed

    Albert, K; Schledjewski, R; Harbaugh, M; Bleser, S; Jamison, R; Friedrich, K

    1994-01-01

    Carbon fiber/PEEK polymer (C/PEEK) composite materials are being developed for use as orthopaedic implant materials. Wear is an issue of increasing importance in orthopaedic implants; particulate debris generated by the wearing of biomaterials may be a causal factor leading to osteolysis and implant loosening. Therefore, numerical and experimental studies were completed to characterize the wear of C/PEEK composite materials in comparison to current orthopaedic implant materials. Finite element analyses (FEA) of a composite material hip stem implanted in a femur and loaded at 890 N determined that peak contact stresses will occur at the proximal-medial and distal regions of the implant. These contact stresses were found to be below 1.0 MPa over most of the implant surface; however the peak stress in the proximal-medial region was 1.8 MPa and higher still at the distal portion of the stem. In vivo forces result in contact stress values up to 9.0 MPa. The composite implant exhibited 10-40% lower contact stresses in the distal region compared to a titanium-alloy implant of identical design. Composite material wear samples were slid against porous hydroxylapatite (HA) to simulate the stem/bone interface. An identical series of experiments was run for comparison to a current orthopaedic implant material--Ti6A14V titanium alloy. Two domains of motion were studied; a composite ring-on-HA disc large amplitude sliding wear test; and a composite pin-on-HA disc small amplitude fretting regimen. Nominal contact pressures during testing were 1.4 MPa and 7.6 MPa for sliding and fretting tests, respectively. Fretting and sliding abrasive wear tests resulted in the composite material exhibiting a lower wear rate than the titanium-alloy. The magnitude of the difference was greatly dependent on the contact pressures, sliding amplitudes, and counterface material properties. PMID:7950869

  17. Idiopathic chondrolysis of the hip.

    PubMed

    Donnan, L; Einoder, B

    1996-08-01

    A case of idiopathic chondrolysis of the hip is described in a 12 year old female who has the characteristics of arthroophthalmopathy (Stickler's syndrome). This common connective tissue dysplasia may go unrecognized and is possibly an aetiological factor in the development of this disease process. A review of the literature is presented. PMID:8712998

  18. Hip: Anatomy and US technique

    PubMed Central

    Molini, L.; Precerutti, M.; Gervasio, A.; Draghi, F.; Bianchi, S.

    2011-01-01

    Ultrasound (US) has always had a relatively limited role in the evaluation of the hip due to the deep location of this joint. However, many hip diseases are well detectable at US, but before approaching such a study it is necessary to be thoroughly familiar with the normal anatomy and related US images. The study technique is particularly important as optimization of various parameters is required, such as probe frequency, focalization, positioning of the probe, etc. Also the patient’s position is important, as it varies according to the area requiring examination. For the study of the anterior structures, the patient should be in the supine position; for the medial structures, the leg should be abducted and rotated outward with the knee flexed; for the lateral structures, the patient should be in the controlateral decubitus position; for the posterior structures the patient must be in the prone position. US study of the hip includes assessment of the soft tissues, tendons, ligaments and muscles, and also of the bone structures, joint space and serous bursae. The purpose of this article is to review the normal anatomy of the hip as well as the US anatomy of this joint. PMID:23397030

  19. Idiopathic chondrolysis of the hip.

    PubMed

    Bleck, E E

    1983-12-01

    The cases of nine patients (eleven hips) with idiopathic chondrolysis of the hip were studied. Seven of the patients were white and two were Hispanic. The age at onset ranged from eight to sixteen years (mean, 11.5 years). Four patients were boys and five were girls. All patients had a decreased passive range of motion of the hip, and radiographic examination showed regional osteoporosis, premature closure of the femoral capital physis, narrowing of the joint space, and lateral overgrowth of the femoral head on the neck. All laboratory examinations were negative for evidence of infection or rheumatoid arthritis. An arthrotomy was done in seven patients. Specimens of the synovial tissue showed no growth on culture, and the histological studies revealed only minimum signs of inflammation. Histological studies of the articular cartilage were normal. Treatment consisted of administration of acetylsalicylic acid in therapeutic dosages to maintain a blood salicylate level of fifteen to twenty-five milligrams per cent, active non-loading exercise of the hip, protected weight-bearing with crutches, short-term traction to overcome or relieve contractures after biopsy, iliopsoas tenotomy or lengthening in three patients, and an adductor myotomy in one patient. At follow-up, 2.3 to 9.4 years after onset (mean, 6.2 years), six patients had either no symptoms or only minor intermittent discomfort in the hip. On radiographic examination, although these six patients had restoration of the joint space they did have lateral overgrowth of the femoral head (lateral buttressing) and overgrowth of the lateral acetabular margin (lateral osteophyte). In three patients who had disabling pain, joint deterioration was evident on the radiographic examination. One of these patients had a resurfacing arthroplasty to relieve pain. PMID:6654940

  20. Cochlear Implants

    MedlinePLUS

    ... during an optimal period to develop speech and language skills. A growing body of research, much of it funded by the NIDCD, has shown that when these children receive a cochlear implant ... a young age develop language skills at a rate comparable to children with ...

  1. The role of spacer surface conditions in the scatter of charge accumulations in SF6

    Microsoft Academic Search

    T. Jing; P. H. F. Morshuis; F. H. Kreuger

    1994-01-01

    A cylindrical epoxy spacer with different surface roughnesses was stressed under +150 kV in SF6. It is found that artificial roughness has no significant influence on the charge accumulation. Influences come from the variation in the surface conditions of the spacer by roughening it artificially. An additional test also shows that the micro structure at the spacer surface is more

  2. Quantum Chemical Calculations of the Influence of Anchor-Cum-Spacer Groups on Femtosecond Electron

    E-print Network

    Goddard III, William A.

    Quantum Chemical Calculations of the Influence of Anchor-Cum-Spacer Groups on Femtosecond Electron different anchor-cum-spacer groups, have been studied theoretically using density functional theory (DFT injection rate depends strongly on the ability of the anchor-cum-spacer unit that separates the d

  3. Effect of nitride sidewall spacer process on boron dose loss in ultrashallow junction formation

    E-print Network

    Dunham, Scott

    Effect of nitride sidewall spacer process on boron dose loss in ultrashallow junction formation P nitride spacer process on the boron profile in silicon and the related dose loss of B from the Si; published 4 February 2004 A nitride spacer with an underlying deposited tetraethoxysilane oxide

  4. Economic viability of geriatric hip fracture centers.

    PubMed

    Clement, R Carter; Ahn, Jaimo; Mehta, Samir; Bernstein, Joseph

    2013-12-01

    Management of geriatric hip fractures in a protocol-driven center can improve outcomes and reduce costs. Nonetheless, this approach has not spread as broadly as the effectiveness data would imply. One possible explanation is that operating such a center is not perceived as financially worthwhile. To assess the economic viability of dedicated hip fracture centers, the authors built a financial model to estimate profit as a function of costs, reimbursement, and patient volume in 3 settings: an average US hip fracture program, a highly efficient center, and an academic hospital without a specific hip fracture program. Results were tested with sensitivity analysis. A local market analysis was conducted to assess the feasibility of supporting profitable hip fracture centers. The results demonstrate that hip fracture treatment only becomes profitable when the annual caseload exceeds approximately 72, assuming costs characteristic of a typical US hip fracture program. The threshold of profitability is 49 cases per year for high-efficiency hip fracture centers and 151 for the urban academic hospital under review. The largest determinant of profit is reimbursement, followed by costs and volume. In the authors’ home market, 168 hospitals offer hip fracture care, yet 85% fall below the 72-case threshold. Hip fracture centers can be highly profitable through low costs and, especially, high revenues. However, most hospitals likely lose money by offering hip fracture care due to inadequate volume. Thus, both large and small facilities would benefit financially from the consolidation of hip fracture care at dedicated hip fracture centers. Typical US cities have adequate volume to support several such centers. PMID:24579222

  5. A Multicenter Approach Evaluating the Impact of Vitamin E-Blended Polyethylene in Cementless Total Hip Replacement

    PubMed Central

    Jäger, Marcus; van Wasen, Andrea; Warwas, Sebastian; Landgraeber, Stefan; Haversath, Marcel; Group, VITAS

    2014-01-01

    Since polyethylene is one of the most frequently used biomaterials as a liner in total hip arthroplasty, strong efforts have been made to improve design and material properties over the last 50 years. Antioxidants seems to be a promising alternative to further increase durability and reduce polyethylene wear in long term. As of yet, only in vitro results are available. While they are promising, there is yet no clinical evidence that the new material shows these advantages in vivo. To answer the question if vitamin-E enhanced ultra-high molecular weight polyethylene (UHMWPE) is able to improve long-term survivorship of cementless total hip arthroplasty we initiated a randomized long-term multicenter trial. Designed as a superiority study, the oxidation index assessed in retrieval analyses of explanted liners was chosen as primary parameter. Radiographic results (wear rate, osteolysis, radiolucency) and functional outcome (Harris Hip Scores, University of California-Los Angeles, Hip Disability and Osteoarthritis Outcome Score, Visual Analogue Scale) will serve as secondary parameters. Patients with the indication for a cementless total hip arthroplasty will be asked to participate in the study and will be randomized to either receive a standard hip replacement with a highly cross-linked UHMWPE-X liner or a highly cross-linked vitamin-E supplemented UHMWPE-XE liner. The follow-up will be 15 years, with evaluation after 5, 10 and 15 years. The controlled randomized study has been designed to determine if Vitamin-E supplemented highly cross-linked polyethylene liners are superior to standard XLPE liners in cementless total hip arthroplasty. While several studies have been started to evaluate the influence of vitamin-E, most of them evaluate wear rates and functional results. The approach used for this multicenter study, to analyze the oxidation status of retrieved implants, should make it possible to directly evaluate the ageing process and development of the implant material itself over a time period of 15 years. PMID:25002933

  6. A multicenter approach evaluating the impact of vitamin e-blended polyethylene in cementless total hip replacement.

    PubMed

    Jäger, Marcus; van Wasen, Andrea; Warwas, Sebastian; Landgraeber, Stefan; Haversath, Marcel; Group, Vitas

    2014-04-22

    Since polyethylene is one of the most frequently used biomaterials as a liner in total hip arthroplasty, strong efforts have been made to improve design and material properties over the last 50 years. Antioxidants seems to be a promising alternative to further increase durability and reduce polyethylene wear in long term. As of yet, only in vitro results are available. While they are promising, there is yet no clinical evidence that the new material shows these advantages in vivo. To answer the question if vitamin-E enhanced ultra-high molecular weight polyethylene (UHMWPE) is able to improve long-term survivorship of cementless total hip arthroplasty we initiated a randomized long-term multicenter trial. Designed as a superiority study, the oxidation index assessed in retrieval analyses of explanted liners was chosen as primary parameter. Radiographic results (wear rate, osteolysis, radiolucency) and functional outcome (Harris Hip Scores, University of California-Los Angeles, Hip Disability and Osteoarthritis Outcome Score, Visual Analogue Scale) will serve as secondary parameters. Patients with the indication for a cementless total hip arthroplasty will be asked to participate in the study and will be randomized to either receive a standard hip replacement with a highly cross-linked UHMWPE-X liner or a highly cross-linked vitamin-E supplemented UHMWPE-XE liner. The follow-up will be 15 years, with evaluation after 5, 10 and 15 years. The controlled randomized study has been designed to determine if Vitamin-E supplemented highly cross-linked polyethylene liners are superior to standard XLPE liners in cementless total hip arthroplasty. While several studies have been started to evaluate the influence of vitamin-E, most of them evaluate wear rates and functional results. The approach used for this multicenter study, to analyze the oxidation status of retrieved implants, should make it possible to directly evaluate the ageing process and development of the implant material itself over a time period of 15 years. PMID:25002933

  7. Implant Chips

    NSDL National Science Digital Library

    Schroeder, Ted.

    2002-01-01

    A group of eight people, including all members of one Florida family, had an implant chip, roughly the size of a grain of rice, injected under their skin on Friday, May 10. Manufactured by Applied Digital Solutions (ADS), the chips store a special identification number that enables the retrieval of personal and medical information. In the event of a medical emergency, a special handheld scanner activates the dormant digital implant, which provides identification data with which medical personnel can query ADS's database, the location of the patient's medical records. Alzheimer's patients seem to be the most promising market for this technology, even though other people, like the Florida family, hope to benefit from it as well. Another product that ADS offers is called Digital Angel, a wearable global positioning system (GPS) device that, among other things, can track in real time the wearer's physical movements. In the future, ADS is planning to release a product that will utilize both of these technologies: an implanted GPS-enabled chip. Unlike VeriChip, though, the GPS-enabled implant would require Food and Drug Administration (FDA) approval, meaning the US market won't see its introduction until after FDA testing. Many organizations, ranging from privacy advocates to religious groups, have already denounced VeriChip and its eventually successors, associated them with "Big Brother" and the biblical "Mark of the Beast."To read about the eight people that received their implants, look at the first and second sites, articles from the Los Angeles Times and Miami Herald respectively. For a non-US perspective, view the news story posted by the British Broadcasting Company (BBC). The fourth site, an extensive analysis of the subject from ABC News, should give readers a broader understanding of implanted chips and their potential uses. Two sites from ADS are next -- VeriChip's product pages and the press release that details a FDA's decision regarding VeriChip in April, 2002. Finally, the last two sites give more information on Digital Angel and a sample of GPS technology already in use.

  8. Health Improvement Program http://hip.stanford.edu HIP Interest Story Dana Forks

    E-print Network

    Sonnenburg, Justin L.

    Health Improvement Program http://hip.stanford.edu HIP Interest Story ­ Dana Forks Alternative by Administrative Associate Dana Forks on her pedometer. Dana takes the Dumbarton Express stress related to finding parking or being in traffic. Dana writes, "I

  9. In-vivo degradation of poly(carbonate-urethane) based spine implants

    PubMed Central

    Cipriani, E.; Bracco, P.; Kurtz, S.M.; Costa, L.; Zanetti, M.

    2013-01-01

    Fourteen explanted Dynesys® spinal devices were analyzed for biostability and compared with a reference, never implanted, control. Both poly(carbonate-urethane) (PCU) spacers and polyethylene-terephthalate (PET) cords were analyzed. The effect of implantation was evaluated through the observation of physical alterations of the device surfaces, evaluation of the chemical degradation and fluids absorption on the devices and examination of the morphological and mechanical features. PCU spacers exhibited a variety of surface damage mechanisms, the most significant being abrasion and localized, microscopic surface cracks. Evidence of oxidation and chain scission were detected on PCU spacers ATR–FTIR. ATR–FTIR, DSC and hardness measurements also showed a slight heterogeneity in the composition of PCU. The extraction carried out on the PCU spacers revealed the presence of extractable polycarbonate segments. One spacer and all PET cords visually exhibited the presence of adherent biological material (proteins), confirmed by the ATR–FTIR results. GC/MS analyses of the extracts from PET cords revealed the presence of biological fluids residues, mainly cholesterol derivatives and fatty acids, probably trapped into the fiber network. No further chemical alterations were observed on the PET cords. Although the observed physical and chemical damage can be considered superficial, greater attention must be paid to the chemical degradation mechanisms of PCU and to the effect of byproducts on the body. PMID:24043907

  10. Clinical and radiological outcome of the treatment of osteonecrosis of the femoral head using the osteonecrosis intervention implant.

    PubMed

    Floerkemeier, Thilo; Thorey, Fritz; Daentzer, Dorothea; Lerch, Matthias; Klages, Phillip; Windhagen, Henning; von Lewinski, Gabriela

    2011-04-01

    The aim of this study was to evaluate the clinical and radiological outcome of the treatment of osteonecrosis of the femoral head by implantation of an osteonecrosis intervention rod. In this retrospective study the follow-up of 19 patients with 23 osteonecrotic femoral heads treated with implantation of an osteonecrosis intervention implant was assessed. From 19 patients with 23 necrotic femoral heads, there were 13 cases in which a total hip replacement was necessary. This implies a survival rate of 44% after implantation of an osteonecrosis intervention rod after a mean follow-up of 1.45 years. The outcome after core decompression combined with the insertion of a tantalum osteonecrosis intervention implant did not show superior results compared to core decompression alone. This is in contrast to existing studies. In addition, this study showed that in cases of total hip replacement, no problems appeared during explantation of the tantalum rod. PMID:20119747

  11. Metabolic Pattern of Asymptomatic Hip-Prosthesis by 18F-FDG-Positron-Emission-Tomography

    PubMed Central

    Beslic, Nermina; Heber, Daniel; Walter Lipp, Rainer; Sonneck-Koenne, Charlotte; Knoll, Peter; Mirzaei, Siroos

    2015-01-01

    Background: Joint replacement is a procedure with a major impact on the quality of life of patients with joint degenerative disease or traumatic injuries. However, some patients develop symptoms after the intervention caused by mechanical loosening or infection. Metabolic imaging by 18F-FDG-PET investigated in these patients isoften hampered by low specificity for diagnosis of possible septic vs. mechanical loosening. The reason for this shortcoming is to our opinion the unawareness of physiological remodeling processes that could be seen in asymptomatic patients. Objectives: In order to overcome this drawback, we aimed to find out the physiological metabolic functional pattern in asymptomatic patients with implanted hip prosthesis Patients and Methods: Twelve patients (6 males, 6 females); mean age 73 ± 7 (range 58 - 91) years were prospectively enrolled in the study. The patients were admitted to our department for oncological referral with implanted hip prostheses. All patients explained no symptoms with regard to their implanted prosthesis. The attenuation corrected images were used for analysis. Results: Fourteen hip prostheses in 12 patients were visually analyzed. Seven out of 14 prostheses among 12 patients showed focal periprosthetic enhanced metabolism, two of which showed two sites of enhanced uptake; whereas, the remaining five prostheses showed singular hypermetabolic areas within the periprosthetic site. The remaining seven prostheses in the other five patients showed no periprosthetic-enhanced uptake. Conclusion: Of the asymptomatic patients investigated, 58% showed focal enhanced periprosthetic glucose metabolism. This finding should be taken into consideration as a more probable unspecific metabolic pattern for correct interpretation of 18F-FDG-PET studies in patients with suspected septic loosening of the hip prosthesis. PMID:25793083

  12. A comprehensive review of hip labral tears

    Microsoft Academic Search

    Megan M. Groh; Joseph Herrera

    2009-01-01

    The hip labrum has many functions, including shock absorption, joint lubrication, pressure distribution, and aiding in stability,\\u000a with damage to the labrum associated with osteoarthritis. The etiology of labral tears includes trauma, femoroacetabular impingement\\u000a (FAI), capsular laxity\\/hip hypermobility, dysplasia, and degeneration. Labral tears present with anterior hip or groin pain,\\u000a and less commonly buttock pain. Frequently, there are also mechanical

  13. Wear and corrosion of sliding counterparts of stainless-steel hip screw-plates.

    PubMed

    Shahgaldi, B F; Compson, J

    2000-03-01

    Wear of the lag screw and barrel of stainless-steel sliding hip screw-plates (SHSP) produces particles and corrosion that jam the sliding screw. This alters the mechanics of the SHSP causing failure and difficulty in removal. We examined 15 surgically-removed SHSP for the extent of wear and corrosion of metal, and damage to the surrounding tissue. SHSP implants were in place from 2 months to 11 years (average 38.9 months) and they were removed because of fracture non-union, implant fracture or pain. None was infected. Electron microscopy was used to examine the implant surfaces and to determine the chemistry of corrosion products both on the metal and in the tissue. The distal ends of all the lag screws and inside walls of the barrels showed wear and corrosion. The severity of corrosion increased with increasing duration of implant use. Surfaces of the inside walls of the barrels were rough from the manufacturing process. This had contributed to wear. Better manufacturing practice to improve surface smoothness of the lag screws and inside wall of the barrels is needed. Use of cobalt-chromium alloys would improve hardness and resistance to corrosion compared with the stainless steel presently used, which would be an advantage for sliding hip screw-plates in younger patients. Deliberate texturing of screws is counter productive and should be avoided. PMID:10748810

  14. Investigation on stick phenomena in metal-on-metal hip joints after resting periods.

    PubMed

    Wimmer, M A; Nassutt, R; Sprecher, C; Loos, J; Täger, G; Fischer, A

    2006-02-01

    Insufficient understanding of tribological behaviour in total joint arthroplasty is considered as one of the reasons for prosthesis failure. Contrary to the continuous motion input profiles of hip simulators, human locomotion contains motion interruptions. These occurring resting periods can cause stick phenomena in metal-on-metal hip joints. The aim of the present study was to investigate the tribological sensitivity of all-metal bearings to motion interruptions on in vitro test specimens and retrieved implants. Friction and wear with and without resting periods were quantified. Unlike the metal-on-polyethylene joints, the static friction of metal-on-metal joints increased up to micros = 0.3 with rest, while wear appeared to be unaffected. This effect is caused by the interlocking of firmly adhered carbon layers, which were generated from the protein-containing lubricant through tribochemical reactions. Since more than 80 per cent of the retrieved implants exhibited macroscopically visible carbon layers, the increase in friction presumably also occurs under physiological conditions, which is then transferred to the bone-implant interface. These recurrent tangential stress peaks should be considered for the design features of the cup-bone interface, in particular when larger-sized implant heads are used. PMID:16669389

  15. The compression-rotation stem: an experimental study on the primary stability of a new revision hip stem.

    PubMed

    Kraenzlein, J; Mazoochian, F; Fottner, A; Birkenmaier, C; von Schulze Pellengahr, C; Jansson, V

    2009-01-01

    In revision hip arthroplasty with bone defects of the proximal femur, a well-established treatment method is reconstruction with impacted allograft spongiosa chips and cemented implantation of a polished stem. Building on this principle of impacted bone grafting, a femoral implant, which is suited to uncemented hip arthroplasty as well as for uncemented revisions, was designed. This so-called compression-rotation stem (CR stem) is collarless and has flanks which compress the impacted bone chips during implantation and thereby increase the rotational stability. To evaluate the primary stability of this new shaft after impaction grafting, the micromotion was determined using six motion transducers. Under physiological loading conditions with simulation of the muscle activities at the proximal femur the application was dynamically loaded for 15,000 cycles with 1000 +/- 500 N and afterwards for 5000 cycles with 1300 +/- 1000 N. Uncemented CR stems and the control Exeter stems were implanted in a standardized manner according to the X-Change method. Therefore they were implanted into artificial femora that had been previously resected, hollowed, and filled with impacted human spongeous bone allograft to simulate bone defects. Subsequently, the femora were loaded under identical conditions and the micromotions measured. In the majority of the implantations, no significant differences could be found. In conclusion, similar clinical results for the two stems should be expected. PMID:19239066

  16. Life Estimation of Hip Joint Prosthesis

    NASA Astrophysics Data System (ADS)

    Desai, C.; Hirani, H.; Chawla, A.

    2014-11-01

    Hip joint is one of the largest weight-bearing structures in the human body. In the event of a failure of the natural hip joint, it is replaced with an artificial hip joint, known as hip joint prosthesis. The design of hip joint prosthesis must be such so as to resist fatigue failure of hip joint stem as well as bone cement, and minimize wear caused by sliding present between its head and socket. In the present paper an attempt is made to consider both fatigue and wear effects simultaneously in estimating functional-life of the hip joint prosthesis. The finite element modeling of hip joint prosthesis using HyperMesh™ (version 9) has been reported. The static analysis (load due to the dead weight of the body) and dynamic analysis (load due to walking cycle) have been described. Fatigue life is estimated by using the S-N curve of individual materials. To account for progressive wear of hip joint prosthesis, Archard's wear law, modifications in socket geometry and dynamic analysis have been used in a sequential manner. Using such sequential programming reduction in peak stress has been observed with increase in wear. Finally life is estimated on the basis of socket wear.

  17. 21 CFR 888.3380 - Hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis. 888...femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis. ...femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented...

  18. 21 CFR 888.3380 - Hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis. 888...femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis. ...femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented...

  19. 21 CFR 888.3380 - Hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis. 888...femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis. ...femoral (hemi-hip) trunnion-bearing metal/ polyacetal cemented...

  20. 21 CFR 888.3380 - Hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis. 888...femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis. ...femoral (hemi-hip) trunnion-bearing metal/ polyacetal cemented...

  1. Biomechanics of Lateral Interbody Spacers: Going Wider for Going Stiffer

    PubMed Central

    Pimenta, Luiz; Turner, Alexander W. L.; Dooley, Zachary A.; Parikh, Rachit D.; Peterson, Mark D.

    2012-01-01

    This study investigates the biomechanical stability of a large interbody spacer inserted by a lateral approach and compares the biomechanical differences with the more conventional transforaminal interbody fusion (TLIF), with and without supplemental pedicle screw (PS) fixation. Twenty-four L2-L3 functional spinal units (FSUs) were tested with three interbody cage options: (i) 18?mm XLIF cage, (ii) 26?mm XLIF cage, and (iii) 11?mm TLIF cage. Each spacer was tested without supplemental fixation, and with unilateral and bilateral PS fixation. Specimens were subjected to multidirectional nondestructive flexibility tests to 7.5?N·m. The range of motion (ROM) differences were first examined within the same group (per cage) using repeated-measures ANOVA, and then compared between cage groups. The 26?mm XLIF cage provided greater stability than the 18?mm XLIF cage with unilateral PS and 11?mm TLIF cage with bilateral PS. The 18?mm XLIF cage with unilateral PS provided greater stability than the 11?mm TLIF cage with bilateral PS. This study suggests that wider lateral spacers are biomechanically stable and offer the option to be used with less or even no supplemental fixation for interbody lumbar fusion. PMID:23213284

  2. Countrywise results of total hip replacement

    PubMed Central

    2014-01-01

    Background and purpose An earlier Nordic Arthroplasty Register Association (NARA) report on 280,201 total hip replacements (THRs) based on data from 1995–2006, from Sweden, Norway, and Denmark, was published in 2009. The present study assessed THR survival according to country, based on the NARA database with the Finnish data included. Material and methods 438,733 THRs performed during the period 1995–2011 in Sweden, Denmark, Norway, and Finland were included. Kaplan-Meier survival analysis was used to calculate survival probabilities with 95% confidence interval (CI). Cox multiple regression, with adjustment for age, sex, and diagnosis, was used to analyze implant survival with revision for any reason as endpoint. Results The 15-year survival, with any revision as an endpoint, for all THRs was 86% (CI: 85.7–86.9) in Denmark, 88% (CI: 87.6–88.3) in Sweden, 87% (CI: 86.4–87.4) in Norway, and 84% (CI: 82.9–84.1) in Finland. Revision risk for all THRs was less in Sweden than in the 3 other countries during the first 5 years. However, revision risk for uncemented THR was less in Denmark than in Sweden during the sixth (HR = 0.53, CI: 0.34–0.82), seventh (HR = 0.60, CI: 0.37–0.97), and ninth (HR = 0.59, CI: 0.36–0.98) year of follow-up. Interpretation The differences in THR survival rates were considerable, with inferior results in Finland. Brand-level comparison of THRs in Nordic countries will be required. PMID:24650019

  3. Do revision total hip augments provide appropriate modularity?

    PubMed Central

    Teeter, Matthew G.; Naudie, Douglas D. R.; Howard, James L.; McCalden, Richard W.; MacDonald, Steven J.

    2015-01-01

    Background Porous metal acetabular augments have become widely used to fill bony defects in patients undergoing revision total hip arthroplasty. The objective of this study was to determine whether the currently offered size range of the augments is appropriate for surgical needs. Methods We reviewed the cases of all patients at 1 centre with a porous revision shell, and when an augment was used we recorded the patient and implant characteristics. Results We reviewed the cases of 281 patients, and augments were used in 24. Augment diameter was skewed toward the small end (p < 0.001), although thickness was not (p = 0.05); 21 of 24 augments were those with the smallest 3 diameters and thicknesses. Conclusion Given the sizes used, the full range of inventory provided by the manufacturer may be unnecessary, as surgeons will likely attempt a larger shell before a larger augment. PMID:25621911

  4. Acetabular fractures: the role of total hip replacement.

    PubMed

    Sierra, R J; Mabry, T M; Sems, S A; Berry, D J

    2013-11-01

    Total hip replacement (THR) after acetabular fracture presents unique challenges to the orthopaedic surgeon. The majority of patients can be treated with a standard THR, resulting in a very reasonable outcome. Technical challenges however include infection, residual pelvic deformity, acetabular bone loss with ununited fractures, osteonecrosis of bone fragments, retained metalwork, heterotopic ossification, dealing with the sciatic nerve, and the difficulties of obtaining long-term acetabular component fixation. Indications for an acute THR include young patients with both femoral head and acetabular involvement with severe comminution that cannot be reconstructed, and the elderly, with severe bony comminution. The outcomes of THR for established post-traumatic arthritis include excellent pain relief and functional improvements. The use of modern implants and alternative bearing surfaces should improve outcomes further. PMID:24187344

  5. Total Hip Arthroplasty Using a Short-Stemmed Femoral Component in the Presence of a Long Dynamic Condylar Screw Osteosynthesis Plate

    PubMed Central

    Buttaro, Martin; Piuzzi, Nicolas; Comba, Fernando; Zanotti, Gerardo; Piccaluga, Francisco

    2014-01-01

    We present a potential indication of a short-stemmed femoral component in a patient with multiple comorbidities presenting with hip posttraumatic osteoarthritis and a long dynamic condylar screw osteosynthesis plate. Removal of the plate and implantation of a long stem would have been related to a much longer operative time and potential local or systemic complications. PMID:25349758

  6. Development of a carbon-carbon hip prosthesis.

    PubMed

    Christel, P; Meunier, A; Leclercq, S; Bouquet, P; Buttazzoni, B

    1987-08-01

    This article deals with the use of carbon-fiber-reinforced-carbon materials for the manufacture of hip prosthesis stems. It considers the manufacturing process of carbon-carbon (C-C) composites made of carbon fibers infiltrated either with dense pyrolytic carbon or silicon carbide (SiC) through chemical vapor infiltration. The chemicophysical properties of these composites are examined according to their structures. The long-term response (2 years) of cortical bone to various types of carbon-carbon was evaluated mainly for bone contact and ingrowth. Carbon-carbon coated with calcium phosphate was found to speed up the bone formation as compared to pyrolytic carbon or SiC coatings. The low modulus of elasticity of the C-C materials could be responsible for quicker bone contact as compared to a much stiffer material like sintered aluminum oxide. The biomechanical performance of C-C hip stems was assessed through (a) implantations into cadaver femurs, (b) fatigue testing, and (c) finite element analysis. These tests showed: (a) a better stress transfer as compared to a metal prosthesis having the same design, (b) no fatigue damage, (c) a computerized stem stress distribution in accordance with the fractures obtained during static mechanical testing. PMID:3624286

  7. Early failure of articular surface replacement XL total hip arthroplasty.

    PubMed

    Steele, Garen D; Fehring, Thomas K; Odum, Susan M; Dennos, Anne C; Nadaud, Matthew C

    2011-09-01

    The ASR (articular surface replacement) XL (DePuy, Warsaw, Ind) metal-on-metal hip arthroplasty offers the advantage of stability and increased motion. However, an alarming number of early failures prompted the evaluation of patients treated with this system. A prospective study of patients who underwent arthroplasty with the ASR XL system was performed. Patients with 2-year follow-up or any revision were included. Failure rates, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores, and radiographs were evaluated. Ninety-five patients (105 hips) were included. There were 16 revisions. Thirteen (12%) were aseptic acetabular failures. Eight were revised for aseptic loosening; 4, for metallosis; 1, for malposition; 2, for infection; and 1, for periprosthetic fracture. Mean time to revision was 1.6 years (0.18-3.4 years). The ASR XL with a revision rate of 12% is the second reported 1 piece metal-on-metal system with a significant failure rate at early follow-up. This particular class of implants has inherent design flaws that lead to early failure. PMID:21550764

  8. The Minimally Invasive Anterolateral Approach Combined with Hip Onlay Resurfacing

    Microsoft Academic Search

    Ludger Gerdesmeyer; Hans Gollwitzer; Peter Diehl; Björn Buttgereit; Maximilian Rudert

    2009-01-01

    \\u000a Abstract\\u000a \\u000a \\u000a Objective\\u000a   Minimally invasive anterolateral approach in hip resurfacing with complete preservation of muscular integrity.\\u000a \\u000a \\u000a \\u000a \\u000a Indications\\u000a   Primary or secondary osteoarthritis of the hip.\\u000a \\u000a \\u000a \\u000a \\u000a Contraindications\\u000a   Approach:\\u000a \\u000a – None.\\u000a \\u000a \\u000a Onlay implant:\\u000a \\u000a \\u000a – Females > 55 years with osteoporosis.\\u000a \\u000a \\u000a – Males > 60 years with osteoporosis.\\u000a \\u000a \\u000a – Severe varus deformity (CCD [collodiaphyseal] angle \\u000a \\u000a \\u000a – History of metal allergy.\\u000a \\u000a \\u000a – Clinically relevant renal insufficiency.

  9. Microbiologic Diagnosis of Prosthetic Shoulder Infection by Use of Implant Sonication

    Microsoft Academic Search

    Melissa J. Jacobson; Robert H. Cofield; John W. Sperling; Joaquin Sanchez-Sotelo; Douglas R. Osmon; Andrew McDowell; Sheila Patrick; James M. Steckelberg; Jayawant N. Mandrekar; Marta Fernandez Sampedro; Robin Patel

    2010-01-01

    We recently described a sonication technique for the diagnosis of prosthetic knee and hip infections. We compared periprosthetic tissue culture to implant sonication followed by sonicate fluid culture for the diag- nosis of prosthetic shoulder infection. One hundred thirty-six patients undergoing arthroplasty revision or resection were studied; 33 had definite prosthetic shoulder infections and 2 had probable prosthetic shoulder infections.

  10. Alternative process for thin layer etching: Application to nitride spacer etching stopping on silicon germanium

    SciTech Connect

    Posseme, N., E-mail: nicolas.posseme@cea.fr; Pollet, O.; Barnola, S. [CEA-LETI-Minatec, 17 rue des martyrs, 38054 Grenoble cedex 09 (France)

    2014-08-04

    Silicon nitride spacer etching realization is considered today as one of the most challenging of the etch process for the new devices realization. For this step, the atomic etch precision to stop on silicon or silicon germanium with a perfect anisotropy (no foot formation) is required. The situation is that none of the current plasma technologies can meet all these requirements. To overcome these issues and meet the highly complex requirements imposed by device fabrication processes, we recently proposed an alternative etching process to the current plasma etch chemistries. This process is based on thin film modification by light ions implantation followed by a selective removal of the modified layer with respect to the non-modified material. In this Letter, we demonstrate the benefit of this alternative etch method in term of film damage control (silicon germanium recess obtained is less than 6?A), anisotropy (no foot formation), and its compatibility with other integration steps like epitaxial. The etch mechanisms of this approach are also addressed.

  11. Alternative process for thin layer etching: Application to nitride spacer etching stopping on silicon germanium

    NASA Astrophysics Data System (ADS)

    Posseme, N.; Pollet, O.; Barnola, S.

    2014-08-01

    Silicon nitride spacer etching realization is considered today as one of the most challenging of the etch process for the new devices realization. For this step, the atomic etch precision to stop on silicon or silicon germanium with a perfect anisotropy (no foot formation) is required. The situation is that none of the current plasma technologies can meet all these requirements. To overcome these issues and meet the highly complex requirements imposed by device fabrication processes, we recently proposed an alternative etching process to the current plasma etch chemistries. This process is based on thin film modification by light ions implantation followed by a selective removal of the modified layer with respect to the non-modified material. In this Letter, we demonstrate the benefit of this alternative etch method in term of film damage control (silicon germanium recess obtained is less than 6 A), anisotropy (no foot formation), and its compatibility with other integration steps like epitaxial. The etch mechanisms of this approach are also addressed.

  12. Death, Debility, and Destitution Following Hip Fracture

    PubMed Central

    2014-01-01

    Background. We examined the effects of hip fracture on mortality, entry into long-term institutional care, and new evidence of poverty. We estimate of the proportion of hip fracture patients who require not just short-term rehabilitation but who become dependent on long-term institutional care, and the risk of becoming newly dependent on Medicaid or eligible for low-income subsidies following hip fracture. Methods. We used data from 2005 through 2010 for a random 5% sample of Medicare beneficiaries (N = 3.1 million) to conduct a retrospective matched cohort study. We used high-dimensional propensity score matching to compare outcomes for patients who experienced a hip fracture with subjects who did not, but had similar propensity for suffering a hip fracture. We then compared the 1-year risk of death, debility, and destitution between groups. Results. We matched 43,210 hip fracture patients to comparators without a hip fracture. Hip fractures were associated with more than a twofold increase in likelihood of mortality (incidence proportion ratio [IPR] of 2.27, 95% CI, 2.20–2.34), a fourfold increase in likelihood of requiring long-term nursing facility care (IPR, 3.96; 95% CI, 3.77–4.16), and a twofold increase in the probability of entering into low-income status (IPR, 2.14; 95% CI 1.99–2.31) within 1 year following hip fracture compared with subjects without a hip fracture. Conclusions. Hip fracture in elderly patients resulted in increased death, debility, and destitution. Initiatives that lead to improved treatment of osteoporosis could result in a decrease in incidence of fractures, subsequent death, debility, and destitution for older adults. PMID:23873945

  13. Tribolayer Formation in a Metal-on-Metal (MoM) Hip Joint: An Electrochemical Investigation

    PubMed Central

    Mathew, MT; Nagelli, C; Pourzal, R; Fischer, A; Laurent, MP; Jacobs, JJ; Wimmer, MA

    2013-01-01

    The demand for total hip replacement (THR) surgery is increasing in the younger population due to faster rehabilitation and more complete restoration of function. Up to 2009, metal-on-metal (MoM) hip joint bearings were a popular choice due to their design flexibility, post-operative stability and relatively low wear rates. The main wear mechanisms that occur along the bearing surface of MoM joints are tribochemical reactions that deposit a mixture of wear debris, metal ions and organic matrix of decomposed proteins known as a tribolayer. No in-depth electrochemical studies have been reported on the structure and characteristics of this tribolayer or about the parameters involved in its formation. In this study, we conducted an electrochemical investigation of different surfaces (bulk-like: control, nano-crystalline: new implant and tribolayer surface: retrieved implant) made out of two commonly used hip CoCrMo alloys (high-carbon and low-carbon). As per ASTM standard, cyclic polarization tests and electrochemical impedance spectroscopy tests were conducted. The results obtained from electrochemical parameters for different surfaces clearly indicated a reduction in corrosion for the tribolayer surface (Icorr: 0.76 ?A/cm2). Further, polarization resistance (Rp:2.39±0.60M?/cm2) and capacitance (Cdl:15.20±0.75 ?F/cm2) indicated variation in corrosion kinetics for the tribolayer surface, that attributed to its structure and stability in a simulated body environment. PMID:24099949

  14. Wear of the polyethylene acetabular cup. Metallic and ceramic heads compared in a hip simulator.

    PubMed

    Saikko, V O; Paavolainen, P O; Slätis, P

    1993-08-01

    Ultra-high molecular weight polyethylene acetabular cups of 5 different total hip systems (Müller, Mallory-Head, Lubinus, P.C.A. and Charnley-Elite) were worn on a new 5-station hip joint simulator. The cups articulated against modular metallic (stainless steel in Müller and Charnley-Elite, ion-implanted Ti-6Al-4V in Mallory-Head, and Co-Cr-Mo in Lubinus and P.C.A.) and modular alumina ceramic femoral heads for 3 million walking cycles. The mean wear rate of cups against alumina heads (range 0-5.7 mg/10(6) cycles, corresponding to 0-0.008 mm/year) was usually lower than against metallic heads (range 3.9-178 mg/10(6) cycles, corresponding to 0.005-0.24 mm/year). In the metal-head prostheses, the mean wear rate was highest against stainless steel heads, and lowest against ion-implanted Ti-6Al-4V heads. As the wear rates are compared with published clinical observations, it can be concluded that the hip joint simulator is capable of producing realistic wear rates; it is a useful instrument in the study of the wear behavior of new designs, materials, surface treatments and coatings prior to clinical trials. However, the taper-fit attachment of modular heads proved problematical, showing corrosion and wear at the conical head-spigot interface. PMID:8213114

  15. Impact of ZnO embedded feed spacer on biofilm development in membrane systems.

    PubMed

    Ronen, Avner; Semiat, Raphael; Dosoretz, Carlos G

    2013-11-01

    The concept of suppressing biofouling formation using an antibacterial feed spacer was investigated in a bench scale-cross flow system mimicking a spiral wound membrane configuration. An antibacterial composite spacer containing zinc oxide-nanoparticles was constructed by modification of a commercial polypropylene feed spacer using sonochemical deposition. The ability of the modified spacers to repress biofilm development on membranes was evaluated in flow-through cells simulating the flow conditions in commercial spiral wound modules. The experiments were performed at laminar flow (Re = 300) with a 200 kDa molecular weight cut off polysulfone ultrafiltration membrane using Pseudomonas putida S-12 as model biofilm bacteria. The modified spacers reduced permeate flux decrease at least by 50% compared to the unmodified spacers (control). The physical properties of the modified spacer and biofilm development were evaluated using high resolution/energy dispersive spectrometry-scanning electron microscopy, atomic force microscopy and confocal laser scanning microscopy imaging (HRSEM, EDS, AFM and CLSM). HRSEM images depicted significantly less bacteria attached to the membranes exposed to the modified spacer, mainly scattered and in a sporadic monolayer structure. AFM analysis indicated the influence of the modification on the spacer surface including a phase change on the upper surface. Dead-live staining assay by CLSM indicated that most of the bacterial cells attached on the membranes exposed to the modified spacer were dead in contrast to a developed biofilm which was predominant in the control samples. PMID:24079967

  16. Surgeons' knowledge about the costs of orthopaedic implants.

    PubMed

    Rohman, Lebur; Hadi, Saifullah; Whitwell, George

    2014-08-01

    PURPOSE. To investigate consultant surgeons' knowledge about the costs of implants for various joint surgeries. METHODS. Questionnaires were distributed to consultant orthopaedic surgeons at 2 hospitals. Respondents were asked to estimate the implant costs of any brand for low-demand and high-demand total hip replacement (THR), total knee replacement (TKR), uni-compartmental knee replacement, arthroscopy shaver blade, total anterior cruciate ligament (ACL) fixation, and meniscal repair. The actual cost of each implant was obtained from the manufacturer. RESULTS. 16 consultant surgeons completed the questionnaires. The respective mean estimated and actual costs for a low-demand THR implant were £1714 (range, £600-3000) and £1448 (range, £985- 2335), with an overestimation of 18.4%. The respective costs for a high-demand THR implant were £2172 (range, £600-6000) and £1737 (range, £1192-2335), with an overestimation of 25%. The respective costs for a TKR implant were £1550 (range, £600-6000) and £1316 (range, £995-1535), with an overestimation of 17.8%. The respective costs for a uni-compartmental knee replacement implant were £1040 (range, £600-2000) and £1296 (range, £698-1470), with an underestimation of 19.7%. The respective costs for an arthroscopy shaver blade were £110 (range, £75-150) and £94 (range, £80-100), with an overestimation of 16.6%. The respective costs for a total ACL fixation implant were £246 (range, £80-500) and £306 (range, £272-335), with an underestimation of 19.4%. The respective costs for a meniscal repair implant were £153 (range, £50-250) and £242 (range, £170-260), with an underestimation of 37%. CONCLUSION. The knowledge among consultant orthopaedic surgeons about implant costs was poor. To reduce implant costs, cooperation between surgeons and hospital managers and measures to increase surgeons' awareness about cost-reduction programmes are needed. PMID:25163960

  17. Hip Joint Replacement Using Monofilament Polypropylene Surgical Mesh: An Animal Model

    PubMed Central

    Bia?ecki, Jacek; Klimowicz-Bodys, Ma?gorzata Dorota; Wierzcho?, Edward; Ko?omecki, Krzysztof

    2014-01-01

    Hip joint dysplasia is a deformation of the articular elements (pelvic acetabulum, head of the femur, and/or ligament of the head of the femur) leading to laxity of the hip components and dislocation of the femoral head from the pelvic acetabulum. Diagnosis is based on symptoms observed during clinical and radiological examinations. There are two treatment options: conservative and surgical. The classic surgical procedures are juvenile pubic symphysiodesis (JPS), triple pelvic osteotomy (TPO), total hip replacement (THR), and femoral head and neck resection (FHNE). The aim of this experiment was to present an original technique of filling the acetabulum with a polypropylene implant, resting the femoral neck directly on the mesh. The experiment was performed on eight sheep. The clinical value of the new surgical technique was evaluated using clinical, radiological, and histological methods. This technique helps decrease the loss of limb length by supporting the femoral neck on the mesh equivalent to the femoral head. It also reduces joint pain and leads to the formation of stable and mobile pseudarthrosis. The mesh manifested osteoprotective properties and enabled the formation of a stiff-elastic connection within the hip joint. The method is very cost-effective and the technique itself is simple to perform. PMID:24987672

  18. Hip joint replacement using monofilament polypropylene surgical mesh: an animal model.

    PubMed

    Bia?ecki, Jacek; Majchrzycki, Marian; Szymczak, Antoni; Klimowicz-Bodys, Ma?gorzata Dorota; Wierzcho?, Edward; Ko?omecki, Krzysztof

    2014-01-01

    Hip joint dysplasia is a deformation of the articular elements (pelvic acetabulum, head of the femur, and/or ligament of the head of the femur) leading to laxity of the hip components and dislocation of the femoral head from the pelvic acetabulum. Diagnosis is based on symptoms observed during clinical and radiological examinations. There are two treatment options: conservative and surgical. The classic surgical procedures are juvenile pubic symphysiodesis (JPS), triple pelvic osteotomy (TPO), total hip replacement (THR), and femoral head and neck resection (FHNE). The aim of this experiment was to present an original technique of filling the acetabulum with a polypropylene implant, resting the femoral neck directly on the mesh. The experiment was performed on eight sheep. The clinical value of the new surgical technique was evaluated using clinical, radiological, and histological methods. This technique helps decrease the loss of limb length by supporting the femoral neck on the mesh equivalent to the femoral head. It also reduces joint pain and leads to the formation of stable and mobile pseudarthrosis. The mesh manifested osteoprotective properties and enabled the formation of a stiff-elastic connection within the hip joint. The method is very cost-effective and the technique itself is simple to perform. PMID:24987672

  19. Joint issues – conflicts of interest, the ASR hip and suggestions for managing surgical conflicts of interest

    PubMed Central

    2014-01-01

    Background Financial and nonfinancial conflicts of interest in medicine and surgery are troubling because they have the capacity to skew decision making in ways that might be detrimental to patient care and well-being. The recent case of the Articular Surface Replacement (ASR) hip provides a vivid illustration of the harmful effects of conflicts of interest in surgery. Discussion We identify financial and nonfinancial conflicts of interest experienced by surgeons, hospitals and regulators in the ASR case. These conflicts may have impacted surgical advice, decision-making and evidence gathering with respect to the ASR prosthesis, and contributed to the significant harms experienced by patients in whom the hip was implanted. Drawing on this case we explore shortcomings in the standard responses to conflicts of interest – disclosure and recusal. We argue disclosure is necessary but by no means sufficient to address conflicts of interest. Using the concept of recusal we develop remedies including second opinions and third party consent which may be effective in mitigating conflicts, but their implementation introduces new challenges. Summary Deployment of the ASR hip is a case of surgical innovation gone wrong. As we show, there were multiple conflicts of interest involved in the introduction of the ASR hip into practice and subsequent attempts to gloss over the mounting body of evidence about its lack of safety and effectiveness. Conflicts of interest in surgery are often not well managed. We suggest strategies in this paper which can minimise the conflicts of interest associated with surgical innovation. PMID:25128372

  20. Autologous Bone Marrow Mesenchymal Stem Cells Associated with Tantalum Rod Implantation and Vascularized Iliac Grafting for the Treatment of End-Stage Osteonecrosis of the Femoral Head

    PubMed Central

    Zhao, Dewei; Liu, Baoyi; Wang, Benjie; Yang, Lei; Xie, Hui; Huang, Shibo; Zhang, Yao; Wei, Xiaowei

    2015-01-01

    Tantalum rod implantation with vascularized iliac grafting has been reported to be an effective method for the treatment of young patients with osteonecrosis of the femoral head (ONFH) to avert the need for total hip arthroplasty (THA). However, there have been unsatisfactory success rates for end-stage ONFH. The authors describe a modified technique using bone marrow mesenchymal stem cells (BMMSCs) associated with porous tantalum rod implantation combined with vascularized iliac grafting for the treatment of end-stage ONFH. A total of 24 patients (31 hips) with end-stage ONFH were treated with surgery; ARCO IIIc stage was observed in 19 hips and ARCO IV stage was observed in 12 hips. All patients were followed for a mean time of 64.35?±?13.03 months (range 26–78). Operations on only five hips were converted to THA. The joint-preserving success rate of the entire group was 89.47% for ARCO stage IIIc and 75% for ARCO stage IV. The mean Harris hip score of the 31 hips improved significantly from 38.74?±?5.88 points (range 22–50) to 77.23?±?14.75 points (range 33–95). This intervention was safe and effective in delaying or avoiding total hip replacement for end-stage ONFH. PMID:25802840

  1. ImplantsHydroxylapatite coated dental implants

    Microsoft Academic Search

    Peter Briggs

    1999-01-01

    Objective To evaluate the clinical effectiveness, common complications and maintenance associated with hydroxylapatite (HA) coated cylindrical implants when used to support single crowns.Design A prospective medium term clinical study of the Calcitek HA-coated implant.Setting Implant placement, crown fabrication and follow-up procedures were carried out at the Leeds Dental Institute, between 1990 and 1998.Subjects and method 26 patients (33 implants) participated

  2. Birmingham hip resurfacing: the prevalence of failure.

    PubMed

    Carrothers, A D; Gilbert, R E; Jaiswal, A; Richardson, J B

    2010-10-01

    Despite the increasing interest and subsequent published literature on hip resurfacing arthroplasty, little is known about the prevalence of its complications and in particular the less common modes of failure. The aim of this study was to identify the prevalence of failure of hip resurfacing arthroplasty and to analyse the reasons for it. From a multi-surgeon series (141 surgeons) of 5000 Birmingham hip resurfacings we have analysed the modes, prevalence, gender differences and times to failure of any hip requiring revision. To date 182 hips have been revised (3.6%). The most common cause for revision was a fracture of the neck of the femur (54 hips, prevalence 1.1%), followed by loosening of the acetabular component (32 hips, 0.6%), collapse of the femoral head/avascular necrosis (30 hips, 0.6%), loosening of the femoral component (19 hips, 0.4%), infection (17 hips, 0.3%), pain with aseptic lymphocytic vascular and associated lesions (ALVAL)/metallosis (15 hips, 0.3%), loosening of both components (five hips, 0.1%), dislocation (five hips, 0.1%) and malposition of the acetabular component (three hips, 0.1%). In two cases the cause of failure was unknown. Comparing men with women, we found the prevalence of revision to be significantly higher in women (women = 5.7%; men = 2.6%, p < 0.001). When analysing the individual modes of failure women had significantly more revisions for loosening of the acetabular component, dislocation, infection and pain/ALVAL/metallosis (p < 0.001, p = 0.004, p = 0.008, p = 0.01 respectively). The mean time to failure was 2.9 years (0.003 to 11.0) for all causes, with revision for fracture of the neck of the femur occurring earlier than other causes (mean 1.5 years, 0.02 to 11.0). There was a significantly shorter time to failure in men (mean 2.1 years, 0.4 to 8.7) compared with women (mean 3.6 years, 0.003 to 11.0) (p < 0.001). PMID:20884969

  3. Hip arthritis presenting as knee pain.

    PubMed

    Lam, Stephen; Amies, Victoria

    2015-01-01

    A 68-year-old man with a history of left total knee replacement presented to his general practitioner with left knee pain. He reported pain onset after a fall in the garden. An X-ray of the knee was arranged but showed no abnormality to explain the pain. He was treated with simple analgesia. However, he reattended with the same knee pain. A further X-ray of the knee was requested, but again showed no abnormality. On his fourth presentation in 6?months, a further musculoskeletal examination was undertaken. This time the hip was also examined and showed that maximal pain was in fact on rotation of the hip joint. A subsequent X-ray of the hip showed severe osteoarthritis of the left hip with complete joint space loss and flattening of the femoral head. The patient was referred to an orthopaedic surgeon for a left hip replacement. PMID:25697301

  4. Dermal burn during hip arthroscopy.

    PubMed

    Curtin, Brian; Friebe, Ilvy

    2014-08-01

    Radiofrequency devices are often used during arthroscopic surgery, most commonly of the shoulder and knee, and increasingly in hip arthroscopy. The most commonly described complication is elevation of joint temperature, leading to capsular shrinkage, chondrolysis, and nerve damage. A less commonly reported complication is that of dermal burns from the heated irrigation fluid. There are several case reports describing dermal burns after shoulder arthroscopy; however, to the authors' knowledge, there are none describing the complication in hip arthroscopy that is often performed by surgeons doing limited if any shoulder arthroscopy. The authors report this case to raise awareness that the use of radiofrequency devices can also lead to extra-articular complications because of the effect of elevated irrigant fluid temperatures on the patient's skin. Sufficiently high temperatures were generated inside the joint, causing a superficial second-degree burn from the outflow irrigant. In the course of instrument switching from sucker/shaver to radiofrequency wand, the outflow valve was inadvertently left open with no attached suction while the radiofrequency wand was in use. Most second-degree burns like the one reported require only conservative therapy with cool compresses to decrease the temperature of the wound. The authors did recommend bacitracin ointment to prevent superficial wound infection, however unlikely with no disruption of the skin. The authors continue to use radio-frequency devices in hip arthroscopy, but are vigilant to maintain dedicated suction at the outflow tubing throughout the procedure. Surgeons should take strict precautions to avoid this preventable complication and follow all manufacturer instructions on the use of such devices. PMID:25102513

  5. Pattern Alteration: Back Hip Fullness

    E-print Network

    2006-08-04

    the pattern to the side seamline at a right angle to the center back or grainline. From the side seam and waist seamline (or waistline mark intersection), draw a vertical line to the hem line and parallel to the center back or grainline (Figs. 9a and 9b... seamline at the hip. Clip the seam allowances at the end of the slashes. Decreasing for fl at buttocks 1. Lap the horizontal slash at the center back by the amount you need, tapering to the vertical slash. Tape the pattern in place. 2. Lap the vertical...

  6. HIP Joining of Cemented Carbides

    SciTech Connect

    Derby, B.; Miodownik, M.

    1999-04-01

    Hot Isostatic Pressing (HIP) is investigated as a technique for joining the cermet WC-15% Co to itself. Encapsulation of the specimens prior to HIPing was carried out using steel encapsulation, glass encapsulation and self encapsulation. The bonds were evaluated using a four point bend method. It is shown that the glass and steel encapsulation methods have a number of inherent problems which make them inappropriate for near net shape processing. In contrast the novel self encapsulation method, described for the first time in this communication, is both simple and effective, producing joined material with bulk strength. The concept of self encapsulation is potentially widely applicable for joining composite materials.

  7. On the validity of the results from the Swedish National Total Hip Arthroplasty register.

    PubMed

    Söderman, P

    2000-12-01

    The Swedish National Total Hip Arthroplasty Register contains more than 200,000 primary and secondary hip replacements. The failure end-point definition is revision. The aim of this thesis was to validate the results presented by the register and to study the outcome of hip replacement surgery in Sweden. The hypothesis was firstly that the number of failure reported to the Swedish THA register are valid and secondly that adding clinical and radiographic failure criteria will dramatically decrease the survival rate for THR implants. The study consisted of three parts with 2-10 years follow-up of patients with total hip replacements (THR). In part I, three general health questionnaires (Nottingham Health Profile, SF-36, EuroQol) and two disease-specific instruments (WOMAC, Harris Hip Score) were tested for validity and reliability (n = 62). The results showed the disease specific questionnaires are at least as valid and reliable as the general instruments are. In part II, all THRs reported to the Swedish THA register 1986 to 1994 (84,884 primary and 10,176 revision hip replacements) were compared with the data from the Discharge register and the Cause of Death register in Sweden. 2,604 patients were randomly selected from the Discharge register to determine if they had undergone any revision surgery. The study showed that the Swedish THA register covers 94% of the revisions actually performed in Sweden and the results did not differ significantly from the data in the Discharge register and the results reported by the patients. In part III, 1,056 patients from the selected cohort were studied further concerning general health and disease-specific health, using the Nottingham Health Profile, SF-36 and WOMAC. An age and gender matched subcohort of 344 patients were then examined clinically, using the Harris Hip Score, and radiographically. The clinical and radiographic failure rates were in several tests as high as the revision rates documented in the Swedish THA register. The clinical results were, however, dependent on demographics, the definition of clinical failure and the scoring system used. The results presented by the register with revision as failure end-point give an exact but limited information about the quality of hip replacement surgery in Sweden. PMID:11138472

  8. Metal on metal total hip arthroplasty and a large groin mass: Not always adverse reaction to metallic debris

    PubMed Central

    Krishnan, Harry; Magnussen, Alex; Sharma, Aadhar; Skinner, John

    2014-01-01

    Due to their improved wear rates, Metal-on-metal bearings have been increasingly used in the past decade by orthopaedic surgeons carrying out total hip arthroplasty. However there is increasing evidence that there are significant complications associated with such implants. One well documented complication is that of metallic debris leading to pseudotumour formation, however there is less known about associations with other tumours within the pelvis. We present two cases where an intra-pelvic mass in patients with metal-on-metal implants were diagnosed as being of a different aetiology. This highlights the need for careful assessment of such patients in order to guide appropriate management. PMID:25560054

  9. Reconstruction of the Acetabulum in Developmental Dysplasia of the Hip in total hip replacement

    PubMed Central

    Sakellariou, Vasileios I.; Christodoulou, Michael; Sasalos, Gregory; Babis, George C.

    2014-01-01

    Developmental dysplasia of the hip (DDH) or congenital hip dysplasia (CDH) is the most prevalent developmental childhood hip disorder. It includes a wide spectrum of hip abnormalities ranging from dysplasia to subluxation and complete dislocation of the hip joint. The natural history of neglected DDH in adults is highly variable. The mean age of onset of symptoms is 34.5 years for dysplastic DDH, 32.5 years for low dislocation, 31.2 years for high dislocation with a false acetabulum, and 46.4 years for high dislocation without a false acetabulum. Thorough understanding of the bony and soft tissue deformities induced by dysplasia is crucial for the success of total hip arthroplasty. It is important to evaluate the existing acetabular deformity three-dimensionally, and customize the correction in accordance with the quantity and location of ace tabular deficiencies. Acetabular reconstruction in patients with DDH is challenging. Interpretation of published data is difficult and should be done with caution because most series include patients with different types of hip disease. In general, the complication rate associated with THA is higher in patients with hip dysplasia than it is in patients with osteoarthritis. Overall, clinical and functional outcomes following THA in patients hip dysplasia (DDH) differ from those treated for primary hip osteoarthritis, possibly due to the lower age and level of activity. Although function scores decline with age, the scores for pain and range of motion presented with a statistically significant improvement in the long-term. PMID:25386570

  10. The effects on bone cells of metal ions released from orthopaedic implants. A review

    PubMed Central

    Sansone, Valerio; Pagani, Davide; Melato, Marco

    2013-01-01

    Summary The increasing use of orthopedic implants and, in particular, of hip and knee joint replacements for young and active patients, has stimulated interest and concern regarding the chronic, long-term effects of the materials used. This review focuses on the current knowledge of the adverse biologic reactions to metal particles released from orthopaedic implants in vivo and in vitro. More specifically, the purpose of this article is to provide an overview of the current literature about the adverse effects of metal particles on bone cells and peri-implant bone. PMID:23858309

  11. Empirical and Computational Pressure Drop Correlations for Pressurized Water Reactor Fuel Spacer Grids

    SciTech Connect

    In, Wang Kee; Oh, Dong Seok; Chun, Tae Hyun [Korea Atomic Energy Research Institute (Korea, Republic of)

    2002-07-15

    Empirical and computational pressure drop correlations were developed to accurately estimate the pressure drop at the fuel spacer grid in a pressurized water reactor. The empirical correlation uses the balance of hydraulic forces acting on the spacer grid. The amount of pressure drop is assumed to depend largely on the reduction of the flow cross section, the flow constriction in the spacer region, and the frictional loss. The grid form drag due to the relative plugging and the flow constriction by the grid components were found to be the primary factors of the total pressure drop. The computational correlation combines the pressure drop due to flow blockage by the spacer grid and the pressure drop calculated by dynamics analysis. The pressure loss coefficients from the empirical correlation agree well with the measured ones for the spacer grids with and without the mixing vane. The computational correlation overpredicts the pressure loss coefficients for the spacer grid with the mixing vane.

  12. An insulating grid spacer for large-area MICROMEGAS chambers

    E-print Network

    Bernard, D; D'Enterria, D G; Le Guay, M; Martínez, G; Mora, M J; Pichot, P; Roy, D; Schutz, Y; Gandi, A; De Oliveira, R

    2002-01-01

    We present an original design for large area gaseous detectors based on the MICROMEGAS technology. This technology incorporates an insulating grid, sandwiched between the micro-mesh and the anode-pad plane, which provides an uniform 200 $\\mu$m amplification gap. The uniformity of the amplification gap thickness has been verified under several experimental conditions. The gain performances of the detector are presented and compared to the values obtained with detectors using cylindrical micro spacers. The new design presents several technical and financial advantages.

  13. Influence of head size on the development of metallic wear and on the characteristics of carbon layers in metal-on-metal hip joints

    PubMed Central

    Sprecher, Christoph M; Wimmer, Markus A; Milz, Stefan; Taeger, Georg

    2009-01-01

    Background and purpose Particles originating from the articulating surfaces of hip endoprostheses often induce an inflammatory response, which can be related to implant failure. We therefore analyzed the metal content in capsular tissue from 44 McKee-Farrar metal-on-metal hip prostheses (with 3 different head sizes) and we also analyzed the morphological structure of layers located on articulating surfaces. Methods Atomic absorption spectrometry (AAS) was used to analyze the metal content in capsular tissue. Visually detectable carbon layers located on the articulating surfaces were evaluated using scanning electron microscopy (SEM), energy-dispersive Xray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS). Results Metallic debris was detected in all capsular tissue samples but no statistically significant differences in metal content were found in relation to implant head size. The morphological characteristics of the different layer zones allowed an exact analysis of contact and non-contact areas. Furthermore, surface layers appear to have a protective function because they can prevent sharp-edged particles from damaging the prostheses surface. Interpretation The implant head size does not appear to influence the amount of metallic debris. The layers obviously act like a lubricating agent because the protection function does not occur in regions without layers where the metal surface often shows numerous scratches. As layers are not generated immediately after the implantation of hip prostheses, these findings may at least partially explain the high amount of wear early after implantation. PMID:19421914

  14. On the matter of synovial fluid lubrication: implications for Metal-on-Metal hip tribology.

    PubMed

    Myant, Connor; Cann, Philippa

    2014-06-01

    Artificial articular joints present an interesting, and difficult, tribological problem. These bearing contacts undergo complex transient loading and multi axes kinematic cycles, over extremely long periods of time (>10 years). Despite extensive research, wear of the bearing surfaces, particularly metal-metal hips, remains a major problem. Comparatively little is known about the prevailing lubrication mechanism in artificial joints which is a serious gap in our knowledge as this determines film formation and hence wear. In this paper we review the accepted lubrication models for artificial hips and present a new concept to explain film formation with synovial fluid. This model, recently proposed by the authors, suggests that interfacial film formation is determined by rheological changes local to the contact and is driven by aggregation of synovial fluid proteins. The implications of this new mechanism for the tribological performance of new implant designs and the effect of patient synovial fluid properties are discussed. PMID:24462265

  15. Catastrophic failure of a metal-on-metal total hip arthroplasty secondary to metal inlay dissociation.

    PubMed

    Alaia, Michael J; Dayan, Alan J

    2011-09-01

    Metal-on-metal bearing surfaces in total hip arthroplasty have been recently shown to have acceptable survivorship properties (J Bone Joint Surg Am. 2006;88:1183; J Bone Joint Surg Am. 2006;88:1173), and they have certain advantages and disadvantages when compared to conventional metal-on-polyethylene bearing surfaces. Like traditional metal-on-polyethylene bearings, these metal-on-metal implants may also suffer from catastrophic failure. This case report represents an unusual situation in a 57-year-old man in which dissociation of a metal inlay in a metal-on-metal total hip arthroplasty resulted in articulation of the inferior aspect of the inlay with the femoral neck, leading to femoral neck notching, extensive periprosthetic soft tissue metallosis, osteolysis, and subsequent prosthetic catastrophic failure. PMID:20875944

  16. The neuromuscularly challenged patient: total hip replacement is now an option.

    PubMed

    Kraay, M J; Bigach, S D

    2014-11-01

    Degenerative problems of the hip in patients with childhood and adult onset neuromuscular disorders can be challenging to treat. Many orthopaedic surgeons are reluctant to recommend total hip replacement (THR) for patients with underlying neuromuscular disorders due to the perceived increased risks of dislocation, implant loosening, and lack of information about the functional outcomes and potential benefits of these procedures in these patients. Modular femoral components and alternative bearings which facilitate the use of large femoral heads, constrained acetabular components and perhaps more importantly, a better understanding about the complications and outcomes of THR in the patient with neuromuscular disorders, make this option viable. This paper will review the current literature and our experience with THR in the more frequently encountered neuromuscular disorders. PMID:25381404

  17. Assessment of Patients with a DePuy ASR Metal-on-Metal Hip Replacement: Results of Applying the Guidelines of the Spanish Society of Hip Surgery in a Tertiary Referral Hospital

    PubMed Central

    Fernández-Valencia, Jenaro; Gallart, Xavier; Bori, Guillem; Ramiro, Sebastián Garcia; Combalía, Andrés; Riba, Josep

    2014-01-01

    The prognosis associated with the DePuy ASR hip cup is poor and varies according to the series. This implant was withdrawn from use in 2010 and all patients needed to be assessed. We present the results of the assessment of our patients treated with this device, according to the Spanish Society of Hip Surgery (SECCA) algorithm published in 2011. This retrospective study evaluates 83 consecutive ASR cups, followed up at a mean of 2.9 years. Serum levels of chromium and cobalt, as well as the acetabular abduction angle, were determined in order to assess their possible correlation with failure, defined as the need for revision surgery. The mean Harris Hip Score was 83.2 (range 42–97). Eight arthroplasties (13.3%) required revision due to persistent pain and/or elevated serum levels of chromium/cobalt. All the cups had a correct abduction angle, and there was no correlation between elevated serum levels of metal ions and implant failure. Since two previous ASR implants were exchanged previously to the recall, the revision rate for ASR cups in our centre is 18.2% at 2.9 years. PMID:25431677

  18. Correlation of corrosion and biomechanics in the retrieval of a single modular neck total hip arthroplasty design: modular neck total hip arthroplasty system.

    PubMed

    Lanting, Brent A; Teeter, Matthew G; Vasarhelyi, Edward M; Ivanov, Todor G; Howard, James L; Naudie, Douglas D R

    2015-01-01

    Increased modularity of total hip arthroplasty components has occurred, with theoretical advantages and disadvantages. Recent literature indicates the potential for elevated revision rates of modular neck systems and the potential for local pseudotumor and metallosis formation at the modular neck/stem site. Retrieval analysis of one modular neck implant design including SEM (SCANNING ELECTRON MICROSCOPY) assessment was done and correlated with FEA (finite element analysis) as well as clinical features of patient demographics, implant and laboratory analysis. Correlation of the consistent corrosion locations to FEA indicates that the material and design features of this system may result in a biomechanical reason for failure. The stem aspect of the modular neck/stem junction may be at particular risk. PMID:25060562

  19. High complication rate in the early experience of minimally invasive total hip arthroplasty by the direct anterior approach

    PubMed Central

    2012-01-01

    Background and purpose There is growing interest in minimally invasive surgery techniques in total hip arthroplasty (THA). In this study, we investigated the learning curve and the early complications of the direct anterior approach in hip replacement. Methods In the period January through December 2010, THA was performed in 46 patients for primary osteoarthritis, using the direct anterior approach. These cases were compared to a matched cohort of 46 patients who were operated on with a conventional posterolateral approach. All patients were followed for at least 1 year. Results Operating time was almost twice as long and mean blood loss was almost twice as much in the group with anterior approach. No learning effect was observed in this group regarding operating time or blood loss. Radiographic evaluation showed adequate placement of the implants in both groups. The early complication rate was higher in the anterior approach group. Mean time of hospital stay and functional outcome (with Harris hip score and Oxford hip score) were similar in both groups at the 1-year follow-up. Interpretation The direct anterior approach is a difficult technique, but adequate hip placement was achieved radiographically. Early results showed no improvement in functional outcome compared to the posterolateral approach, but there was a higher early complication rate. We did not observe any learning effect after 46 patients. PMID:22880711

  20. Retrograde peri-implantitis

    PubMed Central

    Mohamed, Jumshad B.; Shivakumar, B.; Sudarsan, Sabitha; Arun, K. V.; Kumar, T. S. S.

    2010-01-01

    Retrograde peri-implantitis constitutes an important cause for implant failure. Retrograde peri-implantitis may sometimes prove difficult to identify and hence institution of early treatment may not be possible. This paper presents a report of four cases of (the implant placed developing to) retrograde peri-implantitis. Three of these implants were successfully restored to their fully functional state while one was lost due to extensive damage. The paper highlights the importance of recognizing the etiopathogenic mechanisms, preoperative assessment, and a strong postoperative maintenance protocol to avoid retrograde peri-implant inflammation. PMID:20922082

  1. Using the Diffractive Optics for 3D Inspection of Nuclear Reactor Fuel Assembly Grid Spacers

    NASA Astrophysics Data System (ADS)

    Finogenov, L. V.; Lemeshko, Yu. A.; Zav'yalov, P. S.

    2008-01-01

    Ensuring the safety and high operation reliability of nuclear reactors takes 100% inspection of geometrical parameters of fuel assemblies, which include the grid spacers fabricated as cellular structure with fuel elements. The required grid spacers' geometry of assembly in the transverse and longitudinal cross sections is extremely important for maintaining the necessary heat regime. A universal method for 3D grid spacer inspection using the diffractive optical element, which generates, as the structured light, a multiple-ring pattern on the inner surface of a grid spacer cell is investigated. The experimental measurement error for cell centers position deviation is ±7 ?m, and the error for overall dimensions is ±11 ?m.

  2. Accuracy of an adjustable patient-specific guide for acetabular alignment in hip replacement surgery (Optihip).

    PubMed

    Shandiz, Mohsen Akbari; MacKenzie, James R; Hunt, Stephen; Anglin, Carolyn

    2014-09-01

    Implant malalignment in hip arthroplasty increases the risk of revision surgery due to problems such as hip instability, wear, and impingement. Traditional instrumentation lacks accuracy and does not individualize the goal. Computer-assisted surgery (CAS) and patient-specific solutions improve accuracy but add considerably to the cost, amongst other drawbacks. We developed an adjustable mechanical device, called Optihip, which is set to a patient-specific goal preoperatively and is independent of pelvis position intraoperatively. The purpose of the present study was to evaluate Optihip's accuracy ex vivo. Acetabular components were implanted into six cadaveric specimens, 12 hips, by two surgeons, with the device individually adjusted according to preoperative templating on computed tomography (CT) images relative to defined acetabular rim landmarks; options also exist for templating on single or biplanar X-rays. Intraoperatively, the device was positioned on the corresponding anatomical landmarks allowing the insertion of a guide pin, which then defined the desired orientation of the acetabular cup during impaction. Mean absolute difference between the preoperatively planned cup alignment and final acetabular cup orientation, measured from postoperative CT images, was 2.5±1.2° for inclination and 2.5±2.2° for version with maximum values of 4.7° and 6.8°, respectively. Compared with previous in vivo reports, Optihip guided the acetabular cup orientation more accurately than conventional hip arthroplasty, and comparably to CAS or patient-specific systems, while fitting into the normal surgical workflow. Although clinical testing is required to confirm these experimental results, the positive ex vivo accuracy suggests good potential for improving revision rates and patient functional outcome. PMID:25313024

  3. [Pathogenesis and prevention of spastic hip dislocation].

    PubMed

    Heimkes, B; Stotz, S; Heid, T

    1992-01-01

    Based on retrospective analysis of 82 hips of 41 patients with cerebral palsy, a pathogenetic model of spastic paralytic dislocation of the hip is introduced including recent observations of the normal hip development. According to this model the reduced activity of the gluteus maximus, medius, minimus and quadriceps femoris muscles, which normally cause a decrease of valgus and anteversion, results in an increased subluxating coxa valga antetorta with a consecutive dislocation. In order to prevent a dislocation, these muscle groups have to undergo increased activation. Since walking has to be to undergo increased activation. Since walking has to be considered the strongest stimulus for the dislocation-preventing hip abductors, hip extensors, outward rotators and knee extensors, the erect gait should be encouraged with statomotorically favored children early as possible. This can be supported by muscle relaxing surgery of the antagonistically effective hip flexors, hip adductors and inward rotators as well as the knee flexors. These muscle release operations will counteract, although to a limited extent, a dislocation even with a severely handicapped child who is unable to walk. PMID:1462702

  4. Mechanical Evaluation of Polymer Composite Hip Protectors

    PubMed Central

    Melo, Jose Daniel Diniz; Barbosa, Ayrles S. Gonçalves; Guerra, Ricardo Oliveira

    2010-01-01

    Hip fractures often result in serious health implications, particularly in the geriatric population, and have been related to long-term morbidity and death. In most cases, these fractures are caused by impact loads in the area of the greater trochanter, which are produced in a fall. This work is aimed at developing hip protectors using composite materials and evaluating their effectiveness in preventing hip fractures under high impact energy (120?J). The hip protectors were developed with an inner layer of energy absorbing soft material and an outer rigid shell of fiberglass-reinforced polymer composite. According to the experimental results, all tested configurations proved to be effective at reducing the impact load to below the average fracture threshold of proximal femur. Furthermore, an addition of Ethylene Vinyl Acetate (EVA) to the impacted area of the composite shell proved to be beneficial to increase impact strength of the hip protectors. Thus, composite hip protectors proved to be a viable alternative for a mechanically efficient and cost-effective solution to prevent hip fractures. PMID:20871841

  5. Total hip arthroplasty in secondary systemic lupus erythematosus femoral head avascular necrosis.

    PubMed

    Orban, H; Cîrstoiu, C; Adam, R

    2007-01-01

    Systemic lupus erythematosus is a multisystem disease with a large spectrum of clinical manifestations and a variable course. Lupus is marked by both humoral and cellular immunologic abnormalities, including multiple auto-antibodies especially anti DNA antibodies. Epidemiology - female predominance, occurring usually between second and fourth decade of life, more frequently in hispanic and black patients. Family predominance has been noticed. Provocative agents - ultraviolet light, viral infections, drugs and situational stresses. Pathogenesis - pathological features can affect a large spectrum of internal organs and systems - osteoarticulary injuries, skin rash, lymphadenopathy, glomerulonephritis, myocarditis, digestive system lesions. Musculo skeletal abnormalities include migratory arthritis, effusion and stiffness in small and large joints. Articular erosions are uncommon. Skeletal abnormalities include osteopenia and osteonecrosis, due to two pathological mechanisms: vasculitis and long term corticotherapy. Fifteen to twenty percent of SLE patients are affected by femoral head avascular necrosis (FHAN). Diagnosis rests on clinical signs - hip pain, limited range of motion, walking with a limp.; radiological findings - best grouped in Arlet-Ficat standing system; MRI - high sensitivity, especially in infraradiological stages. Treatment - in incipient stages core decompression represents the best therapeutical option. In advanced, arthritis stages, total hip arthroplasty (THA) is the standart treatment. Three implant types are available: bipolar, uncemented and cemented. An increased number of cotyloidites occurred after bipolar implants. Emphasised osteopenia and excessive bleeding represent contraindications for uncemented implants. Considering all of this, cemented implants are considered, the right choice, methacrylate cement providing strong and durable fixation of THA implants to bone. No meaningful differences were observed in postoperative functional recovery between LSE patients and other etiology FHAN patients. PMID:17966453

  6. Eleven Year Results of Total Hip Arthroplasty in Patients with Secondary Osteoarthritis Due to Slipped Capital Femoral Epiphysis

    PubMed Central

    Schoof, Benjamin; Citak, Mustafa; O’Loughlin, Padhraig F; Kendoff, Daniel; Haasper, Carl; Gehrke, Thorsten; Gebauer, Matthias

    2013-01-01

    Background: Total hip arthroplasty (THA) in patients with a history of Slipped Capital Femoral Epiphysis (SCFE), is typically indicated to address the consequent deformity of the proximal femur and/or acetabulum. It can be a challenging procedure for the orthopaedic surgeon. Previous studies have focused on prevention of osteoarthritis post-SCFE. However, there is a paucity of data on the outcomes of total hip arthroplasty in patients with osteoarthritis secondary to SCFE. This study was performed to assess the mid-term results of total hip arthroplasty in this patient cohort. Materials and Methods: All patients with secondary osteoarthritis due to slipped capital femoral epiphysis, treated with total hip arthroplasty between 1987 and 2005, were included in this retrospective study (n=30). Thirty patients (17 male, 13 female) met the inclusion criteria with one patient lost to follow-up and one unrelated death one year before follow up examination, thereby leaving 28 patients (32 hips) eligible for the study with a mean follow-up time period of 11.2 years. The Harris Hip Score (HHS) and MOS 36 short form health survey (SF36) were determined preoperatively and at most recent follow-up for all patients. Complications were also noted for all cases. Results: The mean Harris Hip Score increased significantly from 47 (32-59; SD=8.3) to 92.3 (65-100; SD=8.2) (p<0.0001). The SF-36 health survey showed an improvement of quality-of-life in all sub-scales. Overall, revision surgery was required in six cases (19 %). Aseptic loosening, leading to implant removal, was noted in five cases. A single-stage revision to address infection was performed in one case. The cumulative survival rate at latest follow-up was 81 %. No other complications were encountered during the study. Conclusions: Despite a higher failure rate, compared to total hip arthroplasty in the treatment of primary osteoarthritis, total hip arthroplasty can be considered a feasible option for patients with secondary osteoarthritis of the hip due to slipped capital femoral epiphysis. The current study demonstrates good outcomes in patients treated with a cementless column-preserving prosthesis, which is of particular relevance for this young patient cohort. However, further clinical prospective randomized studies are warranted to provide more definitive evidence. PMID:23730379

  7. An unusual cause of external snapping hip

    PubMed Central

    Battaglia, Milva; Guaraldi, Federica; Monti, Carlo; Vanel, Daniel; Vannini, Francesca

    2011-01-01

    The external snapping hip syndrome is a condition characterized by palpable or audible snap on the lateral region of the hip occurring during movements and sometimes associated with pain. It is typical of young adults and athletes and can be favored by the abnormal sliding of the iliotibial band or of the gluteus maximus muscle over the greater trochanter. We present a case of external snapping hip syndrome occurring in a young woman secondary to a dysmorphic sickle-shaped myotendinous junction of the gluteus maximus muscle. Diagnosis was allowed by an integrated clinical and radiological approach, based on dynamic ultrasound and magnetic resonance imaging (MRI). PMID:22470763

  8. Hip Fracture Prevention Trial Using Hip Protectors in Japanese Nursing Homes

    Microsoft Academic Search

    A. Harada; M. Mizuno; M. Takemura; H. Tokuda; H. Okuizumi; N. Niino

    2001-01-01

    :   A method to protect the hips during falls could effectively reduce the incidence of hip fractures. We report the results\\u000a of the first hip protector trial in Japan, performed between July 1996, and September 1999. One hundred and sixty-four elderly\\u000a female residents of nursing homes, with Activities of Daily Living above the wheelchair level, agreed to participate in this

  9. Accuracy of femoral templating in reproducing anatomical femoral offset in total hip replacement.

    PubMed

    Davies, H; Foote, J; Spencer, R F

    2007-01-01

    Restoration of hip biomechanics is a crucial component of successful total hip replacement. Preoperative templating is recommended to ensure that the size and orientation of implants is optimised. We studied how closely natural femoral offset could be reproduced using the manufacturers' templates for 10 femoral stems in common use in the UK. A series of 23 consecutive preoperative radiographs from patients who had undergone unilateral total hip replacement for unilateral osteoarthritis of the hip was employed. The change in offset between the templated position of the best-fitting template and the anatomical centre of the hip was measured. The templates were then ranked according to their ability to reproduce the normal anatomical offset. The most accurate was the CPS-Plus (Root Mean Square Error 2.0 mm) followed in rank order by: C stem (2.16), CPT (2.40), Exeter (3.23), Stanmore (3.28), Charnley (3.65), Corail (3.72), ABG II (4.30), Furlong HAC (5.08) and Furlong modular (7.14). A similar pattern of results was achieved when the standard error of variability of offset was analysed. We observed a wide variation in the ability of the femoral prosthesis templates to reproduce normal femoral offset. This variation was independent of the seniority of the observer. The templates of modern polished tapered stems with high modularity were best able to reproduce femoral offset. The current move towards digitisation of X-rays may offer manufacturers an opportunity to improve template designs in certain instances, and to develop appropriate computer software. PMID:19197861

  10. Design of Composite Hip Prostheses Considering the Long-Term Behavior of the Femur

    NASA Astrophysics Data System (ADS)

    Lim, Jong Wan; Jeong, Jae Youn; Ha, Sung Kyu

    A design method for the hip prosthesis is proposed which can alleviate problems associated with stress shielding, proximal loosening and the high stress of bone-implant interfaces after total hip replacement. The stress shielding which may lead to bone resorption, can cause a loosening of the stem and a fracture of femoral bone. Generally the composites were more suitable for hip prosthesis material in the long-term stability than metallic alloy because design cases of composite materials produced less stress shielding than titanium alloy. A bone remodeling algorithm was implemented in a nonlinear finite element program to predict the long-term performance of the hip prosthesis. The three neck shapes and three cross sections of composite hip were examined. It was found that the stress concentration in the distal region of the titanium stem which may cause the patient's thigh pains was reduced using composite material. The head neck shape was closely related with the cortical bone resorption and the cancellous bone apposition at proximal region whereas the cross-section was closely related with the relative micromotion between interfaces. The convex head neck type with the quadrangle cross-section produced less subsidence at proximal region on the medial side than the others. For all composite material cases, the cancellous bone apposition occurred at partial interfaces, which may result in a stable bio-fixation. The design performances of the convex neck head type with the hexagonal cross-section designed to insure the long-term stability were found to be more suitable than the others.

  11. Catastrophic failure of ceramic-on-ceramic total hip arthroplasty presenting as squeaking hip

    PubMed Central

    Malem, David; Nagy, Mathias Thomas; Ghosh, Sabyasachi; Shah, Bhavik

    2013-01-01

    A 68-year-old woman with osteoarthritis had a ceramic-on-ceramic left total hip arthroplasty, including ceramic femoral head and acetabular liner. At 5?years after surgery, the patient developed onset of a very loud squeaking noise, which could be heard 25?m from her, associated with limited hip movement. Findings at revision surgery included a broken ceramic femoral head component, complete wear of the ceramic acetabular component, and black wear debris. Squeaking hip after ceramic-on-ceramic total hip arthroplasty may be associated with catastrophic failure of the arthroplasty components. PMID:23429031

  12. A safe zone for acetabular component position in metal-on-metal hip resurfacing arthroplasty: winner of the 2012 HAP PAUL award.

    PubMed

    Liu, Fei; Gross, Thomas P

    2013-08-01

    A safe zone for acetabular component positioning in hip resurfacing (RAIL: Relative Acetabular Inclination Limit) was calculated based on implant size and acetabular inclination angle (AIA). For AIA below the RAIL, there were no adverse wear failures or dislocations, and only 1% of cases with ion levels above 10 ?g/L. Other than high inclination angle and small bearing size, female gender was the only other factor that correlated with high ion levels in the multivariate analysis. Seven hundred sixty-one hip resurfacing cases are included in this study. The UCLA activity score, femoral shaft angle, body mass index, weight, American Society of Anesthesiologists score, combined range of motion, diagnosis, age, gender, implant brand, AIA, bearing size, and duration of implantation were analyzed to determine the potential risk factors for elevated metal ion levels. These findings apply to sub hemispheric metal-on-metal bearings with similar coverage arcs as the Biomet and Corin hip resurfacing brands. Additional problems may occur when these bearings are connected with trunions on stems for total hip arthroplasty. PMID:23540536

  13. The impact of seating forces from a cementless femoral component in hip resurfacing arthroplasty on the femoral head--a cadaver study using ?-CT analysis.

    PubMed

    Lerch, Matthias; Olender, Gavin; Angrisani, Nina; Rittershaus, Dina; Meyer-Lindenberg, Andrea; Thorey, Fritz; Windhagen, Henning; Hurschler, Christof

    2011-01-01

    Recent studies have assumed micro-fractures of the femoral head during hip resurfacing arthroplasty as a possible reason for fractures at the implant/neck junction. The purpose of this study was to analyze whether implantation of a cementless femoral hip resurfacing component which requires high seating forces, causes micro-fractures of the femoral head. A cementless hip resurfacing femoral component was installed on 20 human, cadaveric femoral heads with an impaction device that generated 4.5 kilonewton force in one group and by hand in the other. Before and after impaction, the specimens were scanned with a ?-CT-System. The CT datasets were segmented and registered for detection of small trabecular fractures. The average percentage of shared voxels was 80.29% (standard deviation 3.24%). Change in bone structure after impaction (19.71%) was found on the surfaces of all samples. No formation that was ascribed to fracture was found. No difference between the specimens that were impacted by hand or by impaction device was noted. No fractures of the cancellous femoral head during installation of a cementless femoral THR component occurred. Cementless hip resurfacing might not increase the risk of fracturing the cancellous femoral head during implantation in a cadaveric ?-CT study. PMID:21248410

  14. Hip prosthesis introduction and early revision risk

    PubMed Central

    2013-01-01

    Background and purpose Little is known about the effect of the learning curve for different types of total hip arthroplasties (THAs). We investigated the prostheses survival of THAs just after the implementation of a model new to the hospital, and compared these results with the results of THAs done when more than 100 implantations had been undertaken. In addition, we investigated whether differences exist between different types of femoral stems and acetabular cups at the early implementation phase. Patients and methods We used comprehensive registry data from all units (n = 76) that performed THAs for primary osteoarthritis in Finland between 1998 and 2007. Complete data including follow-up data to December 31, 2010 or until death were available for 33,819 patients (39,125 THAs). The stems and cups used were given order numbers in each hospital and classified into 5 groups: operations with order number (a) 1–15, (b) 16–30, (c) 31–50, (d) 51–100, and (e) > 100. We used Cox’s proportional hazards modeling for calculation of the adjusted hazard ratios for the risk of revision during the 3 years following the implementation of a new THA endoprosthesis type in the groups. Results Introduction of new endoprosthesis types was common, as more than 1 in 7 patients received a type that had been previously used in 15 or less operations. For the first 15 operations after a stem or cup type was introduced, there was an elevated risk of revision (hazard ratio (HR) = 1.3, 95% CI: 1.1–1.5). There were differences in the risk of early revision between stem and cup types at implementation. Interpretation The first 15 operations with a new stem or cup model had an increased risk of early revision surgery. Stems and cups differed in their early revision risk, particularly at the implementation phase. Thus, the risk of early revision at the implementation phase should be considered when a new type of THA is brought into use. PMID:23368748

  15. Metal ion levels in maternal and placental blood after metal-on-metal total hip arthroplasty.

    PubMed

    Novak, Clifford C; Hsu, Andrew R; Della Valle, Craig J; Skipor, Anastasia K; Campbell, Patricia; Amstutz, Harlan C; Jiranek, William A; Onyike, Aham; Pombar, Xavier F; Jacobs, Joshua J

    2014-12-01

    There is concern regarding elevated metal ion levels in the blood during pregnancy and the potential fetal effects in women with metal-on-metal (MOM) implants. We obtained maternal and umbilical cord blood samples from 3 patients with a MOM hip arthroplasty and 7 control subjects without any metallic implants. Serum metal ion levels including chromium, cobalt, titanium, and nickel were tested using high-resolution sector-field inductively-coupled plasma-mass spectrometry. Mothers with MOM-bearing implants had significantly elevated levels of serum cobalt and chromium compared with control-group mothers, and umbilical cord blood from mothers with MOM implants also had significantly higher serum metal ion levels compared with control-group mothers. The results of this study show that circulating serum levels of metal ion degradation products from MOM bearings cross the placenta and expose the fetus to metal ions. However, the placenta exerts a modulatory effect on cord blood, resulting in decreased levels compared with maternal samples (approximately 15% of maternal chromium and 50% of maternal cobalt). Physicians and women of child-bearing age should be aware of this potential effect when considering the use of MOM-bearing implants. PMID:25490017

  16. Total hip arthroplasty for acute acetabular fractures: a review of the literature.

    PubMed

    Jauregui, Julio J; Clayton, Adrian; Kapadia, Bhaveen H; Cherian, Jeffrey J; Issa, Kimona; Mont, Michael A

    2015-05-01

    There have been many advances in the treatment of acetabular fractures; however, the role of total hip arthroplasty (THA) as part of acute fracture management is not well-defined. The indications to acutely manage an acetabular fracture with THA include patients who were older than 65 years of age, who had extensive intra-articular comminution, impaction of the acetabular dome, a displaced-impacted femoral neck fracture, presented with severe osteopenia or osteoporosis, or preexisting osteoarthritis. Implant survivorship and clinical outcomes were favorable with low complications when managing an acetabular fracture with THA. THA may be an effective option for treating acetabular fractures in appropriately selected patients. PMID:25653035

  17. Total Hip Replacement (Arthroplasty) (Beyond the Basics)

    MedlinePLUS

    ... will develop a blood clot. (See "Patient information: Deep vein thrombosis (DVT) (Beyond the Basics)" and "Patient ... information: Hip pain (Beyond the Basics) Patient information: Deep vein thrombosis (DVT) (Beyond the Basics) Patient information: ...

  18. MR imaging of normal hip anatomy.

    PubMed

    Chang, Connie Y; Huang, Ambrose J

    2013-02-01

    Understanding normal anatomy of the hip is important for diagnosing its pathology. MR arthrography is more sensitive for the detection of intra-articular pathology than noncontrast MR imaging. Important elements of the osseous structures on MR imaging include the alignment and the marrow. Acetabular ossicles may be present. Normal variations involving the cartilage include the supra-acetabular fossa and the stellate lesion. Important muscles of the hip are the sartorius, rectus femoris, iliopsoas, gluteus minimus and medius, adductors, and hamstrings. The iliofemoral, ischiofemoral, and pubofemoral ligaments represent thickenings of the joint capsule that reinforce and stabilize the hip joint. Normal variations in the labrum include labral sulcus and absent labrum. The largest nerves in the hip and thigh are the sciatic nerve, the femoral nerve, and the obturator nerve. PMID:23168179

  19. Risks of hip and knee replacement

    MedlinePLUS

    ... stroke during or after surgery. Infection in the knee, lungs (pneumonia), or urinary tract. Poor wound healing. ... to lose blood during and after hip or knee replacement surgery. Some people need a blood transfusion ...

  20. Ten-Year Outcome of Serum Metal Ion Levels After Primary Total Hip Arthroplasty

    PubMed Central

    Levine, Brett R.; Hsu, Andrew R.; Skipor, Anastasia K.; Hallab, Nadim J.; Paprosky, Wayne G.; Galante, Jorge O.; Jacobs, Joshua J.

    2013-01-01

    Abstract: We previously reported on the metal ion concentrations of cobalt, chromium, and titanium that were found in the serum of patients three years after they had undergone primary total hip arthroplasty as compared with the concentrations found in the serum of control patients who did not have an implant. This study is a concise update on the serum metal levels found in a cohort of these patients ten years after the time of hip implantation. Of the original seventy-five subjects, metal ion levels were available for forty patients (53%). Ten patients (hybrid group) had received a hybrid total hip replacement that consisted of a modular cobalt-alloy femoral stem with a cobalt-alloy femoral head that had been inserted with cement and a titanium acetabular socket that had been inserted without cement. Nine patients (cobalt-chromium [CoCr] group) had received an implant with an extensively porous-coated modular cobalt-alloy femoral stem and femoral head along with a titanium acetabular socket; the femoral and acetabular components had each been inserted without cement. Eight patients (titanium group) had undergone insertion of a proximally porous-coated modular titanium-alloy femoral stem with a cobalt-alloy femoral head and a titanium acetabular socket; the femoral and acetabular components had each been inserted without cement. Thirteen patients (control group) from the original control group of patients who had not received an implant served as control subjects. Serum metal levels were measured with use of high-resolution sector field inductively coupled plasma mass spectrometry. The hybrid total hip arthroplasty group had mean cobalt levels that were 3.2 times higher at 120 months than they were at baseline, and the cobalt levels in that group were significantly higher than those in the titanium total hip arthroplasty group at thirty-six, sixty, eighty-four, ninety-six, and 120 months (p < 0.01). The hybrid group had mean chromium levels that were 3.9 times higher at 120 months than they were at baseline, and the CoCr total hip arthroplasty group had chromium levels that were 3.6 times higher at 120 months than they were at baseline. The serum titanium levels were higher in the titanium group at all follow-up time intervals as compared with the levels in all other groups, and the level in the titanium group at 120 months was eighteen times higher than it was at baseline (p < 0.01). Patients with well-functioning primary metal-on-polyethylene total hip replacements had elevated serum metal levels for as many as ten years postoperatively. Furthermore, metal release at the modular femoral head-neck junctions, rather than passive dissolution from porous ingrowth surfaces, was likely the dominant source of serum cobalt and chromium. Level of Evidence: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence. PMID:23515985

  1. Venous thromboembolic prophylaxis for hip fractures

    Microsoft Academic Search

    D. Marsland; S. C. Mears; S. L. Kates

    2010-01-01

    Patients with hip fractures are at very high risk for the development of venous thromboembolism (VTE). To provide an overview\\u000a of cause, risk factors, current treatment strategies, and complications associated with VTE prophylaxis, we reviewed the most\\u000a current, best available evidence on VTE prophylaxis for patients with hip fractures. We comprehensively reviewed the literature\\u000a to assess the efficacy of VTE

  2. The bizarre stiff hip. Possible idiopathic chondrolysis.

    PubMed

    Duncan, J W; Schrantz, J L; Nasca, R J

    1975-01-27

    Idiopathic chondrolysis of the hip is characterized by pain and limp in adolescence, with progressive loss of articular cartilage space and stiffness of the hip. In our five cases, the best results were obtained in those patients immobilized in a position of function. Those cases in which range-of-motion exercises were carried out resulted in ankylosis in a position of excessive flexion. PMID:1172705

  3. Detecting bacterial colonization of implanted orthopaedic devices by ultrasonication.

    PubMed

    Nguyen, Larry L; Nelson, Carl L; Saccente, Michael; Smeltzer, Mark S; Wassell, David L; McLaren, Sandra G

    2002-10-01

    Glycocalyx-producing bacteria have been observed on orthopaedic devices that were removed for reasons other than infection. It has been suggested that the bacteria adhere to foreign surfaces within a biofilm and elude standard culture techniques. The authors adapted previously used ultrasonication protocols that disrupt the surface biofilm before culturing removed orthopaedic devices from patients without clinical evidence of infection. Patients having revision total joint arthroplasty of the hip or knee who lacked current or prior clinical evidence of infection were studied prospectively. During surgery, the femoral component and a corresponding control femoral implant were placed in separate sterile bags of saline. The implant and saline combination was placed in an ultrasonication bath for 30 minutes at 60 Hz. The saline solution was passed through a 0.45-microm pore filter, and the filter residue was cultured on sheep blood agar. None of the 21 implants yielded positive culture on routine microbiologic testing. However, using the ultrasonication protocol, a coagulase-negative Staphylococcus grew from one of the removed implants. Numerous total joint implant failures that are attributed to aseptic loosening may be a result of subclinical infection from bacteria within a biofilm. The current study supports the concept that biofilm-protected bacterial colonization of implants may occur without overt signs of infection and ultrasonication can be used to enhance identification of these bacteria. PMID:12360004

  4. Base-contact proximity effects in bipolar transistors with nitride-spacer technology

    E-print Network

    Technische Universiteit Delft

    Base-contact proximity effects in bipolar transistors with nitride-spacer technology Henk van Zeijl-BJT's with spacer separated Al/Si emitter and base contacts are fabricated and characterized. Due to the proximity of the base contact to the emitter-base junction, the base current is increased by two peripheral effects

  5. Ribosomal Intergenic Spacer (IGS) length variation across the Drosophilinae (Diptera: Drosophilidae)

    E-print Network

    Markow, Therese

    - 1 - Ribosomal Intergenic Spacer (IGS) length variation across the Drosophilinae (Diptera The intergenic spacer of the ribosomal genes in eukaryotes (IGS) contains duplications of the core transcription promoter. The number of these duplicated promoters, as measured by the IGS length, appears to be correlated

  6. Biomedical Applications of Gold Nanoparticles Functionalized Using Hetero-Bifunctional Poly(ethylene glycol) Spacer

    E-print Network

    Sridhar, Srinivas

    on one terminus and a reactive functional group on the other. Coumarin, a model fluorescent dye, was conjugated to the PEG spacer and gold nanoparticles were modified with coumarin-PEG-thiol. Surface attachment of coumarin through the PEG spacer decreases the fluorescence quenching effect of gold nanoparticles

  7. 22nm half-pitch patterning by CVD spacer self alignment double patterning (SADP)

    Microsoft Academic Search

    Chris Bencher; Yongmei Chen; Huixiong Dai; Warren Montgomery; Lior Huli

    2008-01-01

    Self-aligned double patterning (SADP) is a patterning technique that uses CVD spacers formed adjacent to a core (template) pattern that is defined by conventional lithography. After stripping the core (template) material, the spacers serve as a hardmask with double the line density of the original lithographically defined template. This integration scheme is an alternative to conventional double patterning for extending

  8. The Effect of Charge-Reversal Amphiphile Spacer Composition on DNA and siRNA Delivery

    E-print Network

    The Effect of Charge-Reversal Amphiphile Spacer Composition on DNA and siRNA Delivery Xiao April 7, 2010 A series of charge-reversal amphiphiles with different spacers separating the headgroup from the hydrophobic chains are described for delivery of DNA and siRNA. Among them, the amphiphiles

  9. Results of a programme to improve house staff use of metered dose inhalers and spacers

    PubMed Central

    Lee-Wong, M; Mayo, P

    2003-01-01

    Purpose: Metered dose inhalers (MDIs) and spacers are used widely in the treatment of asthma. Medical personnel who are responsible for training patients must themselves be proficient with the devices. The proficiency of a group of new medical interns with use of MDI and spacer devices was determined, and improvement in their use of these devices was sought. Subjects: Fifty six medical interns tested at the start of their first house staff training year. Methods: The ability of medical interns to use MDIs and spacers was assessed using a visual scoring system before and after a large group lecture emphasising proper device use and once again after an intensive one-on-one training session with an attending physician. Results: Initially, only 5% used an MDI perfectly. This improved to 13% after a lecture and demonstration, and 73% after an intensive one-on-one session. Almost no new interns could use a collapsible or tube spacer properly initially. This improved to 15% and 29% respectively after a lecture. After one-on-one training, correct technique was increased to 69% for collapsible spacer and 95% for the tube spacer. Analysis of individual steps of MDI use showed that interns had particular difficulty in coordinating actuation with inhalation. The tube spacer appeared easiest to learn. Conclusions: Incoming medical house staff have limited ability to use MDI with and without spacers. A large group lecture is relatively ineffective when compared with a one-on-one training session in training with these devices. PMID:12743342

  10. Transcriptional regulator-mediated activation of adaptation genes triggers CRISPR de novo spacer acquisition

    PubMed Central

    Liu, Tao; Li, Yingjun; Wang, Xiaodi; Ye, Qing; Li, Huan; Liang, Yunxiang; She, Qunxin; Peng, Nan

    2015-01-01

    Acquisition of de novo spacer sequences confers CRISPR-Cas with a memory to defend against invading genetic elements. However, the mechanism of regulation of CRISPR spacer acquisition remains unknown. Here we examine the transcriptional regulation of the conserved spacer acquisition genes in Type I-A of Sulfolobus islandicus REY15A. Csa3a, a MarR-like transcription factor encoded by the gene located adjacent to csa1, cas1, cas2 and cas4 cluster, but on the reverse strand, was demonstrated to specifically bind to the csa1 and cas1 promoters with the imperfect palindromic sequence. Importantly, it was demonstrated that the transcription level of csa1, cas1, cas2 and cas4 was significantly enhanced in a csa3a-overexpression strain and, moreover, the Csa1 and Cas1 protein levels were increased in this strain. Furthermore, we demonstrated the hyperactive uptake of unique spacers within both CRISPR loci in the presence of the csa3a overexpression vector. The spacer acquisition process is dependent on the CCN PAM sequence and protospacer selection is random and non-directional. These results suggested a regulation mechanism of CRISPR spacer acquisition where a single transcriptional regulator senses the presence of an invading element and then activates spacer acquisition gene expression which leads to de novo spacer uptake from the invading element. PMID:25567986

  11. Relation between dielectric spacer thickness and absorption feature in metamaterials absorber

    Microsoft Academic Search

    Tao Wang; Lu Wang; Yan Nie; Rongzhou Gong

    2010-01-01

    We investigated the influence of dielectric spacer thickness on the metamaterials absorber at microwave frequency. The absorption feature was demonstrated and characterized by the numerical simulations and experiments. The thickness of FR4 spacer was varied to examine the electromagnetic response of the short and long wires structure. It was found that there existed two different absorption mechanisms which were concerned

  12. Thin Dielectric Spacer for the Monolithic Integration of Bulk Germanium or

    E-print Network

    Miller, David A. B.

    Thin Dielectric Spacer for the Monolithic Integration of Bulk Germanium or Germanium Quantum Wells germanium (Ge) or Ge quantum wells with silicon-on-insulator (SOI) waveguides through selective epitaxy process to realize sub-30-nm spacers. Index Terms: Integrated optoelectronics, germanium, quantum wells

  13. Five-year results of a cementless short-hip-stem prosthesis

    PubMed Central

    Wittenberg, Ralf H.; Steffen, Reinhard; Windhagen, Henning; Bücking, Petra; Wilcke, Andreas

    2013-01-01

    Hip prosthesis stems with a short stem length and proximal fixation geometry support a bone-preserving and muscle-sparing implantation and should also allow for revision surgery with a standard hip stem. We present 250 prospectively documented clinical and radiological results from the Metha Short Hip Stem prosthesis (B. Braun-Aesculap, Tuttlingen, Germany) after an average follow-up of 4.9 years. The average patient age at surgery was 60 years. Indication for total hip replacement was primary osteoarthrosis (OA) (78% of patients), OA based on developmental dysplasia of the hip (16%), and other indications (6%). At the last follow-up, the average Harris Hip Score was 97 points. 85% of patients were very satisfied and 14% were satisfied after surgery, whereas 1% were dissatisfied. Pain according to the Visual Analogue Scale improved from 7.4 (min 1.6, max 9.5) pre-operatively to 0.23 (min 0, max 6.6). No joint dislocations occurred when predominantly using 28 mm and 32 mm prosthesis heads. Nine short-stems were revised: three after bacterial infections, two after primary via valsa with penetration of the femoral cortex two and three months after surgery, and three after early aseptic cases of loosening within the first year. A further nine osseously consolidated short-stems had to be replaced due to breakage of the modular titanium cone adapter after an average of 3.1 years (min 1.9, max 4.4). All surgical revisions were performed using primary standard stems. Without taking the material-related adapter failures into account, a five year Kaplan-Meier survival rate of 96.7% (95% confidence interval 93.4–98.3) was determined for the short-stem prostheses. There were no radiological signs of loosening in any of the short-stem prostheses at the last examination. Fine sclerotic lines were detected in Gruen's AP zones 1 (19%) and 2 (10.5%), individual hypertrophies in zone 3 (3.5%), fine seams in zones 4 (5.5%) and 5 (4%), without pedestal formations in zone 4, clear cancellous bone compressions in zone 6 (97.5%), as well as single fine scleroses (1.5%) and atrophies (2.5%) in zone 7. The mid-term clinical results with periprosthetic bone remodeling and without radiological signs of loosening confirm this metaphyseal short-stem treatment and fixation concept and the possibility of revision surgery using standard hip stems. Long-term results must be further observed on a prospective basis as part of this collective study. PMID:23705062

  14. Five-year results of a cementless short-hip-stem prosthesis.

    PubMed

    Wittenberg, Ralf H; Steffen, Reinhard; Windhagen, Henning; Bücking, Petra; Wilcke, Andreas

    2013-02-22

    Hip prosthesis stems with a short stem length and proximal fixation geometry support a bone-preserving and muscle-sparing implantation and should also allow for revision surgery with a standard hip stem. We present 250 prospectively documented clinical and radiological results from the Metha Short Hip Stem prosthesis (B. Braun-Aesculap, Tuttlingen, Germany) after an average follow-up of 4.9 years. The average patient age at surgery was 60 years. Indication for total hip replacement was primary osteoarthrosis (OA) (78% of patients), OA based on developmental dysplasia of the hip (16%), and other indications (6%). At the last follow-up, the average Harris Hip Score was 97 points. 85% of patients were very satisfied and 14% were satisfied after surgery, whereas 1% were dissatisfied. Pain according to the Visual Analogue Scale improved from 7.4 (min 1.6, max 9.5) pre-operatively to 0.23 (min 0, max 6.6). No joint dislocations occurred when predominantly using 28 mm and 32 mm prosthesis heads. Nine short-stems were revised: three after bacterial infections, two after primary via valsa with penetration of the femoral cortex two and three months after surgery, and three after early aseptic cases of loosening within the first year. A further nine osseously consolidated short-stems had to be replaced due to breakage of the modular titanium cone adapter after an average of 3.1 years (min 1.9, max 4.4). All surgical revisions were performed using primary standard stems. Without taking the material-related adapter failures into account, a five year Kaplan-Meier survival rate of 96.7% (95% confidence interval 93.4-98.3) was determined for the short-stem prostheses. There were no radiological signs of loosening in any of the short-stem prostheses at the last examination. Fine sclerotic lines were detected in Gruen's AP zones 1 (19%) and 2 (10.5%), individual hypertrophies in zone 3 (3.5%), fine seams in zones 4 (5.5%) and 5 (4%), without pedestal formations in zone 4, clear cancellous bone compressions in zone 6 (97.5%), as well as single fine scleroses (1.5%) and atrophies (2.5%) in zone 7. The mid-term clinical results with periprosthetic bone remodeling and without radiological signs of loosening confirm this metaphyseal short-stem treatment and fixation concept and the possibility of revision surgery using standard hip stems. Long-term results must be further observed on a prospective basis as part of this collective study. PMID:23705062

  15. Tuberculosis of hip: A current concept review.

    PubMed

    Saraf, Shyam Kumar; Tuli, Surendra Mohan

    2015-01-01

    Tuberculosis (TB) of the hip is second to spine only hence a good number of cases are visiting the medical facilities every year. Many present in the advanced stage of the disease due to delayed diagnosis. In early stages of TB of hip, there is a diagnostic dilemma when plain X-rays are negative. In the present time, diagnostic modalities have improved from the days when diagnosis was based essentially on clinicoradiological presentation alone. By the time definite radiological changes appear on plain X-ray, the disease has moderately advanced. The modern diagnostic facilities like ultrasonography (USG) or magnetic resonance imaging of the hip joint, USG guided aspiration of synovial fluid and obtaining the material for polymerase chain reaction and tissue diagnosis must be utilized. In the treatment, current emphasis is more on mobility with stability at hip. Joint debridement, skeletal traction, and mobilization exercises may give more satisfying results as compared to the immobilization by hip spica. Adults with advanced arthritis and healed infection should be informed and discussed the various treatment modalities including the joint replacement. More and more surgeons are taking up the challenge of putting the total hip replacement in the active stage of the disease. Until the long term results in active disease are well established, we recommend it for the healed disease only in selected cases. PMID:25593352

  16. Tuberculosis of hip: A current concept review

    PubMed Central

    Saraf, Shyam Kumar; Tuli, Surendra Mohan

    2015-01-01

    Tuberculosis (TB) of the hip is second to spine only hence a good number of cases are visiting the medical facilities every year. Many present in the advanced stage of the disease due to delayed diagnosis. In early stages of TB of hip, there is a diagnostic dilemma when plain X-rays are negative. In the present time, diagnostic modalities have improved from the days when diagnosis was based essentially on clinicoradiological presentation alone. By the time definite radiological changes appear on plain X-ray, the disease has moderately advanced. The modern diagnostic facilities like ultrasonography (USG) or magnetic resonance imaging of the hip joint, USG guided aspiration of synovial fluid and obtaining the material for polymerase chain reaction and tissue diagnosis must be utilized. In the treatment, current emphasis is more on mobility with stability at hip. Joint debridement, skeletal traction, and mobilization exercises may give more satisfying results as compared to the immobilization by hip spica. Adults with advanced arthritis and healed infection should be informed and discussed the various treatment modalities including the joint replacement. More and more surgeons are taking up the challenge of putting the total hip replacement in the active stage of the disease. Until the long term results in active disease are well established, we recommend it for the healed disease only in selected cases. PMID:25593352

  17. The Internal Transcribed Spacer Region of Belonolaimus (Nemata: Belonolaimidae)

    PubMed Central

    Cherry, T.; Szalanski, A. L.; Todd, T. C.; Powers, T. O.

    1997-01-01

    Belonolaimus isolates from six U.S. states were compared by restriction endonuclease digestion of amplified first internal transcribed spacer region (ITS1) of the nuclear ribosomal genes. Seven restriction enzymes were selected for evaluation based on restriction sites inferred from the nucleotide sequence of a South Carolina Belonolaimus isolate. Amplified product size from individuals of each isolate was approximately 700 bp. All Midwestern isolates gave distinct restriction digestion patterns. Isolates identified morphologically as Belonolaimus longicaudatus from Florida, South Carolina, and Palm Springs, California, were identical for ITS1 restriction patterns. The correlation between ITS1 restriction patterns and the distribution of B. longicaudatus isolates suggest that the California isolate is a relatively recent introduction into the state. PMID:19274130

  18. Short Term Clinical Outcome of a Porous Tantalum Implant for the Treatment of Advanced Osteonecrosis of the Femoral Head

    Microsoft Academic Search

    Mélissa Nadeau; Chantal Séguin; John S Theodoropoulos; Edward J Harvey

    2007-01-01

    Purpose of the study: Osteonecrosis of the hip mostly affects young individuals and often progresses to a debilitating disease. Several treatment modalities exist, but none are completely satisfactory. This study evaluates the clinical outcome of patients treated with core decompression and insertion of a porous tantalum implant in the femoral head. This procedure is similar to commonly performed procedures, but

  19. Modified Open-door Laminoplasty Using Hydroxyapatite Spacers and Miniplates

    PubMed Central

    Jin, Sung-Won; Kim, Bum-Joon; Choi, Jong-Il; Ha, Sung-Kon; Kim, Sang-Dae; Lim, Dong-Jun

    2014-01-01

    Objective Cervical laminoplasty has been widely accepted as one of the major treatments for cervical myelopathy and various modifications and supplementary procedures have been devised to achieve both proper decompression and stability of the cervical spine. We present the retrospectively analyzed results of a modified unilateral open-door laminoplasty using hydroxyapatite (HA) spacers and malleable titanium miniplates. Methods From June 2008 to May 2012, among patients diagnosed with cervical spondylotic myelopathy and ossification of posterior longitudinal ligament, the patients who received laminoplasty were reviewed. Clinical outcome was assessed using Frankel grade and Japanese Orthopaedic Association score. The radiologic parameters were obtained from plain films, 3-dimensional computed tomography and magnetic resonance images. Results A total of 125 cervical laminae were operated in 38 patients. 11 patients received 4-level laminoplasty and 27 patients received 3-level laminoplasty. Postoperatively, the mean Frankel grade and JOA score were significantly improved from 3.97 to 4.55 and from 12.76 to 14.63, respectively (p<0.001). Radiologically, cervical curvature was worsened from 19.09 to 15.60 (p=0.025). The percentage of range of motion preservation was 73.32±22.39%. The axial dimension of the operated spinal canal was increased from 1.75 to 2.70 cm2 (p<0.001). Conclusion In the presenting study, unilateral open-door laminoplasty using HA spacers and miniplates appears to be a safe, rapid and easy procedure to obtain an immediate and rigid stabilization of the posterior elements of the cervical spine. This modified laminoplasty method showed effective expansion of the spinal canal and favorable clinical outcomes. PMID:25346767

  20. The interspinous spacer: a clinicoanatomical investigation using plastination.

    PubMed

    Kaulhausen, Thomas; Zarghooni, Kourosh; Stein, Gregor; Knifka, Jutta; Eysel, Peer; Koebke, Juergen; Sobottke, Rolf

    2012-01-01

    Purpose. The relatively new and less-invasive therapeutic alternative "interspinous process decompression device (IPD)" is expected to result in improved symptoms of neurogenic intermittent claudication (NIC) caused by lumbar spinal stenosis. The aim of the study was to analyze IPD position particularly regarding damage originating from surgical implantation. Methods. Anatomic assessments were performed on a fresh human cadaver. For the anatomic examination, the lumbar spine was plastinated after implantation of the IPDs. After radiographic control, serial 4 mm thick sections of the block plastinate were cut in the sagittal (L1-L3) and horizontal (L3-L5) planes. The macroanatomical positioning of the implants was then analyzed. The insertion procedure caused only little injury to osteoligamentous or muscular structures. The supraspinous ligament was completely intact, and the interspinous ligaments were not torn as was initially presupposed. No osseous changes at the spinal processes were apparent. Contact of the IPD with the spinous processes was visible, so that sufficient biomechanical limitation of the spinal extension seems likely. Conclusions. Minimally invasive IPD implantation with accurate positioning in the anterior portion of the interspinous place is possible without severe surgical trauma. PMID:22900164

  1. The Interspinous Spacer: A Clinicoanatomical Investigation Using Plastination

    PubMed Central

    Kaulhausen, Thomas; Zarghooni, Kourosh; Stein, Gregor; Knifka, Jutta; Eysel, Peer; Koebke, Juergen; Sobottke, Rolf

    2012-01-01

    Purpose. The relatively new and less-invasive therapeutic alternative “interspinous process decompression device (IPD)” is expected to result in improved symptoms of neurogenic intermittent claudication (NIC) caused by lumbar spinal stenosis. The aim of the study was to analyze IPD position particularly regarding damage originating from surgical implantation. Methods. Anatomic assessments were performed on a fresh human cadaver. For the anatomic examination, the lumbar spine was plastinated after implantation of the IPDs. After radiographic control, serial 4 mm thick sections of the block plastinate were cut in the sagittal (L1–L3) and horizontal (L3–L5) planes. The macroanatomical positioning of the implants was then analyzed. The insertion procedure caused only little injury to osteoligamentous or muscular structures. The supraspinous ligament was completely intact, and the interspinous ligaments were not torn as was initially presupposed. No osseous changes at the spinal processes were apparent. Contact of the IPD with the spinous processes was visible, so that sufficient biomechanical limitation of the spinal extension seems likely. Conclusions. Minimally invasive IPD implantation with accurate positioning in the anterior portion of the interspinous place is possible without severe surgical trauma. PMID:22900164

  2. Preliminary analysis and design optimization of the short spacer truss of Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Gendy, A. S.; Patnaik, S. N.; Hopkins, D. A.; Berke, L.

    1993-01-01

    The analysis, dynamic simulation, and design optimization of the short spacer truss of the Space Station Freedom are presented in this report. The short spacer truss will be positioned between the integrated equipment assembly (IEA) and another truss, called the long spacer truss, in the Space Station Freedom. During its launch in the Space Shuttle, the truss will be subjected to considerable in-span distributed inertia loads due to shuttle accelerations. The short spacer truss, therefore, has been modeled as a space frame to account for flexural response. Several parameters have been assumed, since the design specifications are in the process of development; hence the results presented should be considered preliminary. However, the automated analysis and design capabilities that have been developed can readily be used to generate an optimum design of the short spacer truss once the actual specifications have been determined. This report includes static and dynamic analyses of the short spacer truss, which have been obtained with the linear elastic code LE-HOST (in these analyses, LE-HOST data files have been automated to facilitate their future use for different design specifications of the short spacer truss); the dynamic animation of the short spacer truss, which has been carried out by using the results of the dynamic analysis and a post-processing feature of the modeling code PATRAN; and the optimum-weight design of the spacer truss, which was obtained under prescribed stress, displacement, and frequency constraints by using the design code COMETBOARDS. Examination of the analysis and design results revealed that the design could be improved if the configuration of the short spacer truss were modified to a certain extent. A modified configuration, which may simplify fabrication, has been suggested. The performance of this configuration has been evaluated and was found to be satisfactory under both static and dynamic conditions.

  3. RESEARCH LETTERS waist/hip ratio accounted for only 18%. Waist/hip ratio

    E-print Network

    Cornelissen, Piers

    and waist/hip ratio alone. Previous studies have asked participants to rate line drawings of female figures body-mass index with narrower or wide waists. With images of real women, body-mass index and waist. Adaptive significance of female attractiveness: role of waist-to- hip ratio. J Pers Soc Psychol 1993; 65

  4. HIP HOP for HIV Awareness: Using Hip Hop Culture to Promote Community-Level HIV Prevention

    ERIC Educational Resources Information Center

    Hill, Mandy J.; Hallmark, Camden J.; McNeese, Marlene; Blue, Nike; Ross, Michael W.

    2014-01-01

    The goal of this paper was to determine the effectiveness of the HIP HOP for HIV Awareness intervention, an innovative model utilising an exchange of an HIV test for a hip hop concert ticket, in a metropolitan city among African American youth and young adults. A subset of intervention participants participated in standardised testing, sex…

  5. Femoral stem fracture and in vivo corrosion of retrieved modular femoral hips.

    PubMed

    Huot Carlson, J Caitlin; Van Citters, Douglas W; Currier, John H; Bryant, Amber M; Mayor, Michael B; Collier, John P

    2012-08-01

    A series of 78 retrieved modular hip devices were assessed for fretting and corrosion. Damage was common at both the head-neck junction (54% showing corrosion; 88% showing fretting) and at the stem-sleeve junction (88% corrosion; 65% fretting). Corrosion correlated to in vivo duration, patient activity, and metal (vs ceramic) femoral heads but did not correlate to head carbon content. Femoral stem fatigue fracture was observed in seven retrievals; all had severe corrosion, were under increased stress, and were in vivo longer than the non-fractured cohort. This study emphasizes the potential for stem fracture when small diameter femoral stems with large offsets are used in heavy and active patients. Designs which reduce fretting and corrosion in modular implants is warranted as patients demand longer lasting implants. PMID:22209042

  6. Uncertainty quantification of the optimal stimulation area in an electro-stimulative hip revision system.

    PubMed

    Schmidt, Christian; Zimmermann, Ulf; van Rienen, Ursula

    2014-08-01

    Electro-stimulative hip revision systems accelerate the bone growth around the implant and are capable of reducing the number of side effects such as aseptic implant loosening. A computational model was developed to determine the optimal electrode arrangement for such a system, which is currently under development. The optimization process depends on the electrical properties of bone material and the used bone substitute, which are subject to uncertainty in literature and its production process, respectively. To quantify the influence of these uncertain parameters on the optimal stimulation ratio (OSR), the computationally effective non-intrusive polynomial chaos technique was applied. The results indicate that the conductivity of bone substitute is most sensitive to the OSR, while its uncertainty was comparatively small compared to that of the uncertain parameters. PMID:25570086

  7. Qualitative holographic study of hemi-pelvic deformation caused by loading different hip prostheses.

    PubMed

    Spirakis, A; Learmonth, I D; Gryzagoridis, J; Davis, B L

    1992-03-01

    The dynamic biological response of bone can materially influence the longevity of artificial implants. This paper presents a series of in vitro experiments conducted on epoxy resin models of human hemi-pelves. Different commercially available acetabular components were implanted and used for the construction of simplified three-dimensional models of the artificial hip joint. Boundary conditions included simulation of muscle groups and femoral loading. Real-time holographic interferometry, a stress analysis technique permitting whole-field simultaneous inspection of deformation patterns, was used as the experimental method. The holographic interferograms were interpreted qualitatively rather than quantitatively. High stresses were identified in the hemi-pelvis and it is postulated that these stresses may be implicated in the mechanical pathogenesis of loosening. The observed changes in the detected stress levels could influence both future design of acetabular prostheses and surgical techniques. PMID:1306037

  8. Urinary incontinence - injectable implant

    MedlinePLUS

    Injectable implants are injections of material into the urethra to help control urine leakage ( urinary incontinence ) caused by a ... into the tissue next to the sphincter. The implant procedure is usually done in the hospital. Or ...

  9. Pacemakers and Implantable Defibrillators

    MedlinePLUS

    ... arrhythmia is serious, you may need a cardiac pacemaker or an implantable cardioverter defibrillator (ICD). They are ... are implanted in your chest or abdomen. A pacemaker helps control abnormal heart rhythms. It uses electrical ...

  10. The Ion Implanter

    NSDL National Science Digital Library

    This web site displays and describes the major components of a modern high current ion implanter. It uses a series of clickable image maps to help navigate. The site describes the entire process of ion implantation.

  11. Implant-Supported Denture

    MedlinePLUS

    ... implants for support. Bar-retained dentures — A thin metal bar that follows the curve of your jaw ... dentures) — Each implant in the jawbone holds a metal attachment that fits into another attachment on the ...

  12. SURGICAL SKILLS TRAINING FOR PRIMARY TOTAL HIP ARTHROPLASTY

    PubMed Central

    HASEGAWA, YUKIHARU; AMANO, TAKAFUMI

    2015-01-01

    ABSTRACT A total of 483 hips treated by primary total hip arthroplasty (THA) were investigated to evaluate the surgical skill of the performing surgeon. Surgical trainees operated on 259 hips and instructors on 224 hips. The average age of the patients at the time of THA in the trainee and instructor group was 61.9 and 60.8 years old, respectively. The average follow-up duration was 5.1 years. The operative time in the trainee group and instructor group was 87.0 and 73.1 min, respectively (p=0.031). Complications were noted in 11 hips (3.5%) in the trainee group; acetabular fracture, 3 hips; dislocation, 3 hips; femoral artery lacerations that needed repair surgery, 2 hips; sciatic nerve palsy, 2 hips; and skin necrosis, 1 hip. Complication were noted in three hips (1.3%) in the instructor group; femoral fracture, 1 hip; acetabular fracture, 1 hip; dislocation, 1 hip. Complication rate in the trainee group was higher than in the instructor group. The monitored quality of the surgeries performed by trainees and instructors was not significantly different. Poor quality was identified in 14 hips in the trainee group and 6 hips in instructor group. No significant difference was found in the hip score between the trainees and instructors before and after surgery. Revision arthroplasty was defined as the end-point for primary THA. Kaplan-Meier survivorship at 5 years after primary THA was 97.2% in trainee group and 97.3% in the instructor group. Short-term clinical and radiographic results of primary THA in the trainee and instructor groups were considered safe and satisfactory. PMID:25797970

  13. Trends in Cochlear Implants

    Microsoft Academic Search

    Fan-Gang Zeng

    2004-01-01

    More than 60,000 people worldwide use cochlear implants as a means to restore functional hearing. Although individual performance variability is still high, an average implant user can talk on the phone in a quiet environment. Cochlear-implant research has also matured as a field, as evidenced by the exponential growth in both the patient population and scientific publication. The present report

  14. Cochlear Implantations in Children

    Microsoft Academic Search

    Athena Stinson

    1996-01-01

    Cochlear implant procedures are available for children who are diagnosed with severe hearing loss. Cochlear implants can restore children's perceptions of sound through the use of electronic devices. Perioperative nurses should be knowledgeable about all surgical aspects of cochlear implant procedures and be aware of the months of preparation before surgery and the lengthy rehabilitation afterward. This article discusses the

  15. Effect of multiple actuations, delayed inhalation and antistatic treatment on the lung bioavailability of salbutamol via a spacer device

    Microsoft Academic Search

    D. J. Clark; B. J. Lipworth

    1996-01-01

    BACKGROUND: The aim of this study was to extend previous in vitro observations regarding the effects of multiple actuations of aerosols into spacer devices, delayed inhalation, and antistatic treatment of spacer devices on the amount of drug delivered for inhalation. An in vivo study of lung bioavailability of salbutamol from a large volume (Volumatic) spacer was conducted. METHODS: Ten healthy

  16. Identification of bacteria on the surface of clinically infected and non-infected prosthetic hip joints removed during revision arthroplasties by 16S rRNA gene sequencing and by microbiological culture

    Microsoft Academic Search

    Kate E Dempsey; Marcello P Riggio; Alan Lennon; Victoria E Hannah; Gordon Ramage; David Allan; Jeremy Bagg

    2007-01-01

    It has been postulated that bacteria attached to the surface of prosthetic hip joints can cause localised inflammation, resulting in failure of the replacement joint. However, diagnosis of infection is difficult with traditional microbiological culture methods, and evidence exists that highly fastidious or non-cultivable organisms have a role in implant infections. The purpose of this study was to use culture

  17. Fracture of Ceramic Bearing Surfaces following Total Hip Replacement: A Systematic Review

    PubMed Central

    Traina, Francesco; Faldini, Cesare

    2013-01-01

    Ceramic bearing surfaces are increasingly used for total hip replacement, notwithstanding that concern is still related to ceramic brittleness and its possible mechanical failure. The aim of this systematic review is to answer three questions: (1) Are there risk factors for ceramic component fracture following total hip replacement? (2) Is it possible to perform an early diagnosis of ceramic component failure before catastrophic fracture occurs? (3) Is it possible to draw guidelines for revision surgery after ceramic components failure? A PubMed and Google Scholar search was performed and reference citations from publications identified in the literature search were reviewed. The use of 28?mm short-neck femoral head carries an increased risk of fracture. Acetabular component malposition might increase the risk of ceramic liner fractures. Synovial fluid microanalysis and CT scan are promising in early diagnosis of ceramic head and liner failure. Early revision is suggested in case of component failure; no consensus exists about the better coupling for revision surgery. Ceramic brittleness remains a major concern. Due to the increased number of ceramic on ceramic implants, more revision surgeries and reports on ceramic components failure are expected in the future. An algorithm of diagnosis and treatment for ceramic hip failure is proposed. PMID:23844356

  18. Characterization of macrophage polarizing cytokines in the aseptic loosening of total hip replacements.

    PubMed

    Jämsen, Eemeli; Kouri, Vesa-Petteri; Olkkonen, Juri; Cör, Andrej; Goodman, Stuart B; Konttinen, Yrjö T; Pajarinen, Jukka

    2014-09-01

    Aseptic loosening of hip replacements is driven by the macrophage reaction to wear particles. The extent of particle-induced macrophage activation is dependent on the state of macrophage polarization, which is dictated by the local cytokine microenvironment. The aim of the study was to characterize cytokine microenvironment surrounding failed, loose hip replacements with an emphasis on identification of cytokines that regulate macrophage polarization. Using qRT-PCR, the expression of interferon gamma (IFN-?), interleukin-4 (IL-4), granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-13, and IL-17A was low and similar to the expression in control synovial tissues of patients undergoing primary hip replacement. Using immunostaining, no definite source of IFN-? or IL-4 could be identified. IL-17A positive cells, identified as mast cells by double staining, were detected but their number was significantly reduced in interface tissues compared to the controls. Significant up-regulation of IL-10, M-CSF, IL-8, CCL2-4, CXCL9-10, CCL22, TRAP, cathepsin K, and down regulation of OPG was seen in the interface tissues, while expression of TNF-?, IL-1?, and CD206 were similar between the conditions. It is concluded that at the time of the revision surgery the peri-implant macrophage phenotype has both M1 and M2 characteristics and that the phenotype is regulated by other local and systemic factors than traditional macrophage polarizing cytokines. PMID:24897980

  19. Early Hospital Release May Hurt Broken-Hip Patients

    MedlinePLUS

    ... JavaScript. Early Hospital Release May Hurt Broken-Hip Patients Survival odds improve with longer stay, study finds (* ... Health WEDNESDAY, Feb. 25, 2015 (HealthDay News) -- Older patients with a broken hip are more likely to ...

  20. 21 CFR 890.3665 - Congenital hip dislocation abduction splint.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3665 Congenital hip dislocation abduction splint. (a) Identification. A congenital hip...

  1. Research Shows Cataract Surgery Can Reduce Hip Fracture Risk

    MedlinePLUS

    ... sponsored Research Shows Cataract Surgery Can Reduce Hip Fracture Risk 08/01/2012 09:00:00 AM ... Medicare beneficiaries shows that the risk of hip fractures was significantly reduced in patients who had had ...

  2. Large, rapidly evolving intergenic spacers in the mitochondrial DNA of the salamander family Ambystomatidae (Amphibia: Caudata).

    PubMed

    McKnight, M L; Shaffer, H B

    1997-11-01

    We report the presence, in the mitochondrial DNA (mtDNA) of all of the sexual species of the salamander family Ambystomatidae, of a shared 240-bp intergenic spacer between tRNAThr and tRNAPro. We place the intergenic spacer in context by presenting the sequence of 1,746 bp of mtDNA from Ambystoma tigrinum tigrinum, describe the nucleotide composition of the intergenic spacer in all of the species of Ambystomatidae, and compare it to other coding and noncoding regions of Ambystoma and several other vertebrate mtDNAs. The nucleotide substitution rate of the intergenic spacer is approximately three times faster than the substitution rate of the control region, as shown by comparisons among six Ambystoma macrodactylum sequences and eight members of the Ambystoma tigrinum complex. We also found additional inserts within the intergenic spacers of five species that varied from 87-444 bp in length. The presence of the intergenic spacer in all sexual species of Ambystomatidae suggests that it arose at least 20 MYA and has been a stable component of the ambystomatid mtDNA ever since. As such, it represents one of the few examples of a large and persistent intergenic spacer in the mtDNA of any vertebrate clade. PMID:9364774

  3. Influence of spacer device on drug delivery to young children with asthma.

    PubMed Central

    Agertoft, L; Pedersen, S

    1994-01-01

    The budesonide dose delivered to the patient from three different spacer devices (Nebuhaler = 750 ml, Aerochamber = 140 ml, and Babyspacer = 260 ml) was assessed by measuring the budesonide dose deposited on a filter inserted between the spacer outlet and the mouth of the patient. Twenty children aged 10-25 months were given a single dose of 200 micrograms budesonide from each spacer device in a randomised crossover study. All spacers had a facemask attached and a one way valve system. The children breathed through the inhalation system for 30 seconds. Furthermore, the minute ventilation of the children through a tightly fitting facemask was measured. The filter dose of budesonide was significantly lower after Aerochamber treatment (39.4 micrograms, range 19-67 micrograms) than after Nebuhaler (53.5 micrograms, range 34-88 micrograms) and Babyspacer (55.5 micrograms, range 39-76 micrograms) treatment. The minute ventilation of the children varied from 1.4 l/min to 7.0 l/min (mean 5.0 l/min). This was sufficient to empty all spacers within the 30 seconds of inhalation. It is concluded that spacer volume does not seem to be so important for children aged 10-25 months as long as spacers with a volume lower than 750 ml are used. PMID:7979494

  4. Impact Analysis and Test for the Spacer Grid Assembly of a Nuclear Fuel Assembly

    NASA Astrophysics Data System (ADS)

    Song, Kee-Nam; Lee, Sang-Hoon; Lee, Soo-Bum

    A spacer grid assembly is one of the main structural components of the nuclear fuel assembly for a Pressurized light Water Reactor (PWR). The spacer grid assembly supports and aligns the fuel rods, guides the fuel assemblies past each other during a handling and, if needed, sustains lateral seismic loads. The ability of a spacer grid assembly to resist these lateral loads is usually characterized in terms of its dynamic and static crush strengths, which are acquired from tests. In this study, a finite element analysis on the dynamic crush strength of spacer grid assembly specimens is carried out. Comparisons show that the analysis results are in good agreement with the test results to within about a 30 % difference range. Therefore, we could predict the crush strength of a spacer grid assembly in advance, before performing a dynamic crush test. And also a parametric study on the crush strength of a spacer grid assembly is carried out by adjusting the weld penetration depth for a sub-sized spacer grid, which also shows a good agreement between the test and analysis results.

  5. Do hip protectors decrease the risk of hip fracture in institutional and community-dwelling elderly? A systematic review and meta-analysis of randomized controlled trials

    Microsoft Academic Search

    Anna M. Sawka; Pauline Boulos; Karen Beattie; Lehana Thabane; Alexandra Papaioannou; Amiram Gafni; Ann Cranney; Nicole Zytaruk; David A. Hanley; Jonathan D. Adachi

    2005-01-01

    Hip fractures are an important cause of morbidity and mortality in the elderly. Hip protectors are padded undergarments designed to decrease the impact of a fall on the hip. We systematically reviewed randomized controlled trials of hip protectors to determine if they reduce hip fractures in the elderly. Analyses were pooled according to participant residence—community or institutional (the latter, included

  6. An evolutionary preserved intergenic spacer in gadiform mitogenomes generates a long noncoding RNA

    PubMed Central

    2014-01-01

    Background Vertebrate mitogenomes are economically organized and usually lack intergenic sequences other than the control region. Intergenic spacers located between the tRNAThr and tRNAPro genes (“T-P spacers”) have been observed in several taxa, including gadiform species, but information about their biological roles and putative functions is still lacking. Results Sequence characterization of the complete European hake Merluccius merluccius mitogenome identified a complex T-P spacer ranging in size from 223–532 bp. Further analyses of 32 gadiform species, representing 8 families and 28 genera, revealed the evolutionary preserved presence of T-P spacers across all taxa. Molecular complexity of the T-P spacers was found to be coherent with the phylogenetic relationships, supporting a common ancestral origin and gain of function during codfish evolution. Intraspecific variation of T-P spacer sequences was assessed in 225 Atlantic cod specimens and revealed 26 haplotypes. Pyrosequencing data representing the mito-transcriptome poly (A) fraction in Atlantic cod identified an abundant H-strand specific long noncoding RNA of about 375 nt. The T-P spacer corresponded to the 5’ part of this transcript, which terminated within the control region in a tail-to-tail configuration with the L-strand specific transcript (the 7S RNA). Conclusions The T-P spacer is inferred to be evolutionary preserved in gadiform mitogenomes due to gain of function through a long noncoding RNA. We suggest that the T-P spacer adds stability to the H-strand specific long noncoding RNA by forming stable hairpin structures and additional protein binding sites. PMID:25145347

  7. Natural acetabular orientation in arthritic hips

    PubMed Central

    Goudie, S. T.; Deakin, A. H.; Deep, K.

    2015-01-01

    Objectives Acetabular component orientation in total hip arthroplasty (THA) influences results. Intra-operatively, the natural arthritic acetabulum is often used as a reference to position the acetabular component. Detailed information regarding its orientation is therefore essential. The aim of this study was to identify the acetabular inclination and anteversion in arthritic hips. Methods Acetabular inclination and anteversion in 65 symptomatic arthritic hips requiring THA were measured using a computer navigation system. All patients were Caucasian with primary osteoarthritis (29 men, 36 women). The mean age was 68 years (SD 8). Mean inclination was 50.5° (SD 7.8) in men and 52.1° (SD 6.7) in women. Mean anteversion was 8.3° (SD 8.7) in men and 14.4° (SD 11.6) in women. Results The difference between men and women in terms of anteversion was significant (p = 0.022). In 75% of hips, the natural orientation was outside the safe zone described by Lewinnek et al (anteversion 15° ± 10°; inclination 40° ± 10°). Conclusion When using the natural acetabular orientation to guide component placement, it is important to be aware of the differences between men and women, and that in up to 75% of hips natural orientation may be out of what many consider to be a safe zone. Cite this article: Bone Joint Res 2015;4:6–10. PMID:25628463

  8. Possible Predisposing Factors for the Second Hip Fracture

    Microsoft Academic Search

    K. E. Dretakis; E. K. Dretakis; E. F. Papakitsou; S. Psarakis; K. Steriopoulos

    1998-01-01

    .   Among 1685 patients who sustained a hip fracture at the island of Crete (Greece) in a 4-year period we found 106 patients\\u000a with bilateral noncontemporary hip fractures. Pathologic hip fractures and fractures that emerged from high energy trauma\\u000a were excluded. To investigate the possible factors predisposing to the later fracture in the sound hip, we studied these 106\\u000a patients

  9. Migration of two different cementless hip arthroplasty stems in combination with two different heads: a biomechanical in vitro study.

    PubMed

    Klestil, T; Morlock, M M; Schwieger, K; Sellenschloh, K; Curda, B; Biedermann, R; Hennerbichler, A; Schmoelz, W; Rabl, W; Blauth, M

    2006-08-01

    The aim of the present in vitro study was to evaluate migrational characteristics of cementless primary hip arthroplasty stems in combination with a diameter 50 mm head (hemiarthroplasty) and a diameter 28 mm head in and with a polyethylene cup (total hip arthroplasty) in fresh-frozen human specimens. Two different types (Endo SL, FMT) were implanted into seven pairs of fresh-frozen human femoral specimens. The implanted stems were combined with a diameter 50 mm head (hemiarthroplasty) on one side and with a polyethylene cup and a 28 mm head (total hip arthroplasty) on the other side. Dynamic mechanical loading was applied for 50,000 cycles while recording relative motions between stem and bone stock using a 3-D motion analysis system. The Endo SL stem showed a significantly higher amplitude of relative motion in all translational and rotational components regardless of the head used. In both stem types a strong tendency for higher axial migration with the diameter 50 mm head in comparison to the THA head was found. The lowest axial migration was found in the FMTstem in combination with the small head and a PE cup. The highest axial migration was found in the Endo SL stem combined with the diameter 50 mm head. Our results indicate that the head might play an important role for axial migration of cementless stems. PMID:16557367

  10. Artifact Reduction in X-Ray CT Images of Al-Steel-Perspex Specimens Mimicking a Hip Prosthesis

    SciTech Connect

    Madhogarhia, Manish [Nuclear Engineering and Technology Programme, Indian Institute of Technology, Kanpur 208016 (India); Munshi, P.; Lukose, Sijo; Subramanian, M. P.; Muralidhar, C. [Non Destructive Evaluation Division, Defence Research and Development Laboratory, Hyderabad 500258 (India)

    2008-09-26

    X-ray Computed Tomography (CT) is a relatively new technique developed in the late 1970's, which enables the nondestructive visualization of the internal structure of objects. Beam hardening caused by the polychromatic spectrum is an important problem in X-ray computed tomography (X-CT). It leads to various artifacts in reconstruction images and reduces image quality. In the present work we are considering the Artifact Reduction in Total Hip Prosthesis CT Scan which is a problem of medical imaging. We are trying to reduce the cupping artifact induced by beam hardening as well as metal artifact as they exist in the CT scan of a human hip after the femur is replaced by a metal implant. The correction method for beam hardening used here is based on a previous work. Simulation study for the present problem includes a phantom consisting of mild steel, aluminium and perspex mimicking the photon attenuation properties of a hum hip cross section with metal implant.

  11. Total revision of the hip using allograft to correct particle disease induced osteolysis: a case study.

    PubMed

    Taylor, Drew W; Taylor, Jennifer E; Raizman, Igal; Gross, Allan E

    2009-01-01

    Total hip replacement is considered to be a highly successful and routine surgery; however, the internal components produce particles through friction and wear in the device. These particles are identified as one of the main reasons for total hip revisions. The generated, biologically active, particles provoke the formation of osteolytic areas through the inhibition of bone formation and increased fluid production. The resulting bone loss can be managed through the use of allograft bone in combination with bone chips and cement. In addition, implants constructed with highly porous trabecular metal can be used to further facilitate rapid and extensive tissue infiltration resulting in strong implant attachment. In this case study we show the use of a tibial allograft coupled with bone chips and cement to cover and support a lytic cyst in the proximal femur, distal to the greater trochanter. Additionally, we detail the use of a trabecular metal cup to halt the migration of the component into the acetabulum and promote greater fixation and bone ingrowth. PMID:19753282

  12. Size of metallic and polyethylene debris particles in failed cemented total hip replacements

    NASA Technical Reports Server (NTRS)

    Lee, J. M.; Salvati, E. A.; Betts, F.; DiCarlo, E. F.; Doty, S. B.; Bullough, P. G.

    1992-01-01

    Reports of differing failure rates of total hip prostheses made of various metals prompted us to measure the size of metallic and polyethylene particulate debris around failed cemented arthroplasties. We used an isolation method, in which metallic debris was extracted from the tissues, and a non-isolation method of routine preparation for light and electron microscopy. Specimens were taken from 30 cases in which the femoral component was of titanium alloy (10), cobalt-chrome alloy (10), or stainless steel (10). The mean size of metallic particles with the isolation method was 0.8 to 1.0 microns by 1.5 to 1.8 microns. The non-isolation method gave a significantly smaller mean size of 0.3 to 0.4 microns by 0.6 to 0.7 microns. For each technique the particle sizes of the three metals were similar. The mean size of polyethylene particles was 2 to 4 microns by 8 to 13 microns. They were larger in tissue retrieved from failed titanium-alloy implants than from cobalt-chrome and stainless-steel implants. Our results suggest that factors other than the size of the metal particles, such as the constituents of the alloy, and the amount and speed of generation of debris, may be more important in the failure of hip replacements.

  13. Size of metallic and polyethylene debris particles in failed cemented total hip replacements.

    PubMed

    Lee, J M; Salvati, E A; Betts, F; DiCarlo, E F; Doty, S B; Bullough, P G

    1992-05-01

    Reports of differing failure rates of total hip prostheses made of various metals prompted us to measure the size of metallic and polyethylene particulate debris around failed cemented arthroplasties. We used an isolation method, in which metallic debris was extracted from the tissues, and a non-isolation method of routine preparation for light and electron microscopy. Specimens were taken from 30 cases in which the femoral component was of titanium alloy (10), cobalt-chrome alloy (10), or stainless steel (10). The mean size of metallic particles with the isolation method was 0.8 to 1.0 microns by 1.5 to 1.8 microns. The non-isolation method gave a significantly smaller mean size of 0.3 to 0.4 microns by 0.6 to 0.7 microns. For each technique the particle sizes of the three metals were similar. The mean size of polyethylene particles was 2 to 4 microns by 8 to 13 microns. They were larger in tissue retrieved from failed titanium-alloy implants than from cobalt-chrome and stainless-steel implants. Our results suggest that factors other than the size of the metal particles, such as the constituents of the alloy, and the amount and speed of generation of debris, may be more important in the failure of hip replacements. PMID:1587882

  14. Hip prosthesis infection related to an unchecked intrauterine contraceptive device: a case report.

    PubMed

    Ducharne, G; Girard, J; Pasquier, G; Migaud, H; Senneville, E

    2013-02-01

    Intrauterine devices (IUD) used for contraception can be the source of local infections or can migrate, which justifies regular checking recommendations and limitations around the implantation period. To our knowledge, bone and joint infections related to an infected IUD have not been described in the scientific literature. This paper reports on a case of the repeated infection of a total hip prosthesis related to an infected IUD that had been forgotten after being implanted 34years previously. The arthroplasty infection revealed itself through dislocation of a dual mobility cup. Commensal bacteria that colonize the female genital tract (Streptococcus agalactiae) were identified at the site of hip arthroplasty. This led to the discovery of the IUD that was infected by the same bacterium. Despite lavage of the non-loosened arthroplasty, removal of the IUD and 2months of antibiotic treatment, the dislocation recurred and the prosthesis was again infected with the same microorganism 4months later. This recurrence of the infection, with persistence of a uterine abscess containing the same bacterium, was treated with repeated lavage of the joint, total hysterectomy and antibiotics treatment. The infection had resolved when followed-up 3years later. The occurrence of a bone and joint infection with this type of bacterium should trigger the evaluation of a possible IUD infection. PMID:23238208

  15. Trends in Cochlear Implants

    PubMed Central

    Zeng, Fan-Gang

    2004-01-01

    More than 60,000 people worldwide use cochlear implants as a means to restore functional hearing. Although individual performance variability is still high, an average implant user can talk on the phone in a quiet environment. Cochlear-implant research has also matured as a field, as evidenced by the exponential growth in both the patient population and scientific publication. The present report examines current issues related to audiologic, clinical, engineering, anatomic, and physiologic aspects of cochlear implants, focusing on their psychophysical, speech, music, and cognitive performance. This report also forecasts clinical and research trends related to presurgical evaluation, fitting protocols, signal processing, and postsurgical rehabilitation in cochlear implants. Finally, a future landscape in amplification is presented that requires a unique, yet complementary, contribution from hearing aids, middle ear implants, and cochlear implants to achieve a total solution to the entire spectrum of hearing loss treatment and management. PMID:15247993

  16. Resolving controversies in hip fracture care: the need for large collaborative trials in hip fractures.

    PubMed

    Bhandari, Mohit; Sprague, Sheila; Schemitsch, Emil H

    2009-07-01

    Hip fractures are a significant cause of morbidity and mortality worldwide and the burden of disability associated with hip fractures globally vindicate the need for high-quality research to advance the care of patients with hip fractures. Historically, large, multi-centre randomized controlled trials have been rare in the orthopaedic trauma literature. Similar to other medical specialties, orthopaedic research is currently undergoing a paradigm shift from single centre initiatives to larger collaborative groups. This is evident with the establishment of several collaborative groups in Canada, in the United States, and in Europe, which has proven that multi-centre trials can be extremely successful in orthopaedic trauma research.Despite ever increasing literature on the topic of his fractures, the optimal treatment of hip fractures remains unknown and controversial. To resolve this controversy large multi-national collaborative randomized controlled trials are required. In 2005, the International Hip Fracture Research Collaborative was officially established following funding from the Canadian Institute of Health Research International Opportunity Program with the mandate of resolving controversies in hip fracture management. This manuscript will describe the need, the information, the organization, and the accomplishments to date of the International Hip Fracture Research Collaborative. PMID:19550238

  17. Effects of preoperative physiotherapy in hip osteoarthritis patients awaiting total hip replacement

    PubMed Central

    Czy?ewska, Anna; Walesiak, Katarzyna; Krawczak, Karolina; Cabaj, Dominika; Górecki, Andrzej

    2014-01-01

    Introduction The World Health Organization (WHO) claimed osteoarthritis as a civilization-related disease. The effectiveness of preoperative physiotherapy among patients suffering hip osteoarthritis (OA) at the end of their conservative treatment is rarely described in the literature. The aim of this study was to assess the quality of life and musculoskeletal health status of patients who received preoperative physiotherapy before total hip replacement (THR) surgery within a year prior to admission for a scheduled THR and those who did not. Material and methods Forty-five patients, admitted to the Department of Orthopaedics and Traumatology of Locomotor System for elective total hip replacement surgery, were recruited for this study. The assessment consisted of a detailed interview using various questionnaires: the Harris Hip Score (HHS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the 36-Item Short Form Health Survey (SF-36), and the Hip disability and Osteoarthritis Outcome Score (HOOS), as well as physical examination. Patients were assigned to groups based on their attendance of preoperative physiotherapy within a year prior to surgery. Results Among patients who received preoperative physiotherapy a significant improvement was found for pain, daily functioning, vitality, psychological health, social life, and (active and passive) internal rotation (p < 0.05). Conclusions Patients are not routinely referred to physiotherapy within a year before total hip replacement surgery. This study confirmed that pre-operative physiotherapy may have a positive influence on selected musculoskeletal system status indicators and quality of life in hip osteoarthritis patients awaiting surgery. PMID:25395951

  18. Resolving Controversies in Hip Fracture Care: The Need for Large Collaborative Trials in Hip Fractures

    PubMed Central

    Bhandari, Mohit; Sprague, Sheila; Schemitsch, Emil H.

    2010-01-01

    Summary Hip fractures are a significant cause of morbidity and mortality worldwide and the burden of disability associated with hip fractures globally vindicates the need for high-quality research to advance the care of patients with hip fractures. Historically, large, multi-centre randomized controlled trials have been rare in the orthopaedic trauma literature. Similar to other medical specialties, orthopaedic research is currently undergoing a paradigm shift from single centre initiatives to larger collaborative groups. This is evident with the establishment of several collaborative groups in Canada, in the United States, and in Europe, which has proven that multi-centre trials can be extremely successful in orthopaedic trauma research. Despite ever increasing literature on the topic of his fractures, the optimal treatment of hip fractures remains unknown and controversial. To resolve this controversy large multi-national collaborative randomized controlled trials are required. In 2005, the International Hip Fracture Research Collaborative was officially established following funding from the Canadian Institute of Health Research International Oppurtunity Program with the mandate of resolving controversies in hip fracture management. This manuscript will describe the need, the information, the organization, and the accomplishments to date of the International Hip Fracture Research Collaborative. PMID:19550238

  19. In Vitro Performance of Spacers for Aerosol Delivery during Adult Mechanical Ventilation.

    PubMed

    Boukhettala, Nabile; Porée, Thierry; Diot, Patrice; Vecellio, Laurent

    2014-07-22

    Abstract Background: During mechanical ventilation, different aerosol generators are employed with various interfaces. The objective of this study was to evaluate the performance of a range of spacers, including a new device called Combihaler(®) designed for connection with both nebulizers and pressurized Metered-Dose Inhalers (pMDIs). Methods: To assess the spacers, we used a ventilator and the Dual Adult Training and Test Lung (model 5600i, Michigan Instruments). Ventilation parameters were measured with and without spacers in volume-controlled and pressure-controlled mode. A filter was placed at the end of the endotracheal tube to measure aerosol delivery. Amikacin (1?g/8?mL) and salbutamol (5?mg/5?mL) were nebulized with an Aeroneb Solo(®) connected to its T-adapter or the Combihaler(®) spacer. Salbutamol (100??g/actuation with 10 actuations) and beclomethasone (250??g/actuation with 10 actuations) were delivered with a pMDI connected to a Minispacer(®), an ACE(®) spacer, or a Combihaler(®) spacer. Drug delivery measurements were performed in volume-controlled mode in dry and humidified conditions. Drug deposits on the filter were assayed. Results: The use of spacers and the T-adapter did not change the ventilation parameters (p>0.9). Aerosol delivery of salbutamol and Amikacin by nebulization increased up to three-fold with the Combihaler(®) compared with the T-adapter in humidified and nonhumidified conditions (p<0.05). Aerosol delivery of salbutamol and beclometasone by pMDI increased up to three-fold with the Combihaler(®) and the ACE(®) spacer compared with the Minispacer(®) in humidified and nonhumidified conditions (p<0.05). Aerosol delivery by pMDIs and vibrating mesh nebulizers using either a T-adapter or spacers was reduced by up to 62.5% in a humidified circuit compared with a nonhumidified circuit. Conclusion: Aerosol delivery via pMDIs and vibrating mesh nebulizers is greater with large spacers (Combihaler(®) and ACE(®)) than with smaller spacers (Minispacer(®)) or a T-adapter, in both humidified and nonhumidified conditions. In humidified conditions, the aerosol delivery decreased with all spacers. PMID:25050644

  20. Increase of the electron mobility in HEMT heterostructures with composite spacers containing AlAs nanolayers

    SciTech Connect

    Vinichenko, A. N., E-mail: vanaxel@gmail.com; Gladkov, V. P.; Kargin, N. I.; Strikhanov, M. N.; Vasil’evskii, I. S. [National Research Nuclear University “MEPhI” (Russian Federation)

    2014-12-15

    The effect of the hybridization of quantum states on electron transport in a two-barrier quantum well ?-doped through a spacer layer at the limit of heavy doping is shown theoretically and experimentally. A method for increasing the electron mobility in the quantum well by suppressing the tunnel coupling with the donor region through the introduction of an AlAs nanobarrier into the spacer layer is proposed. It is experimentally shown that, in the samples with a shallow quantum well, the AlAs nanobarrier introduced into the spacer layer provides a larger than threefold increase in the electron mobility at low temperatures.

  1. [Viscosity determination of synovial fluids from the canine hip and elbow joint as well as the human knee joint].

    PubMed

    Helms, Gabriele; Rittmann, Pia; Wefstaedt, Patrick; Windhagen, Henning; Pressel, Thomas; Behrens, Bernd-Arno; Nolte, Ingo

    2008-01-01

    The development of pathological changes in both human and canine hip joints is mainly caused by a lack of synovial fluid lubrication. This results in an increased joint abrasion. Even after implantation of joint prosthesis, inadequate lubrication can lead to abrasion in the tribological pair. This can finally result in aseptic loosening of the prosthesis. In spite of the enormous number of studies that have been performed on human, only little knowledge about the tribological properties of the joints in dogs is available in the literature. For this reason the viscosities of synovial fluid, derived from physiological and pathologically changed canine elbow joints were measured. The viscosities were determined by the use of a cone-plate viscometer at different temperatures and shear rates. The obtained values were compared with the viscosity values of pathologically changed synovial fluids from human knee joints as well as with pathological samples from the canine hip joint. The results show that the viscosity values vary within a series of measurements and are inversely proportional to the temperature of the sample and the shear rate. The differences between the average viscosities of canine and human synovial fluids taken from pathologically changed joints are below 4% (22.5 s(-1) at theta1 = 25 degrees C). The findings of this study are being implemented in a FE-Model for the computation of actual forces in the hip joint during different movements. This would represent a contribution to an improved prosthetic treatment of canine and human hips. PMID:18822609

  2. Reducing falls and resulting hip fractures among older women

    Microsoft Academic Search

    Judy A. Stevens; Sarah Olson

    2000-01-01

    Scope of the problem: Fall-related injuries are the leading cause of injury, deaths, and disabilities among people older than 65. The most serious fall injury is hip fracture; half of all older adults hospitalized for hip fracture never regain their former level of function. In 1996, a total of 340,000 hospitalizations for hip fracture occurred among this population, and 80%

  3. Increasing hip fracture incidence in California Hispanics, 1983 to 2000

    Microsoft Academic Search

    David S. Zingmond; L. Joseph Melton; Stuart L. Silverman

    2004-01-01

    Background: Hip fracture incidence in non-Hispanic whites (NHW) has decreased nationwide for the past 20 years. Little is known regarding hip fracture incidence among Hispanics, the largest, fastest growing minority in the United States. Objective: To assess the change in standardized hip fracture incidence from 1983 through 2000 in California Hispanics relative to other racial groups. Design: Hospitalizations for individuals older

  4. [Geometry of the hip joint: methodology and guidelines].

    PubMed

    Gaspar, Drago; Crnkovi?, Tomislav

    2013-03-01

    An hip fracture is an significant personal, family and health issue of people older than 65 years. In the first year of the fracture up to 30% of the injured die and about 50% of them never regain their formal degree of independence in fulfilling day-to-day activities. Estimations are that throughout 30 years in the world there will be around 6 million hip fractures per year which is about four times the todays amount. Todays predictions of hip fractures based on the hip geometry have shown us that the hip geometry is an independent variable of the bone mineral density. The hip geometry is more resistant to the effect of various factors than the bone mineral density and the changes throu life are a lot slower. The uniqueness and the sensitivity of the hip geometry in predicting a fracture is high and acceptable in research results of most authors. In this review we present the previous relevant knowledge about the measures and factors which determines the hip geometry and the accepted amount of pictorial methods of hip display. We have compared the methodology and the patients of eleven randomly picked writings on predicting hip fracture based on the hip geometry. We highlight the need of further refinement of the methodology and the more balanced selection of patients for a greater conformity in future writings. The hip geometry has shown it self as an useful diagnostical instrument but there is still more room for its improvement. PMID:24279254

  5. Primary hyperparathyroidism: an uncommon cause of hip pain.

    PubMed

    Waseem, Muhammad; Erickson, Evelyn; Agyare, Samuel; Godil, Mushtaq A

    2015-04-01

    Hip pain is a common complaint in a pediatric emergency department. The causes of hip pain are diverse and generally include traumatic and infectious causes. We report a case of hip pain caused by deep soft tissue infection associated with hypercalcemia and primary hyperparathyroidism. Atypical presentation of primary hyperparathyroidism may result in a delay in diagnosis. PMID:25831028

  6. Timing, Intensity, and Duration of Rehabilitation for Hip and Stroke

    E-print Network

    Rau, Don C.

    Timing, Intensity, and Duration of Rehabilitation for Hip and Stroke Fracture BETHESDA, MD on rehabilitation for stroke and hip fracture was held August 4 by the National Center for Medical Rehabilitation, intensity, and duration of rehabilitation. Stroke and hip fracture were included together because these two

  7. Return to sport after hip arthroscopy: aggregate recommendations from high-volume hip arthroscopy centers.

    PubMed

    Domb, Benjamin G; Stake, Christine E; Finch, Nathan A; Cramer, T Luke

    2014-10-01

    Hip arthroscopy is a minimally invasive surgical technique often performed in athletes who want an expeditious return to sport. To the authors' knowledge, no studies in the literature provide a time frame or criteria for return to sport after hip arthroscopy. The purpose of this study was to develop an aggregate recommendation for return to sport after hip arthroscopy based on data assimilated from high-volume hip arthroscopy centers. Twenty-seven orthopedic surgeons from high-volume hip arthroscopy centers completed a survey regarding return to sport after hip arthroscopy. The questionnaire asked surgeons to give a time frame for return to sport and to choose meaningful criteria that an athlete must meet prior to return to sport. Surgeons were asked to categorize various common sports as high, medium, or low risk with regard to the hip. The aggregate results were used to create standardized recommendations for time, criteria, and risk for return to competitive sports. Regarding time frame for return to sport, 70% of surgeons recommended 12 to 20 weeks. In addressing criteria for return to sport, 85% of surgeons recommended that patients need to be able to reproduce all motions involved in their sport without pain. A majority of surgeons recommended criteria of pain-free running, jumping, lateral agility drills, and single-leg squats. Finally, surgeons categorized sports requiring the most movement and impact of the hip joint (football, basketball, wrestling, and martial arts) as high-risk sports. Sports with less impact on the hip, such as golf, were ranked as low risk. PMID:25275978

  8. Overweight and obesity in hip and knee arthroplasty: Evaluation of 6078 cases

    PubMed Central

    Guenther, Daniel; Schmidl, Stefan; Klatte, Till O; Widhalm, Harald K; Omar, Mohamed; Krettek, Christian; Gehrke, Thorsten; Kendoff, Daniel; Haasper, Carl

    2015-01-01

    AIM: To evaluate a possible association between the various levels of obesity and peri-operative charac-teristics of the procedure in patients who underwent endoprosthetic joint replacement in hip and knee joints. METHODS: We hypothesized that obese patients were treated for later stage of osteoarthritis, that more conservative implants were used, and the intra-and perioperative complications increased for such patients. We evaluated all patients with body mass index (BMI) ? 25 who were treated in our institution from January 2011 to September 2013 for a primary total hip arthroplasty (THA) or total knee arthroplasty (TKA). Patients were split up by the levels of obesity according to the classification of the World Health Organization. Average age at the time of primary arthroplasty, preoperative Harris Hip Score (HHS), Hospital for Special Surgery score (HSS), gender, type of implanted prosthesis, and intra-and postoperative complications were evaluated. RESULTS: Six thousand and seventy-eight patients with a BMI ? 25 were treated with a primary THA or TKA. Age decreased significantly (P < 0.001) by increasing obesity in both the THA and TKA. HHS and HSS were at significantly lower levels at the time of treatment in the super-obese population (P < 0.001). Distribution patterns of the type of endoprostheses used changed with an increasing BMI. Peri- and postoperative complications were similar in form and quantity to those of the normal population. CONCLUSION: Higher BMI leads to endoprosthetic treat-ment in younger age, which is carried out at significantly lower levels of preoperative joint function. PMID:25621218

  9. Painful prosthesis: approaching the patient with persistent pain following total hip and knee arthroplasty

    PubMed Central

    Piscitelli, Prisco; Iolascon, Giovanni; Innocenti, Massimo; Civinini, Roberto; Rubinacci, Alessandro; Muratore, Maurizio; D’Arienzo, Michele; Leali, Paolo Tranquilli; Carossino, Anna Maria; Brandi, Maria Luisa

    2013-01-01

    Summary Background Symptomatic severe osteoarthritis and hip osteoporotic fractures are the main conditions requiring total hip arthroplasty (THA), whereas total knee arthroplasty (TKA) is mainly performed for pain, disability or deformity due to osteoarthritis. After surgery, some patients suffer from “painful prosthesis”, which currently represents a clinical problem. Methods A systematic review of scientific literature has been performed. A panel of experts has examined the issue of persistent pain following total hip or knee arthroplasty, in order to characterize etiopathological mechanisms and define how to cope with this condition. Results Four major categories (non infective, septic, other and idiopathic causes) have been identified as possible origin of persistent pain after total joint arthroplasty (TJA). Time to surgery, pain level and function impairment before surgical intervention, mechanical stress following prosthesis implant, osseointegration deficiency, and post-traumatic or allergic inflammatory response are all factors playing an important role in causing persistent pain after joint arthroplasty. Diagnosis of persistent pain should be made in case of post-operative pain (self-reported as VAS ?3) persisting for at least 4 months after surgery, or new onset of pain (VAS ?3) after the first 4 months, lasting ?2 months. Acute pain reported as VAS score ?7 in patients who underwent TJA should be always immediately investigated. Conclusions The cause of pain needs always to be indentified and removed whenever possible. Implant revision is indicated only when septic or aseptic loosening is diagnosed. Current evidence has shown that peri-and/or post-operative administration of bisphosphonates may have a role in pain management and periprosthetic bone loss prevention. PMID:24133526

  10. Postoperative Changes in In Vivo Measured Friction in Total Hip Joint Prosthesis during Walking

    PubMed Central

    Damm, Philipp; Bender, Alwina; Bergmann, Georg

    2015-01-01

    Loosening of the artificial cup and inlay is the most common reasons for total hip replacement failures. Polyethylene wear and aseptic loosening are frequent reasons. Furthermore, over the past few decades, the population of patients receiving total hip replacements has become younger and more active. Hence, a higher level of activity may include an increased risk of implant loosening as a result of friction-induced wear. In this study, an instrumented hip implant was used to measure the contact forces and friction moments in vivo during walking. Subsequently, the three-dimensional coefficient of friction in vivo was calculated over the whole gait cycle. Measurements were collected from ten subjects at several time points between three and twelve months postoperative. No significant change in the average resultant contact force was observed between three and twelve months postoperative. In contrast, a significant decrease of up to 47% was observed in the friction moment. The coefficient of friction also decreased over postoperative time on average. These changes may be caused by ‘running-in’ effects of the gliding components or by the improved lubricating properties of the synovia. Because the walking velocity and contact forces were found to be nearly constant during the observed period, the decrease in friction moment suggests an increase in fluid viscosity. The peak values of the contact force individually varied by 32%-44%. The friction moment individually differed much more, by 110%-129% at three and up to 451% at twelve months postoperative. The maximum coefficient of friction showed the highest individual variability, about 100% at three and up to 914% at twelve months after surgery. These individual variations in the friction parameters were most likely due to different ‘running-in’ effects that were influenced by the individual activity levels and synovia properties. PMID:25806805

  11. [Rotator cuff tear of the hip].

    PubMed

    Jeanneret, Luc; Kurmann, Patric T; van Linthoudt, Daniel

    2008-05-14

    We report the observations of two women with a recurrent periarthritis of the hip complicated by a spontaneous rupture of the tendons of the gluteus medius and minimus. These patients usually complain from an acute lateral hip pain and show a Trendelenburg gait. When the rupture is complete, clinical evaluation reveals a drop of the pelvis on the non-stance side and resisted rotation starting from the extreme external rotation position is weak. MRI plays a key role in the diagnosis and the evaluation of a possible surgical repair. Hip rotator-cuff rupture is probably insufficiently diagnosed by ignorance. Nonetheless, optimized handling could relieve the pain of most these patients and improve the disability of some of them. PMID:18561829

  12. Management of hip fractures in the elderly.

    PubMed

    Roberts, Karl C; Brox, W Timothy; Jevsevar, David S; Sevarino, Kaitlyn

    2015-02-01

    The purpose of this clinical practice guideline is to help improve treatment and management of hip fractures in the elderly based on current best evidence. The guideline contains twenty-five recommendations, including both diagnosis and treatment. Of those recommendations, strong evidence supports regional analgesia to improve preoperative pain control, similar outcomes for general or spinal anesthesia, arthroplasty for patients with unstable (displaced) femoral neck fractures, the use of a cephalomedullary device for the treatment of patients with subtrochanteric or reverse obliquity fractures, a blood transfusion threshold of no higher than 8 g/dL in asymptomatic postoperative patients, intensive physical therapy postdischarge, use of an interdisciplinary care program in patients with mild to moderate dementia, and multimodal pain management after hip fracture surgery. In addition to the recommendations, the work group highlighted the need for better research in the treatment of hip fractures. PMID:25624365

  13. Septic arthritis of the hip - current concepts.

    PubMed

    Rutz, E; Brunner, R

    2009-01-01

    Septic arthritis of the hip is the commonest septic condition during growth, reaching a distinct peak in frequency during infancy. The aetiology is a haematogenous joint infection. Indicative signs are severe pain when moving the joint, septic appearance and a poor general condition of these small and young patients. The diagnosis often can be difficult in infants since septic temperatures are not always present. An ultrasound scan shows the hip joint effusion and the capsular distension. X-ray investigation helps to exclude defective situations. Therapeutic options are: in patients with short history without radiologically visible complications we recommend repeated arthroscopic irrigation and in patients with long history and a radiologically visible defect of the femoral head or dislocation we recommend arthrotomy and open revision or reduction of the hip joint. PMID:19306242

  14. Total hip arthroplasty after rotational acetabular osteotomy.

    PubMed

    Ito, Hideya; Takatori, Yoshio; Moro, Toru; Oshima, Hirofumi; Oka, Hiroyuki; Tanaka, Sakae

    2015-03-01

    In this study, we aimed to determine whether the outcomes of total hip arthroplasty (THA) after rotational acetabular osteotomy (RAO) are equal to those of primary THA, and to elucidate the characteristics of THA after RAO. The clinical and radiographic findings of THA after RAO (44 hips), with minimum 24months of follow-up, were compared with a matched control group of 58 hips without prior RAO. We found that the outcomes in terms of functional scores and complication rates did not differ between THA after RAO and THA without previous pelvic osteotomy, indicating that the results of THA after RAO are equivalent to those of primary THA. Although THA after RAO requires technical considerations, similar clinical outcomes to primary THA can be expected. PMID:25456635

  15. Septic arthritis of the hip with Propionibacterium avidum bacteremia after intraarticular treatment for hip osteoarthritis.

    PubMed

    Million, Matthieu; Roux, Fabienne; Cohen Solal, Julien; Bréville, Philippe; Desplaces, Nicole; Barthas, Jean; Nguyen Van, Jean-Claude; Rajzbaum, Gérald

    2008-05-01

    Propionibacterium avidum is a Gram-positive, nonsporulating, facultative anaerobe that has a low level of virulence and is rarely pathogenic. This ubiquitous inhabitant of the sebaceous glands and hair follicles can cause acne vulgaris. Very rarely, P. avidum causes systemic infections after invasive procedures, most notably in immunocompromised patients. Two cases of sacroiliitis due to P. avidum have been reported. We report a case of P. avidum arthritis of the hip with severe sepsis that developed in a 78-year-old woman after intraarticular glucocorticoid treatment for hip osteoarthritis. We are unaware of previous reports of P. avidum hip arthritis. PMID:18329936

  16. Modulation of porphyrin photoluminescence by nanoscale spacers on silicon substrates

    NASA Astrophysics Data System (ADS)

    Fang, Y. C.; Zhang, Y.; Gao, H. Y.; Chen, L. G.; Gao, B.; He, W. Z.; Meng, Q. S.; Zhang, C.; Dong, Z. C.

    2013-11-01

    We investigate photoluminescence (PL) properties of quasi-monolayered tetraphenyl porphyrin (TPP) molecules on silicon substrates modulated by three different nanoscale spacers: native oxide layer (NOL), hydrogen (H)-passivated layer, and Ag nanoparticle (AgNP) thin film, respectively. In comparison with the PL intensity from the TPP molecules on the NOL-covered silicon, the fluorescence intensity from the molecules on the AgNP-covered surface was greatly enhanced while that for the H-passivated surface was found dramatically suppressed. Time-resolved fluorescence spectra indicated shortened lifetimes for TPP molecules in both cases, but the decay kinetics is believed to be different. The suppressed emission for the H-passivated sample was attributed to the weaker decoupling effect of the monolayer of hydrogen atoms as compared to the NOL, leading to increased nonradiative decay rate; whereas the enhanced fluorescence with shortened lifetime for the AgNP-covered sample is attributed not only to the resonant excitation by local surface plasmons, but also to the increased radiative decay rate originating from the emission enhancement in plasmonic "hot-spots".

  17. Successful implementation of spacer treatment guideline for acute asthma

    PubMed Central

    Powell, C; Maskell, G; Marks, M; South, M; Robertson, C; LENNEY, W.

    2001-01-01

    AIMS—To develop and implement an evidence based guideline for the treatment of acute asthma using a metered dose inhaler and spacer combination.?METHODS—Defined strategies were used for the development and implementation of a guideline, assessed by a prospective, descriptive, study using notes review, and patient, nursing, and medical staff telephone contact. The setting was a tertiary referral hospital in Victoria, Australia with 25 000 yearly admissions, and asthma accounting for about 7% of total. The first 200 children and families to use the guideline after its introduction were evaluated.?RESULTS—A total of 191 (95.5%) children were treated according to the guideline. Six (3.0%) children were given nebulisers appropriately based on severity; five (2.5%) were given nebulisers at parental or child choice; and four (2.0 %) who did not have severe asthma, received nebulised treatment inappropriately.?CONCLUSIONS—Successful implementation of a new evidence based guideline can be achieved using specific strategies for promoting the application of research findings in the clinical arena.?? PMID:11159290

  18. A biomechanical comparison of composite femurs and cadaver femurs used in experiments on operated hip fractures.

    PubMed

    Basso, Trude; Klaksvik, Jomar; Syversen, Unni; Foss, Olav A

    2014-12-18

    Fourth generation composite femurs (4GCFs, models #3406 and #3403) simulate femurs of males <80 years with good bone quality. Since most hip fractures occur in old women with fragile bones, concern is raised regarding the use of standard 4GCFs in biomechanical experiments. In this study the stability of hip fracture fixations in 4GCFs was compared to human cadaver femurs (HCFs) selected to represent patients with hip fractures. Ten 4GCFs (Sawbones, Pacific Research Laboratories, Inc., Vashon, WA, USA) were compared to 24 HCFs from seven females and five males >60 years. Proximal femur anthropometric measurements were noted. Strain gauge rosettes were attached and femurs were mounted in a hip simulator applying a combined subject-specific axial load and torque. Baseline measurements of resistance to deformation were recorded. Standardized femoral neck fractures were surgically stabilized before the constructs were subjected to 20,000 load-cycles. An optical motion tracking system measured relative movements. Median (95% CI) head fragment migration was 0.8mm (0.4 to 1.1) in the 4GCF group versus 2.2mm (1.5 to 4.6) in the cadaver group (p=0.001). This difference in fracture stability could not be explained by observed differences in femoral anthropometry or potential overloading of 4GCFs. 4GCFs failed with fracture-patterns different from those observed in cadavers. To conclude, standard 4GCFs provide unrealistically stable bone-implant constructs and fail with fractures not observed in cadavers. Until a validated osteopenic or osteoporotic composite femur model is provided, standard 4GCFs should only be used when representing the biomechanical properties of young healthy femurs. PMID:25468304

  19. Assessment of the functional method of hip joint center location subject to reduced range of hip motion

    Microsoft Academic Search

    Stephen J. Piazza; Ahmet Erdemir; Noriaki Okita; Peter R. Cavanagh

    2004-01-01

    Motion analysis of the lower extremities usually requires determination of the location of the hip joint center. The results of several recent studies have suggested that kinematic and kinetic variables calculated from motion analysis data are highly sensitive to errors in hip joint center location. “Functional” methods in which the location of the hip joint center is determined from the

  20. Anatomic correlates of reduced hip extension during walking in individuals with mild-moderate radiographic hip osteoarthritis.

    PubMed

    Kumar, Deepak; Wyatt, Cory; Chiba, Ko; Lee, Sonia; Nardo, Lorenzo; Link, Thomas M; Majumdar, Sharmila; Souza, Richard B

    2015-04-01

    To identify radiographic and MR features of hip osteoarthritis (OA) related to reduced hip extension during walking. Sixty six subjects, were stratified into those with (n?=?36, KL?=?2, 3) and without (n?=?30, KL?=?0, 1) radiographic hip OA. Cartilage and labrum lesions were graded semi-quantitatively on hip MRI. Alpha angle and lateral center edge (LCE) angle were measured. Sagittal kinematics and kinetics were calculated during walking at speed of 1.35?m/s using 3-D motion capture. All subjects completed Hip disability and Osteoarthritis Outcome Score (HOOS), timed up and go, and 6?min walk tests. Variables were compared between the two groups using one-way ANOVA (adjusting for age). Correlations of radiographic and MR parameters with peak hip extension were calculated. The OA group was older, had greater pain, and limitation of function. They also had lower peak hip extension and higher peak hip flexion; and worse acetabular and femoral cartilage lesions. Peak hip extension and flexion correlated with KL grade, cartilage lesions in the inferior and posterior femur. Reduced hip extension and greater hip flexion during walking are present in high functioning (HOOS?>?85%) individuals with mild-moderate hip OA, and are associated with cartilage lesions. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:527-534, 2015. PMID:25678302

  1. Rotator-cuff tear of the hip.

    PubMed

    Bunker, T D; Esler, C N; Leach, W J

    1997-07-01

    We describe an apparently unreported finding during hip operations: a tear at the insertion of gluteus medius and gluteus minimus. This defect may well be known to many surgeons with experience of hip replacement and hemiarthroplasty for fractures of the neck of the femur, but a Medline search has failed to find a previous description. We made a prospective study of 50 consecutive patients with fractures of the neck of the femur to quantify the incidence of this condition: 11 (22%) had such a tear. PMID:9250749

  2. [Acquired pathology of the hip in children].

    PubMed

    Guyot-Drouot, Marie-Hélène; Giard, Hervé; Barbier, Catherine; Mazingue, Françoise

    2002-03-15

    Hip pathology is a frequent motive for consultation in the field of paediatrics. The clinical examination and the radio-imagery both play a central role in the diagnostic process. If acute benign synovitis is the principal cause in the child, it remains a diagnosis of exclusion and must not in any case lead to a missed diagnosis of septic arthritis. Other diagnoses should be evoked according to the age of the child: epiphysiolysis, true surgical emergency, primary osteochondritis of the hip, early inflammatory polyarthritidies. PMID:12001414

  3. Vaginal mass following uncemented total hip arthroplasty

    PubMed Central

    Shin, Young-Soo; Jung, Tae-Wan; Han, Seung-Beom

    2014-01-01

    A 53-year-old woman developed a vaginal mass following an uncemented total hip arthroplasty. The mass was in direct communication with the hip through an acetabular medial wall defect after loosening of the acetabular component. The mass formation was caused simultaneously by changes secondary to polyethylene wear, a tiny delamination of the porous titanium mesh coating and a broken antirotational tab on the acetabular cup, all of which may have served as sources of metal particles. A careful evaluation of the patient's history, symptoms, X-ray findings and computed tomography scans should always be performed to ensure accurate diagnosis. PMID:25404779

  4. Suppression of subthreshold characteristics variation for junctionless multigate transistors using high-k spacers

    NASA Astrophysics Data System (ADS)

    Lou, Haijun; Zhang, Baili; Li, Dan; Lin, Xinnan; He, Jin; Chan, Mansun

    2015-01-01

    In this work, the high-k spacer is proposed to suppress the subthreshold characteristics variation of junctionless multigate transistor (JMT) with non-ideal sidewall angle for the first time. It is demonstrated that the variation of subthreshold characteristics induced by the changing sidewall angle is efficiently suppressed by high-k spacers due to the enhanced corner effect through the fringe capacitance, and the electrostatic integrity of JMTs is also improved at sub-22 nm gate length. Two key parameters of high-k spacer, the thickness and length, have been optimized in terms of the suppression of subthreshold characteristics variation. Then their optimal values are proposed. The benefit of high-k spacer makes JMTs more scalable.

  5. Modeling of CD and placement error in multi-spacer patterning technology

    NASA Astrophysics Data System (ADS)

    Babin, S.; Bay, K.

    2010-04-01

    The spacer patterning technique is an attractive way to fabricate patterns at resolutions far beyond the limits of traditional optical lithography. In this paper, we have simulated film deposition and dry etch in spacer patterning at 32 nm and 22 nm designs using the commercially available TRAVIT software. Various resist thicknesses and profiles were used, as well as process conditions for film deposition and dry etch. Dynamics of etch profiles, resulting profiles, and critical dimensions (CDs) were extracted, as well as positional errors of features. It was found that the placement error can be significant, especially when using thin resists. Multi-spacer patterning was also simulated. In the multispacer technique, the spacer patterning processes were applied consequently, resulting in the reduction of the lithographic pitch. The fabrication of 11 nm half-pitch lines were simulated using available lithographic techniques at 45 nm.

  6. Method of forming a spacer for field emission flat panel displays

    DOEpatents

    Bernhardt, A.F.; Contolini, R.J.

    1997-08-19

    Spacers are disclosed for applications such as field emission flat panel displays and vacuum microelectronics, and which involves the application of aerogel/xerogel technology to the formation of the spacer. In a preferred approach the method uses a mold and mold release agent wherein the gel precursor is a liquid which can be applied to the mold filling holes which expose the substrate (either the baseplate or the faceplate). A release agent is applied to the mold prior to precursor application to ease removal of the mold after formation of the dielectric spacer. The shrinkage of the gel during solvent extraction also improves mold removal. The final spacer material is a good dielectric, such as silica, secured to the substrate. 3 figs.

  7. CFD Analysis of Nuclear Fuel Bundles and Spacer Grids for PWR Reactors

    E-print Network

    Capone, Luigi

    2012-10-19

    generated in a fuel bundle with Spacer Grids (SG) and Mixing Vanes (MV). CFD calculations were performed using different turbulence models for steady state simulations. Large Eddy Simulations (LES) scheme was applied to time dependent cases. The simulations...

  8. Synthesis and characterization of novel cholesterol derivatives with or without spacer

    NASA Astrophysics Data System (ADS)

    Yu, Yun-Long; Zhang, Jun-Hua

    2012-03-01

    Cholesterol can be modified not only on C3sbnd OH, but also on C5dbnd C6. In this article, a new method was used to synthesize a series of novel cholesterol derivates, and the structures of these monomers were similar to those of mesogen-jacketed liquid crystal monomers without spacer. As comparison, types of soft-side-chain monomers with spacer were successfully synthesized in the analogical methods. After polymerization, the molecular structure and composition of those monomers and polymers were confirmed by 1H NMR, FTIR and Single Crystal Diffractometer. The molecular weight, distribution and thermal properties of the polymers were characterized by GPC, DSC, TGA, respectively. All the results proved that the polymers have excellent thermal stability, and the Tg of polymers without spacer is much higher than those with spacer.

  9. Manufacturing and Process-based Property Analysis of Textile-Reinforced Thermoplastic Spacer Composites

    NASA Astrophysics Data System (ADS)

    Hufenbach, Werner; Adam, Frank; Füßel, René; Krahl, Michael; Weck, Daniel

    2012-12-01

    Novel woven spacer fabrics based on hybrid yarns are suitable for an efficient fabrication of three-dimensional composite structures in high volume production. In this paper, an innovative manufacturing process with short cycle times and high automatisation is introduced for textile-reinforced thermoplastic spacer structures suited for bending load cases. The different process steps hybrid yarn fabrication, weaving technology for three-dimensional textile preforms and consolidation with unique kinematics and hot pressing technology are described in detail. The bending properties of the manufactured spacer structures are evaluated by means of experiments as well as finite element simulations. Numerical parametric studies are performed in order to validate the influence of manufacturing tolerances on the bending stiffness of the spacer structures.

  10. Spacer geometry and particle deposition in spiral wound membrane feed channels.

    PubMed

    Radu, A I; van Steen, M S H; Vrouwenvelder, J S; van Loosdrecht, M C M; Picioreanu, C

    2014-11-01

    Deposition of microspheres mimicking bacterial cells was studied experimentally and with a numerical model in feed spacer membrane channels, as used in spiral wound nanofiltration (NF) and reverse osmosis (RO) membrane systems. In-situ microscopic observations in membrane fouling simulators revealed formation of specific particle deposition patterns for different diamond and ladder feed spacer orientations. A three-dimensional numerical model combining fluid flow with a Lagrangian approach for particle trajectory calculations could describe very well the in-situ observations on particle deposition in flow cells. Feed spacer geometry, positioning and cross-flow velocity sensitively influenced the particle transport and deposition patterns. The deposition patterns were not influenced by permeate production. This combined experimental-modeling approach could be used for feed spacer geometry optimization studies for reduced (bio)fouling. PMID:25055226

  11. Method of forming a spacer for field emission flat panel displays

    DOEpatents

    Bernhardt, Anthony F. (Berkeley, CA); Contolini, Robert J. (Pleasanton, CA)

    1997-01-01

    Spacers for applications such as field emission flat panel displays and vacuum microelectronics, and which involves the application of aerogel/xerogel technology to the formation of the spacer. In a preferred approach the method uses a mold and mold release agent wherein the gel precursor is a liquid which can be applied to the mold filling holes which expose the substrate (either the baseplate or the faceplate). A release agent is applied to the mold prior to precursor application to ease removal of the mold after formation of the dielectric spacer. The shrinkage of the gel during solvent extraction also improves mold removal. The final spacer material is a good dielectric, such as silica, secured to the substrate.

  12. Hip resurfacing femoral neck fracture influenced by valgus placement.

    PubMed

    Anglin, Carolyn; Masri, Bassam A; Tonetti, Jérôme; Hodgson, Antony J; Greidanus, Nelson V

    2007-12-01

    Femoral neck fracture is the most common short-term concern after hip resurfacing arthroplasty. Currently, there is little basis to decide between neutral and valgus placement. We loaded 10 notched cadaveric femur pairs to failure; one side was implanted at 0 degrees relative to the femoral neck and the other at 10 degrees valgus. All 20 were dual-energy X-ray absorptiometry-scanned. Failure load correlated with bone mineral density. Valgus placement increased the fracture load by an average of 28% over neutral for specimens with normal bone mineral density but had no effect on fracture load in specimens with low bone mineral density. For specimens with normal bone mineral density (typical of patients undergoing resurfacing arthroplasty), neutral-valgus placement had a greater effect than bone mineral density, explaining 54% of the fracture load variance. Component placement greater than 10 degrees valgus is likely undesirable because this can lead to an increase in component size and a greater likelihood of notching. To reduce fracture risk, we recommend placing the femoral component in valgus and selecting patients with higher bone mineral density. PMID:17589356

  13. Applications of porous tantalum in total hip arthroplasty.

    PubMed

    Levine, Brett; Della Valle, Craig J; Jacobs, Joshua J

    2006-11-01

    Porous tantalum is an alternative metal for total joint arthroplasty components that offers several unique properties. Its high volumetric porosity (70% to 80%), low modulus of elasticity (3 MPa), and high frictional characteristics make it conducive to biologic fixation. Tantalum has excellent biocompatibility and is safe to use in vivo. The low modulus of elasticity allows for more physiologic load transfer and relative preservation of bone stock. Because of its bioactive nature and ingrowth properties, tantalum is used in primary as well as revision total hip arthroplasty components, with good to excellent early clinical results. In revision arthroplasty, standard and custom augments may serve as a structural bone graft substitute. Formation of a bone-like apatite coating in vivo affords strong fibrous ingrowth properties and allows for substantial soft-tissue attachment, indicating potential for use in cases requiring reattachment of muscles and tendons to a prosthesis. Development of modular components and femoral stems also is being evaluated. The initial clinical data and basic science studies support further investigation of porous tantalum as an alternative to traditional implant materials. PMID:17077337

  14. [Release of metals from metal-on-metal hip prostheses].

    PubMed

    Nicolli, A; Chiara, F; Bortoletti, I; Pasqualato, F; Mongillo, M; Gambalunga, A; Biggi, F; Trevisan, A

    2011-01-01

    The present study examined blood and urinary concentrations of Cr and Co in 30 patients with metal-on-metal hip prostheses without signs of wear and 6 patients with prosthetic bearing and clear signs of wear and metallosis. The determination in biological fluids showed in patients with not signs of wear the geometric mean concentration of metals only modestly increased (CoS 0.5 microg/l, CoU 5.7 microg/l, CrS 0.8 microg/l, CrU 3.4 microg/l) compared to the reference values, while the wear caused a significant increase in the concentration of both Co (CoS 94.6 microg/l, CoU 334.5 microg/l) and Cr (CrS 57.7 microg/l, CrU 89.4 microg/I). As the results, the not functioning implants are a risks to the patients and are associated with high levels of metals in biological fluids. Currently, the patients with metallosis had not signs and symptoms associated with metal toxicity, but high concentrations could to cause kidney, peripheral nervous system, heart, and thyroid damage. PMID:23393850

  15. A new neuroimplantable device: the tulgar implant. Initial results of animal testing.

    PubMed

    Kalkan, Erdal; Arican, Mustafa; Kalkan, S Serpil; Erayman, Ibrahim; Erol, Atila; Tulgar, Ayse Oya; Tulgar, Metin

    2005-10-01

    A new neuroimplant system, namely the Tulgar implant, developed to solve the practical problems encountered with the presently available implants, was tested as a spinal cord stimulator in ten sheep. The response of living tissue and technical performance of the new system were evaluated. Electrodes implanted in the low thoracic (T9-10) vertebral levels by means of hemilaminectomy were subcutaneously connected to the passive coil receiver element located in the anterior-inferior chest wall for 28 days. Laboratory parameters including hematology, biochemistry, and microbiology were investigated over the study, and histopathologic examinations were done by the end of study. Animal tests showed that the new system could reliably be implantable in the living tissue. Intra-operative radicular stimulation of the right dorsal root in T13-L1 levels, by means of burst mode of signals, resulted in observable contractions of hip muscles in the right upper leg. PMID:22151553

  16. Minimally invasive versus conventional exposure for total hip arthroplasty: a systematic review and meta-analysis of clinical and radiological outcomes

    Microsoft Academic Search

    Toby O. Smith; Vicky Blake; Caroline B. Hing

    2011-01-01

    Over the past decade, minimally invasive surgery has gained popularity as a means of optimising early postoperative rehabilitation\\u000a and increasing patient satisfaction and cosmesis following total hip arthroplasty (THA). However, this surgical exposure has\\u000a also been associated with increased risk of iatrogenic nerve injury and implant mal-positioning due to limited visibility\\u000a compared to conventionally larger surgical incisions. The purpose of

  17. Implantable sensor technology: measuring bone and joint biomechanics of daily life in vivo

    PubMed Central

    2013-01-01

    Stresses and strains are major factors influencing growth, remodeling and repair of musculoskeletal tissues. Therefore, knowledge of forces and deformation within bones and joints is critical to gain insight into the complex behavior of these tissues during development, aging, and response to injury and disease. Sensors have been used in vivo to measure strains in bone, intraarticular cartilage contact pressures, and forces in the spine, shoulder, hip, and knee. Implantable sensors have a high impact on several clinical applications, including fracture fixation, spine fixation, and joint arthroplasty. This review summarizes the developments in strain-measurement-based implantable sensor technology for musculoskeletal research. PMID:23369655

  18. Is There a Risk in Placing a Ceramic Head on a Previously Implanted Trunion?

    Microsoft Academic Search

    Didier Hannouche; Jérôme Delambre; Frédéric Zadegan; Laurent Sedel; Rémy Nizard

    2010-01-01

    Background  Strategies for revising a ceramic-on-ceramic total hip prosthesis are controversial. Some consider reimplantation of a ceramic\\u000a head on a well-fixed femoral stem inadvisable as it may lead to a fracture of the newly implanted head.\\u000a \\u000a \\u000a \\u000a \\u000a Questions\\/purposes  We assessed (1) the risk of fracture when a new ceramic head was placed on a previously implanted trunion; (2) the survival\\u000a rate of the

  19. Dependence of model-based RSA accuracy on higher and lower implant surface model quality

    PubMed Central

    2013-01-01

    Background Model-based Roentgen Stereophotogrammetric Analysis (MBRSA) allows the accurate in vivo measurement of the relative motion between an implant and the surrounding bone (migration), using pose-estimation algorithms and three dimensional geometric surface models of the implant. The goal of this study was thus to investigate the effect of surface model resolution on the accuracy of the MBRSA method. Methods Four different implant geometries (knee femoral and tibial components, and two different hip stems) were investigated, for each of which two reversed engineering (RE) models of differing spatial digitizing resolution were generated. Accuracy of implant migration measurement using MBRSA was assessed in dependence on surface model resolution using an experimental phantom-model set up. Results When using the lower quality RE models, the worst bias observed ranged from -0.048 to 0.037 mm, and -0.057 to 0.078 deg for translation and rotation respectively. For higher quality reverse engineering models, bias ranged from -0.042 to 0.048 mm, and -0.449 to 0.029 deg. The pair-wise comparisons of digitizing resolution (higher vs. lower quality) within the different implant type revealed significant differences only for the hip stems (p?implant migration, in particular for implants with non symmetrical geometries (total knee arthroplasty). Implants with larger length to width aspect ratio (total hip arthroplasty) may require high resolution RE models in order to achieve acceptable accuracy. Conversely, for some axis the bias for translation are clearly worse for translation, and are marginally better for rotations using the lower resolution RE models instead of the higher ones. However, performed box plots ranges were well within what has been reported in the literature. The observed lower accuracy and precision of the measurements for hip stem components for rotations about the superior-inferior direction is presumably the result of the nature of the MBRSA method. This well known effect within MBRSA for rotations about the axis of symmetry of axially-symmetric objects do not change the contour of the projected image to as large a degree as motion about a non-symmetric axes. It is not possible to detected this small motion as accurately using pose-estimation methods. This may affect the “higher” accuracy for the applied lower resolution RE models. PMID:23587251

  20. Cutaneous manifestation of metallosis in a metal-on-metal total hip arthroplasty after acetabular liner dissociation.

    PubMed

    Sporer, Scott M; Chalmers, Peter N

    2012-09-01

    In this case report, we describe a cutaneous manifestation of extensive metallosis in a patient 4 months post-metal-on-metal total hip arthroplasty with a Pinnacle cup with dissociation of the liner from the shell and resultant stripe burnishing of the shell and notch wear of the femoral neck. Dissociation of a metal liner has not been previously reported with this implant. Cutaneous metallosis has only been reported once in the literature. Clinicians should heighten their suspicion for metallosis secondary to hardware failure when encountering patients with skin discoloration in the setting of a painful and poorly functioning hip arthroplasty. In patients with failure of a metal-on-metal prosthesis with a modular metal liner in the acetabular component, liner dissociation must be considered. PMID:22397858

  1. Marginal discrepancy as affected by selective placement of die-spacer: an in vitro study.

    PubMed

    Aditya, Priyam; Madhav, V N V; Bhide, S V; Aditya, Amita

    2012-09-01

    An increase in the marginal discrepancy is seen after cementation with a luting agent and provision of cement space with a die-spacer is the most preferred method to avoid it. Recommended thickness of die-spacer is 25-40 ?m. Smaller die-spacer thickness was consistently found at the axio-occlusal line angles as compared to the other surfaces which has been postulated to that the spacer paint tends to flow away from the sharp line angles and cusp tips as a result of increased surface tension. The absence of adequate relief spaces in these areas impedes the flow of cement beyond the occlusal portion of the casting, which would result in incomplete seating because of hydraulic pressure. Fifty stone dies were duplicated from a steel die and were divided into five groups of sample size 10, where the die-spacer was selectively placed. Measurements were taken at four points, 90° apart from each other with the help of optical microscope. Later all the castings were cemented using Glass Inomer cement as a luting agent, under a 10 kg static load and measurements were recorded. Statistical analysis showed samples with no spacer had the maximum pre and post cementation gap while the least discrepancy was seen in group with additional layer of die-spacer painted over the axio-occlusal line angle. The results were highly significant which clearly indicated the superiority of this group over others. Within limitations of the study, it can be said that application of additional layer of die-spacer at the axio-occlusal line angle will help in decreasing the post cementation marginal discrepancy in full cast metal crowns. PMID:23997463

  2. Characterization of Polymetal Gate Transistors With Low-Temperature Atomic-Layer-Deposition-Grown Oxide Spacer

    Microsoft Academic Search

    Ga-Won Lee; Hi-Duck Lee; Kwan-Yong Lim; Yong Soo Kim; Hong-Sun Yang; Gyu-Seog Cho; Sung-Kye Park; Sung-Joo Hong

    2009-01-01

    In this letter, W\\/WNx\\/poly-Si gate DRAM transistors with oxide spacers grown by low-temperature atomic layer deposition (ALD) have been fabricated, and the electrical characteristics are analyzed. The low-temperature ALD oxide effectively prevents the oxidation of exposed tungsten, and the fabricated devices show superior electrical properties to those with nitride\\/oxide spacer. The data retention time is improved by 30%, and the

  3. The Internal Transcribed Spacer 2 Exhibits a Common Secondary Structure in Green Algae and Flowering Plants

    Microsoft Academic Search

    Jeffrey C. Mai; Annette W. Coleman

    1997-01-01

    .   Sequences of the Internal Transcribed Spacer 2 (ITS-2) regions of the nuclear rDNA repeats from 111 organisms of the family\\u000a Volvocaceae (Chlorophyta) and unicellular organisms of the Volvocales, including Chlamydomonas reinhardtii, were determined. The use of thermodynamic energy optimization to generate secondary structures and phylogenetic comparative\\u000a analysis of the spacer regions revealed a common secondary structure that is conserved

  4. A high-density, self-aligned power MOSFET structure fabricated using sacrificial spacer technology

    Microsoft Academic Search

    Krishna Shenai

    1992-01-01

    A novel power MOSFET structure fabricated using sacrificial spacer technology is described. Anisotropically etched sidewall oxide spacers were used to implement self-aligned shallow p+ surface diffused regions to reduce the p-base sheet resistance and its contact resistance. Vertical power DMOSFETs with VDB=150 V and Rsp=9.7 m?-cm2 were fabricated using this technology, where VDB is the drain-source avalanche breakdown voltage and

  5. The structure of the rDNA intergenic spacer of Avena sativa L.: a comparative study

    Microsoft Academic Search

    C. Polanco; M. Pérez Vega

    1994-01-01

    The sequence of the 18S–25S ribosomal RNA gene intergenic spacer (IGS) of Avena sativa was determined. DNA was cloned after polymerase chain reaction amplification of the IGS. The spacer of 3980 bp is composed of non-repeated sequences and five tandem arrays of repeated sequences, named A to E. Homology between oats IGS and other grass species was found. Tandem arrays

  6. Biofouling of spiral-wound nanofiltration and reverse osmosis membranes: A feed spacer problem

    Microsoft Academic Search

    J. S. Vrouwenvelder; J. C. Kruithof; M. L. Johns

    2009-01-01

    Biofouling was studied in full-scale and pilot-scale installations, test-rigs and membrane fouling monitors by conventional methods as well as Magnetic Resonance Imaging (MRI). Independent of permeate production, the feed spacer channel pressure drop and biomass concentration increased similarly in a nanofiltration pilot installation. In the presence of a feed spacer the absolute feed channel pressure drop increase caused by biomass

  7. 21 CFR 888.3370 - Hip joint (hemi-hip) acetabular metal cemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...888.3370 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT...the hip joint. This generic type of device includes...cobalt-chromium-molybdenum. This generic type of device is limited...filed with the Food and Drug...

  8. 21 CFR 888.3370 - Hip joint (hemi-hip) acetabular metal cemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...888.3370 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT...the hip joint. This generic type of device includes...cobalt-chromium-molybdenum. This generic type of device is limited...filed with the Food and Drug...

  9. 21 CFR 888.3400 - Hip joint femoral (hemi-hip) metallic resurfacing prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...replace a portion of the hip joint. This generic type of device includes prostheses that have a femoral resurfacing component made of alloys, such as cobalt-chromium-molybdenum. (b) Classification. Class...

  10. Low revision rate after total hip arthroplasty in patients with pediatric hip diseases

    PubMed Central

    2012-01-01

    Background The results of primary total hip arthroplasties (THAs) after pediatric hip diseases such as developmental dysplasia of the hip (DDH), slipped capital femoral epiphysis (SCFE), or Perthes’ disease have been reported to be inferior to the results after primary osteoarthritis of the hip (OA). Materials and methods We compared the survival of primary THAs performed during the period 1995–2009 due to previous DDH, SCFE, Perthes’ disease, or primary OA, using merged individual-based data from the Danish, Norwegian, and Swedish arthroplasty registers, called the Nordic Arthroplasty Register Association (NARA). Cox multiple regression, with adjustment for age, sex, and type of fixation of the prosthesis was used to calculate the survival of the prostheses and the relative revision risks. Results 370,630 primary THAs were reported to these national registers for 1995–2009. Of these, 14,403 THAs (3.9%) were operated due to pediatric hip diseases (3.1% for Denmark, 8.8% for Norway, and 1.9% for Sweden) and 288,435 THAs (77.8%) were operated due to OA. Unadjusted 10-year Kaplan-Meier survival of THAs after pediatric hip diseases (94.7% survival) was inferior to that after OA (96.6% survival). Consequently, an increased risk of revision for hips with a previous pediatric hip disease was seen (risk ratio (RR) 1.4, 95% CI: 1.3–1.5). However, after adjustment for differences in sex and age of the patients, and in fixation of the prostheses, no difference in survival was found (93.6% after pediatric hip diseases and 93.8% after OA) (RR 1.0, CI: 1.0–1.1). Nevertheless, during the first 6 postoperative months more revisions were reported for THAs secondary to pediatric hip diseases (RR 1.2, CI: 1.0–1.5), mainly due to there being more revisions for dislocations (RR 1.8, CI: 1.4–2.3). Comparison between the different diagnosis groups showed that the overall risk of revision after DDH was higher than after OA (RR 1.1, CI: 1.0–1.2), whereas the combined group Perthes’ disease/SCFE did not have a significantly different risk of revision to that of OA (RR 0.9, CI: 0.7–1.0), but had a lower risk than after DDH (RR 0.8, CI: 0.7–1.0). Interpretation After adjustment for differences in age, sex, and type of fixation of the prosthesis, no difference in risk of revision was found for primary THAs performed due to pediatric hip diseases and those performed due to primary OA. PMID:23043269

  11. Hip Rotational Velocities During the Full Golf Swing

    PubMed Central

    Gulgin, Heather; Armstrong, Charles; Gribble, Phillip

    2009-01-01

    Since labral pathology in professional golfers has been reported, and such pathology has been associated with internal/external hip rotation, quantifying the rotational velocity of the hips during the golf swing may be helpful in understanding the mechanism involved in labral injury. Thus, the purpose of this study was to determine the peak internal/external rotational velocities of the thigh relative to the pelvis during the golf swing. Fifteen female, collegiate golfers participated in the study. Data were acquired through high-speed three dimensional (3-D) videography using a multi-segment bilateral marker set to define the segments, while the subjects completed multiple repetitions of a drive. The results indicated that the lead hip peak internal rotational velocity was significantly greater than that of the trail hip external rotational velocity (p = 0.003). It appears that the lead hip of a golfer experiences much higher rotational velocities during the downswing than that of the trail hip. In other structures, such as the shoulder, an increased risk of soft tissue injury has been associated with high levels of rotational velocity. This may indicate that, in golfers, the lead hip may be more susceptible to injury such as labral tears than that of the trailing hip. Key points Lead hip of golfer experiences significantly higher rotational velocities than the trail hip. Golfers may be more susceptible to injuries on the lead hip. Clubhead velocities were consistent with elite female golfers. PMID:24149541

  12. Do novice runners have weak hips and bad running form?

    PubMed Central

    Schmitz, Anne; Russo, Kelsey; Nicholson, Lauren; Noehren, Brian

    2014-01-01

    First, we sought to better understand the predisposition of novice female runners to injury by identifying potential differences in running mechanics and strength between experienced female runners and active novice runners. Secondly, we aimed to assess the relationship between hip and trunk strength with non-sagittal hip kinematics during running. Two female populations were recruited: 19 healthy experienced runners and 19 healthy active novice runners. Strength measurements of the hip abductors and external rotators were measured using a hand held dynamometer while trunk endurance was assessed via a side-plank. Next, an instrumented gait analysis was performed while each participant ran at 3.3 m/s. Group comparisons were made using an independent t-test to identify differences in the impact peak, loading rate, peak non-sagittal hip joint angles, trunk endurance, and hip strength. Pearson’s correlation coefficients were calculated between hip kinematics and strength measurements. There were no statistically significant differences in impact peak, loading rate, peak non-sagittal hip kinematics, or strength. However, the novice runners did show a clinically meaningful trend towards increased peak hip internal rotation by 3.8 degrees (effect size 0.520). A decrease in trunk side-plank endurance was associated with an increased peak hip internal rotation angle (r=?.357, p=0.03), whereas isometric strength was not related to kinematics. Programs aiming to prevent injuries in novice runners should target trunk performance and possibly hip neuromuscular control, rather than hip strength. PMID:24656715

  13. Total hip arthroplasties: What are the reasons for revision?

    PubMed Central

    Ulrich, Slif D.; Bennett, Derek; Delanois, Ronald E.; Saleh, Khaled J.; Thongtrangan, Issada; Kuskowski, Michael; Cheng, Edward Y.; Sharkey, Peter F.; Parvizi, Javad; Stiehl, James B.; Mont, Michael A.

    2007-01-01

    Primary total hip arthroplasties have reported success rates of greater than 95% in many series with a longer than 10-year follow-up. Revision total hip arthroplasty due to such factors as increased high-activity levels, younger patients undergoing the procedure and increasing life expectancy has become more prevalent. An understanding of the mechanisms and timing of total hip arthroplasty failure can direct efforts aimed at reducing revision rates. This study was conducted to evaluate the indications for revision hip arthroplasty and relate these to the time after the index primary hip arthroplasty. A review of all revision hip arthroplasties at two centres over a 6-year time period identified 225 patients who underwent 237 revisions. The overall mean time to revision was 83 months (range: 0–360 months). The cause of failure was aseptic loosening in 123 hips (51.9%), instability in 40 hips (16.9%) and infection in 37 hips (5.5%). When stratified into two groups (less than 5 years, more than 5 years after the index primary hip arthroplasty), 118 of 237 (50%) revisions occurred in less than 5 years, with 33% due to instability and 24% resulting from infection. The majority of the causes of failure within 5 years in these early revisions were instability and deep infection. The success of hip arthroplasty is likely to be compromized if technical aspects of the surgery for appropriate component positioning and critical protocols to minimise complications such as infection are not given the proper attention. PMID:17443324

  14. Pressurised aerosol deposition in the human lung with and without an "open" spacer device.

    PubMed Central

    Newman, S P; Clark, A R; Talaee, N; Clarke, S W

    1989-01-01

    A radiotracer technique has been used to assess aerosol delivery from a pressurised metered dose inhaler, used both with and without a 10 cm cylindrical spacer attachment (Syncroner), which has an open section in its upper surface. The radionuclide technetium-99m (99mTc) was added to sodium cromoglycate in a canister (Intal inhaler; 1 mg/puff); in vitro studies with a multistage liquid impinger showed that the radiolabel acted as a marker for the presence of drug over a wide range of particle sizes. Ten healthy volunteers were studied after they had inhaled from (1) a metered dose inhaler alone (slow inhaled flow rate, about 25 l/min); (2) metered dose inhaler plus spacer (slow flow rate); and (3) metered dose inhaler plus spacer (fast inhaled flow rate, about 100 l/min). Inhalation was coordinated with firing the spray and was followed by 10 seconds' breath holding. With the metered dose inhaler alone a mean 11.0% (SEM 1.4%) of the dose reached the lungs, compared with significantly higher doses for slow (16.1% (2.2%] and fast (13.3% (1.7%] inhalations through the spacer. The distribution pattern within the lungs was significantly more peripheral after slow inhalation. Oropharyngeal deposition was halved by the spacer. The open spacer should teach patients good coordination and delivers more aerosol to the lungs than a correctly used metered dose inhaler. Images PMID:2588205

  15. The nonsignaling extracellular spacer domain of chimeric antigen receptors is decisive for in vivo antitumor activity.

    PubMed

    Hudecek, Michael; Sommermeyer, Daniel; Kosasih, Paula L; Silva-Benedict, Anne; Liu, Lingfeng; Rader, Christoph; Jensen, Michael C; Riddell, Stanley R

    2015-02-01

    The use of synthetic chimeric antigen receptors (CAR) to redirect T cells to recognize tumor provides a powerful new approach to cancer immunotherapy; however, the attributes of CARs that ensure optimal in vivo tumor recognition remain to be defined. Here, we analyze the influence of length and composition of IgG-derived extracellular spacer domains on the function of CARs. Our studies demonstrate that CD19-CARs with a long spacer from IgG4 hinge-CH2-CH3 are functional in vitro but lack antitumor activity in vivo due to interaction between the Fc domain within the spacer and the Fc receptor-bearing myeloid cells, leading to activation-induced T-cell death. We demonstrate that in vivo persistence and antitumor effects of CAR-T cells with a long spacer can be restored by modifying distinct regions in the CH2 domain that are essential for Fc receptor binding. Our studies demonstrate that modifications that abrogate binding to Fc receptors are crucial for CARs in which a long spacer is obligatory for tumor recognition as shown here for a ROR1-specific CAR. These results demonstrate that the length and composition of the extracellular spacer domain that lacks intrinsic signaling function can be decisive in the design of CARs for optimal in vivo activity. PMID:25212991

  16. Innovation in hip arthroscopy: is hip arthritis preventable in the athlete?

    Microsoft Academic Search

    Henry B Ellis; Karen K Briggs; Marc J Philippon

    2011-01-01

    IntroductionThe hip is the second most common area for injury in collegiate athletes and may account for 2–5% of all sports injuries. Hip and groin pain in the athlete has long been associated with structural abnormalities of the femoral neck, acetabulum and labral pathology.ReviewThe relationship between osteoarthritis and femoroacetabular impingement (FAI) is well established now with clinical studies, radiographic studies

  17. Validation of a computer-assisted method for measurement of radiographic wear in total hip arthroplasty using all polyethylene cemented acetabular components.

    PubMed

    Langlois, Jean; Zaoui, Amine; Scemama, Caroline; Martell, John; Bragdon, Charles; Hamadouche, Moussa

    2015-03-01

    Although cemented all polyethylene (PE) cups have been routinely used in total hip arthroplasty for decades, no computer-assisted method for measurement of radiographic wear has ever been specifically validated for these implants. Using a validated hip phantom model, AP plain hip radiographs were obtained consecutively for eight simulated wear positions. A version of Martell's Hip Analysis Suite software dedicated to all polyethylene sockets was used by three different examiners of varied experience. Bias (mean, standard deviation and 95% confidence interval limit), repeatability (standard deviation and 95% limit) and reproducibility (standard deviation and 95% limit) for two-dimensional wear measurements were assessed, as recommended by the current ASTM guidelines. Using this protocol, the dedicated software showed an overall mean bias of 0.089?±?0.060?mm (mean?±?SD), and 0.118?mm for 95% CI limit. Repeatability (intra examiner) standard deviation and 95% limit were respectively 0.106?mm and 0.292?mm. Reproducibility (inter examiner) standard deviation and 95% limit were respectively 0.112?mm and 0.308?mm. Martell Hip Analysis for all PE cemented cups is a reliable and low-cost instrument in the assessment of wear, despite being less precise than its original version dedicated to cementless components. PMID:25564735

  18. Ion implantation method

    SciTech Connect

    Takigawa, T.; Sasaki, I.

    1984-11-06

    An ion implantation method is provided which uses an ion implantation apparatus which is capable of focusing an ion beam into a spot having a diameter smaller than the size of a region into which ions are to be implanted. The ion dose is varied in accordance with the gate region, source and drain regions, and the field region of a semiconductor device including a transistor having short gate length and width.

  19. Contributions of human tissue analysis to understanding the mechanisms of loosening and osteolysis in total hip replacement

    PubMed Central

    Gallo, Jiri; Vaculova, Jana; Goodman, Stuart B.; Konttinen, Yrjö T.; Thyssen, Jacob P.

    2015-01-01

    Aseptic loosening and osteolysis are the most frequent late complications of total hip arthroplasty (THA) leading to revision of the prosthesis. This review aims to demonstrate how histopathological studies contribute to our understanding of the mechanisms of aseptic loosening/osteolysis development. Only studies analysing periprosthetic tissues retrieved from failed implants in humans were included. Data from 101 studies (5532 patients with failure of THA implants) published in English or German between 1974 and 2013 were included. “Control” samples were reported in 45 of the 101 studies. The most frequently examined tissues were the bone-implant interface membrane and pseudosynovial tissues. Histopathological studies contribute importantly to determination of key cell populations underlying the biological mechanisms of aseptic loosening and osteolysis. The studies demonstrated the key molecules of the host response at the protein level (chemokines, cytokines, nitric oxide metabolites, metalloproteinases). However, these studies also have important limitations. Tissues harvested at revision surgery reflect specifically end-stage failure and may not adequately reveal the evolution of pathophysiological events that lead to prosthetic loosening and osteolysis. One possible solution is to examine tissues harvested from stable total hip arthroplasties that have been revised at various time periods due to dislocation or periprosthetic fracture in multicenter studies. PMID:24525037

  20. Histologic, serologic, and tribologic findings in failed metal-on-metal total hip arthroplasty: AAOS exhibit selection.

    PubMed

    Pelt, Christopher E; Erickson, Jill; Clarke, Ian; Donaldson, Thomas; Layfield, Lester; Peters, Christopher L

    2013-11-01

    Despite multiple changes in second-generation metal-on-metal hip implants, greater-than-expected revision rates have led to alarm. We hypothesized that the finding of intraoperative metallosis would be associated with a high metal load on histologic analysis and that both would be associated with increased wear, greater serum metal ion levels, and predictable biologic responses in the histologic sections. We evaluated the implant positioning, serum ion levels, intraoperative findings of metallosis, wear characteristics of retrieved implants (tribology), histology, and outcomes in a series of eighteen large-diameter metal-on-metal total hip arthroplasties. The arthroplasties were divided into two groups on the basis of the intraoperative finding of metallosis and into two groups on the basis of the metal load score. Intraoperative metallosis was not associated with a high metal load score (p = 0.15). The finding of intraoperative metallosis was associated with greater serum metal ion levels, greater wear rates, and greater complication rates. Aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL) scores were similar between the metallosis and non-metallosis groups (p = 0.49) as well as between the high and low-metal-load groups (p = 0.56). PMID:24196475