Numerical simulation of artificial hip joint motion based on human age factor

NASA Astrophysics Data System (ADS)

Ramdhani, Safarudin; Saputra, Eko; Jamari, J.

2018-05-01

Artificial hip joint is a prosthesis (synthetic body part) which usually consists of two or more components. Replacement of the hip joint due to the occurrence of arthritis, ordinarily patients aged or older. Numerical simulation models are used to observe the range of motion in the artificial hip joint, the range of motion of joints used as the basis of human age. Finite- element analysis (FEA) is used to calculate stress von mises in motion and observes a probability of prosthetic impingement. FEA uses a three-dimensional nonlinear model and considers the position variation of acetabular liner cups. The result of numerical simulation shows that FEA method can be used to analyze the performance calculation of the artificial hip joint at this time more accurate than conventional method.

[Clinical evaluation of the ceramic femoral component used for reconstruction of total knee replacement].

PubMed

Vavrík, P; Landor, I; Denk, F

2008-12-01

The study evaluates mid-term results of total knee replacement with a zirconia ceramic (ZrO2) femoral component. The evaluated group comprised 20 knees in 19 patients (4 men and 15 women). In one patient the replacement was performed bilaterally. Two patients had in the contralateral knee the same type of prosthesis with a femoral chrome-cobalt component.The mean age at the time of operation was 65.2 years (range, 38-81 years).The primary indication was 14 times osteoarthritis and 5 times rheumatoid arthritis. The average follow-up period was 6.5 years (range, 2.1-8.5 years). Patients included in the study regardless of age, body mass and the basic diagnosis, agreed with the use of the ceramic femoral component. The evaluation covered a range of motion, mechanical axis, joint stability, pain, swelling, ability to walk on level ground and on stairs, subjective satisfaction (EULAR Knee Chart). Radiograph were assessed at one year intervals in two projections to identify the incidence of radiolucency around the implant. The Kaplan-Meier survival curve was used and compared with the survival curve in identical chrome-cobalt implants. At he final follow-up, 14 knees were evaluated, because 3 patients died without any connection with the implant, in one case the tibial component migrated due to necrosis of the tibial condyle in a patient with RA and two implants had to be revised and replaced due to polyethylene wear. No infection or negative tissue reaction was recorded in the evaluated group. The average flexion range was 109 degrees. All knees were stable and without swelling, in two cases there occurred slight femoropatellar pain. Twelve patients were fully satisfied, 2 patients were satisfied with a certain reservation. The differences in the course of the survival curves of chrome-cobalt and ceramic implants were statistically insignificant. Although the use of zirconia ceramics in vitro reduces the amount of polyethylene wear, the clinical outcomes of total knee replacements as compared to the hip are not convincing. One of the causes may be the substantially different and more complex biomechanics of the knee. Tribology improvement of the femoral ceramic component cannot compensate the deficiencies in the joint balancing in flexion and extension. The economically and technologically demanding production of these implants may be justified in patients with allergies caused by chrome-cobalt components. The results of mid-term follow-up of the use of zirconia ceramic femoral components proved no impact on the improvement of the period of survival of the knee implant. No adverse response to the material or mechanical failure of the ceramic components was encountered. Key words: total knee replacement, zirconia ceramic femoral component, TKR mid-term results, ceramic knee survival curve.

Wear analysis and finishing of bioceramic implant surfaces.

PubMed

Denkena, Berend; Reichstein, Martin; van der Meer, Marijke; Ostermeier, Sven; Hurschler, Christof

2008-01-01

A primary cause for revision operations of joint replacements is the implant loosening, due to immune reactions resulting from the agglomeration of polyethylene wear debris. Motivated by the successful application of bioceramic materials in hip joint prostheses, a trend towards the development of hard implant materials has occurred. Nonetheless in the area of total knee arthroplasty (TKA), modern efforts have still utilized polyethylene as the tibial-inlay joint component. The use of bioceramic hard-hard-pairings for total knee arthroplasty has been prevented by the complex kinematics and geometries required. Ceramics cannot cope with non-uniform loads, which suggests the need for new designs appropriate to the material. Furthermore, biomechanical requirements should be considered. A rolling-gliding wear simulator, which reproduces the movements and stresses of the knee joint on specimens of simplified geometry, has therefore been developed. High-precision machining processes for free formed bioceramic surfaces, with suitable grinding and polishing tools which adjust to constantly changing contact conditions, are essential. The goal is to put automated finishing in one clamping with five simultaneous controlled axes into practice. The developed manufacturing technologies will allow the advantageous bioceramic materials to be applied and accepted for more complex joint replacements such as knee prostheses.

Development of a Mandibular Motion Simulator for Total Joint Replacement

PubMed Central

Celebi, Nukhet; Rohner, E. Carlos; Gateno, Jaime; Noble, Philip C.; Ismaily, Sabir K.; Teichgraeber, John F.; Xia, James J.

2015-01-01

Purpose The purpose of this study was to develop a motion simulator capable of recreating and recording the full range of mandibular motions in a cadaveric preparation for an intact temporomandibular joint (TMJ) and after total joint replacement. Material and Methods A human cadaver head was used. Two sets of tracking balls were attached to the forehead and mandible, respectively. Computed tomographic (CT) scan was performed and 3-dimensional CT models of the skull were generated. The cadaver head was then dissected to attach the muscle activation cables and mounted onto the TMJ simulator. Realistic jaw motions were generated through the application of the following muscle forces: lateral pterygoid muscle, suprahyoid depressors (geniohyoid, mylohyoid, and digastric muscles), and elevator muscles. To simulate muscle contraction, cables were inserted into the mandible at the center area of each muscle's attachment. To provide a minimum mouth closing force at the initial position, the elevator muscles were combined at the anterior mandible. During mandibular movement, each motion was recorded using a high-resolution laser scanner. The right TMJ of the same head was reconstructed with a total TMJ prosthesis. The same forces were applied and the jaw motions were recorded again. CT scan was performed and 3-dimensional CT models of the skull with TMJ prosthesis were generated. Results Mandibular motions, before and after TMJ replacement, with and without lateral pterygoid muscle reattachment, were re-created in a cadaveric preparation. The laser-scanned data during the mandibular motion were used to drive 3-dimensional CT models. A movie for each mandibular motion was subsequently created for motion path analysis. Compared with mandibular motion before TMJ replacement, mandibular lateral and protrusive motions after TMJ replacement, with and without lateral pterygoid muscle reattachment, were greatly limited. The jaw motion recorded before total joint replacement was applied to the mandibular and prostheses models after total TMJ replacement. The condylar component was observed sinking into the fossa during jaw motion. Conclusion A motion simulator capable of re-creating and recording full range of mandibular motions in a cadaveric preparation has been developed. It can be used to simulate mandibular motions for the intact TMJ and total joint prosthesis, and to re-create and record their full range of mandibular motions. In addition, the full range of the recorded motion can be re-created as motion images in a computer. These images can be used for motion path analysis and to study the causation of limited range of motion after total joint replacement and strategies for improvement. PMID:21050636

Orthopaedic management of haemophilia arthropathy of the ankle.

PubMed

Pasta, G; Forsyth, A; Merchan, C R; Mortazavi, S M J; Silva, M; Mulder, K; Mancuso, E; Perfetto, O; Heim, M; Caviglia, H; Solimeno, L

2008-07-01

Joint bleeding, or haemarthrosis, is the most common type of bleeding episode experienced by individuals with haemophilia A and B. This leads to changes within the joints, including synovial proliferation, which results in further bleeding and chronic synovitis. Blood in the joint can also directly damage the cartilage, and with repeated bleeding, there is progressive destruction of both cartilage and bone. The end result is known as haemophilic arthropathy. The joints most commonly affected are the knees, elbows and ankles, although any synovial joint may be involved. In the ankle, both the tibiotalar and subtalar joints may be affected and joint bleeding and arthropathy can lead to a number of deformities. Haemophilic arthropathy can be prevented through regular factor replacement prophylaxis and implementing physiotherapy. However, when necessary, there are multiple surgical and non-surgical options available. In early ankle arthropathy with absent or minimal joint changes, both radioisotopic and chemical synoviorthesis can be used to reduce the hypertrophied synovium. These procedures can decrease the frequency of bleeding episodes, minimizing the risk of articular cartilage damage. Achilles tendon lengthening can be performed, in isolation or in combination with other surgical measures, to correct Achilles tendon contractures. Both arthroscopic and open synovectomies are available as a means to remove the friable villous layer of the synovium and are often indicated when bleeding episodes cannot be properly controlled by factor replacement therapy or synoviorthesis. In the later stages of ankle arthropathy, other surgical options may be considered. Debridement may be indicated when there are loose pieces of cartilage or anterior osteophytes, and can help to improve the joint function, even in the presence of articular cartilage damage. Supramalleolar tibial osteotomy may be indicated in patients with a valgus deformity of the hindfoot without degenerative radiographic findings. Joint fusion, or arthrodesis, is the treatment of choice in the advanced stages of ankle arthropathy although total ankle replacement is currently available. Early ankle replacement components were associated with a poor outcome, but as implant designs have improved, there have been successful outcomes achieved. As the ankle is a commonly affected joint in many individuals with haemophilia, it is important to add to the knowledge base to validate indications and timing of surgical and non-surgical interventions in ankle arthropathy.

The Measurement Of Total Joint Loosening By X-Ray Photogrammetry

NASA Astrophysics Data System (ADS)

Lippert, Frederick G.; Veress, Sandor A.; Tiwari, Rama S.; Harrington, Richard M.

1980-07-01

Failure of total joint replacement due to loosening of the composents either between the implant and cement or between the cement and bone is emerging as a late complication with an incidence as high as 20 percent. Loosening may not only cause pain but progressive loss of support for the prosthesis with eventual structural failure. Early diagnosis is important so that revision may be carried when deterioration or pain occurs. No method is currently available which clearly establishes loosening at an early stage except surgical exploration. We have devised a method based on our in vivo photogrammetry studies of patellar tracking patterns using metallic markers placed in bone near both components of the total joint. Stereo x-rays taken with the joint loaded and unloaded are measured for relative motion between the implant and the metallic markers. Laboratory studies using prosthetic hip components mounted in plastic bone have revealed the ability of this method to detect pistoning movements as small as 80 microns. These findings were confirmed by physical measurements.

Current Space Station Experiments Investigating Component Level Electronics Repair

NASA Technical Reports Server (NTRS)

Easton, John W.; Struk, Peter M.

2010-01-01

The Soldering in a Reduced Gravity Experiment (SoRGE) and Component Repair Experiment (CRE)-1 are tests performed on the International Space Station to determine the techniques, tools, and training necessary to allow future crews to perform manual electronics repairs at the component level. SoRGE provides information on the formation and internal structure of through-hole solder joints, illustrating the challenges and implications of soldering in reduced gravity. SoRGE showed a significant increase in internal void defects for joints formed in low gravity compared to normal gravity. Methods for mitigating these void defects were evaluated using a modified soldering process. CRE-1 demonstrated the removal, cleaning, and replacement of electronics components by manual means on functional circuit boards. The majority of components successful passed a post-repair functional test demonstrating the feasibility of component-level repair within the confines of a spacecraft. Together, these tasks provide information to recommend material and tool improvements, training improvements, and future work to help enable electronics repairs in future space missions.

The cementless anatomic medullary locking femoral component: an independent clinical and radiographic assessment

PubMed Central

Chess, David G.; Grainger, R. Wayne; Phillips, Tom; Zarzour, Zane D.; Sheppard, Bruce R.

1996-01-01

Objective To review the clinical performance of the anatomic medullary locking (AML) femoral stem in total hip arthroplasty. Design A clinical and radiographic review. Setting A tertiary lower limb joint replacement centre. Patients Two hundred and twenty-one patients with noninflammatory gonarthrosis. Interventions Two hundred and twenty-seven primary total hip arthroplasties with the noncemented AML component completed by two surgeons. Main Outcome Measures Independent review by two experienced reviewers of the postoperative Harris hip score, radiographs of component fixation, size and degree of diaphyseal fill. Results Harris hip score was 84 (range from 43 to 98); component fixation showed bone ingrowth in 41%, stable fixation with fibrous ingrowth in 56% and unstable fixation in 3%; severe thigh pain in 4% of cases correlated with unstable fixation, and there was mild thigh pain in 20% of cases. Conclusion The AML femoral stem performs well in replacement arthroplasty compared with other noncemented stems. PMID:8857987

The design and development of a triaxial wear-testing joint simulator.

PubMed

Green, A S; O'Connell, M K; Lyons, A S; James, S P

1999-01-01

Most of the existing wear testers created to wear test total hip replacements, specifically the acetabular component, are designed to exert only an axial force and provide rotation in a close approximation of the actual femoral movement. The Rocky Mountain Joint Simulator was designed to exert three orthogonal forces and provide rotations about the X-, Y- and Z-axes to more closely simulate the physiological forces and motions found in the human gait cycle. The RMJS was also designed with adaptability for other joints, such as knees or canine hips, through the use of hydraulics and a computer-programmable control system. Such adaptability and functionality allows the researcher to more closely model a gait cycle, thereby obtaining wear patterns that resemble those found in retrieved implants more closely than existing simulators. Research is ongoing into the tuning and evaluation of the machine and preliminary acetabular component wear test results will be presented at the conference.

A patterned microtexture to reduce friction and increase longevity of prosthetic hip joints

PubMed Central

Chyr, Anthony; Qiu, Mingfeng; Speltz, Jared; Jacobsen, Ronald L.; Sanders, Anthony P.; Raeymaekers, Bart

2014-01-01

More than 285,000 total hip replacement surgeries are performed in the US each year. Most prosthetic hip joints consist of a cobalt-chromium (CoCr) femoral head that articulates with a polyethylene acetabular component, lubricated with synovial fluid. The statistical survivorship of these metal-on-polyethylene prosthetic hip joints declines significantly after 10 to 15 years of use, primarily as a result of polyethylene wear and wear debris incited disease. The current engineering paradigm to increase the longevity of prosthetic hip joints is to improve the mechanical properties of the polyethylene component, and to manufacture ultra-smooth articulating surfaces. In contrast, we show that adding a patterned microtexture to the ultra-smooth CoCr femoral head reduces friction when articulating with the polyethylene acetabular liner. The microtexture increases the load-carrying capacity and the thickness of the joint lubricant film, which reduces contact between the articulating surfaces. As a result, friction and wear is reduced. We have used a lubrication model to design the geometry of the patterned microtexture, and experimentally demonstrate reduced friction for the microtextured compared to conventional smooth surrogate prosthetic hip joints. PMID:25013240

Process for fabrication of cermets

DOEpatents

Landingham, Richard L [Livermore, CA

2011-02-01

Cermet comprising ceramic and metal components and a molten metal infiltration method and process for fabrication thereof. The light weight cermets having improved porosity, strength, durability, toughness, elasticity fabricated from presintered ceramic powder infiltrated with a molten metal or metal alloy. Alumina titanium cermets biocompatible with the human body suitable for bone and joint replacements.

The Influence of Component Alignment and Ligament Properties on Tibiofemoral Contact Forces in Total Knee Replacement.

PubMed

Smith, Colin R; Vignos, Michael F; Lenhart, Rachel L; Kaiser, Jarred; Thelen, Darryl G

2016-02-01

The study objective was to investigate the influence of coronal plane alignment and ligament properties on total knee replacement (TKR) contact loads during walking. We created a subject-specific knee model of an 83-year-old male who had an instrumented TKR. The knee model was incorporated into a lower extremity musculoskeletal model and included deformable contact, ligamentous structures, and six degrees-of-freedom (DOF) tibiofemoral and patellofemoral joints. A novel numerical optimization technique was used to simultaneously predict muscle forces, secondary knee kinematics, ligament forces, and joint contact pressures from standard gait analysis data collected on the subject. The nominal knee model predictions of medial, lateral, and total contact forces during gait agreed well with TKR measures, with root-mean-square (rms) errors of 0.23, 0.22, and 0.33 body weight (BW), respectively. Coronal plane component alignment did not affect total knee contact loads, but did alter the medial-lateral load distribution, with 4 deg varus and 4 deg valgus rotations in component alignment inducing +17% and -23% changes in the first peak medial tibiofemoral contact forces, respectively. A Monte Carlo analysis showed that uncertainties in ligament stiffness and reference strains induce ±0.2 BW uncertainty in tibiofemoral force estimates over the gait cycle. Ligament properties had substantial influence on the TKR load distributions, with the medial collateral ligament and iliotibial band (ITB) properties having the largest effects on medial and lateral compartment loading, respectively. The computational framework provides a viable approach for virtually designing TKR components, considering parametric uncertainty and predicting the effects of joint alignment and soft tissue balancing procedures on TKR function during movement.

The Influence of Component Alignment and Ligament Properties on Tibiofemoral Contact Forces in Total Knee Replacement

PubMed Central

Smith, Colin R.; Vignos, Michael F.; Lenhart, Rachel L.; Kaiser, Jarred; Thelen, Darryl G.

2016-01-01

The study objective was to investigate the influence of coronal plane alignment and ligament properties on total knee replacement (TKR) contact loads during walking. We created a subject-specific knee model of an 83-year-old male who had an instrumented TKR. The knee model was incorporated into a lower extremity musculoskeletal model and included deformable contact, ligamentous structures, and six degrees-of-freedom (DOF) tibiofemoral and patellofemoral joints. A novel numerical optimization technique was used to simultaneously predict muscle forces, secondary knee kinematics, ligament forces, and joint contact pressures from standard gait analysis data collected on the subject. The nominal knee model predictions of medial, lateral, and total contact forces during gait agreed well with TKR measures, with root-mean-square (rms) errors of 0.23, 0.22, and 0.33 body weight (BW), respectively. Coronal plane component alignment did not affect total knee contact loads, but did alter the medial–lateral load distribution, with 4 deg varus and 4 deg valgus rotations in component alignment inducing +17% and −23% changes in the first peak medial tibiofemoral contact forces, respectively. A Monte Carlo analysis showed that uncertainties in ligament stiffness and reference strains induce ±0.2 BW uncertainty in tibiofemoral force estimates over the gait cycle. Ligament properties had substantial influence on the TKR load distributions, with the medial collateral ligament and iliotibial band (ITB) properties having the largest effects on medial and lateral compartment loading, respectively. The computational framework provides a viable approach for virtually designing TKR components, considering parametric uncertainty and predicting the effects of joint alignment and soft tissue balancing procedures on TKR function during movement. PMID:26769446

Musculoskeletal disease burden of hereditary hemochromatosis.

PubMed

Sahinbegovic, Enijad; Dallos, Tomáš; Aigner, Elmar; Axmann, Roland; Manger, Bernhard; Englbrecht, Matthias; Schöniger-Hekele, Maximilian; Karonitsch, Thomas; Stamm, Tanja; Farkas, Martin; Karger, Thomas; Stölzel, Ulrich; Keysser, Gernot; Datz, Christian; Schett, Georg; Zwerina, Jochen

2010-12-01

To determine the prevalence, clinical picture, and disease burden of arthritis in patients with hereditary hemochromatosis. In this cross-sectional observational study of 199 patients with hemochromatosis and iron overload, demographic and disease-specific variables, genotype, and organ involvement were recorded. The prevalence, intensity, and localization of joint pain were assessed, and a complete rheumatologic investigation was performed. Radiographs of the hands, knees, and ankles were scored for joint space narrowing, erosions, osteophytes, and chondrocalcinosis. In addition, the number and type of joint replacement surgeries were recorded. Joint pain was reported by 72.4% of the patients. Their mean ± SD age at the time of the initial joint symptoms was 45.8 ± 13.2 years. If joint pain was present, it preceded the diagnosis of hemochromatosis by a mean ± SD of 9.0 ± 10.7 years. Bony enlargement was observed in 65.8% of the patients, whereas synovitis was less common (13.6%). Joint space narrowing and osteophytes as well as chondrocalcinosis of the wrist and knee joints were frequent radiographic features of hemochromatosis. Joint replacement surgery was common, with 32 patients (16.1%) undergoing total joint replacement surgery due to severe OA. The mean ± SD age of these patients was 58.3 ± 10.4 years at time of joint replacement surgery. Female sex, metacarpophalangeal joint involvement, and the presence of chondrocalcinosis were associated with a higher risk of early joint failure (i.e., the need for joint replacement surgery). Arthritis is a frequent, early, and severe symptom of hemochromatosis. Disease is not confined to involvement of the metacarpophalangeal joints and often leads to severe damage requiring the replacement of joints. Copyright © 2010 by the American College of Rheumatology.

Electron beam weld development on a Filter Pack Assembly

NASA Astrophysics Data System (ADS)

Dereskiewicz, J. P.

1994-06-01

A continuous electron beam welding procedure was developed to replace the manual gas tungsten arc welding procedure on the Filter Pack Assembly. A statistical study was used to evaluate the feasibility of electron beam welding 6061-T6 aluminum covers to A356 cast weldments throughout the joint tolerance range specified on product drawings. Peak temperature exposures were not high enough to degrade the heat sensitive electrical components inside the cast weldment. Actual weldments with alodine coating on the weld joint area were successfully cleaned using a nonmetallic fiberglass brush cleaning method.

Hip or knee replacement - after - what to ask your doctor

MedlinePlus

... chap 7. Read More Hip joint replacement Hip pain Knee joint replacement Knee pain Osteoarthritis Patient Instructions Getting your home ready - knee or hip surgery Hip or knee replacement - before - ...

Hip or knee replacement - before - what to ask your doctor

MedlinePlus

... chap 7. Read More Hip joint replacement Hip pain Knee joint replacement Knee pain Osteoarthritis Patient Instructions Getting your home ready - knee or hip surgery Hip or knee replacement - after - ...

Medicare Program; Comprehensive Care for Joint Replacement Payment Model for Acute Care Hospitals Furnishing Lower Extremity Joint Replacement Services. Final rule.

PubMed

2015-11-24

This final rule implements a new Medicare Part A and B payment model under section 1115A of the Social Security Act, called the Comprehensive Care for Joint Replacement (CJR) model, in which acute care hospitals in certain selected geographic areas will receive retrospective bundled payments for episodes of care for lower extremity joint replacement (LEJR) or reattachment of a lower extremity. All related care within 90 days of hospital discharge from the joint replacement procedure will be included in the episode of care. We believe this model will further our goals in improving the efficiency and quality of care for Medicare beneficiaries with these common medical procedures.

Influence of clamp-up force on the strength of bolted composite joints

NASA Astrophysics Data System (ADS)

Horn, Walter J.; Schmitt, Ron R.

1994-03-01

Composite materials offer the potential for a reduction in the number of individual parts and joints in a structure because large one-piece components can replace multipart assemblies. Nevertheless, there are many situations where composite parts must be joined and often mechanical fasteners provide the only practical method of joining those parts. The long-term strength of mechanically fastened joints of composite members can be directly affected by the clamp-up force of the fastener and thus perhaps by the relaxation of this force due to the viscoelastic character of the composite materials of the joint. Methods for predicting the effect of bolt clamp-up force relaxation on the strength of mechanically fastened joints of thermoplastic composite materials were investigated during the present study. A test program, using two thermoplastic composite materials, was conducted to determine the influence of clamp-up force on joint strength, to measure the relaxation of the joint clamp-up force with time, and to measure the change of joint strength as a function of time.

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

PubMed

Białecki, Jacek; Majchrzycki, Marian; Szymczak, Antoni; Klimowicz-Bodys, Małgorzata Dorota; Wierzchoś, Edward; Kołomecki, 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.

Construction of Finite Element Model for an Artificial Atlanto-Odontoid Joint Replacement and Analysis of Its Biomechanical Properties.

PubMed

Hu, Yong; Dong, Wei-Xin; Hann, Shannon; Yuan, Zhen-Shan; Sun, Xiao-Yang; Xie, Hui; Zhang, Meichao

To investigate the stress distribution on artificial atlantoaxial-odontoid joint (AAOJ) components during flexion, extension, lateral bending and rotation of AAOJ model constructed with the finite element (FE) method. Human cadaver specimens of normal AAOJ were CT scanned with 1 mm -thickness and transferred into Mimics software to reconstruct the three-dimensional models of AAOJ. These data were imported into Freeform software to place a AAOJ into a atlantoaxial model. With Ansys software, a geometric model of AAOJ was built. Perpendicular downward pressure of 40 N was applied to simulate gravity of a skull, then 1.53 N• m torque was exerted separately to simulate the range of motion of the model. An FE model of atlantoaxial joint after AAOJ replacement was constructed with a total of 103 053 units and 26 324 nodes. In flexion, extension, right lateral bending and right rotation, the AAOJ displacement was 1.109 mm, 3.31 mm, 0.528 mm, and 9.678 mm, respectively, and the range of motion was 1.6°, 5.1°, 4.6° and 22°. During all ROM, stress distribution of atlas-axis changed after AAOJ replacement indicating that AAOJ can offload stress. The stress distribution in the AAOJ can be successfully analyzed with the FE method.

An investigation of the validity of six measures of physical function in people awaiting joint replacement surgery of the hip or knee.

PubMed

Gill, Stephen D; de Morton, Natalie A; Mc Burney, Helen

2012-10-01

To assess and compare the validity of six physical function measures in people awaiting hip or knee joint replacement. Eighty-two people awaiting hip or knee replacement were assessed using six physical function measures including the WOMAC Function scale, SF-36 Physical Function scale, SF-36 Physical Component Summary scale, Patient Specific Functional Scale, 30-second chair stand test, and 50-foot timed walk. Validity was assessed using a head-to-head comparison design. Convergent validity was demonstrated with significant correlations between most measures (Spearman's rho 0.22 to 0.71). The Patient Specific Functional Scale had the lowest correlations with other measures of physical function. Discriminant validity was demonstrated with low correlations between mental health and physical function scores (Spearman's rho -0.12 to 0.33). Only the WOMAC Function scale, 30-second chair stand test, and 50-foot timed walk demonstrated known groups validity when scores for participants who walked with a gait aid were compared with those who did not. Standardized response means and Guyatt's responsiveness indexes indicated that the SF-36 was the least responsive measure. For those awaiting joint replacement surgery of the hip or knee, the current investigation found that the WOMAC Function scale, 30-second chair stand test, and 50-foot timed walk demonstrated the most evidence of validity. The Patient Specific Functional Scale might complement other measures by capturing a different aspect of physical function.

Outcome of prosthesis matched and unmatched patella components in primary and revision total knee replacement.

PubMed

Lewis, Peter L; Gamboa, Ai E; Campbell, David G; Lorimer, Michelle

2017-10-01

Although knee replacements have specifically designed patella prostheses that correspond to the geometry of their femoral components, a patella prosthesis that is unmatched to the femoral component may occasionally be inserted. In revision total knee arthroplasty (TKA), an originally resurfaced patella may be left, but the femoral component revised to one that does not match the patella. Few studies have compared the outcome of matched and unmatched patella components in TKA. This study compared the primary or revision TKA outcome of procedures where patella components matched to their femoral counterparts were inserted, with procedures using patella and femoral components that were unmatched. Data on all primary and revision TKA procedures without a patella component or a matched or an unmatched patella component were obtained from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). Revision surgery was the outcome measure. Cumulative percent revised (CPR) were calculated and Hazard ratios with p values were used to test statistical significance. In primary TKA, there were higher rates of revision where unmatched patella components were used, regardless of implant design. There was no difference in the second revision rates of unmatched versus matched patella component groups. This was evident where delayed resurfacing was carried out, and where the patella prosthesis was left alone but the femoral component was changed. All primary TKA procedures require a patella component corresponding to the femoral component if the patella is resurfaced. Conversely, revision knee arthroplasties are not affected by the use of dissimilar patella and femoral components. Copyright © 2017 Elsevier B.V. All rights reserved.

Tribo-electrochemical characterization of metallic biomaterials for total joint replacement.

PubMed

Diomidis, N; Mischler, S; More, N S; Roy, Manish

2012-02-01

Knee and hip joint replacement implants involve a sliding contact between the femoral component and the tibial or acetabular component immersed in body fluids, thus making the metallic parts susceptible to tribocorrosion. Micro-motions occur at points of fixation leading to debris and ion release by fretting corrosion. β-Titanium alloys are potential biomaterials for joint prostheses due to their biocompatibility and compatibility with the mechanical properties of bone. The biotribocorrosion behavior of Ti-29Nb-13Ta-4.6Zr was studied in Hank's balanced salt solution at open circuit potential and at an applied potential in the passive region. Reciprocating sliding tribocorrosion tests were carried out against technical grade ultra high molecular weight polyethylene, while fretting corrosion tests were carried out against alumina. The wear of the alloy is insignificant when sliding against polyethylene. However, depassivation does take place, but the tested alloy showed an ability to recover its passive state during sliding. The abrasivity of the alloy depends on the electrochemical conditions of the contact, while the wear of polyethylene proceeds through third body formation and material transfer. Under fretting corrosion conditions recovery of the passive state was also achieved. In a fretting contact wear of the alloy proceeds through plastic deformation of the bulk material and wear resistance depends on the electrochemical conditions. Copyright © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

[Endoprostheses in geriatric traumatology].

PubMed

Buecking, B; Eschbach, D; Bliemel, C; Knobe, M; Aigner, R; Ruchholtz, S

2017-01-01

Geriatric traumatology is increasing in importance due to the demographic transition. In cases of fractures close to large joints it is questionable whether primary joint replacement is advantageous compared to joint-preserving internal fixation. The aim of this study was to describe the importance of prosthetic joint replacement in the treatment of geriatric patients suffering from frequent periarticular fractures in comparison to osteosynthetic joint reconstruction and conservative methods. A selective search of the literature was carried out to identify studies and recommendations concerned with primary arthroplasty of fractures in the region of the various joints (hip, shoulder, elbow and knee). The importance of primary arthroplasty in geriatric traumatology differs greatly between the various joints. Implantation of a prosthesis has now become the gold standard for displaced fractures of the femoral neck. In addition, reverse shoulder arthroplasty has become an established alternative option to osteosynthesis in the treatment of complex proximal humeral fractures. Due to a lack of large studies definitive recommendations cannot yet be given for fractures around the elbow and the knee. Nowadays, joint replacement for these fractures is recommended only if reconstruction of the joint surface is not possible. The importance of primary joint replacement for geriatric fractures will probably increase in the future. Further studies with larger patient numbers must be conducted to achieve more confidence in decision making between joint replacement and internal fixation especially for shoulder, elbow and knee joints.

Alloplastic total temporomandibular joint replacements: do they perform like natural joints? Prospective cohort study with a historical control.

PubMed

Wojczyńska, A; Leiggener, C S; Bredell, M; Ettlin, D A; Erni, S; Gallo, L M; Colombo, V

2016-10-01

The aim of this study was to qualitatively and quantitatively describe the biomechanics of existing total alloplastic reconstructions of temporomandibular joints (TMJ). Fifteen patients with unilateral or bilateral TMJ total joint replacements and 15 healthy controls were evaluated via dynamic stereometry technology. This non-invasive method combines three-dimensional imaging of the subject's anatomy with jaw tracking. It provides an insight into the patient's jaw joint movements in real time and provides a quantitative evaluation. The patients were also evaluated clinically for jaw opening, protrusive and laterotrusive movements, pain, interference with eating, and satisfaction with the joint replacements. The qualitative assessment revealed that condyles of bilateral total joint replacements displayed similar basic motion patterns to those of unilateral prostheses. Quantitatively, mandibular movements of artificial joints during opening, protrusion, and laterotrusion were all significantly shorter than those of controls. A significantly restricted mandibular range of motion in replaced joints was also observed clinically. Fifty-three percent of patients suffered from chronic pain at rest and 67% reported reduced chewing function. Nonetheless, patients declared a high level of satisfaction with the replacement. This study shows that in order to gain a comprehensive understanding of complex therapeutic measures, a multidisciplinary approach is needed. Copyright © 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

77 FR 59082 - Drawbridge Operation Regulation; Atlantic Intracoastal Waterway (AIWW), Elizabeth River, Southern...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-26

... Chesapeake, VA. This deviation is necessary to facilitate replacing lift joints on the Norfolk Southern 7... accommodate lift joint replacement. Under the current operating schedule the bridge shall be left in the open.... To facilitate lift joint replacement, the drawbridge will be maintained in the closed-to-navigation...

Differences in the stress distribution in the distal femur between patellofemoral joint replacement and total knee replacement: a finite element study

PubMed Central

2012-01-01

Background Patellofemoral joint replacement is a successful treatment option for isolated patellofemoral osteoarthritis. However, results of later conversion to total knee replacement may be compromised by periprosthetic bone loss. Previous clinical studies have demonstrated a decrease in distal femoral bone mineral density after patellofemoral joint replacement. It is unclear whether this is due to periprosthetic stress shielding. The main objective of the current study was to evaluate the stress shielding effect of prosthetic replacement with 2 different patellofemoral prosthetic designs and with a total knee prosthesis. Methods We developed a finite element model of an intact patellofemoral joint, and finite element models of patellofemoral joint replacement with a Journey PFJ prosthesis, a Richards II prosthesis, and a Genesis II total knee prosthesis. For each of these 4 finite element models, the average Von Mises stress in 2 clinically relevant regions of interest were evaluated during a simulated squatting movement until 120 degrees of flexion. Results During deep knee flexion, in the anterior region of interest, the average Von Mises stress with the Journey PFJ design was comparable to the physiological knee, while reduced by almost 25% for both the Richards II design and the Genesis II total knee joint replacement design. The average Von Mises stress in the supracondylar region of interest was similar for both patellofemoral prosthetic designs and the physiological model, with slightly lower stress for the Genesis II design. Conclusions Patellofemoral joint replacement results in periprosthetic stress-shielding, although to a smaller degree than in total knee replacement. Specific patellofemoral prosthetic design properties may result in differences in femoral stress shielding. PMID:22704638

Satisfaction with joint replacement in public versus private hospitals: a cohort study.

PubMed

Adie, Sam; Dao, Alan; Harris, Ian A; Naylor, Justine M; Mittal, Rajat

2012-09-01

In Australia, the majority of total knee and hip replacement surgeries occur in the private sector. Outcome-based research needs to be inclusive of this sector if the findings are intended to reflect the broader picture. This study compares outcomes up to 1 year post knee and hip replacement between patients treated in the public and private sectors. A prospective, observational study was performed in four high-volume joint replacement centres: two public, two private. Experienced orthopaedic surgeons contributed via their public and private practices. Knee and hip patients were recruited preoperatively. Self-reported questionnaires were completed preoperatively and at 6 and 12 months post-operatively. The primary outcome was satisfaction with surgery. Secondary outcomes included Oxford score, and SF-36 physical and mental component summary scores. Regression modelling was performed to adjust for potential confounders. Three hundred and thirty-one patients (184 public, 147 private; 215 knees, 116 hips) were recruited, with 6- and 12-month follow-up rates of 95% and 89%, respectively. Satisfaction rates were high in both public and private patients (approximately 90%) at 6 and 12 months, but private patients were less likely to be satisfied after adjusting for the strong effect of patient expectation. For both hip and knee cohorts, no between-sector differences were found in either the magnitude or rate of improvement in Oxford score or quality of life post-operatively. Joint replacement outcomes are similar for patients treated in public and private hospitals. Surgeons should manage patient expectation prior to surgery, particularly in private patients. © 2012 The Authors. ANZ Journal of Surgery © 2012 Royal Australasian College of Surgeons.

Hip joint replacement - slideshow

MedlinePlus

... this page: //medlineplus.gov/ency/presentations/100006.htm Hip joint replacement - series—Normal anatomy To use the ... to slide 5 out of 5 Overview The hip joint is made up of two major parts: ...

The anteroposterior axis of the tibia in Korean patients undergoing total knee replacement.

PubMed

Kim, C W; Seo, S S; Kim, J H; Roh, S M; Lee, C R

2014-11-01

The aim of this study was to find anatomical landmarks for rotational alignment of the tibial component in total knee replacement (TKR) in a CT-based study. Pre-operative CT scanning was performed on 94 South Korean patients (nine men, 85 women, 188 knees) with osteoarthritis of the knee joint prior to TKR. The tibial anteroposterior (AP) axis was defined as a line perpendicular to the femoral surgical transepicondylar axis and passing through the centre of the posterior cruciate ligament (PCL). The angles between the defined tibial AP axis and anatomical landmarks at various levels of the tibia were measured. The mean values of the angles between the defined tibial AP axis and the line connecting the anterior border of the proximal third of the tibia to the centre of the PCL was -0.2° (-17 to 14.1, sd 4.1). This was very close to the defined tibial axis, and remained so regardless of lower limb alignment and the degree of tibial bowing. Therefore, AP axis defined as described, is a reliable anatomical landmark for rotational alignment of tibial components. ©2014 The British Editorial Society of Bone & Joint Surgery.

Managed care and critical pathway development: the joint replacement experience.

PubMed

Benham, A J

1999-01-01

This article examines the economic, social, ethical, and political issues affecting total joint replacement patients in a managed care environment. Using general systems theory as a framework, it examines the interrelated historical events that have shaped the development of both joint replacement procedures and managed care, and discusses the extent to which these two phenomena have been mutually influential. Specifically, the article examines the initial development, implementation, and continuing evolution of clinical pathways as an easily identified and relatively discrete manifestation of managed care for the joint replacement population. While the overall impact of managed care is beyond the scope of this presentation, it is hoped that a focus on the practical application of clinical pathways to joint replacement will allow some general principles to emerge that may be useful for both patients and practitioners operating in other aspects of the managed care environment.

Diabetes is associated with persistent pain after hip and knee replacement

PubMed Central

Rajamäki, Tuomas J; Jämsen, Esa; Puolakka, Pia A; Nevalainen, Pasi I; Moilanen, Teemu

2015-01-01

Background and purpose In some patients, for unknown reasons pain persists after joint replacement, especially in the knee. We determined the prevalence of persistent pain following primary hip or knee replacement and its association with disorders of glucose metabolism, metabolic syndrome (MetS), and obesity. Patients and methods The incidence of pain in the operated joint was surveyed 1–2 years after primary hip replacement (74 patients (4 bilateral)) or primary knee replacement (119 patients (19 bilateral)) in 193 osteoarthritis patients who had participated in a prospective study on perioperative hyperglycemia. Of the 155 patients who completed the survey, 21 had undergone further joint replacement surgery during the follow-up and were excluded, leaving 134 patients for analysis. Persistent pain was defined as daily pain in the operated joint that had lasted over 3 months. Factors associated with persistent pain were evaluated using binary logistic regression with adjustment for age, sex, and operated joint. Results 49 of the134 patients (37%) had a painful joint and 18 of them (14%) had persistent pain. A greater proportion of knee patients than hip patients had a painful joint (46% vs. 24%; p = 0.01) and persistent pain (20% vs. 4%; p = 0.007). Previously diagnosed diabetes was strongly associated with persistent pain (5/19 vs. 13/115 in those without; adjusted OR = 8, 95% CI: 2–38) whereas MetS and obesity were not. However, severely obese patients (BMI ≥ 35) had a painful joint (but not persistent pain) more often than patients with BMI < 30 (14/21 vs. 18/71; adjusted OR = 5, 95% CI: 2–15). Interpretation Previously diagnosed diabetes is a risk factor for persistent pain in the operated joint 1–2 years after primary hip or knee replacement. PMID:25953426

Imaging and Analysis of Void-defects in Solder Joints Formed in Reduced Gravity using High-Resolution Computed Tomography

NASA Technical Reports Server (NTRS)

Easton, John W.; Struk, Peter M.; Rotella, Anthony

2008-01-01

As a part of efforts to develop an electronics repair capability for long duration space missions, techniques and materials for soldering components on a circuit board in reduced gravity must be developed. This paper presents results from testing solder joint formation in low gravity on a NASA Reduced Gravity Research Aircraft. The results presented include joints formed using eutectic tin-lead solder and one of the following fluxes: (1) a no-clean flux core, (2) a rosin flux core, and (3) a solid solder wire with external liquid no-clean flux. The solder joints are analyzed with a computed tomography (CT) technique which imaged the interior of the entire solder joint. This replaced an earlier technique that required the solder joint to be destructively ground down revealing a single plane which was subsequently analyzed. The CT analysis technique is described and results presented with implications for future testing as well as implications for the overall electronics repair effort discussed.

Health Information in Bosnian (bosanski)

MedlinePlus

... new window. A Expand Section After Surgery Home Care After Total Joint Replacement - bosanski (Bosnian) Bilingual PDF Health Information ... Information Translations J Expand Section Joint Disorders Home Care After Total Joint Replacement - bosanski (Bosnian) Bilingual PDF Health Information ...

Doppler Lidar System Design via Interdisciplinary Design Concept at NASA Langley Research Center - Part III

NASA Technical Reports Server (NTRS)

Barnes, Bruce W.; Sessions, Alaric M.; Beyon, Jeffrey; Petway, Larry B.

2014-01-01

Optimized designs of the Navigation Doppler Lidar (NDL) instrument for Autonomous Landing Hazard Avoidance Technology (ALHAT) were accomplished via Interdisciplinary Design Concept (IDEC) at NASA Langley Research Center during the summer of 2013. Three branches in the Engineering Directorate and three students were involved in this joint task through the NASA Langley Aerospace Research Summer Scholars (LARSS) Program. The Laser Remote Sensing Branch (LRSB), Mechanical Systems Branch (MSB), and Structural and Thermal Systems Branch (STSB) were engaged to achieve optimal designs through iterative and interactive collaborative design processes. A preliminary design iteration was able to reduce the power consumption, mass, and footprint by removing redundant components and replacing inefficient components with more efficient ones. A second design iteration reduced volume and mass by replacing bulky components with excessive performance with smaller components custom-designed for the power system. The existing power system was analyzed to rank components in terms of inefficiency, power dissipation, footprint and mass. Design considerations and priorities are compared along with the results of each design iteration. Overall power system improvements are summarized for design implementations.

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

PubMed Central

Białecki, Jacek; Klimowicz-Bodys, Małgorzata Dorota; Wierzchoś, Edward; Kołomecki, 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

[Effect of sterilisation with formaldehyde, gamma irradiation and ethylene oxide on the properties of polyethylene joint replacement components].

PubMed

Fulín, P; Pokorný, D; Slouf, M; Vacková, T; Dybal, J; Sosna, A

2014-01-01

Each method of sterilisation has some effect on the structure and properties of UHMWPE and thus also on joint replacement longevity. This study was designed to compare, using objective methods of measurement, several kinds of sterilisation and to recommend the one which has the best prospect for making joint replacements last longer. Two groups of UHMWPE samples were tested. Group 1 included virgin GUR 1020 polyethylene, non-modified and non-sterilised (Meditech, Germany). Group 2 comprised of three sets of samples sterilised with formaldehyde, gamma irradiation and ethylene oxide, respectively. In both groups, physicochemical properties were assessed by infrared spectroscopy (IR), and the oxidation (OI) and trans-vinyl (VI) indices, which show the degree of oxidation of a material, were determined. Free-radical concentrations were measured by the method of electron spin resonance (ESR). The mechanical properties of each sample were studied using small punch tests (SPT) and testing microhardness (MH). Any change in mechanical properties can affect, to various degrees, the quality and longevity of a prosthetic joint. The samples sterilised by gamma irradiation showed higher values of both the OI (0.37) and the VI index (0.038) than the other samples (OI, 0.02 to 0.05 and VI, 0). Also, the free-radical concentration was detectable only in the gamma-sterilised sample. Values obtained for mechanical properties were as follows: peak load in the range of 58.48 N (gamma irradiation) to 59.60 N (ethylene oxide); ultimate load in the range of 46.69 N (gamma irradiation) to 57.50 N (ethylene oxide); ultimate displacement in the range of 4.29 mm (gamma irradiation) to 4.58 mm (virgin polyethylene and formaldehyde); and work to failure in the range of 185.18 mJ (gamma irradiation) to 205.89 mJ (virgin polyethylene). Microhardness values were obtained in the following ranges: 41.2 to 44.6 MPa (virgin polyethylene); 40.2 to 44.1 MPa (formaldehyde); 46.1 to 49.3 MPa (gamma irradiation); and 40.3 to 44.2 MPa (ethylene oxide). The samples sterilised with formaldehyde and ethylene oxide have mechanical properties very similar to virgin polyethylene, they are not damaged by oxidation and do not contain free radicals. Owing to these characteristics, the immediate and long-term oxidation stability of the three samples is higher. The sample sterilised by gamma irradiation showed the presence of free radicals and immediate and long-term oxidative degradation. This results in the deterioration of mechanical properties and the growth of crystallinity due to enhanced oxidation and leads to higher polyethylene microhardness. Sterilisation with gamma irradiation results in oxidative degradation and mechanical property deterioration, which is one of the potential risks of a shorter life span of joint replacements. The use of ethylene oxide or formaldehyde does not change polymer properties nor has any effect on oxidation of materials. Therefore, a longer life expectancy of the joint replacements sterilised with ethylene oxide can be expected. The life span of their joint replacements is a key issue for the patients. Prosthetic joint loosening is painful and the patient often requires re-implantation. A higher number of re-implantations is associated with higher costs for the institution involved and, consequently, for the whole health care system. Although this study basically deals with chemical issues, it informs the surgeon of the latest developments leading to the improvement of implanted materials, which can increase the life expectancy of joint replacements and patients' satisfaction.

Viscoplastic crack initiation and propagation in crosslinked UHMWPE from clinically relevant notches up to 0.5mm radius.

PubMed

Sirimamilla, P Abhiram; Rimnac, Clare M; Furmanski, Jevan

2018-01-01

Highly crosslinked UHMWPE is now the material of choice for hard-on-soft bearing couples in total joint replacements. However, the fracture resistance of the polymer remains a design concern for increased longevity of the components in vivo. Fracture research utilizing the traditional linear elastic fracture mechanics (LEFM) or elastic plastic fracture mechanics (EPFM) approach has not yielded a definite failure criterion for UHMWPE. Therefore, an advanced viscous fracture model has been applied to various notched compact tension specimen geometries to estimate the fracture resistance of the polymer. Two generic crosslinked UHMWPE formulations (remelted 65kGy and remelted 100kGy) were analyzed in this study using notched test specimens with three different notch radii under static loading conditions. The results suggest that the viscous fracture model can be applied to crosslinked UHMWPE and a single value of critical energy governs crack initiation and propagation in the material. To our knowledge, this is one of the first studies to implement a mechanistic approach to study crack initiation and propagation in UHMWPE for a range of clinically relevant stress-concentration geometries. It is believed that a combination of structural analysis of components and material parameter quantification is a path to effective failure prediction in UHMWPE total joint replacement components, though additional testing is needed to verify the rigor of this approach. Copyright © 2017 Elsevier Ltd. All rights reserved.

The gap technique does not rotate the femur parallel to the epicondylar axis.

PubMed

Matziolis, Georg; Boenicke, Hinrich; Pfiel, Sascha; Wassilew, Georgi; Perka, Carsten

2011-02-01

In the analysis of painful total knee replacements, the surgical epicondylar axis (SEA) has become established as a standard in the diagnosis of femoral component rotation. It remains unclear whether the gap technique widely used to determine femoral rotation, when applied correctly, results in a rotation parallel to the SEA. In this prospective study, 69 patients (69 joints) were included who received a navigated bicondylar surface replacement due to primary arthritis of the knee joint. In 67 cases in which a perfect soft-tissue balancing of the extension gap (<1° asymmetry) was achieved, the flexion gap and the rotation of the femoral component necessary for its symmetry was determined and documented. The femoral component was implanted additionally taking into account the posterior condylar axis and the Whiteside's line. Postoperatively, the rotation of the femoral component to the SEA was determined and this was used to calculate the angle between a femur implanted according to the gap technique and the SEA. If the gap technique had been used consistently, it would have resulted in a deviation of the femoral components by -0.6° ± 2.9° (-7.4°-5.9°) from the SEA. The absolute deviation would have been 2.4° ± 1.8°, with a range between 0.2° and 7.4°. Even if the extension gap is perfectly balanced, the gap technique does not lead to a parallel alignment of the femoral component to the SEA. Since the clinical results of this technique are equivalent to those of the femur first technique in the literature, an evaluation of this deviation as a malalignment must be considered critically.

Pelvic position and movement during hip replacement.

PubMed

Grammatopoulos, G; Pandit, H G; da Assunção, R; Taylor, A; McLardy-Smith, P; De Smet, K A; Murray, D W; Gill, H S

2014-07-01

The orientation of the acetabular component is influenced not only by the orientation at which the surgeon implants the component, but also the orientation of the pelvis at the time of implantation. Hence, the orientation of the pelvis at set-up and its movement during the operation, are important. During 67 hip replacements, using a validated photogrammetric technique, we measured how three surgeons orientated the patient's pelvis, how much the pelvis moved during surgery, and what effect these had on the final orientation of the acetabular component. Pelvic orientation at set-up, varied widely (mean (± 2, standard deviation (sd))): tilt 8° (2sd ± 32), obliquity -4° (2sd ± 12), rotation -8° (2sd ± 14). Significant differences in pelvic positioning were detected between surgeons (p < 0.001). The mean angular movement of the pelvis between set-up and component implantation was 9° (sd 6). Factors influencing pelvic movement included surgeon, approach (posterior > lateral), procedure (hip resurfacing > total hip replacement) and type of support (p < 0.001). Although, on average, surgeons achieved their desired acetabular component orientation, there was considerable variability (2sd ± 16) in component orientation. We conclude that inconsistency in positioning the patient at set-up and movement of the pelvis during the operation account for much of the variation in acetabular component orientation. Improved methods of positioning and holding the pelvis are required. ©2014 The British Editorial Society of Bone & Joint Surgery.

Management of the patient with a total joint replacement: the primary care practitioner's role.

PubMed

Palmer, L M

1999-01-01

The primary care practitioner assumes chief responsibility for patients with arthritis. More than 40 million Americans experience some form of arthritis. Management of the patient with arthritis may include a referral to an orthopedic surgeon for surgical intervention. As estimated, up to 500,000 total joint replacement procedures are performed by orthopedic surgeons each year in the United States. Presurgical evaluation for a total joint replacement is imperative to ensure that the patient can safely undergo this surgical procedure. Postsurgical care of a patient with total joint replacement involves coordinating care with the physical therapist and orthopedic surgeon to ensure adequate follow-through with the recommended rehabilitation program, prophylactic antibiotic coverage, and observation for any complications including infection, deep-vein thrombosis, or loosening of the total-joint prosthesis.

A new universal, standardized implant database for product identification: a unique tool for arthroplasty registries.

PubMed

Blömer, Wilhelm; Steinbrück, Arnd; Schröder, Christian; Grothaus, Franz-Josef; Melsheimer, Oliver; Mannel, Henrich; Forkel, Gerhard; Eilers, Thomas; Liebs, Thoralf R; Hassenpflug, Joachim; Jansson, Volkmar

2015-07-01

Every joint registry aims to improve patient care by identifying implants that have an inferior performance. For this reason, each registry records the implant name that has been used in the individual patient. In most registries, a paper-based approach has been utilized for this purpose. However, in addition to being time-consuming, this approach does not account for the fact that failure patterns are not necessarily implant specific but can be associated with design features that are used in a number of implants. Therefore, we aimed to develop and evaluate an implant product library that allows both time saving barcode scanning on site in the hospital for the registration of the implant components and a detailed description of implant specifications. A task force consisting of representatives of the German Arthroplasty Registry, industry, and computer specialists agreed on a solution that allows barcode scanning of implant components and that also uses a detailed standardized classification describing arthroplasty components. The manufacturers classified all their components that are sold in Germany according to this classification. The implant database was analyzed regarding the completeness of components by algorithms and real-time data. The implant library could be set up successfully. At this point, the implant database includes more than 38,000 items, of which all were classified by the manufacturers according to the predefined scheme. Using patient data from the German Arthroplasty Registry, several errors in the database were detected, all of which were corrected by the respective implant manufacturers. The implant library that was developed for the German Arthroplasty Registry allows not only on-site barcode scanning for the registration of the implant components but also its classification tree allows a sophisticated analysis regarding implant characteristics, regardless of brand or manufacturer. The database is maintained by the implant manufacturers, thereby allowing registries to focus their resources on other areas of research. The database might represent a possible global model, which might encourage harmonization between joint replacement registries enabling comparisons between joint replacement registries.

Redesigning a joint replacement program using Lean Six Sigma in a Veterans Affairs hospital.

PubMed

Gayed, Benjamin; Black, Stephen; Daggy, Joanne; Munshi, Imtiaz A

2013-11-01

In April 2009, an analysis of joint replacement surgical procedures at the Richard L. Roudebush Veterans Affairs Medical Center, Indianapolis, Indiana, revealed that total hip and knee replacements incurred $1.4 million in non-Veterans Affairs (VA) care costs with an average length of stay of 6.1 days during fiscal year 2008. The Joint Replacement Program system redesign project was initiated following the Vision-Analysis-Team-Aim-Map-Measure-Change-Sustain (VA-TAMMCS) model to increase efficiency, decrease length of stay, and reduce non-VA care costs. To determine the effectiveness of Lean Six Sigma process improvement methods applied in a VA hospital. Perioperative processes for patients undergoing total joint replacement were redesigned following the VA-TAMMCS model--the VA's official, branded method of Lean Six Sigma process improvement. A multidisciplinary team including the orthopedic surgeons, frontline staff, and executive management identified waste in the current processes and initiated changes to reduce waste and increase efficiency. Data collection included a 1-year baseline period and a 20-month sustainment period. The primary endpoint was length of stay; a secondary analysis considered non-VA care cost reductions. Length of stay decreased 36% overall, decreasing from 5.3 days during the preproject period to 3.4 days during the 20-month sustainment period (P < .001). Non-VA care was completely eliminated for patients undergoing total hip and knee replacement at the Richard L. Roudebush Veterans Affairs Medical Center, producing an estimated return on investment of $1 million annually when compared with baseline cost and volumes. In addition, the volume of total joint replacements at this center increased during the data collection period. The success of the Joint Replacement Program demonstrates that VA-TAMMCS is an effective tool for Lean and Six Sigma process improvement initiatives in a surgical practice, producing a 36% sustained reduction in length of stay and completely eliminating non-VA care for total hip and knee replacements while increasing total joint replacement volume at this medical center.

Laser hybrid joining of plastic and metal components for lightweight components

NASA Astrophysics Data System (ADS)

Rauschenberger, J.; Cenigaonaindia, A.; Keseberg, J.; Vogler, D.; Gubler, U.; Liébana, F.

2015-03-01

Plastic-metal hybrids are replacing all-metal structures in the automotive, aerospace and other industries at an accelerated rate. The trend towards lightweight construction increasingly demands the usage of polymer components in drive trains, car bodies, gaskets and other applications. However, laser joining of polymers to metals presents significantly greater challenges compared with standard welding processes. We present recent advances in laser hybrid joining processes. Firstly, several metal pre-structuring methods, including selective laser melting (SLM) are characterized and their ability to provide undercut structures in the metal assessed. Secondly, process parameter ranges for hybrid joining of a number of metals (steel, stainless steel, etc.) and polymers (MABS, PA6.6-GF35, PC, PP) are given. Both transmission and direct laser joining processes are presented. Optical heads and clamping devices specifically tailored to the hybrid joining process are introduced. Extensive lap-shear test results are shown that demonstrate that joint strengths exceeding the base material strength (cohesive failure) can be reached with metal-polymer joining. Weathering test series prove that such joints are able to withstand environmental influences typical in targeted fields of application. The obtained results pave the way toward implementing metalpolymer joints in manufacturing processes.

The effect of local anaesthetic wound infiltration on chronic pain after lower limb joint replacement: A protocol for a double-blind randomised controlled trial

PubMed Central

2011-01-01

Background For the majority of patients with osteoarthritis (OA), joint replacement is a successful intervention for relieving chronic joint pain. However, between 10-30% of patients continue to experience chronic pain after joint replacement. Evidence suggests that a risk factor for chronic pain after joint replacement is the severity of acute post-operative pain. The aim of this randomised controlled trial (RCT) is to determine if intra-operative local anaesthethic wound infiltration additional to a standard anaethesia regimen can reduce the severity of joint pain at 12-months after total knee replacement (TKR) and total hip replacement (THR) for OA. Methods 300 TKR patients and 300 THR patients are being recruited into this single-centre double-blind RCT. Participants are recruited before surgery and randomised to either the standard care group or the intervention group. Participants and outcome assessors are blind to treatment allocation throughout the study. The intervention consists of an intra-operative local anaesthetic wound infiltration, consisting of 60 mls of 0.25% bupivacaine with 1 in 200,000 adrenaline. Participants are assessed on the first 5 days post-operative, and then at 3-months, 6-months and 12-months. The primary outcome is the WOMAC Pain Scale, a validated measure of joint pain at 12-months. Secondary outcomes include pain severity during the in-patient stay, post-operative nausea and vomiting, satisfaction with pain relief, length of hospital stay, joint pain and disability, pain sensitivity, complications and cost-effectiveness. A nested qualitative study within the RCT will examine the acceptability and feasibility of the intervention for both patients and healthcare professionals. Discussion Large-scale RCTs assessing the effectiveness of a surgical intervention are uncommon, particulary in orthopaedics. The results from this trial will inform evidence-based recommendations for both short-term and long-term pain management after lower limb joint replacement. If a local anaesthetic wound infiltration is found to be an effective and cost-effective intervention, implementation into clinical practice could improve long-term pain outcomes for patients undergoing lower limb joint replacement. Trial registration Current Controlled Trials ISRCTN96095682 PMID:21352559

Dual-joint modeling for estimation of total knee replacement contact forces during locomotion.

PubMed

Hast, Michael W; Piazza, Stephen J

2013-02-01

Model-based estimation of in vivo contact forces arising between components of a total knee replacement is challenging because such forces depend upon accurate modeling of muscles, tendons, ligaments, contact, and multibody dynamics. Here we describe an approach to solving this problem with results that are tested by comparison to knee loads measured in vivo for a single subject and made available through the Grand Challenge Competition to Predict in vivo Tibiofemoral Loads. The approach makes use of a "dual-joint" paradigm in which the knee joint is alternately represented by (1) a ball-joint knee for inverse dynamic computation of required muscle controls and (2) a 12 degree-of-freedom (DOF) knee with elastic foundation contact at the tibiofemoral and patellofemoral articulations for forward dynamic integration. Measured external forces and kinematics were applied as a feedback controller and static optimization attempted to track measured knee flexion angles and electromyographic (EMG) activity. The resulting simulations showed excellent tracking of knee flexion (average RMS error of 2.53 deg) and EMG (muscle activations within ±10% envelopes of normalized measured EMG signals). Simulated tibiofemoral contact forces agreed qualitatively with measured contact forces, but their RMS errors were approximately 25% of the peak measured values. These results demonstrate the potential of a dual-joint modeling approach to predict joint contact forces from kinesiological data measured in the motion laboratory. It is anticipated that errors in the estimation of contact force will be reduced as more accurate subject-specific models of muscles and other soft tissues are developed.

Temporomandibular Joint Disorders: A Review of Etiology, Clinical Management, and Tissue Engineering Strategies

PubMed Central

Murphy, Meghan K.; MacBarb, Regina F.; Wong, Mark E.; Athanasiou, Kyriacos A.

2015-01-01

Epidemiology reports state temporomandibular joint disorders (TMD) affect up to 25% of the population, yet their etiology and progression are poorly understood. As a result, treatment options are limited and fail to meet the long-term demands of the relatively young patient population. TMD are a class of degenerative musculoskeletal conditions associated with morphological and functional deformities. In up to 70% of cases, TMD are accompanied by malpositioning of the TMJ disc, termed “internal derangement.” Though onset is not well characterized, correlations between internal derangement and osteoarthritic change have been identified. Due to the complex and unique nature of each TMD case, diagnosis requires patient-specific analysis accompanied by various diagnostic modalities. Likewise, treatment requires customized plans to address the specific characteristics of each patient’s disease. In the mechanically demanding and biochemically active environment of the TMJ, therapeutic approaches capable of restoring joint functionality while responding to changes in the joint have become a necessity. Capable of integration and adaptation in the TMJ, one such approach, tissue engineering, carries significant potential in the development of repair and replacement tissues. The following review presents a synopsis of etiology, current treatment methods, and the future of tissue engineering for repairing and/or replacing diseased joint components, specifically the mandibular condyle and TMJ disc. Preceding the current trends in tissue engineering is an analysis of native tissue characterization, toward identifying tissue engineering objectives and validation metrics for restoring healthy and functional structures of the TMJ. PMID:24278954

Joint Disorders - Multiple Languages

MedlinePlus

... a new window. Arabic (العربية) Expand Section Home Care After Total Joint Replacement - العربية (Arabic) Bilingual PDF Health Information Translations Bosnian (bosanski) Expand Section Home Care After Total Joint Replacement - bosanski (Bosnian) Bilingual PDF Health Information ...

Improving transition of care for veterans after total joint replacement.

PubMed

Green, Uthona R; Dearmon, Valorie; Taggart, Helen

2015-01-01

Patients transitioning from hospital to home are at risk for readmission to the hospital. Readmissions are costly and occur too often. Standardized discharge education processes have shown to decrease readmissions. The purpose of this quality improvement project was to utilize evidence-based practice changes to decrease 30-day all-cause readmissions after total joint replacement. Review of literature revealed that improved discharge education can decrease unnecessary readmissions after discharge. A quality improvement project was developed including standardized total joint replacement discharge education, teach-back education methodology, and improved postdischarge telephone follow-up. The quality improvement project was initiated and outcomes were evaluated. Improving coordination of the discharge process, enhanced education for patients/caregivers, and postdischarge follow-up decreased total joint replacement readmissions.

Evaluation of total alloplastic temporo-mandibular joint replacement with two different types of prostheses: A three-year prospective study

PubMed Central

Gonzalez-Perez-Somarriba, Borja; Centeno, Gabriel; Vallellano, Carpóforo; Montes-Carmona, Jose-Francisco

2016-01-01

Background Temporo-Mandibular Joint (TMJ) replacement has been used clinically for years. The objective of this study was to evaluate outcomes achieved in patients with two different categories of TMJ prostheses. Material and Methods All patients who had a TMJ replacement (TMJR) implanted during the study period from 2006 through 2012 were included in this 3-year prospective study. All procedures were performed using the Biomet Microfixation TMJ Replacement System, and all involved replacing both the skull base component (glenoid fossa) and the mandibular condyle. Results Fifty-seven patients (38 females and 19 males), involving 75 TMJs with severe disease requiring reconstruction (39 unilateral, 18 bilateral) were operated on consecutively, and 68 stock prostheses and 7 custom-made prostheses were implanted. The mean age at surgery was 52.6±11.5 years in the stock group and 51.8±11.7 years in the custom-made group. In the stock group, after three years of TMJR, results showed a reduction in pain intensity from 6.4±1.4 to 1.6±1.2 (p<0.001), and an improvement in jaw opening from 2.7±0.9 cm to 4.2±0.7 cm (p<0.001). In the custom-made group, after three years of TMJR, results showed a reduction in pain intensity from 6.0±1.6 to 2.2±0.4 (p<0.001), and an improvement in jaw opening from 1.5±0.5 cm to 4.3±0.6 cm (p<0.001). No statistically significant differences between two groups were detected. Conclusions The results of this three-year prospective study support the surgical placement of TMJ prostheses (stock prosthetic, and custom-made systems), and show that the approach is efficacious and safe, reduces pain, and improves maximum mouth opening movement, with few complications. As such, TMJR represents a viable technique and a stable long-term solution for cranio-mandibular reconstruction in patients with irreversible end-stage TMJ disease. Comparing stock and custom-made groups, no statistically significant differences were detected with respect to pain intensity reduction and maximum mouth opening improvement. Key words:Temporo-mandibular joint, temporo-mandibular joint replacement, prosthesis, biomaterials, biomedical engineering, computer-aided design and manufacturing. PMID:27475697

STS-111 Flight Day 09 Highlights

NASA Technical Reports Server (NTRS)

2002-01-01

The STS-111 flight crew consists of Kenneth D. Cockrell, Commander, Paul S. Lockhart, Pilot, Franklin R. Chang-Diaz, Mission Specialist, Philippe Perrin, (CNES), Mission Specialist, Valery G. Korzun, (RSA), ISS Up, Peggy A. Whitson, ISS Up , Sergei Y. Treschev (RSC), ISS Up, Yuri I. Onufriyenko (RSA), ISS Down, Carl E. Walz, and Daniel W. Bursch (ISS) Down. The main goal on this ninth day of flight STS-111, is to replace the wrist roll joint of the Robotic Arm on the International Space Station. Live footage of the wrist roll joint replacement is presented. Paul Lockhart is the spacewalk coordinator for this mission. Franklin Chang-Diaz and Philippe Perrin, are responsible for replacing the wrist roll joint and performing maintenance activities. The spacewalk to repair this joint occurs outside the Space Station's Quest Airlock. The wrist roll joint was replaced successfully. The spacewalk took approximately 7 hours and 17 minutes to complete.

Validating Future Force Performance Measures (Army Class): Reclassification Test and Criterion Development

DTIC Science & Technology

2009-09-01

Replace CV boot assembly. 11 Replace propeller shafts , universal joints, and center bearings. 11 Replace front axle spindle . 5 Replace...propeller shafts , universal joints, and center bearings. (SL1/2) 12 Troubleshoot axles. (SL1/2) 11 Replace front axle spindle . (SL1/2) 6...Social Sciences. NOTE: The findings in this report are not to be construed as an official Department of the Army position, unless so designated by

A novel dynamic mechanical testing technique for reverse shoulder replacements.

PubMed

Dabirrahmani, Danè; Bokor, Desmond; Appleyard, Richard

2014-04-01

In vitro mechanical testing of orthopedic implants provides information regarding their mechanical performance under simulated biomechanical conditions. Current in vitro component stability testing methods for reverse shoulder implants are based on anatomical shoulder designs, which do not capture the dynamic nature of these loads. With glenoid component loosening as one of the most prevalent modes of failure in reverse shoulder replacements, it is important to establish a testing protocol with a more realistic loading regime. This paper introduces a novel method of mechanically testing reverse shoulder implants, using more realistic load magnitudes and vectors, than is currently practiced. Using a custom made jig setup within an Instron mechanical testing system, it is possible to simulate the change in magnitude and direction of the joint load during arm abduction. This method is a step towards a more realistic testing protocol for measuring reverse shoulder implant stability.

Thermal Fatigue Evaluation of Pb-Free Solder Joints: Results, Lessons Learned, and Future Trends

NASA Astrophysics Data System (ADS)

Coyle, Richard J.; Sweatman, Keith; Arfaei, Babak

2015-09-01

Thermal fatigue is a major source of failure of solder joints in surface mount electronic components and it is critically important in high reliability applications such as telecommunication, military, and aeronautics. The electronic packaging industry has seen an increase in the number of Pb-free solder alloy choices beyond the common near-eutectic Sn-Ag-Cu alloys first established as replacements for eutectic SnPb. This paper discusses the results from Pb-free solder joint reliability programs sponsored by two industry consortia. The characteristic life in accelerated thermal cycling is reported for 12 different Pb-free solder alloys and a SnPb control in 9 different accelerated thermal cycling test profiles in terms of the effects of component type, accelerated thermal cycling profile and dwell time. Microstructural analysis on assembled and failed samples was performed to investigate the effect of initial microstructure and its evolution during accelerated thermal cycling test. A significant finding from the study is that the beneficial effect of Ag on accelerated thermal cycling reliability (measured by characteristic lifetime) diminishes as the severity of the accelerated thermal cycling, defined by greater ΔT, higher peak temperature, and longer dwell time increases. The results also indicate that all the Pb-free solders are more reliable in accelerated thermal cycling than the SnPb alloy they have replaced. Suggestions are made for future work, particularly with respect to the continued evolution of alloy development for emerging application requirements and the value of using advanced analytical methods to provide a better understanding of the effect of microstructure and its evolution on accelerated thermal cycling performance.

Effect of process parameters on microstructure and electrical conductivity during FSW of Al-6101 and Pure Copper

NASA Astrophysics Data System (ADS)

Sharma, Nidhi; Khan, Zahid A.; Siddiquee, Arshad Noor; Shihab, Suha K.; Atif Wahid, Mohd

2018-04-01

Copper (Cu) is predominantly used material as a conducting element in electrical and electronic components due to its high conductivity. Aluminum (Al) being lighter in weight and more conductive on weight basis than that of Cu is able to replace or partially replace Cu to make lighter and cost effective electrical components. Conventional methods of joining Al to Cu, such as, fusion welding process have many shortcomings. Friction Stir Welding (FSW) is a solid state welding process which overcomes the shortcoming of the fusion welding. FSW parameters affect the mechanical and electrical properties of the joint. This study aims to evaluate the effect of different process parameters such as shoulder diameter, pin offset, welding and rotational speed on the microstructure and electrical conductivity of the dissimilar Al-Cu joint. FSW is performed using cylindrical pin profile, and four process parameters. Each parameter at different levels is varied according to Taguchi’s L18 standard orthogonal array. It is found that the electrical conductivity of the FSWed joints are equal to that of aluminum at all the welded sections. FSW is found to be an effective technique to join Al to Cu without compromising with the electrical properties. However, the electrical conductivity gets influenced by the process parameters in the stir zone. The optimal combination of the FSW parameters for maximum electrical conductivity is determined. The analysis of variance (ANOVA) technique applied on stir zone suggests that the rotational speed and tool pin offset are the significant parameters to influence the electrical conductivity.

Nanostructured diamond coatings for orthopaedic applications

PubMed Central

CATLEDGE, S.A.; THOMAS, V.; VOHRA, Y.K.

2013-01-01

With increasing numbers of orthopaedic devices being implanted, greater emphasis is being placed on ceramic coating technology to reduce friction and wear in mating total joint replacement components, in order to improve implant function and increase device lifespan. In this chapter, we consider ultra-hard carbon coatings, with emphasis on nanostructured diamond, as alternative bearing surfaces for metallic components. Such coatings have great potential for use in biomedical implants as a result of their extreme hardness, wear resistance, low friction and biocompatibility. These ultra-hard carbon coatings can be deposited by several techniques resulting in a wide variety of structures and properties. PMID:25285213

Can combined use of low-level lasers and hyaluronic acid injections prolong the longevity of degenerative knee joints?

PubMed Central

Ip, David; Fu, Nga Yue

2015-01-01

Background This study evaluated whether half-yearly hyaluronic acid injection together with low-level laser therapy in addition to standard conventional physical therapy can successfully postpone the need for joint replacement surgery in elderly patients with bilateral symptomatic tricompartmental knee arthritis. Methods In this prospective, double-blind, placebo-controlled study, 70 consecutive unselected elderly patients with bilateral tricompartmental knee arthritis were assigned at random to either one of two conservative treatment protocols to either one of the painful knees. Protocol A consisted of conventional physical therapy plus a sham light source plus saline injection, and protocol B consisted of protocol A with addition of half-yearly hyaluronic acid injection as well as low-level laser treatment instead of using saline and a sham light source. Treatment failure was defined as breakthrough pain necessitating joint replacement. Results Among the 140 painful knees treated with either protocol A or protocol B, only one of the 70 painful knees treated by protocol B required joint replacement, whereas 15 of the 70 painful knees treated by protocol A needed joint replacement surgery (P<0.05). Conclusion We conclude that half-yearly hyaluronic acid injections together with low-level laser therapy should be incorporated into the standard conservative treatment protocol for symptomatic knee arthritis, because it may prolong the longevity of the knee joint without the need for joint replacement. PMID:26346122

Impact of the economic downturn on total joint replacement demand in the United States: updated projections to 2021.

PubMed

Kurtz, Steven M; Ong, Kevin L; Lau, Edmund; Bozic, Kevin J

2014-04-16

Few studies have explored the role of the National Health Expenditure and macroeconomics on the utilization of total joint replacement. The economic downturn has raised questions about the sustainability of growth for total joint replacement in the future. Previous projections of total joint replacement demand in the United States were based on data up to 2003 using a statistical methodology that neglected macroeconomic factors, such as the National Health Expenditure. Data from the Nationwide Inpatient Sample (1993 to 2010) were used with United States Census and National Health Expenditure data to quantify historical trends in total joint replacement rates, including the two economic downturns in the 2000s. Primary and revision hip and knee arthroplasty were identified using codes from the International Classification of Diseases, Ninth Revision, Clinical Modification. Projections in total joint replacement were estimated using a regression model incorporating the growth in population and rate of arthroplasties from 1993 to 2010 as a function of age, sex, race, and census region using the National Health Expenditure as the independent variable. The regression model was used in conjunction with government projections of National Health Expenditure from 2011 to 2021 to estimate future arthroplasty rates in subpopulations of the United States and to derive national estimates. The growth trend for the incidence of joint arthroplasty, for the overall United States population as well as for the United States workforce, was insensitive to economic downturns. From 2009 to 2010, the total number of procedures increased by 6.0% for primary total hip arthroplasty, 6.1% for primary total knee arthroplasty, 10.8% for revision total hip arthroplasty, and 13.5% for revision total knee arthroplasty. The National Health Expenditure model projections for primary hip replacement in 2020 were higher than a previously projected model, whereas the current model estimates for total knee arthroplasty were lower. Economic downturns in the 2000s did not substantially influence the national growth trends for hip and knee arthroplasty in the United States. These latest updated projections provide a basis for surgeons, hospitals, payers, and policy makers to plan for the future demand for total joint replacement surgery.

Higher Rate of Revision in PFC Sigma Primary Total Knee Arthroplasty With Mismatch of Femoro-Tibial Component Sizes.

PubMed

Young, Simon W; Clarke, Henry D; Graves, Stephen E; Liu, Yen-Liang; de Steiger, Richard N

2015-05-01

Total knee arthroplasty (TKA) systems permit a degree of femoro-tibial component size mismatch. The effect of mismatched components on revision rates has not been evaluated in a large study. We reviewed 21,906 fixed-bearing PFC Sigma primary TKAs using the Australian Orthopaedic Association National Joint Replacement Registry, dividing patients into three groups: no femoro-tibial size mismatch, tibial component size > femoral component size, and femoral component > tibial component. Revision rates were higher when the femoral size was greater than the tibia, compared to both equal size (HR = 1.20 (1.00, 1.45), P = 0.047) and to tibial size greater than femoral (HR = 1.60 (1.08, 2.37), P = 0.019). Potential mechanisms to explain these findings include edge loading of polyethylene and increased tibial component stresses. Copyright © 2014 Elsevier Inc. All rights reserved.

[Comparison of in vivo characteristics of polyethylene wear particles produced by a metal and a ceramic femoral component in total knee replacement].

PubMed

Veigl, D; Vavřík, P; Pokorný, D; Slouf, M; Pavlova, E; Landor, I

2011-01-01

The aim of the study was to evaluate in vivo and compare, in terms of the quality and number of ultra high-molecular polyethylene (UHMWPE) wear particles, total knee replacements of identical construction differing only in the material used for femoral component production, i.e., CoCrMo alloy or ZrO2 ceramics. Samples of peri-prosthetic granuloma tissue were collected in two patients with total knee replacement suffering from implant migration, who were matched in relevant characteristics. The primary knee replacement in Patient 1 with a CoCrMo femoral component was done 7.2 years and in Patient 2 with a ZrO2 implant 6.8 years before this assessment. The polyethylene wear-induced granuloma was analysed by the MORF method enabling us to assess the shape and size of wear debris and the IRc method for assessment of particle concentration. In the granuloma tissue samples of Patient 1, on the average, particles were 0.30 mm in size and their relative volume was 0.19. In the Patient 2 tissue samples, the average size of particles was 0.33 mm and their relative volume was 0.26. There was no significant difference in either particle morphology or their concentration in the granuloma tissue between the two patients. One of the options of how to reduce the production of polyethylene wear particles is to improve the tribological properties of contacting surfaces in total knee replacement by substituting a cobalt-chrome femoral component with a zirconia ceramic femoral component. The previous in vitro testing carried out with a mechanical simulator under conditions approaching real weight-bearing in the human body did show a nearly three-fold decrease in the number of UHMWPE wear particles in zirconia components. The evaluation of granuloma tissue induced by the activity of a real prosthetic joint for nearly seven years, however, did not reveal any great difference in either quality or quantity of polyethylene debris between the two replacements. The difference of surface roughness between CoCrMo (Ra = 0.05) and ZrO2 (Ra = 0.02) components did not play any role in in vivo conditions. CONCLUSIONS In accordance with a previous clinical study, this evaluation of the quality and quantity of UHMWPE wear particles produced by a ceramic femoral component in vivo failed to demonstrate any advantage of zirconia ceramic components over the cobalt-chrome femoral components so far used.

Hip joint replacement

MedlinePlus

... Total hip replacement; Hip hemiarthroplasty; Arthritis - hip replacement; Osteoarthritis - hip replacement ... total hip replacement surgery in patients with hip osteoarthritis: a long-term follow-up of a randomised ...

CRUCIFORM CONTROL ROD JOINT

DOEpatents

Thorp, A.G. II

1962-08-01

An invention is described which relates to nuclear reactor control rod components and more particularly to a joint between cruciform control rod members and cruciform control rod follower members. In one embodiment this invention provides interfitting crossed arms at adjacent ends of a control rod and its follower in abutting relation. This holds the members against relative opposite longitudinal movement while a compression member keys the arms against relative opposite rotation around a common axis. Means are also provided for centering the control rod and its follower on a common axis and for selectively releasing the control rod from its follower for the insertion of a replacement of the control rod and reuse of the follower. (AEC)

Tissue sparing surgery in knee reconstruction: unicompartmental (UKA), patellofemoral (PFA), UKA + PFA, bi-unicompartmental (Bi-UKA) arthroplasties

PubMed Central

Manzotti, A.; Montironi, F.; Pullen, C.

2008-01-01

Recently mini-invasive joint replacement has become one of the hottest topics in the orthopaedic world. However, these terms have been improperly misunderstood as a “key-hole” surgery where traditional components are implanted with shorter surgical approaches, with few benefits and several possible dangers. Small implants as unicompartmental knee prostheses, patellofemoral prostheses and bi-unicompartmental knee prostheses might represent real less invasive procedures: Tissue sparing surgery, the Italian way to minimally invasive surgery (MIS). According to their experience the authors go through this real tissue sparing surgery not limited only to a small incision, but where the surgeons can respect the physiological joint biomechanics. PMID:19384616

[A primary application and evaluation of temporomandibular joint replacement with stock prosthesis].

PubMed

Zhang, Xiao-hu; Chen, Min-jie; Qiu, Ya-ting; Yang, Chi

2012-06-01

To evaluate the effect of total joint replacement in treatment of temporomandibular joint(TMJ) osteoarthropathy with stock prostheses. Six female patients involving 10 joints (2 unilateral and 4 bilateral), with an average age of 59 years old, were involved in this study. Three patients (5 joints) were diagnosed as internal derangement in V stage depending on MRI, 3D-CT findings and clinical characteristics. The other 3 patients (5 joints) had histories of failed temporomandibular joint operation using costochondral graft or temporalis fascial flap. The maximal mouth opening was 1.9 cm on average (range, 1.0 to 2.9cm). All the joints were replaced with Biomet standard prosthesis under general anesthesia. The follow-up period was from 7 to 49 months (average, 17.5 months). All the operations were successfully performed. Heterotopic ossification happened in a bilateral case 1 year postoperatively. One patient with bilateral joint disease complained of severe uncomfortable feeling in the region of the ears and the temples, although there was no significant positive signs according to an ENT examination. Pain relief of the joint and mouth opening improvement were significant in 4 patients. No failure was noted secondary to infection or loosening of the prostheses. The occlusal relationship kept stable postoperatively in all cases. Total TMJ joint replacement with standard prosthesis is a good choice for TMJ reconstruction. It can significantly reduce joint pain and the mouth opening limitation resulted from osteoarthritis. Long-term result remains to be evaluated based on a long-term follow-up.

The John Charnley Award Paper. The role of joint fluid in the tribology of total joint arthroplasty.

PubMed

Mazzucco, Daniel; Spector, Myron

2004-12-01

The effect of joint fluid on the tribology (ie, lubrication, friction, and wear) of total hip arthroplasty has not yet been investigated adequately. In the current study, a friction assay was used to assess four hypotheses relating to the effect of human joint fluid and its principal components on the articulation of metal-on-polyethylene. First, joint fluid was found to produce a widely varying amount of friction between cobalt-chromium and polyethylene; this range exceeded the range produced when the articulation was lubricated by water or bovine serum. Second, it was shown that hyaluronic acid, phospholipid, albumin, and gamma-globulin were not acting as boundary lubricants, but that one or more other proteins (as yet unidentified) were responsible for reducing friction in this couple. Third, lower friction was found when oxidized zirconium alloy replaced cobalt-chromium as a bearing surface on polyethylene. Finally, a pilot study suggested that lubricin, which contributes to cartilage-on-cartilage lubrication, is not a protein responsible for the tribological variabiation found among joint fluid samples. The current study showed that joint fluid is a patient factor that influences the tribology of metal-on-polyethylene arthroplasty.

Converging flow joint insert system at an intersection between adjacent transitions extending between a combustor and a turbine assembly in a gas turbine engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brooks, Robert T.

A transition duct system (100) for routing a gas flow from a combustor (102) to the first stage (104) of a turbine section (106) in a combustion turbine engine (108), wherein the transition duct system (100) includes one or more converging flow joint inserts (120) forming a trailing edge (122) at an intersection (124) between adjacent transition ducts (126, 128) is disclosed. The transition duct system (100) may include a transition duct (126, 128) having an internal passage (130) extending between an inlet (132, 184) to an outlet (134, 186) and may expel gases into the first stage turbine (104)more » with a tangential component. The converging flow joint insert (120) may be contained within a converging flow joint insert receiver (136) and disconnected from the transition duct bodies (126, 128) by which the converging flow joint insert (120) is positioned. Being disconnected eliminates stress formation within the converging flow joint insert (120), thereby enhancing the life of the insert. The converging flow joint insert (120) may be removable such that the insert (120) can be replaced once worn beyond design limits.« less

Raman spectroscopy of dried synovial fluid droplets as a rapid diagnostic for knee joint damage

NASA Astrophysics Data System (ADS)

Esmonde-White, Karen A.; Mandair, Gurjit S.; Raaii, Farhang; Roessler, Blake J.; Morris, Michael D.

2008-02-01

Human synovial fluid droplets were investigated using drop deposition in combination with Raman spectroscopy. Following informed consent, synovial fluid was obtained from forty human patients with various severities of knee pain and/or osteoarthritis at the time of knee arthroscopy or total joint replacement. Synovial fluid was aspirated from the knee joint of each patient and stored at -80°C until examination by near-infrared Raman spectroscopy. Synovial fluid aspirates from the knee joint of each patient were deposited onto a clean fused silica microscope slide and the droplet dried under ambient laboratory conditions. Each droplet was illuminated by a line-focused or a ring-focused 785 nm laser. As the droplet dries, biofluid components segregated based on solubility differences and a deposit that is spatially heterogeneous was made. Spectra taken from the droplet edges and center were dominated by protein bands and showed the presence of at least two protein moieties in the droplet. Band area and band height ratios (1410 cm -1/1450 cm -1) showed the greatest change between specimens from patients with mild/early osteoarthritis compared to those with severe/late stage osteoarthritis. The greatest differences were found in the center of the droplet, which contains more soluble protein components than the edges.

Knee joint replacement

MedlinePlus

... Knee joint replacement - series References American Academy of Orthopedic Surgeons (AAOS) website. Treatment of osteoarthritis of the knee: evidence-based guideline 2nd edition (summary) . www.aaos.org/research/guidelines/TreatmentofOsteoarthritisoftheKneeGuideline.pdf . Updated May 18, 2013. Accessed ...

Etidronate

MedlinePlus

... the skeleton) in people who have had total hip replacement surgery (surgery to replace the hip joint with an artificial joint) or in people ... 8 ounces [180 to 240 mL]) of plain water while you are sitting or standing. Sit or ...

77 FR 25591 - Drawbridge Operation Regulation; Intracoastal Waterway, Chesapeake, VA

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-01

... replacing the lift joints of the drawbridge. This deviation restricts operation of the draw span, allowing... and to perform periodic maintenance. To facilitate replacement of the lift joints of the draw span...

Getting your home ready - knee or hip surgery

MedlinePlus

... Philadelphia, PA: Elsevier; 2017:chap 55. Read More ACL reconstruction Hip fracture surgery Hip joint replacement Knee ... Knee joint replacement Knee microfracture surgery Patient Instructions ACL reconstruction - discharge Hip fracture - discharge Hip or knee ...

Rapid replacement of bridge deck expansion joints study - phase I : [tech transfer summary].

DOT National Transportation Integrated Search

2014-12-01

This initial research phase focused on documenting the current : means and methods of bridge expansion joint deterioration, : maintenance, and replacement and on identifying improvements : through all of the input gathered.

Early medication use in new-onset rheumatoid arthritis may delay joint replacement: results of a large population-based study.

PubMed

Moura, Cristiano S; Abrahamowicz, Michal; Beauchamp, Marie-Eve; Lacaille, Diane; Wang, Yishu; Boire, Gilles; Fortin, Paul R; Bessette, Louis; Bombardier, Claire; Widdifield, Jessica; Hanly, John G; Feldman, Debbie; Maksymowych, Walter; Peschken, Christine; Barnabe, Cheryl; Edworthy, Steve; Bernatsky, Sasha

2015-08-03

Use of disease-modifying anti-rheumatic drugs (DMARDs) in rheumatoid arthritis (RA) may prevent joint damage and potentially reduce joint replacement surgeries. We assessed the association between RA drug use and joint replacement in Quebec, Canada. A cohort of new-onset RA patients was identified from Quebec's physician billing and hospitalization databases from 2002-2011. The outcome was defined using procedure codes submitted by orthopedic surgeons. Medication use was obtained from pharmacy databases. We used alternative Cox regression models with time-dependent variables measuring the cumulative effects of past use during different time windows (one model focussing on the first year after cohort entry) for methotrexate (MTX), and other DMARDs. Models were adjusted for baseline sociodemographics, co-morbidity and prior health service use, time-dependent cumulative use of other drugs (anti-tumor necrosis factor [anti-TNF] agents, other biologics, cyclooxygenase-2 inhibitors [COXIBs], nonselective nonsteroidal antiinflammatory drugs [NSAIDs], and systemic steroids), and markers of disease severity. During follow-up, 608 joint replacements occurred among 11,333 patients (median follow-up: 4.6 years). The best-fitting model relied on the cumulative early use (within the first year after cohort entry) of MTX and of other DMARDs, with an interaction between MTX and other DMARDs. In this model, greater exposure within the first year, to either MTX (adjusted hazard ratio, HR = 0.95 per 1 month, 95% confidence interval, 95% CI 0.93-0.97) or other DMARDs (HR = 0.97, 95% CI 0.95-0.99) was associated with longer time to joint replacement. Our results suggest that longer exposure to either methotrexate (MTX) or other DMARDs within the first year after RA diagnosis is associated with longer time to joint replacement surgery.

Vibration arthrometry in the patients with failed total knee replacement.

PubMed

Jiang, C C; Lee, J H; Yuan, T T

2000-02-01

This is a preliminary research on the vibration arthrometry of artificial knee joint in vivo. Analyzing the vibration signals measured from the accelerometer on patella, there are two speed protocols in knee kinematics: 1) 2 degrees/s, the signal is called "physiological patellofemoral crepitus (PPC)", and 2) 67 degrees/s, the signal is called "vibration signal in rapid knee motion". The study has collected 14 patients who had revision total knee arthroplasty due to prosthetic wear or malalignment represent the failed total knee replacement (FTKR), and 12 patients who had just undergone the primary total knee arthroplasty in the past two to six months and have currently no knee pain represent the normal total knee replacement (NTKR). FTKR is clinically divided into three categories: metal wear, polyethylene wear of the patellar component, and no wear but with prosthesis malalignment. In PPC, the value of root mean square (rms) is used as a parameter; in vibration signals in rapid knee motion, autoregressive modeling is used for adaptive segmentation and extracting the dominant pole of each signal segment to calculate the spectral power ratios in f < 100 Hz and f > 500 Hz. It was found that in the case of metal wear, the rms value of PPC signal is far greater than a knee joint with polyethylene wear and without wear, i.e., PPC signal appears only in metal wear. As for vibration signals in rapid knee motion, prominent time-domain vibration signals could be found in the FTKR patients with either polyethylene or metal wear of the patellar component. We also found that for normal knee joint, the spectral power ratio of dominant poles has nearly 80% distribution in f < 100 Hz, is between 50% and 70% for knee with polyethylene wear and below 30% for metal wear, whereas in f > 500 Hz, spectral power ratio of dominant poles has over 30% distribution in metal wear but only nonsignificant distribution in polyethylene wear, no wear, and normal knee. The results show that vibration signals in rapid knee motion can be used for effectively detecting polyethylene wear of the patellar component in the early stage, while PPC signals can only be used to detect prosthetic metal wear in the late stage.

A custom-made temporomandibular joint prosthesis for fabrication by selective laser melting: Finite element analysis.

PubMed

Xu, Xiangliang; Luo, Danmei; Guo, Chuanbin; Rong, Qiguo

2017-08-01

A novel and custom-made selective laser melting (SLM) 3D-printed alloplastic temporomandibular joint (TMJ) prosthesis is proposed. The titanium-6aluminium-4vanadium (Ti-6Al-4V) condyle component and ultra-high molecular weight polyethylene (UHMWPE) fossa component comprised the total alloplastic TMJ replacement prosthesis. For the condyle component, an optimized tetrahedral open-porous scaffold with combined connection structures, i.e. an inlay rod and an onlay plate, between the prosthesis and remaining mandible was designed. The trajectory of movement of the intact condyle was assessed via kinematic analysis to facilitate the design of the fossa component. The behaviours of the intact mandible and mandible with the prosthesis were compared. The biomechanical behaviour was analysed by assessing the stress distribution on the prosthesis and strain distribution on the mandible. After muscle force was applied, the magnitude of the compressive strain on the condyle neck of the mandible with the prosthesis was lower than that on the condyle neck of the intact mandible, with the exception of the area about the screws; additionally, the magnitude of the strain at the scaffold-bone interface was relatively high. Copyright © 2017. Published by Elsevier Ltd.

Temporomandibular disorders: a review of etiology, clinical management, and tissue engineering strategies.

PubMed

Murphy, Meghan K; MacBarb, Regina F; Wong, Mark E; Athanasiou, Kyriacos A

2013-01-01

Temporomandibular disorders (TMD) are a class of degenerative musculoskeletal conditions associated with morphologic and functional deformities that affect up to 25% of the population, but their etiology and progression are poorly understood and, as a result, treatment options are limited. In up to 70% of cases, TMD are accompanied by malpositioning of the temporomandibular joint (TMJ) disc, termed "internal derangement." Although the onset is not well characterized, correlations between internal derangement and osteoarthritic change have been identified. Because of the complex and unique nature of each TMD case, diagnosis requires patient-specific analysis accompanied by various diagnostic modalities. Likewise, treatment requires customized plans to address the specific characteristics of each patient's disease. In the mechanically demanding and biochemically active environment of the TMJ, therapeutic approaches that can restore joint functionality while responding to changes in the joint have become a necessity. One such approach, tissue engineering, which may be capable of integration and adaptation in the TMJ, carries significant potential for the development of repair and replacement tissues. The following review presents a synopsis of etiology, current treatment methods, and the future of tissue engineering for repairing and/or replacing diseased joint components, specifically the mandibular condyle and TMJ disc. An analysis of native tissue characterization to assist clinicians in identifying tissue engineering objectives and validation metrics for restoring healthy and functional structures of the TMJ is followed by a discussion of current trends in tissue engineering.

The Survival of Total Knee Arthroplasty: Current Data from Registries on Tribology: Review Article.

PubMed

Civinini, Roberto; Carulli, Christian; Matassi, Fabrizio; Lepri, Andrea Cozzi; Sirleo, Luigi; Innocenti, Massimo

2017-02-01

Polyethylene (PE) wear is a major contributor to implant loosening following total knee arthroplasty (TKA), and advanced bearings in TKA are being investigated with hopes of reducing or eliminate wear-related loosening. Currently, information on knee tribology is available from national joint registries and may be the best tools to evaluate the efficacy and safety of design innovations in joint arthroplasty. We performed a review of national joint registries trying to answer the following questions: "Which is the main factor directly related to revisions rate in TKA?" and "Are there new bearing options better than conventional ones?" A review was performed of all published annual reports of National Joint Registers, as well as of the literature. The search was carried out using and comparing the National Joint Registers. Current data from registries for total knee arthroplasty indicates that age is the major factor affecting the outcome of primary total knee replacement. The 10-year cumulative revision rate for non-cross-linked PE was 5.8% and for XLPE it was 3.5%. The effect of cross-linked polyethylene was more evident in the younger patients. The survival of the oxidized zirconium (OxZr) femoral component appears better when compared to a similar age group of patients with conventional group of prostheses. Our review suggests that the revision rates are half for the OxZr components compared to conventional CoCr femoral components. Age is the most relevant single factor related to revision rate. Cross-linked PE has a statistical lower revision rate at 10 years compared to conventional PE and, in the OxZr group, the revision rate is 2 times lower than Co-Cr in the same group of age.

Experience with the use of a partial ossicular replacement prosthesis with a ball-and-socket joint between the plate and the shaft.

PubMed

Birk, Stephanie; Brase, Christoph; Hornung, Joachim

2014-08-01

In the further development of alloplastic prostheses for use in middle ear surgery, the Dresden and Cologne University Hospitals, working together with a company, introduced a new partial ossicular replacement prosthesis in 2011. The ball-and-socket joint between the prosthesis and the shaft mimics the natural articulations between the malleus and incus and between the incus and stapes, allowing reaction to movements of the tympanic membrane graft, particularly during the healing process. Retrospective evaluation To reconstruct sound conduction as part of a type III tympanoplasty, partial ossicular replacement prosthesis with a ball-and-socket joint between the plate and the shaft was implanted in 60 patients, with other standard partial ossicular replacement prosthesis implanted in 40 patients and 64 patients. Pure-tone audiometry was carried out, on average, 19 and 213 days after surgery. Results of the partial ossicular replacement prosthesis with a ball-and-socket joint between the plate and the shaft were compared with those of the standard prostheses. Early measurements showed a mean improvement of 3.3 dB in the air-bone gap (ABG) with the partial ossicular replacement prosthesis with a ball-and-socket joint between the plate and the shaft, giving similar results than the standard implants (6.6 and 6.0 dB, respectively), but the differences were not statistically significant. Later measurements showed a statistically significant improvement in the mean ABG, 11.5 dB, compared with 4.4 dB for one of the standard partial ossicular replacement prosthesis and a tendency of better results to 6.9 dB of the other standard prosthesis. In our patients, we achieved similarly good audiometric results to those already published for the partial ossicular replacement prosthesis with a ball-and-socket joint between the plate and the shaft. Intraoperative fixation posed no problems, and the postoperative complication rate was low.

Patient and implant survival following joint replacement because of metastatic bone disease

PubMed Central

2013-01-01

Background Patients suffering from a pathological fracture or painful bony lesion because of metastatic bone disease often benefit from a total joint replacement. However, these are large operations in patients who are often weak. We examined the patient survival and complication rates after total joint replacement as the treatment for bone metastasis or hematological diseases of the extremities. Patients and methods 130 patients (mean age 64 (30–85) years, 76 females) received 140 joint replacements due to skeletal metastases (n = 114) or hematological disease (n = 16) during the period 2003–2008. 21 replaced joints were located in the upper extremities and 119 in the lower extremities. Clinical and survival data were extracted from patient files and various registers. Results The probability of patient survival was 51% (95% CI: 42–59) after 6 months, 39% (CI: 31–48) after 12 months, and 29% (CI: 21–37) after 24 months. The following surgical complications were seen (8 of which led to additional surgery): 2–5 hip dislocations (n = 8), deep infection (n = 3), peroneal palsy (n = 2), a shoulder prosthesis penetrating the skin (n = 1), and disassembly of an elbow prosthesis (n = 1). The probability of avoiding all kinds of surgery related to the implanted prosthesis was 94% (CI: 89–99) after 1 year and 92% (CI: 85–98) after 2 years. Conclusion Joint replacement operations because of metastatic bone disease do not appear to have given a poorer rate of patient survival than other types of surgical treatment, and the reoperation rate was low. PMID:23530874

Perioperative Pain Management and Anesthesia: A Critical Component to Rapid Recovery Total Joint Arthroplasty.

PubMed

Russo, Matthew W; Parks, Nancy L; Hamilton, William G

2017-10-01

Multimodal pain management has become the standard of care following total hip and knee replacement. The advantages include decreasing opioid consumption and its associated side effects, facilitating earlier mobilization, and faster return to function. An effective rapid recovery protocol includes the use of multiple different types of medications targeting each area of the pain pathway, preemptive analgesia, regional nerve blockade, and local infiltration analgesia. Copyright © 2017 Elsevier Inc. All rights reserved.

Basic kinematics and biomechanics of the patellofemoral joint part 2: the patella in total knee arthroplasty.

PubMed

Schindler, Oliver S

2012-02-01

Patellar and femoral component in total knee arthroplasty are inextricably linked as a functional unit. The configuration of this unit has been a matter of ongoing debate, and the myriad of different patellar and femoral components currently available reflect the lack of consensus with respect to the ideal design. One of the major challenges is to overcome the biomechanical disadvantages of a small contact area through which high contact pressures are transferred, making this mechanical construct the weakest part of the prosthetic knee. Contact areas are highly dependent on the congruency of the patellofemoral joint articulation, and are significantly smaller for dome shaped patellar components compared to those of more anatomic designs. However, when exposed to 3-dimensional movements, the contact areas of the dome shaped patella are significantly greater, indicating enhanced forgiveness regarding patellar malpositioning. Although contact stresses, a function of implant design and surface conformity, can reach levels far beyond the yield strength of UHMWPE, catastrophic failure of resurfaced patellar components, commonly seen in metal backed patellae, fashionable in the 1980s, has rarely been observed since. Although plastic deformation and wear of UHMWPE continue to represent a problem, in the absence of suitable alternatives polyethylene remains the bearing surface of choice. The appreciation of the consequences of the mechanical environment on the behaviour of the patellofemoral joint is of particular importance in the endeavour to develop knee replacement systems which provide satisfactory function together with clinical long-term success.

Human motion energy harvesting using a piezoelectric MFC patch.

PubMed

Bassani, Giulia; Filippeschi, Alessandro; Ruffaldi, Emanuele

2015-01-01

The improvements in efficiency of electronic components and miniaturization is quickly pushing wearable devices. Kinetic human energy harvesting is a way to power these components reducing the need of batteries replacement since walking or running is how humans already expend much of their daily energy. This work explores the case of kinetic energy from bending of a piezoelectric patch. For assessing the quality of the system, a testing setup has been designed and controlled by means of knee joint recordings obtained from a large motion dataset. The promising result of the chosen patch is an output power of 2.6μW associated to a run activity.

[Local infiltration analgesia in total joint replacement].

PubMed

de Jonge, Tamás; Görgényi, Szabolcs; Szabó, Gabriella; Torkos, Miklós Bulcsú

2017-03-01

Total hip and knee replacment surgeries are characterized by severe postoperative pain. Local infiltration analgesia is proved to be very effective. However this method has not been widely used in Hungary. To evaluate the efficacy of the local infiltration analgesia with modified components in patients underwent total hip or knee replacement surgery. Data of 99 consecutive patients underwent primary total hip or knee replacement surgery were evaluated prospectively. In all the 99 surgeries modified local infiltration analgesia was applied. Postoperative pain reported on a visual analog scale was recorded as well as the need for further analgetics during the first 18 hours after surgery. The cost of the analgetic drugs was calculated. The control group comprised 97 consecutive patients underwent total hip or knee replacement, where local infiltration analgesia was not applied. Statistical analysis was done. Patients received local infiltration analgesia reported significantly less pain (p<0.001). The need for postoperatively given analgetics was almost 50% less, and the cost of all postoperative analgetics was 47% less than in the control group. In total hip and knee replacement surgeries the modified local infiltration analgesia decreases postoperative pain effectively and contribute to the early mobilization of the patients. Orv. Hetil., 2017, 158(9), 352-357.

Substitutions of short heterologous DNA segments of intragenomic or extragenomic origins produce clustered genomic polymorphisms

PubMed Central

Harms, Klaus; Lunnan, Asbjørn; Hülter, Nils; Mourier, Tobias; Vinner, Lasse; Andam, Cheryl P.; Marttinen, Pekka; Fridholm, Helena; Hansen, Anders Johannes; Hanage, William P.; Nielsen, Kaare Magne; Willerslev, Eske; Johnsen, Pål Jarle

2016-01-01

In a screen for unexplained mutation events we identified a previously unrecognized mechanism generating clustered DNA polymorphisms such as microindels and cumulative SNPs. The mechanism, short-patch double illegitimate recombination (SPDIR), facilitates short single-stranded DNA molecules to invade and replace genomic DNA through two joint illegitimate recombination events. SPDIR is controlled by key components of the cellular genome maintenance machinery in the gram-negative bacterium Acinetobacter baylyi. The source DNA is primarily intragenomic but can also be acquired through horizontal gene transfer. The DNA replacements are nonreciprocal and locus independent. Bioinformatic approaches reveal occurrence of SPDIR events in the gram-positive human pathogen Streptococcus pneumoniae and in the human genome. PMID:27956618

The treatment and outcome of peri-prosthetic infection of the ankle: a single cohort-centre experience of 34 cases.

PubMed

Kessler, B; Knupp, M; Graber, P; Zwicky, L; Hintermann, B; Zimmerli, W; Sendi, P

2014-06-01

The treatment of peri-prosthetic joint infection (PJI) of the ankle is not standardised. It is not clear whether an algorithm developed for hip and knee PJI can be used in the management of PJI of the ankle. We evaluated the outcome, at two or more years post-operatively, in 34 patients with PJI of the ankle, identified from a cohort of 511 patients who had undergone total ankle replacement. Their median age was 62.1 years (53.3 to 68.2), and 20 patients were women. Infection was exogenous in 28 (82.4%) and haematogenous in six (17.6%); 19 (55.9%) were acute infections and 15 (44.1%) chronic. Staphylococci were the cause of 24 infections (70.6%). Surgery with retention of one or both components was undertaken in 21 patients (61.8%), both components were replaced in ten (29.4%), and arthrodesis was undertaken in three (8.8%). An infection-free outcome with satisfactory function of the ankle was obtained in 23 patients (67.6%). The best rate of cure followed the exchange of both components (9/10, 90%). In the 21 patients in whom one or both components were retained, four had a relapse of the same infecting organism and three had an infection with another organism. Hence the rate of cure was 66.7% (14 of 21). In these 21 patients, we compared the treatment given to an algorithm developed for the treatment of PJI of the knee and hip. In 17 (80.9%) patients, treatment was not according to the algorithm. Most (11 of 17) had only one criterion against retention of one or both components. In all, ten of 11 patients with severe soft-tissue compromise as a single criterion had a relapse-free survival. We propose that the treatment concept for PJI of the ankle requires adaptation of the grading of quality of the soft tissues. ©2014 The British Editorial Society of Bone & Joint Surgery.

Critical bending moment of four implant-abutment interface designs.

PubMed

Lee, Frank K; Tan, Keson B; Nicholls, Jack I

2010-01-01

Critical bending moment (CBM), defined as the bending moment at which the external nonaxial load applied overcomes screw joint preload and causes loss of contact between the mating surfaces of the implant screw joint components, was measured for four different implants and their single-tooth replacement abutments. CBM at the implant-abutment screw joint for four implant-abutment test groups was measured in vitro at 80%, 100%, and 120% of the manufacturers' recommended torque levels. Regular-platform implants with their corresponding single-tooth abutments were used. Microstrain was measured while known loads were applied to the abutment at known distances from the implant-abutment interface. Strain instrumentation was used to record the strain data dynamically to determine the point of gap opening. All torque applications and strain measurements were repeated five times for the five samples in each group. For the Branemark/CeraOne assemblies, the mean CBMs were 72.14 Ncm, 102.21 Ncm, and 119.13 Ncm, respectively, at 80%, 100%, and 120% of the manufacturer's recommended torque. For the Replace/Easy assemblies, mean CBMs were 86.20 Ncm, 109.92 Ncm, and 120.93 Ncm; for the Biomet 3i/STA assemblies, they were 67.97 Ncm, 83.14 Ncm, and 91.81 Ncm; and for the Lifecore/COC assemblies, they were 58.32 Ncm, 76.79 Ncm, and 78.93 Ncm. Two-way analysis of variance revealed significant effects for the test groups and torque levels. Subsequent tests confirmed that significant differences existed between test groups and torque levels. The results appear to confirm the primary role of the compressive preload imparted by the abutment screw in maintaining screw joint integrity. CBM was found to differ among implant systems and torque levels. Torque levels recommended by the manufacturer should be followed to ensure screw joint integrity.

MP Joint Arthritis

MedlinePlus

... is extensive and severe, joint replacement or joint fusion are effective surgical options. Learn more about joint ... the tabs at the top (Video, Articles/WEB, Images, JHS, Products/Vendors), or the filters on the ...

Does addition of low-level laser therapy (LLLT) in conservative care of knee arthritis successfully postpone the need for joint replacement?

PubMed

Ip, David

2015-12-01

The current study evaluates whether the addition of low-level laser therapy into standard conventional physical therapy in elderly with bilateral symptomatic tri-compartmental knee arthritis can successfully postpone the need for joint replacement surgery. A prospective randomized cohort study of 100 consecutive unselected elderly patients with bilateral symptomatic knee arthritis with each knee randomized to receive either treatment protocol A consisting of conventional physical therapy or protocol B which is the same as protocol A with added low-level laser therapy. The mean follow-up was 6 years. Treatment failure was defined as breakthrough pain which necessitated joint replacement surgery. After a follow-up of 6 years, patients clearly benefited from treatment with protocol B as only one knee needed joint replacement surgery, while nine patients treated with protocol A needed surgery (p < 0.05). We conclude low-level laser therapy should be incorporated into standard conservative treatment protocol for symptomatic knee arthritis.

Recent advances and future directions in the management of knee osteoarthritis: Can biological joint reconstruction replace joint arthroplasty and when?

PubMed Central

Paschos, Nikolaos K

2015-01-01

In this article, a concise description of the recent advances in the field of osteoarthritis management is presented. The main focus is to highlight the most promising techniques that emerge in both biological joint replacement and artificial joint arthroplasty. A critical view of high quality evidence regarding outcome and safety profile of these techniques is presented. The potential role of kinematically aligned total knee replacement, navigation, and robotic-assisted surgery is outlined. A critical description of both primary and stem cell-based therapies, the cell homing theory, the use of biologic factors and recent advancements in tissue engineering and regenerative medicine is provided. Based on the current evidence, some thoughts on a realistic approach towards answering these questions are attempted. PMID:26495242

Burden of Restraint, Disablement and Ethnic Identity: A Case Study of Total Joint Replacement for Osteoarthritis

PubMed Central

Harrison, Tracie

2010-01-01

Health disparities in total joint replacement have been documented based on gender and ethnicity in multiple countries. Absent are studies exploring the meaning of the procedures among diverse women, which is necessary to fully understand the impact of the disparity. Drawing on ethnographic data from a life course exploration of disablement among Mexican American women with mobility impairments, one woman’s reasons for forgoing a joint replacement are considered. It is suggested that inequalities in disablement cannot be understood without considering the mulitple cultural conflicts and loyalties that push and pull women in multiple directions. PMID:21767094

Analytical and finite element performance evaluation of embedded piezoelectric sensors in polyethylene

NASA Astrophysics Data System (ADS)

Safaei, Mohsen; Anton, Steven R.

2017-04-01

A common application of piezoelectric transducers is to obtain operational data from working structures and dynamic components. Collected data can then be used to evaluate dynamic characterization of the system, perform structural health monitoring, or implement various other assessments. In some applications, piezoelectric transducers are bonded inside the host structure to satisfy system requirements; for example, piezoelectric transducers can be embedded inside the biopolymers of total joint replacements to evaluate the functionality of the artificial joint. The interactions between the piezoelectric device (inhomogeneity) and the surrounding polymer matrix determine the mechanical behavior of the matrix and the electromechanical behavior of the sensor. In this work, an analytical approach is employed to evaluate the electromechanical performance of 2-D plane strain piezoelectric elements of both circular and rectangular-shape inhomogeneities. These piezoelectric elements are embedded inside medical grade ultra-high molecular weight (UHMW) polyethylene, a material commonly used for bearing surfaces of joint replacements, such as total knee replacements (TKRs). Using the famous Eshelby inhomogeneity solution, the stress and electric field inside the circular (elliptical) inhomogeneity is obtained by decoupling the solution into purely elastic and dielectric systems of equations. For rectangular (non-elliptical) inhomogeneities, an approximation method based on the boundary integral function is utilized and the same decoupling method is employed. In order to validate the analytical result, a finite element analysis is performed for both the circular and rectangular inhomogeneities and the error for each case is calculated. For elliptical geometry, the error is less than 1% for stress and electric fields inside and outside the piezoelectric inhomogeneity, whereas, the error for non-elliptical geometry is obtained as 11% and 7% for stress and electric field inside the inhomogeneity, respectively.

Development and application of biomimetic electrospun nanofibers in total joint replacement

NASA Astrophysics Data System (ADS)

Song, Wei

Failure of osseointegration (direct anchorage of an implant by bone formation at the bone-implant surface) and implant infection (such as that caused by Staphylococcus aureus, S. aureus) are the two main causes of implant failure and loosening. There is a critical need for orthopedic implants that promote rapid osseointegration and prevent bacterial colonization, particularly when placed in bone compromised by disease or physiology of the patients. A better understanding of the key factors that influence cell fate decisions at the bone-implant interface is required. Our study is to develop a class of "bone-like" nanofibers (NFs) that promote osseointegration while preventing bacterial colonization and subsequent infections. This research goal is supported by our preliminary data on the preparation of coaxial electrospun NFs composed of polycaprolactone (PCL) and polyvinyl alcohol (PVA) polymers arranged in a core-sheath shape. The PCL/PVA NFs are biocompatible and biodegradable with appropriate fiber diameter, pore size and mechanical strength, leading to enhanced cell adhesion, proliferation and differentiation of osteoblast precursor cells. The objective is to develop functionalized "bone-like" PCL/PVA NFs matrix embedded with antibiotics (doxycycline (Doxy), bactericidal and anti-osteoclastic) on prosthesis surface. Through a rat tibia implantation model, the Doxy incorporated coaxial NFs has demonstrated excellent in promoting osseointegration and bacteria inhibitory efficacy. NFs coatings significantly enhanced the bonding between implant and bone remodeling within 8 weeks. The SA-induced osteomyelitis was prevented by the sustained release of Doxy from NFs. The capability of embedding numerous bio-components including proteins, growth factors, drugs, etc. enables NFs an effective solution to overcome the current challenged issue in Total joint replacement. In summary, we proposed PCL/PVA electrospun nanofibers as promising biomaterials that can be applied on joint replacement prosthesis to improve osseointegration and prevent osteomyelitis.

[Ankle arthrodesis with interposition graft as a salvage procedure after failed total ankle replacement].

PubMed

Schill, Stephan

2007-12-01

Restoration of painless function to the lower limb by ankle fusion after failure of total ankle arthroplasty. Loose total ankle replacement. Severe ankle destruction and axial deviation in rheumatoid patients. Severe osteoarthritis in the subtalar and ankle joints. Infected total ankle replacement. Severe arterial occlusive disease of the affected extremity. Transfibular approach to the subtalar and ankle joints. Osteotomy and resection of the distal fibula 7-8 cm proximal to the tip of the lateral malleolus. Removal of the prosthetic components, synovectomy, and revitalization of the remaining bone surface. Removal of any residual articular cartilage from the subtalar joint surfaces. Determination of the extent of bone loss and defect filling with horizontally or vertically placed tricortical and cancellous bone graft from the resected fibula and, if necessary, from the ipsilateral anterior iliac crest. Tibiotalocalcaneal arthrodesis by retrograde insertion of a retrograde locking nail. Wound closure in layers. Split below-knee cast. Mobilization with below-knee cast without weight bearing for 6 weeks. Dynamic locking of the intramedullary nail. Partial weight bearing with a walker up to 20 kg for an additional 6 weeks. Gradual increase in weight bearing in accordance with radiologic evidence of consolidation. Fitted orthopedic shoe with rocker-bottom sole, and made to measure insoles. From January 2003 to September 2006, 15 patients with infected ankle prosthesis loosening (six Thompson-Richards prostheses, eight S.T.A.R. prostheses, and one Salto prosthesis) were treated. All patients underwent tibiotalocalcaneal interposition arthrodesis with femoral nailing in retrograde technique. The average AOFAS (American Orthopaedic Foot and Ankle Society) Score was 57.9 points (35-81 points) postoperatively. One patient developed a nonunion and revision surgery will have to be performed. Another patient with delayed wound healing and skin necrosis needed plastic surgery.

J-integral fracture toughness and tearing modulus measurement of radiation cross-linked UHMWPE.

PubMed

Gomoll, A; Wanich, T; Bellare, A

2002-11-01

Radiation and chemical cross-linking of medical grade ultrahigh molecular weight polyethylene (UHMWPE) has recently been utilized in an effort to improve wear performance of total joint replacement components. However, reductions in mechanical properties with cross-linking are cause for concern regarding the use of cross-linked UHMWPE for high-stress applications such as in total knee replacement prostheses. In this study, the fracture behavior of radiation cross-linked UHMWPE was compared to that of uncross-linked UHMWPE. The Rice and Sorensen model that utilizes mechanical parameters obtained from uniaxial tensile and compact tension tests was used to calculate the steady state J-integral fracture toughness, Jss, for radiation cross-linked UHMWPE. Jss decreased monotonically with increase in radiation dose. UHMWPE exhibited tough, ductile tearing behavior with stable crack growth when it was cross-linked using a gamma radiation dose of 0-50 kGy. However, in cross-linked UHMWPE irradiated to a dose of 100 and 200 kGy, unstable fracture occurred spontaneously upon attaining the initial crack driving force, J1c. This indicates that a high degree of cross-linking is less desirable for high-stress applications in orthopaedic implants. However, a substantial increase in J1c, even at a low degree of cross-linking, suggests that a low degree of cross-linking may be beneficial for resistance to delamination and catastrophic failure, both of which require an initiation step for the fracture to propagate in the material. This mechanical test should, however, be considered along with fatigue tests and joint simulator testing before determination of an appropriate amount of cross-linking for total joint replacement prostheses that experience high stresses.

A new three-dimensional, print-on-demand temporomandibular prosthetic total joint replacement system: Preliminary outcomes.

PubMed

Dimitroulis, George; Austin, Stephen; Sin Lee, Peter Vee; Ackland, David

2018-05-16

The aim of this study is to present the preliminary clinical data on the OMX Temporomandibular Joint (TMJ) Prosthetic total joint replacement system. A prospective, cohort, clinical study was undertaken of consecutive adult patients with Category 5 end-stage joint disease who were implanted with the OMX TMJ prosthesis between May 2015 and April 2017. A total of 50 devices were implanted in 38 patients, with 12 patients receiving bilateral prosthetic joints. There were 31 females and 7 males in this cohort, who ranged in age from 20 to 66 years, with a mean of 43.8 years (±14.0 years). Ten of the 50 prosthetic joints (20%) were fully customized, while the remaining were patient matched using virtual planning software. Based on a mean follow-up period of 15.3 months (range 12-24 months) following the TMJ total joint replacement, preliminary results suggest the OMX TMJ prosthesis has made a positive impact on clinical outcomes, with a mean 74.4% reduction in joint pain levels and significant improvements (p < 0.05) in jaw function as measured by the visual analogue scales for mouth opening (30.8%), diet (77.1%), and function (59.2%). No device failures were reported during the study period. This study suggests that the print-on-demand OMX TMJ prosthesis, designed for rapid delivery of both patient-matched and fully customize devices, represents a safe, reliable and versatile implantable joint replacement system for the treatment of category 5 end-stage TMJ disease. Copyright © 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Pre-operative interventions (non-surgical and non-pharmacological) for patients with hip or knee osteoarthritis awaiting joint replacement surgery--a systematic review and meta-analysis.

PubMed

Wallis, Jason A; Taylor, Nicholas F

2011-12-01

To determine if pre-operative interventions for hip and knee osteoarthritis provide benefit before and after joint replacement. Systematic review with meta-analysis of randomised controlled trials (RCTs) of pre-operative interventions for people with hip or knee osteoarthritis awaiting joint replacement surgery. Standardised mean differences (SMD) were calculated for pain, musculoskeletal impairment, activity limitation, quality of life, and health service utilisation (length of stay and discharge destination). The GRADE approach was used to determine the quality of the evidence. Twenty-three RCTs involving 1461 participants awaiting hip or knee replacement surgery were identified. Meta-analysis provided moderate quality evidence that pre-operative exercise interventions for knee osteoarthritis reduced pain prior to knee replacement surgery (SMD (95% CI)=0.43 [0.13, 0.73]). None of the other meta-analyses investigating pre-operative interventions for knee osteoarthritis demonstrated any effect. Meta-analyses provided low to moderate quality evidence that exercise interventions for hip osteoarthritis reduced pain (SMD (95% CI)=0.52 [0.04, 1.01]) and improved activity (SMD (95% CI)=0.47 [0.11, 0.83]) prior to hip replacement surgery. Meta-analyses provided low quality evidence that exercise with education programs improved activity after hip replacement with reduced time to reach functional milestones during hospital stay (e.g., SMD (95% CI)=0.50 [0.10, 0.90] for first day walking). Low to moderate evidence from mostly small RCTs demonstrated that pre-operative interventions, particularly exercise, reduce pain for patients with hip and knee osteoarthritis prior to joint replacement, and exercise with education programs may improve activity after hip replacement. Copyright © 2011 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Load Variation Influences on Joint Work During Squat Exercise in Reduced Gravity

NASA Technical Reports Server (NTRS)

DeWitt, John K.; Fincke, Renita S.; Logan, Rachel L.; Guilliams, Mark E.; Ploutz-Snyder, Lori L.

2011-01-01

Resistance exercises that load the axial skeleton, such as the parallel squat, are incorporated as a critical component of a space exercise program designed to maximize the stimuli for bone remodeling and muscle loading. Astronauts on the International Space Station perform regular resistance exercise using the Advanced Resistive Exercise Device (ARED). Squat exercises on Earth entail moving a portion of the body weight plus the added bar load, whereas in microgravity the body weight is 0, so all load must be applied via the bar. Crewmembers exercising in microgravity currently add approx.70% of their body weight to the bar load as compensation for the absence of the body weight. This level of body weight replacement (BWR) was determined by crewmember feedback and personal experience without any quantitative data. The purpose of this evaluation was to utilize computational simulation to determine the appropriate level of BWR in microgravity necessary to replicate lower extremity joint work during squat exercise in normal gravity based on joint work. We hypothesized that joint work would be positively related to BWR load.

Doppler Lidar System Design via Interdisciplinary Design Concept at NASA Langley Research Center - Part II

NASA Technical Reports Server (NTRS)

Crasner, Aaron I.; Scola,Salvatore; Beyon, Jeffrey Y.; Petway, Larry B.

2014-01-01

Optimized designs of the Navigation Doppler Lidar (NDL) instrument for Autonomous Landing Hazard Avoidance Technology (ALHAT) were accomplished via Interdisciplinary Design Concept (IDEC) at NASA Langley Research Center during the summer of 2013. Three branches in the Engineering Directorate and three students were involved in this joint task through the NASA Langley Aerospace Research Summer Scholars (LARSS) Program. The Laser Remote Sensing Branch (LRSB), Mechanical Systems Branch (MSB), and Structural and Thermal Systems Branch (STSB) were engaged to achieve optimal designs through iterative and interactive collaborative design processes. A preliminary design iteration was able to reduce the power consumption, mass, and footprint by removing redundant components and replacing inefficient components with more efficient ones. A second design iteration reduced volume and mass by replacing bulky components with excessive performance with smaller components custom-designed for the power system. Thermal modeling software was used to run steady state thermal analyses, which were used to both validate the designs and recommend further changes. Analyses were run on each redesign, as well as the original system. Thermal Desktop was used to run trade studies to account for uncertainty and assumptions about fan performance and boundary conditions. The studies suggested that, even if the assumptions were significantly wrong, the redesigned systems would remain within operating temperature limits.

[Minimally invasive approaches to hip and knee joints for total joint replacement].

PubMed

Rittmeister, M; König, D P; Eysel, P; Kerschbaumer, F

2004-11-01

The manuscript features the different minimally invasive approaches to the hip for joint replacement. These include medial, anterior, anterolateral, and posterior approaches. The concept of minimally invasive hip arthroplasty makes sense if it is an integral part of a larger concept to lower postoperative morbidity. Besides minimal soft tissue trauma, this concept involves preoperative patient education, preemptive analgesia, and postoperative physiotherapy. It is our belief that minimal incision techniques for the hip are not suited for all patients and all surgeons. The different minimally invasive approaches to the knee joint for implantation of a knee arthroplasty are described and discussed. There have been no studies published yet that fulfill EBM criteria. The data so far show that minimally invasive approaches and implantation techniques for total knee replacements lead to quicker rehabilitation of patients.

Poly(ethylene glycol)/chitosan/sodium glycerophosphate gel replaced the joint capsule with slow-release lubricant after joint surgery.

PubMed

Lu, Hailin; Ren, Shanshan; Li, Xing; Guo, Junde; Dong, Guangneng; Li, Jianhui; Gao, Li

2018-08-01

Body fluid is normally the only lubricant after joint replacement surgery, but wear problems have occurred because body fluid has poor lubrication ability. However, traditional lubricant would be diluted by body fluids and then absorbed by the human body. Therefore, an injectable gel with the ability to slow-release lubricant was designed to replace the joint capsule. The proposed gel, poly(ethylene glycol)/chitosan/sodium glycerophosphate (PEG/CS/GP) composite gel was then tested. The tribology results showed that the PEG/CS/GP gel had excellent slow-release properties, especially under pressure, and the PEG played an important role in improving the gel's rheological and mechanical properties. Moreover, this study revealed that the release solution had a good lubrication effect because the PEG and GP could crosslink via the hydrogen bond effect.

Stockpile Model of Personal Protective Equipment in Taiwan.

PubMed

Chen, Yu-Ju; Chiang, Po-Jung; Cheng, Yu-Hsin; Huang, Chun-Wei; Kao, Hui-Yun; Chang, Chih-Kai; Huang, Hsun-Miao; Liu, Pei-Yin; Wang, Jen-Hsin; Chih, Yi-Chien; Chou, Shu-Mei; Yang, Chin-Hui; Chen, Chang-Hsun

The Taiwan Centers for Disease Control (Taiwan CDC) has established a 3-tier personal protective equipment (PPE) stockpiling framework that could maintain a minimum stockpile for the surge demand of PPE in the early stage of a pandemic. However, PPE stockpiling efforts must contend with increasing storage fees and expiration problems. In 2011, the Taiwan CDC initiated a stockpile replacement model in order to optimize the PPE stockpiling efficiency, ensure a minimum stockpile, use the government's limited funds more effectively, and achieve the goal of sustainable management. This stockpile replacement model employs a first-in-first-out principle in which the oldest stock in the central government stockpile is regularly replaced and replenished with the same amount of new and qualified products, ensuring the availability and maintenance of the minimum stockpiles. In addition, a joint electronic procurement platform has been established for merchandising the replaced PPE to local health authorities and medical and other institutions for their routine or epidemic use. In this article, we describe the PPE stockpile model in Taiwan, including the 3-tier stockpiling framework, the operational model, the components of the replacement system, implementation outcomes, epidemic supports, and the challenges and prospects of this model.

Stockpile Model of Personal Protective Equipment in Taiwan

PubMed Central

Chen, Yu-Ju; Cheng, Yu-Hsin; Huang, Chun-Wei; Kao, Hui-Yun; Chang, Chih-Kai; Huang, Hsun-Miao; Liu, Pei-Yin; Wang, Jen-Hsin; Chih, Yi-Chien; Chou, Shu-Mei; Yang, Chin-Hui; Chen, Chang-Hsun

2017-01-01

The Taiwan Centers for Disease Control (Taiwan CDC) has established a 3-tier personal protective equipment (PPE) stockpiling framework that could maintain a minimum stockpile for the surge demand of PPE in the early stage of a pandemic. However, PPE stockpiling efforts must contend with increasing storage fees and expiration problems. In 2011, the Taiwan CDC initiated a stockpile replacement model in order to optimize the PPE stockpiling efficiency, ensure a minimum stockpile, use the government's limited funds more effectively, and achieve the goal of sustainable management. This stockpile replacement model employs a first-in-first-out principle in which the oldest stock in the central government stockpile is regularly replaced and replenished with the same amount of new and qualified products, ensuring the availability and maintenance of the minimum stockpiles. In addition, a joint electronic procurement platform has been established for merchandising the replaced PPE to local health authorities and medical and other institutions for their routine or epidemic use. In this article, we describe the PPE stockpile model in Taiwan, including the 3-tier stockpiling framework, the operational model, the components of the replacement system, implementation outcomes, epidemic supports, and the challenges and prospects of this model. PMID:28418743

Doppler Lidar System Design via Interdisciplinary Design Concept at NASA Langley Research Center - Part I

NASA Technical Reports Server (NTRS)

Boyer, Charles M.; Jackson, Trevor P.; Beyon, Jeffrey Y.; Petway, Larry B.

2013-01-01

Optimized designs of the Navigation Doppler Lidar (NDL) instrument for Autonomous Landing Hazard Avoidance Technology (ALHAT) were accomplished via Interdisciplinary Design Concept (IDEC) at NASA Langley Research Center during the summer of 2013. Three branches in the Engineering Directorate and three students were involved in this joint task through the NASA Langley Aerospace Research Summer Scholars (LARSS) Program. The Laser Remote Sensing Branch (LRSB), Mechanical Systems Branch (MSB), and Structural and Thermal Systems Branch (STSB) were engaged to achieve optimal designs through iterative and interactive collaborative design processes. A preliminary design iteration was able to reduce the power consumption, mass, and footprint by removing redundant components and replacing inefficient components with more efficient ones. A second design iteration reduced volume and mass by replacing bulky components with excessive performance with smaller components custom-designed for the power system. Mechanical placement collaboration reduced potential electromagnetic interference (EMI). Through application of newly selected electrical components and thermal analysis data, a total electronic chassis redesign was accomplished. Use of an innovative forced convection tunnel heat sink was employed to meet and exceed project requirements for cooling, mass reduction, and volume reduction. Functionality was a key concern to make efficient use of airflow, and accessibility was also imperative to allow for servicing of chassis internals. The collaborative process provided for accelerated design maturation with substantiated function.

Soldering in a Reduced Gravity Environment (SoRGE)

NASA Technical Reports Server (NTRS)

Easton, John W.; Struk, Peter M.

2012-01-01

Future long-duration human exploration missions will be challenged by constraints on mass and volume allocations available for spare parts. Addressing this challenge will be critical to the success of these missions. As a result, it is necessary to consider new approaches to spacecraft maintenance and repair that reduce the need for large replacement components. Currently, crew members on the International Space Station (ISS) recover from faults by removing and replacing, using backup systems, or living without the function of Orbital Replacement Units (ORUs). These ORUs are returned to a depot where the root cause of the failure is determined and the ORU is repaired. The crew has some limited repair capability with the Modulation/DeModulation (MDM) ORU, where circuit cards are removed and replace in faulty units. The next step to reducing the size of the items being replaced would be to implement component-level repair. This mode of repair has been implemented by the U.S. Navy in an operational environment and is now part of their standard approach for maintenance. It is appropriate to consider whether this approach can be adapted for future spaceflight operations. To this end, the Soldering in a Reduced Gravity Environment (SoRGE) experiment studied the effect of gravity on the formation of solder joints on electronic circuit boards. This document describes the SoRGE experiment, the analysis methods, and results to date. This document will also contain comments from the crew regarding their experience conducting the SoRGE experiment as well as recommendations for future improvements. Finally, this document will discuss the plans for the SoRGE samples which remain on ISS.

Regional analgesia for improvement of long-term functional outcome after elective large joint replacement.

PubMed

Atchabahian, Arthur; Schwartz, Gary; Hall, Charles B; Lajam, Claudette M; Andreae, Michael H

2015-08-13

Regional analgesia is more effective than conventional analgesia for controlling pain and may facilitate rehabilitation after large joint replacement in the short term. It remains unclear if regional anaesthesia improves functional outcomes after joint replacement beyond three months after surgery. To assess the effects of regional anaesthesia and analgesia on long-term functional outcomes 3, 6 and 12 months after elective major joint (knee, shoulder and hip) replacement surgery. We performed an electronic search of several databases (CENTRAL, MEDLINE, EMBASE, CINAHL), and handsearched reference lists and conference abstracts. We updated our search in June 2015. We included randomized controlled trials (RCTs) comparing regional analgesia versus conventional analgesia in patients undergoing total shoulder, hip or knee replacement. We included studies that reported a functional outcome with a follow-up of at least three months after surgery. We used standard methodological procedures expected by Cochrane. We contacted study authors for additional information. We included six studies with 350 participants followed for at least three months. All of these studies enrolled participants undergoing total knee replacement. Studies were at least partially blinded. Three studies had a high risk of performance bias and one a high risk of attrition bias, but the risk of bias was otherwise unclear or low.Only one study assessed joint function using a global score. Due to heterogeneity in outcome and reporting, we could only pool three out of six RCTs, with range of motion assessed at three months after surgery used as a surrogate for joint function. All studies had a high risk of detection bias. Using the random-effects model, there was no statistically significant difference between the experimental and control groups (mean difference 3.99 degrees, 95% confidence interval (CI) - 2.23 to 10.21; P value = 0.21, 3 studies, 140 participants, very low quality evidence).We did not perform further analyses because immediate adverse effects were not part of the explicit outcomes of any of these typically small studies, and long-term adverse events after regional anaesthesia are rare.None of the included studies elicited or reported long-term adverse effects like persistent nerve damage. More high-quality studies are needed to establish the effects of regional analgesia on function after major joint replacement, as well as on the risk of adverse events (falls).

Computer Assisted Surgery and Current Trends in Orthopaedics Research and Total Joint Replacements

NASA Astrophysics Data System (ADS)

Amirouche, Farid

2008-06-01

Musculoskeletal research has brought about revolutionary changes in our ability to perform high precision surgery in joint replacement procedures. Recent advances in computer assisted surgery as well better materials have lead to reduced wear and greatly enhanced the quality of life of patients. The new surgical techniques to reduce the size of the incision and damage to underlying structures have been the primary advance toward this goal. These new techniques are known as MIS or Minimally Invasive Surgery. Total hip and knee Arthoplasties are at all time high reaching 1.2 million surgeries per year in the USA. Primary joint failures are usually due to osteoarthristis, rheumatoid arthritis, osteocronis and other inflammatory arthritis conditions. The methods for THR and TKA are critical to initial stability and longevity of the prostheses. This research aims at understanding the fundamental mechanics of the joint Arthoplasty and providing an insight into current challenges in patient specific fitting, fixing, and stability. Both experimental and analytical work will be presented. We will examine Cementless total hip arthroplasty success in the last 10 years and how computer assisted navigation is playing in the follow up studies. Cementless total hip arthroplasty attains permanent fixation by the ingrowth of bone into a porous coated surface. Loosening of an ingrown total hip arthroplasty occurs as a result of osteolysis of the periprosthetic bone and degradation of the bone prosthetic interface. The osteolytic process occurs as a result of polyethylene wear particles produced by the metal polyethylene articulation of the prosthesis. The total hip arthroplasty is a congruent joint and the submicron wear particles produced are phagocytized by macrophages initiating an inflammatory cascade. This cascade produces cytokines ultimately implicated in osteolysis. Resulting bone loss both on the acetabular and femoral sides eventually leads to component instability. As patients are living longer and total hip arthroplasty is performed in younger patients the risks of osteolysis associated with cumulative wear is increased. Computer-assisted surgery is based on sensing feedback; vision and imaging that help surgeons align the patient's joints during total knee or hip replacement with a degree of accuracy not possible with the naked eye. For the first time, the computer feedback is essential for ligament balancing and longevity of the implants. The computers navigation systems also help surgeons to use smaller incisions instead of the traditional larger openings. Small-incision surgery offers the potential for faster recovery, less bleeding and less pain for patients. The development of SESCAN imaging technique to create a patient based model of a 3D joint will be presented to show the effective solution of complex geometry of joints.

Total hip arthroplasty in dwarfism. A case report.

PubMed

De Fine, Marcello; Traina, Francesco; Palmonari, Massimo; Tassinari, Enrico; Toni, Aldo

2008-05-01

In dwarfism hip arthritis, usually secondary to hip dysplasia, is a common finding at an early age. In these patients a joint replacement is a demanding procedure due to the peculiar joint deformity and the small size of the bones. We present a case of a bilateral hip replacement in a dwarf patient. In order to reduce intraoperative complications and improve the joint kinematics a thorough preoperative planning was performed by a CT based computerised system. On the basis of the planning we chose a conical shaped stem that enable as to restore limb length and offset with a low risk of femoral fracture. In conclusion, we consider total hip replacement in dwarfism a safe and effective procedure if an accurate preoperative planning is performed.

Healthcare Utilization and Costs of Knee or Hip Replacements versus Pain-Relief Injections

PubMed Central

Pasquale, Margaret K.; Louder, Anthony M.; Cheung, Raymond Y.; Reiners, Andrew T.; Mardekian, Jack; Sanchez, Robert J.; Goli, Veerainder

2015-01-01

Background Given the dramatic increase in total knee and hip replacement procedures among the US population aged 45 years and older, there is a need to compare the downstream healthcare utilization and costs between patients who undergo joint replacement and those who receive intraarticular injections as a low-cost alternative. Objective To compare changes in osteoarthritis (OA)-related healthcare utilization and costs for Medicare members with OA who underwent knee or hip replacement versus those receiving steroid or viscosupplementation injections. Methods Medicare members aged ≥45 years diagnosed with OA were identified for this retrospective longitudinal study. Data were compared for patients who underwent primary knee or hip replacement surgery between July 1, 2007, and June 30, 2012, and those receiving injection of pain-relief medication during the same period. The date of joint replacement surgery was considered the index date. For the comparison cohort, the index date was 180 days postinjection of the first intraarticular injection. Medical and pharmacy claims were examined longitudinally in 90-day increments, from 180 days preindex until 360 days postindex. Difference-in-difference analyses were conducted to compare the change in OA-related healthcare costs, postindex versus preindex, between the study cohorts. Time-to-event analyses were used to measure rates of readmissions and venous thromboembolism (VTE). Results The mean age was 70.7 years for patients with knee replacement, 71.7 years for those with hip replacement, and 71.1 years for those receiving pain-relief injection (P <.0001). The RxRisk-V comorbidity index scores were 4.7, 4.4, and 4.8, respectively (P <.0001). Difference-in-difference analyses indicated that decreases in OA-related costs were greater for the joint replacement cohorts (coefficient for knee replacement*time: −0.603; hip replacement*time: −0.438; P <.001 for both) than for the comparison cohort. The VTE rates were 5.6% (knee) and 5.1% (hip) postsurgery versus 1.4% (knee) and 1.3% (hip) presurgery. Conclusion The overall difference-in-difference results showed a greater decrease in healthcare utilization and costs for the members with joint replacement than for those receiving injection. PMID:26557232

Hip contact forces in asymptomatic total hip replacement patients differ from normal healthy individuals: Implications for preclinical testing.

PubMed

Li, Junyan; Redmond, Anthony C; Jin, Zhongmin; Fisher, John; Stone, Martin H; Stewart, Todd D

2014-08-01

Preclinical durability testing of hip replacement implants is standardised by ISO-14242-1 (2002) which is based on historical inverse dynamics analysis using data obtained from a small sample of normal healthy individuals. It has not been established whether loading cycles derived from normal healthy individuals are representative of loading cycles occurring in patients following total hip replacement. Hip joint kinematics and hip contact forces derived from multibody modelling of forces during normal walking were obtained for 15 asymptomatic total hip replacement patients and compared to 38 normal healthy individuals and to the ISO standard for pre-clinical testing. Hip kinematics in the total hip replacement patients were comparable to the ISO data and the hip contact force in the normal healthy group was also comparable to the ISO cycles. Hip contact forces derived from the asymptomatic total hip replacement patients were comparable for the first part of the stance period but exhibited 30% lower peak loads at toe-off. Although the ISO standard provides a representative kinematic cycle, the findings call into question whether the hip joint contact forces in the ISO standard are representative of those occurring in the joint following total hip replacement. Copyright © 2014. Published by Elsevier Ltd.

PEEK-OPTIMA™ as an alternative to cobalt chrome in the femoral component of total knee replacement: A preliminary study

PubMed Central

Cowie, Raelene M; Briscoe, Adam; Fisher, John; Jennings, Louise M

2016-01-01

PEEK-OPTIMA™ (Invibio Ltd, UK) has been considered as an alternative joint arthroplasty bearing material due to its favourable mechanical properties and the biocompatibility of its wear debris. In this study, the potential to use injection moulded PEEK-OPTIMA™ as an alternative to cobalt chrome in the femoral component of a total knee replacement was investigated in terms of its wear performance. Experimental wear simulation of three cobalt chrome and three PEEK-OPTIMA™ femoral components articulating against all-polyethylene tibial components was carried out under two kinematic conditions: 3 million cycles under intermediate kinematics (maximum anterior-posterior displacement of 5 mm) followed by 3 million cycles under high kinematic conditions (anterior-posterior displacement 10 mm). The wear of the GUR1020 ultra-high-molecular-weight polyethylene tibial components was assessed by gravimetric analysis; for both material combinations under each kinematic condition, the mean wear rates were low, that is, below 5 mm3/million cycles. Specifically, under intermediate kinematic conditions, the wear rate of the ultra-high-molecular-weight polyethylene tibial components was 0.96 ± 2.26 mm3/million cycles and 2.44 ± 0.78 mm3/million cycle against cobalt chrome and PEEK-OPTIMA™ implants, respectively (p = 0.06); under high kinematic conditions, the wear rates were 2.23 ± 1.85 mm3/million cycles and 4.44 ± 2.35 mm3/million cycles, respectively (p = 0.03). Following wear simulation, scratches were apparent on the surface of the PEEK-OPTIMA™ femoral components. The surface topography of the femoral components was assessed using contacting profilometry and showed a statistically significant increase in measured surface roughness of the PEEK-OPTIMA™ femoral components compared to the cobalt chrome implants. However, this did not appear to influence the wear rate, which remained linear over the duration of the study. These preliminary findings showed that PEEK-OPTIMA™ gives promise as an alternative bearing material to cobalt chrome alloy in the femoral component of a total knee replacement with respect to wear performance. PMID:27637723

Analysis of the plugging of the systems autonomy demonstration project brassboard filters

NASA Technical Reports Server (NTRS)

Clay, John C.

1989-01-01

A fine gray powder was clogging the brassboard filters. The powder appeared to be residue from a galvanic corrosive attack by ammonia of the aluminum and stainless steel components in the system. The corrosion was caused by water and chlorine that had entered into the system and combined with the ammonia. This combination made an electrolyte and a corrosive agent of the ammonia that attacked the metals in the system. The corroded material traveled through the system with the ammonia and clogged the filters. Key conclusions are: the debris collecting in the filters is a by-product of galvanic corrosion; the debris is principally corroded aluminum and stainless from the system; and galvanic corrosion occurred from water and chlorine that entered the system during normal and/or extreme operating and servicing conditions. Key recommendations are: use only one metal in the ammonia system-titanium, aluminum, or stainless steel; make the system as air-tight as possible (replace fittings with welded joints); and replace electron paramagnetic resonance (EPR) O-rings with neoprene O-rings, and do not use freon to clean system components.

21 CFR 888.3800 - Wrist joint metal/polymer semi-constrained cemented prosthesis.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Wrist joint metal/polymer semi-constrained... Wrist joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. A wrist joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a wrist joint...

21 CFR 888.3800 - Wrist joint metal/polymer semi-constrained cemented prosthesis.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Wrist joint metal/polymer semi-constrained... Wrist joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. A wrist joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a wrist joint...

21 CFR 888.3800 - Wrist joint metal/polymer semi-constrained cemented prosthesis.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Wrist joint metal/polymer semi-constrained... Wrist joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. A wrist joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a wrist joint...

21 CFR 888.3800 - Wrist joint metal/polymer semi-constrained cemented prosthesis.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Wrist joint metal/polymer semi-constrained... Wrist joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. A wrist joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a wrist joint...

21 CFR 888.3800 - Wrist joint metal/polymer semi-constrained cemented prosthesis.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Wrist joint metal/polymer semi-constrained... Wrist joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. A wrist joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a wrist joint...

The relationship between operative and radiographic acetabular component orientation: which factors influence resultant cup orientation?

PubMed

Grammatopoulos, G; Pandit, H G; da Assunção, R; McLardy-Smith, P; De Smet, K A; Gill, H S; Murray, D W

2014-10-01

There is great variability in acetabular component orientation following hip replacement. The aims of this study were to compare the component orientation at impaction with the orientation measured on post-operative radiographs and identify factors that influence the difference between the two. A total of 67 hip replacements (52 total hip replacements and 15 hip resurfacings) were prospectively studied. Intra-operatively, the orientation of the acetabular component after impaction relative to the operating table was measured using a validated stereo-photogrammetry protocol. Post-operatively, the radiographic orientation was measured; the mean inclination/anteversion was 43° (sd 6°)/ 19° (sd 7°). A simulated radiographic orientation was calculated based on how the orientation would have appeared had an on-table radiograph been taken intra-operatively. The mean difference between radiographic and intra-operative inclination/anteversion was 5° (sd 5°)/ -8° (sd 8°). The mean difference between simulated radiographic and intra-operative inclination/anteversion, which quantifies the effect of the different way acetabular orientation is measured, was 3°/-6° (sd 2°). The mean difference between radiographic and simulated radiographic orientation inclination/anteversion, which is a manifestation of the change in pelvic position between component impaction and radiograph, was 1°/-2° (sd 7°). This study demonstrated that in order to achieve a specific radiographic orientation target, surgeons should implant the acetabular component 5° less inclined and 8° more anteverted than their target. Great variability (2 sd about ± 15°) in the post-operative radiographic cup orientation was seen. The two equally contributing causes for this are variability in the orientation at which the cup is implanted, and the change in pelvic position between impaction and post-operative radiograph. ©2014 The British Editorial Society of Bone & Joint Surgery.

Simultaneous bilateral total knee and ankle arthroplasty as a single surgical procedure.

PubMed

Pagenstert, Geert; Hintermann, Beat

2011-10-13

Simultaneous osteoarthritis (OA) of the ankle joint complicates primary total knee arthroplasty (TKA). In such cases, rehabilitation of TKA is limited by debilitating ankle pain, but varus or valgus ankle arthritis may even compromise placement of knee prosthetic components. We present a patient with simultaneous bilateral valgus and patellofemoral OA of the knees and bilateral varus OA of the ankle joints that equally contributed to overall disability. This 63 years old, motivated and otherwise healthy patient was treated by simultaneous bilateral total knee and ankle arthroplasty (quadruple total joint arthroplasty, TJA) during the same anesthesia. Two years outcome showed excellent alignment and function of all four replaced joints. Postoperative time for rehabilitation, back to work (6th week) and hospital stay (12 days) of this special patient was markedly reduced compared to the usual course of separate TJA. Simultaneous quadruple TJA in equally disabling OA of bilateral deformed knees and ankles resulted in a better functional outcome and faster recovery compared to the average reported results after TKA and TAA in literature. However, careful preoperative planning, extensive patient education, and two complete surgical teams were considered essential for successful performance. To the best of our knowledge this is the first case report in literature about quadruple major total joint arthroplasty implanted during the same anesthesia in the same patient.

[Efficacy analysis on hip replacement for hip-joint diseases with Parkinson disease].

PubMed

Sun, Qi-Cai; Ru, Xuan-Liang; Xia, Yan-Fei; Liu, Xiao-Li; Song, Bai-Shan; Qiao, Song; Yan, Shi-Gui; Wang, Xiang-Hua

2017-12-25

To explore clinical efficacy of hip replacement for hip-joint diseases with Parkinson disease. From December 2011 to December 2016, 18 patients with hip-joint diseases with Parkinson disease treated by hip replacement, including 8 males and 10 females aged from 59 to 87 years old with an average of 71 years old. Among them, 3 cases were developmental dysplasia of hip, 3 cases were femoral head necrosis and 12 cases were femoral neck fracture. All patients manifested with obvious pain and limitation of stepping ability. Postoperative complications were observed and Harris score were used to compare hip joint function after operation. The incision were healed well, and pain were alleviated or disappeared, and hip joint function were improved. Eighteen patients were followed up from 1 to 3 years with an average of 2.3 years. At the latest follow up, 14 cases recovered freedom-walk, 2 cases could walk with walking stick, 1 case could walk with walking aid and 1 case was died. Among 18 patients, 2 cases were occurred dislocation, and 1 case were died for cardiac disease at 3 months after operation. Four patients were occurred slight pain. There were significant differences in Harris scores among preoperative (41.7±1.4), 6 months after operation(80.1±5.4) and the final follow-up (83.4±2.1), and 10 cases got excellent result, 4 good, 1 fair and 2 poor. Application of hip replacement for hip-joint diseases with Parkinson disease is a safe and effective clinical therapy, and has advantages of less complications and rapid recovery of hip joint function.

Cervical facet force analysis after disc replacement versus fusion.

PubMed

Patel, Vikas V; Wuthrich, Zachary R; McGilvray, Kirk C; Lafleur, Matthew C; Lindley, Emily M; Sun, Derrick; Puttlitz, Christian M

2017-05-01

Cervical total disc replacement was developed to preserve motion and reduce adjacent-level degeneration relative to fusion, yet concerns remain that total disc replacement will lead to altered facet joint loading and long-term facet joint arthrosis. This study is intended to evaluate changes in facet contact force, pressure and surface area at the treated and superior adjacent levels before and after discectomy, disc replacement, and fusion. Ten fresh-frozen human cadaveric cervical spines were potted from C2 to C7 with pressure sensors placed into the facet joints of C3-C4 and C4-C5 via slits in the facet capsules. Moments were applied to the specimens to produce axial rotation, lateral bending and extension. Facet contact force and pressure were measured at both levels for intact, discectomy at C4-C5, disc replacement with ProDisc-C (Synthes Spine, West Chester, Pennsylvania, USA) at C4-C5, and anterior discectomy and fusion with Cervical Spine Locking Plate (Synthes Spine, West Chester, Pennsylvania, USA) at C4-C5. Facet contact area was calculated from the force and pressure measurements. An analysis of variance was used to determine significant differences with P-values <0.05 indicating significance. Facet contact force was elevated at the treated level under extension following both discectomy and disc replacement, while facet contact pressure and area were relatively unchanged. Facet contact force and area were decreased at the treated level following fusion for all three loading conditions. Total disc replacement preserved facet contact force for all scenarios except extension at the treated level, highlighting the importance of the anterior disco-ligamentous complex. This could promote treated-level facet joint disease. Copyright © 2017 Elsevier Ltd. All rights reserved.

49 CFR 213.351 - Rail joints.

Code of Federal Regulations, 2011 CFR

2011-10-01

... replaced. (d) Each rail shall be bolted with at least two bolts at each joint. (e) Each joint bar shall be... in this subpart. (f) No rail shall have a bolt hole which is torch cut or burned. (g) No joint bar shall be reconfigured by torch cutting. ...

Regional analgesia for improvement of long-term functional outcome after elective large joint replacement

PubMed Central

Atchabahian, Arthur; Schwartz, Gary; Hall, Charles B; Lajam, Claudette M; Andreae, Michael H

2015-01-01

Background Regional analgesia is more effective than conventional analgesia for controlling pain and may facilitate rehabilitation after large joint replacement in the short term. It remains unclear if regional anaesthesia improves functional outcomes after joint replacement beyond three months after surgery. Objectives To assess the effects of regional anaesthesia and analgesia on long-term functional outcomes 3, 6 and 12 months after elective major joint (knee, shoulder and hip) replacement surgery. Search methods We performed an electronic search of several databases (CENTRAL, MEDLINE, EMBASE, CINAHL), and handsearched reference lists and conference abstracts. We updated our search in June 2015. Selection criteria We included randomized controlled trials (RCTs) comparing regional analgesia versus conventional analgesia in patients undergoing total shoulder, hip or knee replacement. We included studies that reported a functional outcome with a follow-up of at least three months after surgery. Data collection and analysis We used standard methodological procedures expected by Cochrane. We contacted study authors for additional information. Main results We included six studies with 350 participants followed for at least three months. All of these studies enrolled participants undergoing total knee replacement. Studies were at least partially blinded. Three studies had a high risk of performance bias and one a high risk of attrition bias, but the risk of bias was otherwise unclear or low. Only one study assessed joint function using a global score. Due to heterogeneity in outcome and reporting, we could only pool three out of six RCTs, with range of motion assessed at three months after surgery used as a surrogate for joint function. All studies had a high risk of detection bias. Using the random-effects model, there was no statistically significant difference between the experimental and control groups (mean difference 3.99 degrees, 95% confidence interval (CI) − 2.23 to 10.21; P value = 0.21, 3 studies, 140 participants, very low quality evidence). We did not perform further analyses because immediate adverse effects were not part of the explicit outcomes of any of these typically small studies, and long-term adverse events after regional anaesthesia are rare. None of the included studies elicited or reported long-term adverse effects like persistent nerve damage. Authors’ conclusions More high-quality studies are needed to establish the effects of regional analgesia on function after major joint replacement, as well as on the risk of adverse events (falls). PMID:26269416

A systematic review of the relationship between subchondral bone features, pain and structural pathology in peripheral joint osteoarthritis.

PubMed

Barr, Andrew J; Campbell, T Mark; Hopkinson, Devan; Kingsbury, Sarah R; Bowes, Mike A; Conaghan, Philip G

2015-08-25

Bone is an integral part of the osteoarthritis (OA) process. We conducted a systematic literature review in order to understand the relationship between non-conventional radiographic imaging of subchondral bone, pain, structural pathology and joint replacement in peripheral joint OA. A search of the Medline, EMBASE and Cochrane library databases was performed for original articles reporting association between non-conventional radiographic imaging-assessed subchondral bone pathologies and joint replacement, pain or structural progression in knee, hip, hand, ankle and foot OA. Each association was qualitatively characterised by a synthesis of the data from each analysis based upon study design, adequacy of covariate adjustment and quality scoring. In total 2456 abstracts were screened and 139 papers were included (70 cross-sectional, 71 longitudinal analyses; 116 knee, 15 hip, six hand, two ankle and involved 113 MRI, eight DXA, four CT, eight scintigraphic and eight 2D shape analyses). BMLs, osteophytes and bone shape were independently associated with structural progression or joint replacement. BMLs and bone shape were independently associated with longitudinal change in pain and incident frequent knee pain respectively. Subchondral bone features have independent associations with structural progression, pain and joint replacement in peripheral OA in the hip and hand but especially in the knee. For peripheral OA sites other than the knee, there are fewer associations and independent associations of bone pathologies with these important OA outcomes which may reflect fewer studies; for example the foot and ankle were poorly studied. Subchondral OA bone appears to be a relevant therapeutic target. PROSPERO registration number: CRD 42013005009.

21 CFR 888.3100 - Ankle joint metal/composite semi-constrained cemented prosthesis.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ankle joint metal/composite semi-constrained... Ankle joint metal/composite semi-constrained cemented prosthesis. (a) Identification. An ankle joint metal/composite semi-constrained cemented prosthesis is a device intended to be implanted to replace an...

21 CFR 888.3510 - Knee joint femorotibial metal/polymer constrained cemented prosthesis.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint femorotibial metal/polymer constrained... Knee joint femorotibial metal/polymer constrained cemented prosthesis. (a) Identification. A knee joint femorotibial metal/polymer constrained cemented prosthesis is a device intended to be implanted to replace part...

21 CFR 888.3660 - Shoulder joint metal/polymer semi-constrained cemented prosthesis.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Shoulder joint metal/polymer semi-constrained... Shoulder joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. A shoulder joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a...

21 CFR 888.3650 - Shoulder joint metal/polymer non-constrained cemented prosthesis.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Shoulder joint metal/polymer non-constrained... Shoulder joint metal/polymer non-constrained cemented prosthesis. (a) Identification. A shoulder joint metal/polymer non-constrained cemented prosthesis is a device intended to be implanted to replace a...

21 CFR 888.3100 - Ankle joint metal/composite semi-constrained cemented prosthesis.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ankle joint metal/composite semi-constrained... Ankle joint metal/composite semi-constrained cemented prosthesis. (a) Identification. An ankle joint metal/composite semi-constrained cemented prosthesis is a device intended to be implanted to replace an...

Meat consumption and risk of primary hip and knee joint replacement due to osteoarthritis: a prospective cohort study

PubMed Central

2011-01-01

Background There is emerging evidence for a beneficial effect of meat consumption on the musculoskeletal system. However, whether it affects the risk of knee and hip osteoarthritis is unknown. We performed a prospective cohort study to examine the relationship between meat consumption and risk of primary hip and knee replacement for osteoarthritis. Methods Eligible 35,331 participants were selected from the Melbourne Collaborative Cohort Study recruited during 1990-1994. Consumption of fresh red meat, processed meat, chicken, and fish was assessed using a food frequency questionnaire. Primary hip and knee replacement for osteoarthritis during 2001-2005 was determined by linking the cohort records to the Australian National Joint Replacement Registry. Results There was a negative dose-response relationship between fresh red meat consumption and the risk of hip replacement (hazard ratio (HR) 0.94 per increase in intake of one time/week, 95% confidence interval (CI) 0.89-0.98). In contrast, there was no association with knee replacement risk (HR 0.98, 95% CI 0.94-1.02). Consumption of processed meat, chicken and fish were not associated with risk of hip or knee replacement. Conclusion A high level consumption of fresh red meat was associated with a decreased risk of hip, but not knee, joint replacement for osteoarthritis. One possible mechanism to explain these differential associations may be via an effect of meat intake on bone strength and hip shape. Further confirmatory studies are warranted. PMID:21235820

Meat consumption and risk of primary hip and knee joint replacement due to osteoarthritis: a prospective cohort study.

PubMed

Wang, Yuanyuan; Simpson, Julie Anne; Wluka, Anita E; English, Dallas R; Giles, Graham G; Graves, Stephen; Cicuttini, Flavia M

2011-01-16

There is emerging evidence for a beneficial effect of meat consumption on the musculoskeletal system. However, whether it affects the risk of knee and hip osteoarthritis is unknown. We performed a prospective cohort study to examine the relationship between meat consumption and risk of primary hip and knee replacement for osteoarthritis. Eligible 35,331 participants were selected from the Melbourne Collaborative Cohort Study recruited during 1990-1994. Consumption of fresh red meat, processed meat, chicken, and fish was assessed using a food frequency questionnaire. Primary hip and knee replacement for osteoarthritis during 2001-2005 was determined by linking the cohort records to the Australian National Joint Replacement Registry. There was a negative dose-response relationship between fresh red meat consumption and the risk of hip replacement (hazard ratio (HR) 0.94 per increase in intake of one time/week, 95% confidence interval (CI) 0.89-0.98). In contrast, there was no association with knee replacement risk (HR 0.98, 95% CI 0.94-1.02). Consumption of processed meat, chicken and fish were not associated with risk of hip or knee replacement. A high level consumption of fresh red meat was associated with a decreased risk of hip, but not knee, joint replacement for osteoarthritis. One possible mechanism to explain these differential associations may be via an effect of meat intake on bone strength and hip shape. Further confirmatory studies are warranted.

Moje first metatarsophalangeal replacement--a case series with functional outcomes using the AOFAS-HMI score.

PubMed

Brewster, Mark; McArthur, John; Mauffrey, Cyril; Lewis, Andrew Charles; Hull, Peter; Ramos, James

2010-01-01

We report the functional results of a case series of Moje first metatarsophalangeal total joint replacements carried out between February 2001 and November 2006. All patients who underwent Moje arthroplasty under the care of a single surgeon were included; outcome scores and complications were recorded annually. A total of 32 joints in 29 consecutive patients were followed for a mean duration of 34 (range 6 to 74) months, and the mean patient age at the time of operation was 56 (range 38 to 79) years. Hallux rigidus was the primary diagnosis in 28 (87.5%) of the cases. The mean American Orthopaedic Foot & Ankle Society Hallux-Metatarsophalangeal-Interphalangeal score at final follow-up was 74/100 (range 9 to 100), with 13 (40.63%) joints rated good to excellent. Two (6.25%) joints were revised to arthrodesis at a mean of 52 (range 41 to 63) months following the arthroplasty procedure, and the overall prevalence of postoperative complications was 6 (18.75%). Based on these results, we concluded that first MTPJ total joint replacement with the Moje device remains promising, but still has room for improvement before the results match those obtained with larger joint (knee, hip) arthroplasty. Copyright 2010 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Nuclear medicine and the failed joint replacement: Past, present, and future

PubMed Central

Palestro, Christopher J

2014-01-01

Soon after the introduction of the modern prosthetic joint, it was recognized that radionuclide imaging provides useful information about these devices. The bone scan was used extensively to identify causes of prosthetic joint failure. It became apparent, however, that although sensitive, regardless of how the images were analyzed or how it was performed, the test was not specific and could not distinguish among the causes of prosthetic failure. Advances in anatomic imaging, notably cross sectional modalities, have facilitated the diagnosis of many, if not most, causes of prosthetic failure, with the important exception of infection. This has led to a shift in the diagnostic paradigm, in which nuclear medicine investigations increasingly have focused on diagnosing infection. The recognition that bone scintigraphy could not reliably diagnose infection led to the development of combined studies, first bone/gallium and subsequently leukocyte/bone and leukocyte/marrow imaging. Labeled leukocyte imaging, combined with bone marrow imaging is the most accurate (about 90%) imaging test for diagnosing joint arthroplasty infection. Its value not withstanding, there are significant disadvantages to this test. In-vivo techniques for labeling leukocytes, using antigranulocyte antibodies have been explored, but have their own limitations and the results have been inconsistent. Fluorodeoxyglucose (FDG)-positron emission tomography (FDG-PET) has been extensively investigated for more than a decade but its role in diagnosing the infected prosthesis has yet to be established. Antimicrobial peptides bind to bacterial cell membranes and are infection specific. Data suggest that these agents may be useful for diagnosing prosthetic joint infection, but large scale studies have yet to be undertaken. Although for many years nuclear medicine has focused on diagnosing prosthetic joint infection, the advent of hybrid imaging with single-photon emission computed tomography(SPECT)/electronic computer X-ray tomography technique (CT) and the availability of fluorine-18 fluoride PET suggests that the diagnostic paradigm may be shifting again. By providing the anatomic information lacking in conventional radionuclide studies, there is renewed interest in bone scintigraphy, performed as a SPECT/CT procedure, for detecting joint instability, mechanical loosening and component malpositioning. Fluoride-PET may provide new insights into periprosthetic bone metabolism. The objective of this manuscript is to provide a comprehensive review of the evolution of nuclear medicine imaging of joint replacements. PMID:25071885

The influence of resting periods on friction in the artificial hip.

PubMed

Nassutt, Roman; Wimmer, Markus A; Schneider, Erich; Morlock, Michael M

2003-02-01

Insufficient tribologic performance of total joint components is a major cause of prostheses failure. Wear has been studied intensively using testing machines that apply continuous motions. Human locomotion, however, is not well represented by continuous motions alone. Singular events and resting periods are a substantial part of daily activities. Resting does influence adhesion in the artificial joint with possible effects on friction, wear, and loosening. The current study evaluated the effects of resting on the frictional properties of hip prosthesis components. The activity measurements of 32 patients with artificial hip replacements were analyzed for resting durations of the hip. A pin-on-ball screening device was used to determine friction after characteristic resting periods and during continuous oscillating motion. All common articulation pairings were investigated. Prolonged and frequent resting periods of the hip were found for the patients. Initial friction increased with increasing resting duration for all tested materials (between 41% and 191%). The metal-on-metal articulations showed the highest friction level (0.098 for sliding) and the highest increase (191%) in friction with resting duration (0.285 after resting periods of 60 seconds). A high static frictional moment after resting periods might present a risk for aseptic implant loosening. Therefore, large head diameters of metal-on-metal joints should be used with caution, especially when additional unfavorable risk factors such as obesity, weak bone-implant interface, or high activity level are present.

Patients with Revision Modern Megaprostheses of the Distal Femur Have Improved Disease-Specific and Health-Related Outcomes Compared to Those with Primary Replacements.

PubMed

Heyberger, Clémence; Auberger, Guillaume; Babinet, Antoine; Anract, Philippe; Biau, David J

2017-12-21

We asked whether there would be any difference between primary and revision modern cemented fixed hinge megaprosthesis of the distal femur in function and activity-related outcomes following treatment of a bone tumor. An identical custom-made fixed hinge cemented megaprosthesis with a hydroxyapatite collar was used in all cases. The main outcomes were joint-specific function, disease-specific activity, and health-related quality of life. Implant survival was also evaluated. Patients in the revision group performed slightly better than patients in the primary group on disease-specific (Toronto Extremity Salvage Score, p  = 0.033; Musculoskeletal Tumor Society, p  = 0.072) and health-related outcomes (Short Form 36 [SF-36] physical component, p  = 0.085; SF-36 mental component, p  = 0.069) but not on joint-specific outcomes (Knee Society Score, p  = 0.94). The cumulative probabilities of revision for any reason were 14.5% (7-25%) at 5 years with no statistically significant difference between primary and revision procedures ( p  = 0.77). In conclusion, patients undergoing a revision have similar joint-specific functional outcome but improved disease-specific and health-related outcomes. Implant survival are similar between groups. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Comparison of the effects of forefoot joint-preserving arthroplasty and resection-replacement arthroplasty on walking plantar pressure distribution and patient-based outcomes in patients with rheumatoid arthritis.

PubMed

Ebina, Kosuke; Hirao, Makoto; Takagi, Keishi; Ueno, Sachi; Morimoto, Tokimitsu; Matsuoka, Hozo; Kitaguchi, Kazuma; Iwahashi, Toru; Hashimoto, Jun; Yoshikawa, Hideki

2017-01-01

The purpose of this retrospective study is to clarify the difference in plantar pressure distribution during walking and related patient-based outcomes between forefoot joint-preserving arthroplasty and resection-replacement arthroplasty in patients with rheumatoid arthritis (RA). Four groups of patients were recruited. Group1 included 22 feet of 11 healthy controls (age 48.6 years), Group2 included 36 feet of 28 RA patients with deformed non-operated feet (age 64.8 years, Disease activity score assessing 28 joints with CRP [DAS28-CRP] 2.3), Group3 included 27 feet of 20 RA patients with metatarsal head resection-replacement arthroplasty (age 60.7 years, post-operative duration 5.6 years, DAS28-CRP 2.4), and Group4 included 34 feet of 29 RA patients with metatarsophalangeal (MTP) joint-preserving arthroplasty (age 64.6 years, post-operative duration 3.2 years, DAS28-CRP 2.3). Patients were cross-sectionally examined by F-SCAN II to evaluate walking plantar pressure, and the self-administered foot evaluation questionnaire (SAFE-Q). Twenty joint-preserving arthroplasty feet were longitudinally examined at both pre- and post-operation. In the 1st MTP joint, Group4 showed higher pressure distribution (13.7%) than Group2 (8.0%) and Group3 (6.7%) (P<0.001). In the 2nd-3rd MTP joint, Group4 showed lower pressure distribution (9.0%) than Group2 (14.5%) (P<0.001) and Group3 (11.5%) (P<0.05). On longitudinal analysis, Group4 showed increased 1st MTP joint pressure (8.5% vs. 14.7%; P<0.001) and decreased 2nd-3rd MTP joint pressure (15.2% vs. 10.7%; P<0.01) distribution. In the SAFE-Q subscale scores, Group4 showed higher scores than Group3 in pain and pain-related scores (84.1 vs. 71.7; P<0.01) and in shoe-related scores (62.5 vs. 43.1; P<0.01). Joint-preserving arthroplasty resulted in higher 1st MTP joint and lower 2nd-3rd MTP joint pressures than resection-replacement arthroplasty, which were associated with better patient-based outcomes.

Description of the rates, trends and surgical burden associated with revision for prosthetic joint infection following primary and revision knee replacements in England and Wales: an analysis of the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man.

PubMed

Lenguerrand, Erik; Whitehouse, Michael R; Beswick, Andrew D; Toms, Andrew D; Porter, Martyn L; Blom, Ashley W

2017-07-10

To describe the prevalence rates of revision surgery for the treatment of prosthetic joint infection (PJI) for patients undergoing knee replacement, their time trends, the cumulative incidence function of revision for PJI and estimate the burden of PJI at health service level. We analysed revision knee replacements performed due to a diagnosis of PJI and the linked index procedures recorded in the National Joint Registry from 2003 to 2014 for England and Wales. The cohort analysed consisted of 679 010 index primary knee replacements, 33 920 index revision knee replacements and 8247 revision total knee replacements performed due to a diagnosis of PJI. The prevalence rates, their time trends investigated by time from index surgery to revision for PJI, cumulative incidence functions and the burden of PJI (total procedures) were calculated. Overall linear trends were investigated with log-linear regression. The incidence of revision total knee replacement due to PJI at 2 years was 3.2/1000 following primary and 14.4/1000 following revision knee replacement, respectively. The prevalence of revision due to PJI in the 3 months following primary knee replacement has risen by 2.5-fold (95% CI 1.2 to 5.3) from 2005 to 2013 and 7.5-fold (95% CI 1.0 to 56.1) following revision knee replacement. Over 1000 procedures per year are performed as a consequence of knee PJI, an increase of 2.8 from 2005 to 2013. Overall, 75% of revisions were two-stage with an increase in use of single-stage from 7.9% in 2005 to 18.8% in 2014. Although the risk of revision due to PJI following knee replacement is low, it is rising, and coupled with the established and further predicted increased incidence of both primary and revision knee replacements, this represents an increasing and substantial treatment burden for orthopaedic service delivery in England and Wales. This has implications for future service design and the funding of individual and specialist centres. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Description of the rates, trends and surgical burden associated with revision for prosthetic joint infection following primary and revision knee replacements in England and Wales: an analysis of the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man

PubMed Central

Lenguerrand, Erik; Whitehouse, Michael R; Beswick, Andrew D; Toms, Andrew D; Porter, Martyn L; Blom, Ashley W

2017-01-01

Objectives To describe the prevalence rates of revision surgery for the treatment of prosthetic joint infection (PJI) for patients undergoing knee replacement, their time trends, the cumulative incidence function of revision for PJI and estimate the burden of PJI at health service level. Design We analysed revision knee replacements performed due to a diagnosis of PJI and the linked index procedures recorded in the National Joint Registry from 2003 to 2014 for England and Wales. The cohort analysed consisted of 679 010 index primary knee replacements, 33 920 index revision knee replacements and 8247 revision total knee replacements performed due to a diagnosis of PJI. The prevalence rates, their time trends investigated by time from index surgery to revision for PJI, cumulative incidence functions and the burden of PJI (total procedures) were calculated. Overall linear trends were investigated with log-linear regression. Results The incidence of revision total knee replacement due to PJI at 2 years was 3.2/1000 following primary and 14.4/1000 following revision knee replacement, respectively. The prevalence of revision due to PJI in the 3 months following primary knee replacement has risen by 2.5-fold (95% CI 1.2 to 5.3) from 2005 to 2013 and 7.5-fold (95% CI 1.0 to 56.1) following revision knee replacement. Over 1000 procedures per year are performed as a consequence of knee PJI, an increase of 2.8 from 2005 to 2013. Overall, 75% of revisions were two-stage with an increase in use of single-stage from 7.9% in 2005 to 18.8% in 2014. Conclusions Although the risk of revision due to PJI following knee replacement is low, it is rising, and coupled with the established and further predicted increased incidence of both primary and revision knee replacements, this represents an increasing and substantial treatment burden for orthopaedic service delivery in England and Wales. This has implications for future service design and the funding of individual and specialist centres. PMID:28698316

A2-3: Impact of Mild Chronic Kidney Disease Stage on Outcomes after Total Hip or Knee Arthroplasty

PubMed Central

Graham, Jove; Deegan, Brian; Bowen, Thomas; Richard, Raveesh; Perkins, Robert; Foltzer, Michael

2014-01-01

Background/Aims Dialysis and kidney transplantation adversely impact outcomes of total hip or knee arthroplasty (THA, TKA), but complication rates have not been reported for patients with less advanced stages of chronic kidney disease (CKD). Surgeons lack the data necessary to have informed discussions regarding anticipated outcomes of joint replacement for these patients. Methods We retrospectively reviewed electronic health records of 779 adults with stages 1, 2, and 3 CKD not requiring dialysis or transplantation who underwent THA or TKA from 2004–2011, to assess infection, revision, 90-day readmission and mortality rates. Patients with less than 12 months follow-up, open fracture, prior joint surgery, pregnancy, or acute kidney injury were excluded. Chi-square analysis and Cox survival analysis compared these outcomes between the stage 1–2 and stage 3 groups, stratified by joint replaced (THA vs TKA). All models adjusted for age, sex and BMI at surgery. Results No statistically different rates of revision or infection between Stage 3 vs. Stages 1–2 were seen, although there was a trend toward increased infections in Stage 3. THA patients with Stage 3 showed a significantly increased mortality rate compared to Stage 1–2 THA patients (HR 3.40, 95% CI = 1.25–9.23, P = 0.02). Conclusions CKD affects nearly 15% of the U.S. population many of whom undergo joint replacement. End stage kidney disease (patients post-transplant or on hemodialysis) has been consistently associated with increased rates of infection and revision in excess of our observed outcomes, but the overall rate of infection/revision in our study population was only slightly higher than reported rates in the general population (2–7% vs. 1–2%, respectively). CKD should not preclude joint replacement, but these data can help clinicians engage in meaningful informed discussions with patients with mild kidney disease regarding risks for infection, revision and death following joint replacement.

Cost feasibility of a pre-checking medical tourism system for U.S. patients undertaking joint replacement surgery in Taiwan.

PubMed

Haung, Ching-Ying; Wang, Sheng-Pen; Chiang, Chih-Wei

2010-01-01

Medical tourism is a relatively recent global economic and political phenomenon that has assumed increasing importance for developing countries, particularly in Asia. In fact, Taiwan possesses a niche for developing medical tourism because many hospitals provide state-of-the-art medicine in all disciplines and many doctors are trained in the United States (US). Among the most common medical procedures outsourced, joint replacements such as total knee replacement (TKR) and total hip replacement (THR) are two surgeries offered to US patients at a lower cost and shorter waiting time than in the US. This paper proposed a pre-checking medical tourism system (PCMTS) and evaluated the cost feasibility of recruiting American clients traveling to Taiwan for joint replacement surgery. Cost analysis was used to estimate the prime costs for each stage in the proposed PCMTS. Sensitivity analysis was implemented to examine how different pricings for medical checking and a surgical operation (MC&SO) and recovery, can influence the surplus per patient considering the PCMTS. Finally, the break-even method was adopted to test the tradeoff between the sunk costs of investment in the PCMTS and the annual surplus for participating hospitals. A novel business plan was built showing that pre-checking stations in medical tourism can provide post-operative care and recovery follow-up. Adjustable pricing for hospital administrators engaged in the PCMTS consisted of two main costs: US$3,700 for MC&SO and US$120 for the hospital stay. Guidelines for pricing were provided to maximize the annual surplus from this plan with different number of patients participating in PCMTS. The maximal profit margin from each American patient undertaking joint surgery is about US$24,315. Using cost analysis, this article might be the first to evaluate the feasibility of PCMTS for joint replacement surgeries. The research framework in this article is applicable when hospital administrators evaluate the feasibility of outsourced medical procedures other than TKR and THR.

The contact mechanics and occurrence of edge loading in modular metal-on-polyethylene total hip replacement during daily activities.

PubMed

Hua, Xijin; Li, Junyan; Jin, Zhongmin; Fisher, John

2016-06-01

The occurrence of edge loading in hip joint replacement has been associated with many factors such as prosthetic design, component malposition and activities of daily living. The present study aimed to quantify the occurrence of edge loading/contact at the articulating surface and to evaluate the effect of cup angles and edge loading on the contact mechanics of a modular metal-on-polyethylene (MoP) total hip replacement (THR) during different daily activities. A three-dimensional finite element model was developed based on a modular MoP bearing system. Different cup inclination and anteversion angles were modelled and six daily activities were considered. The results showed that edge loading was predicted during normal walking, ascending and descending stairs activities under steep cup inclination conditions (≥55°) while no edge loading was observed during standing up, sitting down and knee bending activities. The duration of edge loading increased with increased cup inclination angles and was affected by the cup anteversion angles. Edge loading caused elevated contact pressure at the articulating surface and substantially increased equivalent plastic strain of the polyethylene liner. The present study suggested that correct positioning the component to avoid edge loading that may occur during daily activities is important for MoP THR in clinical practice. Copyright © 2016. Published by Elsevier Ltd.

Surface protection overview

NASA Technical Reports Server (NTRS)

Levine, S. R.

1982-01-01

A first-cut integrated environmental attack life prediction methodology for hot section components is addressed. The HOST program is concerned with oxidation and hot corrosion attack of metallic coatings as well as their degradation by interdiffusion with the substrate. The effects of the environment and coatings on creep/fatigue behavior are being addressed through a joint effort with the Fatigue sub-project. An initial effort will attempt to scope the problem of thermal barrier coating life prediction. Verification of models will be carried out through benchmark rig tests including a 4 atm. replaceable blade turbine and a 50 atm. pressurized burner rig.

International reference reagents: antihuman globulin. An ISBT/ICSH joint working party report. International Society of Blood Transfusion. International Committee for Standardization in Haematology.

PubMed

Case, J; Ford, D S; Chung, A; Collins, R; Kochman, S; Mazda, T; Overbeeke, M; Perera, R; Sakuldamrongpanich, T; Scott, M; Voak, D; Zupańska, B

1999-01-01

An international working party has conducted a study designed to select a suitable reference reagent for antihuman globulin, to replace those first made available in 1987. The chosen preparation contains levels of anti-IgG and anti-C3 (anti-C3c and anti-C3d) potency that are considered suitable to serve for reference when evaluating either polyspecific antihuman globulin reagents or those containing their separate monospecific components. The reference material is available in 2-ml freeze-dried aliquots from seven assigned distribution centres.

49 CFR 213.351 - Rail joints.

Code of Federal Regulations, 2014 CFR

2014-10-01

... shall be replaced. (c) If a joint bar is cracked or broken between the middle two bolt holes it shall be... in this subpart. (f) No rail shall have a bolt hole which is torch cut or burned. (g) No joint bar...

49 CFR 213.351 - Rail joints.

Code of Federal Regulations, 2013 CFR

2013-10-01

... shall be replaced. (c) If a joint bar is cracked or broken between the middle two bolt holes it shall be... in this subpart. (f) No rail shall have a bolt hole which is torch cut or burned. (g) No joint bar...

Joint modelling of repeated measurement and time-to-event data: an introductory tutorial.

PubMed

Asar, Özgür; Ritchie, James; Kalra, Philip A; Diggle, Peter J

2015-02-01

The term 'joint modelling' is used in the statistical literature to refer to methods for simultaneously analysing longitudinal measurement outcomes, also called repeated measurement data, and time-to-event outcomes, also called survival data. A typical example from nephrology is a study in which the data from each participant consist of repeated estimated glomerular filtration rate (eGFR) measurements and time to initiation of renal replacement therapy (RRT). Joint models typically combine linear mixed effects models for repeated measurements and Cox models for censored survival outcomes. Our aim in this paper is to present an introductory tutorial on joint modelling methods, with a case study in nephrology. We describe the development of the joint modelling framework and compare the results with those obtained by the more widely used approaches of conducting separate analyses of the repeated measurements and survival times based on a linear mixed effects model and a Cox model, respectively. Our case study concerns a data set from the Chronic Renal Insufficiency Standards Implementation Study (CRISIS). We also provide details of our open-source software implementation to allow others to replicate and/or modify our analysis. The results for the conventional linear mixed effects model and the longitudinal component of the joint models were found to be similar. However, there were considerable differences between the results for the Cox model with time-varying covariate and the time-to-event component of the joint model. For example, the relationship between kidney function as measured by eGFR and the hazard for initiation of RRT was significantly underestimated by the Cox model that treats eGFR as a time-varying covariate, because the Cox model does not take measurement error in eGFR into account. Joint models should be preferred for simultaneous analyses of repeated measurement and survival data, especially when the former is measured with error and the association between the underlying error-free measurement process and the hazard for survival is of scientific interest. © The Author 2015; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.

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

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Hip joint (hemi-hip) acetabular metal cemented... (hemi-hip) acetabular metal cemented prosthesis. (a) Identification. A hip joint (hemi-hip) acetabular metal cemented prosthesis is a device intended to be implanted to replace a portion of the hip joint...

21 CFR 888.3110 - Ankle joint metal/polymer semi-constrained cemented prosthesis.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ankle joint metal/polymer semi-constrained... Ankle joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. An ankle joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an ankle...

21 CFR 888.3160 - Elbow joint metal/polymer semi-constrained cemented prosthesis.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Elbow joint metal/polymer semi-constrained... Elbow joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. An elbow joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an elbow...

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

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hip joint metal/composite semi-constrained... Hip joint metal/composite semi-constrained cemented prosthesis. (a) Identification. A hip joint metal/composite semi-constrained cemented prosthesis is a two-part device intended to be implanted to replace a...

21 CFR 888.3110 - Ankle joint metal/polymer semi-constrained cemented prosthesis.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ankle joint metal/polymer semi-constrained... Ankle joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. An ankle joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an ankle...

21 CFR 888.3160 - Elbow joint metal/polymer semi-constrained cemented prosthesis.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Elbow joint metal/polymer semi-constrained... Elbow joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. An elbow joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an elbow...

21 CFR 888.3110 - Ankle joint metal/polymer semi-constrained cemented prosthesis.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ankle joint metal/polymer semi-constrained... Ankle joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. An ankle joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an ankle...

21 CFR 888.3160 - Elbow joint metal/polymer semi-constrained cemented prosthesis.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Elbow joint metal/polymer semi-constrained... Elbow joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. An elbow joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an elbow...

21 CFR 888.3160 - Elbow joint metal/polymer semi-constrained cemented prosthesis.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Elbow joint metal/polymer semi-constrained... Elbow joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. An elbow joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an elbow...

21 CFR 888.3110 - Ankle joint metal/polymer semi-constrained cemented prosthesis.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ankle joint metal/polymer semi-constrained... Ankle joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. An ankle joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an ankle...

Joint replacement recipients' views about health information privacy.

PubMed

Terry, Amanda L; Chesworth, Bert M; Bourne, Robert B; Stolee, Paul; Speechley, Mark

2015-10-01

Researchers are concerned about the possibility of restricted access to data as a result of specific consent requirements in privacy legislation, potentially resulting in smaller samples and a lack of representativeness which could bias results. In addition, there is uncertainty about what influences individuals to give consent for the use of their personal health information. To measure joint replacement recipients' health information privacy views and to assess potential predictors of these views. Cross-sectional survey. Potential joint replacement recipients from two teaching hospitals in London, Ontario, Canada. Age, gender, education, employment status, anticipated joint replacement, and expectations for surgery. Privacy concerns as measured by the Concern Scale. The response rate was 182/253 or 72%. The mean Concern score was 143.9/235.0 for the total sample (range = 82-216). Women had higher levels of privacy concerns than men on slightly over half of the individual questionnaire items. In women, surgical joint, age and employment explained 15% of the variance in concerns about personal health information privacy (P = 0.001). The model explained 6% of the variance in concerns in men (P = 0.138) and was not statistically significant. This study indicates that demographic characteristics and health-care experiences play a role in the variability of health information privacy concerns. A greater understanding of patients' privacy views about health information could lead to a greater harmonization among privacy rules, research and data access, and the preferences of health-care consumers. © 2013 John Wiley & Sons Ltd.

Associations between socioeconomic status and primary total knee joint replacements performed for osteoarthritis across Australia 2003-10: data from the Australian Orthopaedic Association National Joint Replacement Registry.

PubMed

Brennan, Sharon L; Lane, Stephen E; Lorimer, Michelle; Buchbinder, Rachelle; Wluka, Anita E; Page, Richard S; Osborne, Richard H; Pasco, Julie A; Sanders, Kerrie M; Cashman, Kara; Ebeling, Peter R; Graves, Stephen E

2014-10-28

Relatively little is known about the social distribution of total knee joint replacement (TKR) uptake in Australia. We examine associations between socioeconomic status (SES) and TKR performed for diagnosed osteoarthritis 2003-10 for all Australian males and females aged ≥ 30 yr. Data of primary TKR (n=213,018, 57.4% female) were ascertained from a comprehensive national joint replacement registry. Residential addresses were matched to Australian Census data to identify area-level social disadvantage, and categorised into deciles. Estimated TKR rates were calculated. Poisson regression was used to model the relative risk (RR) of age-adjusted TKR per 1,000py, stratified by sex and SES. A negative relationship was observed between TKR rates and SES deciles. Females had a greater rate of TKR than males. Surgery utilisation was greatest for all adults aged 70-79 yr. In that age group differences in estimated TKR per 1,000py between deciles were greater for 2010 than 2003 (females: 2010 RR 4.32 and 2003 RR 3.67; males: 2010 RR 2.04 and 2003 RR 1.78). Identifying factors associated with TKR utilisation and SES may enhance resource planning and promote surgery utilisation for end-stage osteoarthritis.

Effect of total shoulder replacements on airport security screening in the post-9/11 era.

PubMed

Dines, Joshua S; Elkousy, Hussein; Edwards, T Bradley; Gartsman, Gary M; Dines, David M

2007-01-01

There are few reports in the literature on the effect of orthopaedic implants on airport security devices and none on shoulder arthroplasty implants after September 11, 2001. Since 9/11, airport security screening devices have become more sensitive in response to the increasing threat of terrorism. Often, patients with joint implants activate the metal detectors and are subsequently subjected to more intensive screening. We assess the effects of shoulder joint implants on different airport security devices and what effect the results had on passenger travel. In this study, 154 patients who had previously undergone shoulder replacement responded to a questionnaire regarding their travel experiences after 9/11. Of these, 85 had flown during the time period studied (47 men and 38 women; mean age, 67.8 years); 79 had traveled domestically (mean, 7 flights), and 22 had taken international flights (mean, 6.1 flights). The questionnaire addressed each patient's height/weight, the number of flight segments flown (domestic and international), the number of times that a patient activated the doorway alarm/wand alarm, and the effect of a card stating that the patient had joint replacement (when applicable). On average, patients with shoulder replacement traveling domestically activated the security gate 52% of the time. The average for international travel was 42%. Of the patients who flew both domestically and internationally, there was a high correlation of activation (R = 0.54). Twenty-six patients had multiple joint implants (mean, 2.8). Multiple joint implants caused increased alarm activation (P < .001). All patients reported that their travel was delayed during the instances of security activation. There was no statistically significant effect of body mass index, height, weight, age, or sex on security device activation. Of the patients, 71% were told by their doctor that the shoulder replacement may activate security devices. Of these, 46 were given a card by their doctor indicating the presence of a total joint implant. In only 30% of the security encounters of these patients did the card expedite the screening process. This is the largest study on the effects of joint implants, and shoulder implants in particular, on airport security devices and the only one that has analyzed the data of post-9/11 travel. Patients traveling after total shoulder replacement are often delayed and subjected to more rigorous screening when traveling, especially in the post-9/11 environment. Doctors often warn their patients of potential problems and may try to avert this by giving them cards documenting the presence of a joint implant. The acceptance of these cards is sporadic. This study raises the importance of notifying patients of potential security delays, especially those with multiple joint implants, as they may directly affect travel plans. In addition, these patients may benefit from the establishment of an international joint registry.

Compatibility of Halthane 88-3 urethane adhesive with the replacement cleaning solvent D-Limonene

DOE Office of Scientific and Technical Information (OSTI.GOV)

LeMay, J.D.; Mendoza, B.

1991-08-01

D-Limonene, (R)1-methyl-4-isopropenyl-1-cyclohexene, has been identified as a leading replacement for chlorinated solvents traditionally used to clean electrical assemblies and critical components in some phases of weapons production. Unfortunately, d-limonene has a much lower vapor pressure than the chlorinated solvents if replaces (<2 torr at ambient). This makes its complete elimination from cleaned subassemblies potentially difficult, and gives rise to concerns about the compatibility of d-limonene with materials in the warhead. During the past year many WR polymers and adhesives have been surveyed for their compatibility with d-limonene. Preliminary test results obtained at Sandia (Albuquerque) and Allied-Signal (KCD) showed that Aluminum/Halthanemore » 88-3/Aluminum joints were destroyed during exposure to saturated d-limonene vapor. The cause of bond failure appeared to be d-limonene induced swelling of the Halthane polymer. This report describes recent work performed at LLNL to study the swelling behavior and bond strength degradation of Halthane 88-3 resulting from exposure to d-limonene vapor.« less

Rapid replacement of bridge deck expansion joints study - phase I.

DOT National Transportation Integrated Search

2014-12-01

Bridge deck expansion joints are used to allow for movement of the bridge deck due to thermal expansion, dynamics loading, and : other factors. More recently, expansion joints have also been utilized to prevent the passage of winter de-icing chemical...

Medium-term outcomes and complications after total replacement of the temporomandibular joint. Prospective outcome analysis after 3 and 5 years.

PubMed

Gruber, E A; McCullough, J; Sidebottom, A J

2015-05-01

In this prospective analysis, we assess the medium-term benefits, efficacy, and safety of the TMJ Concepts joint replacement system in the United Kingdom. Outcome measures of pain, maximum mouth opening, and diet were recorded preoperatively and at intervals up to 3 and 5 years. All patients who had replacement temporomandibular joints (TMJ) within a 6-year period were included. A total of 58 patients (84 joints) were followed up for 3 years (mean age 47, range 19-72) and 26 (42 joints) for 5 years (mean age 46, range 27-70). The female to male ratio was 52:6 at 3 years and 23:3 at 5 years. The most common diagnosis was degenerative disease, and the mean number of previous TMJ procedures was 2.4 (range 0-14). There were significant improvements in pain scores (7.4 reduced to 0.6 at 3 years and 0.8 at 5 years), maximum mouth opening (21.0-35.5mm at 3 years and 23.8-33.7mm at 5 years), and dietary scores (4.1-9.7 at 3 years and 3.7-9.6 at 5 years). Revision operations were required in 2 patients (not included in the outcome data) for biofilm infection of the prosthesis secondary to local infection in the head and neck. One patient had weakness of the temporal branch of the facial nerve that needed correction. TMJ replacement is an effective form of management for an irreparably damaged joint, particularly in cases of ankylosis. It lessens pain and improves function with minimal long-term morbidity. Copyright © 2014 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Readmission Patterns Over 90-Day Episodes of Care Among Medicare Fee-for-Service Beneficiaries Discharged to Post-acute Care.

PubMed

Middleton, Addie; Kuo, Yong-Fang; Graham, James E; Karmarkar, Amol; Lin, Yu-Li; Goodwin, James S; Haas, Allen; Ottenbacher, Kenneth J

2018-04-21

Examine readmission patterns over 90-day episodes of care in persons discharged from hospitals to post-acute settings. Retrospective cohort study. Acute care hospitals. Medicare fee-for-service enrollees (N = 686,877) discharged from hospitals to post-acute care in 2013-2014. The cohort included beneficiaries >65 years of age hospitalized for stroke, joint replacement, or hip fracture and who survived for 90 days following discharge. 90-day unplanned readmissions. The cohort included 127,680 individuals with stroke, 442,195 undergoing joint replacement, and 117,002 with hip fracture. Thirty-day readmission rates ranged from 3.1% for knee replacement patients discharged to home health agencies (HHAs) to 14.4% for hemorrhagic stroke patients discharged to skilled nursing facilities (SNFs). Ninety-day readmission rates ranged from 5.0% for knee replacement patients discharged to HHAs to 26.1% for hemorrhagic stroke patients discharged to SNFs. Differences in readmission rates decreased between stroke subconditions (hemorrhagic and ischemic) and increased between joint replacement subconditions (knee, elective hip, and nonelective hip) from 30 to 90 days across all initial post-acute discharge settings. We observed clear patterns in readmissions over 90-day episodes of care across post-acute discharge settings and subconditions. Our findings suggest that patients with hemorrhagic stroke may be more vulnerable than those with ischemic over the first 30 days after hospital discharge. For patients receiving nonelective joint replacements, readmission prevention efforts should start immediately after discharge and continue, or even increase, over the 90-day episode of care. Copyright © 2018 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

[Implant with a mobile or a fixed bearing in unicompartmental knee joint replacemen].

PubMed

Matziolis, G; Tohtz, S; Gengenbach, B; Perka, C

2007-12-01

Although the goal of anatomical and functional joint reconstruction in unicompartmental knee replacement is well defined, no uniform implant design has become established. In particular, the differential indications for implantation of an implant with a mobile or a fixed bearing are still not clear. The long-term results of mobile and with fixed bearings are comparable, but there are significant differences in resulting knee joint kinematics, tribological properties and implant-associated complications. In unicompartmental knee replacement mobile bearings restore the physiological joint kinematics better than fixed implants, although the differences to total knee arthroplasty seem minor. The decoupling of mobile bearings from the tibia implant allows a high level of congruence with the femoral implant, resulting in larger contact areas than with fixed bearings. This fact in combination with the more physiological joint kinematics leads to less wear and a lower incidence of osteolyses with mobile bearings. Disadvantages of mobile bearings are the higher complication and early revision rates resulting from bearing dislocation and impingement syndromes caused by suboptimal implantation technique or instability. Especially in cases with ligamentous pathology fixed bearings involve a lower complication rate. It seems their use can also be beneficial in patients with a low level of activity, as problems related to wear are of minor importance for this subgroup. The data currently available allow differentiations between various indications for implants with mobile or fixed bearings, so that the implants can be matched to the patient and the joint pathology in unicompartmental knee joint replacement.

[Orthopedic surgical implants and allergies. Joint statement by the Implant Allergy Working Group (AK 20) of the DGOOC (German Association of Orthopedics and Orthopedic Surgery), DKG (German Contact Dermatitis Research Group) and DGAKI (German Society for Allergology and Clinical Immunology)].

PubMed

Thomas, P; Schuh, A; Ring, J; Thomsen, M

2008-03-01

Materials used in osteosynthesis or artificial joint replacement are usually well tolerated. Complaints after such operations are mostly related to infection or mechanical problems but may also be caused by allergic reactions. The latter encompass skin changes, e.g., eczema, delayed wound/bone healing, recurrent effusion, pain, or implant loosening. In contrast to the high incidence of cutaneous metal contact allergy, allergies associated with implants are a rare condition. However, epidemiological data on the incidence of implant-related allergic reactions are still missing. Typical elicitors are nickel, chromium, cobalt, and constituents of bone cement (acrylates und additives such as gentamicin or benzoyl peroxide). After exclusion of the most common differential diagnoses, allergy diagnostic procedures are primarily based on patch tests including a metal and bone cement component series. Additional analysis of periimplant tissue is recommended. However, further studies are necessary to show the significance of the histologic findings and the role of the lymphocyte transformation test (LTT). Which combinations of factors will induce allergic sensitization to implants or trigger periimplant allergic reactions in the case of preexisting cutaneous metal allergy is still unknown. Titanium-based osteosynthesis materials are recommended for metal allergic patients. In elective hip replacements, a ceramic/polyethylene (PE) articulation should be used, and in knee replacements "alternative materials". If a regular, potentially applicable CoCr/PE articulation is preferred, the patient must be well informed and must give his/her written consent.

A new software tool for 3D motion analyses of the musculo-skeletal system.

PubMed

Leardini, A; Belvedere, C; Astolfi, L; Fantozzi, S; Viceconti, M; Taddei, F; Ensini, A; Benedetti, M G; Catani, F

2006-10-01

Many clinical and biomechanical research studies, particularly in orthopaedics, nowadays involve forms of movement analysis. Gait analysis, video-fluoroscopy of joint replacement, pre-operative planning, surgical navigation, and standard radiostereometry would require tools for easy access to three-dimensional graphical representations of rigid segment motion. Relevant data from this variety of sources need to be organised in structured forms. Registration, integration, and synchronisation of segment position data are additional necessities. With this aim, the present work exploits the features of a software tool recently developed within a EU-funded project ('Multimod') in a series of different research studies. Standard and advanced gait analysis on a normal subject, in vivo fluoroscopy-based three-dimensional motion of a replaced knee joint, patellar and ligament tracking on a knee specimen by a surgical navigation system, stem-to-femur migration pattern on a patient operated on total hip replacement, were analysed with standard techniques and all represented by this innovative software tool. Segment pose data were eventually obtained from these different techniques, and were successfully imported and organised in a hierarchical tree within the tool. Skeletal bony segments, prosthesis component models and ligament links were registered successfully to corresponding marker position data for effective three-dimensional animations. These were shown in various combinations, in different views, from different perspectives, according to possible specific research interests. Bioengineering and medical professionals would be much facilitated in the interpretation of the motion analysis measurements necessary in their research fields, and would benefit therefore from this software tool.

A prospective study on the risk of glove fingertip contamination during draping in joint replacement surgery.

PubMed

Makki, D; Deierl, K; Pandit, A; Trakru, S

2014-09-01

The aim of this prospective study was to investigate the risk of contamination of surgical gloves during preparation and draping in joint replacement surgery. During 46 hip and knee replacement procedures, the gloves of orthopaedic consultants (n=5) and registrars (n=3) were assessed for contamination immediately after draping by impression of gloved fingers on blood agar. Contamination was evaluated by the surgeon's grade, the type of procedure, the role of the assistant and the dominance of the hand. A total of 125 pairs of top gloves were examined (79 pairs from registrars and 46 pairs from consultants). Bacterial contamination was isolated on 19 pairs (15.2%) (16 pairs from registrars and 3 pairs from consultants, p=0.04). Coagulase negative staphylococci were the main isolates and contamination was considered low in all cases (1-5 colonies). Contamination was seen more on the dominant hand (16 gloves from dominant hands and 6 from non-dominant hands, p=0.04), on the index finger and thumb. More contaminated gloves were seen in hip arthroplasty procedures (16 pairs from total hip replacements vs 3 pairs from total knee replacements, p=0.02). Contamination of glove fingertips during draping in joint replacement procedures is more likely to occur among junior surgeons, in hip rather than knee arthroplasty procedures and on the dominant hand. It is therefore essential that surgeons of different grades replace gloves used in draping to avoid exposing patients to the risk of infection.

Distraction to treat knee osteoarthritis.

PubMed

Flouzat-Lachaniette, Charles-Henri; Roubineau, François; Heyberger, Clémence; Bouthors, Charlie

2017-03-01

The objective of this article is to review data on joint distraction used to treat knee osteoarthritis. Joint distraction is a surgical procedure in which the two bony ends of the joint are gradually pulled apart then kept separated for 2 months in an external fixation frame. Weight bearing is continued to ensure variations in hydrostatic pressure within the joint. In published studies, joint distraction provided substantial clinical and structural improvements in patients with knee osteoarthritis, delaying joint replacement surgery for at least 2 years. Animal studies showed that joint distraction was associated with decrease in the secondary inflammatory response, cartilage breakdown, and subchondral bone remodeling. In vitro, the intermittent application of hydrostatic pressure stimulated the production of extracellular matrix, particularly in joints with osteoarthritis. Nevertheless, several considerations invite caution when considering the more widespread use of joint distraction. Published studies have short follow-ups and small sample sizes. In addition, the high frequency of pin tract infection is of concern, since most patients eventually require knee replacement surgery. These two considerations indicate a need for longer-term prospective studies of patient cohorts. Copyright © 2016 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.

[Juvenile rheumatoid diseases: Endoprosthetic care of destroyed hip joints].

PubMed

Rehart, S; Henniger, M

2015-07-01

Patients with juvenile idiopathic arthritis (JIA) often suffer from involvement of the hip joints, with joint destruction and related functional limitations, making hip replacement necessary. To discover what special features are to be expected in patients with JIA and hip arthroplasty and what impact they have on surgical indication, choice of implant, and technique. Selective literature review and evaluation of our patient population. Compared with osteoarthritis patients, JIA patients are on average much younger at the time of hip replacement. Owing to the onset of the disease in childhood or adolescence and the frequent glucocorticoid therapy, growth disorders or abnormal anatomical findings are common in these patients. Bone density is often reduced at an early age. The perioperative management of medication has to be planned. Special implants for patients with rheumatic diseases do not exist, but the above peculiarities of this group of patients should be considered for surgical procedure and choice of implant and material. Overall, the results of hip arthroplasty in juvenile rheumatic diseases, in terms of pain relief and functional improvement, are good. The limited life of the arthroplasty is problematic. By relieving pain, improvement of the range of motion and activity level very high patient satisfaction is usually achieved by hip arthroplasty in JIA patients. In the case of involvement of the contralateral hip or the ipsilateral knee joint it may be useful to perform a simultaneous, single-stage joint replacement of both joints.

The tribology of metal-on-metal total hip replacements.

PubMed

Scholes, S C; Unsworth, A

2006-02-01

Total hip surgery is an effective way of alleviating the pain and discomfort caused by diseased or damaged joints. However, in the majority of cases, these joints have a finite life. The main reason for failure is osteolysis (bone resorption). It is well documented that an important cause of osteolysis, and therefore the subsequent loosening and failure of conventional metal- or ceramic-on-ultra-high molecular weight polyethylene joints, is the body's immunological response to the polyethylene wear particles. To avoid this, interest has been renewed in metal-on-metal joints. The intention of this paper is to review the studies that have taken place within different laboratories to determine the tribological performance of new-generation metal-on-metal total hip replacements. These types of joint offer a potential solution to enhance the longevity of prosthetic hip systems; however, problems may arise owing to the effects of metal ion release, which are, as yet, not fully understood.

Mandatory bundled payment getting into formation for value-based care.

PubMed

Fink, John

2015-10-01

Succeeding under Medicare's enterprise Comprehensive Care for Joint Replacement Model will require collaboration among caregivers and financial arrangements to align incentives Priorities for most organization's transition to becoming a value-based hospitals will be care redesign, supply-purchasing strategy, and post-acute care provider partnering. Pursuing value for your joint replacement program will chart a path for other service lines and lead your organization's transition to becoming a value-based enterprise.

On the stiffness matrix of the intervertebral joint: application to total disk replacement.

PubMed

O'Reilly, Oliver M; Metzger, Melodie F; Buckley, Jenni M; Moody, David A; Lotz, Jeffrey C

2009-08-01

The traditional method of establishing the stiffness matrix associated with an intervertebral joint is valid only for infinitesimal rotations, whereas the rotations featured in spinal motion are often finite. In the present paper, a new formulation of this stiffness matrix is presented, which is valid for finite rotations. This formulation uses Euler angles to parametrize the rotation, an associated basis, which is known as the dual Euler basis, to describe the moments, and it enables a characterization of the nonconservative nature of the joint caused by energy loss in the poroviscoelastic disk and ligamentous support structure. As an application of the formulation, the stiffness matrix of a motion segment is experimentally determined for the case of an intact intervertebral disk and compared with the matrices associated with the same segment after the insertion of a total disk replacement system. In this manner, the matrix is used to quantify the changes in the intervertebral kinetics associated with total disk replacements. As a result, this paper presents the first such characterization of the kinetics of a total disk replacement.

Risk factors for renal dysfunction after total knee joint replacement.

PubMed

Hassan, Basim K; Sahlström, Arne; Dessau, Ram B

2015-12-01

Renal injury and dysfunction are serious complications after major surgery, which may lead to increased morbidity and mortality. The objective of our study was to identify the possible risk factors for renal dysfunction after total knee joint replacement. A retrospective study was conducted among 702 consecutive primary knee joint replacements performed between January 2009 and December 2012 in our department. Increased postoperative serum creatinine was considered indicative of postoperative renal injury according to RIFLE criteria. Sixty three patients (9.7%) had significant moderate or severe postoperative renal dysfunction in which 8 patients (1.2%) ended with severe and permanent renal impairment. Advanced age, low intraoperative blood pressure, hypertension, general anaesthesia, and prophylactic dicloxacillin were identified as significant risk factors. Male gender and BMI were independent risk factors for postoperative increase in serum creatinine. Smoking, female gender, diabetes mellitus and duration of surgery were not identified as significant risk factors.

Ethnicity and patient's perception of risk in joint replacement surgery.

PubMed

Gandhi, Rajiv; Razak, Fahad; Davey, J Roderick; Mahomed, Nizar N

2008-08-01

Despite much evidence showing racial disparities in the use of surgical procedures, it is unknown whether ethnicity affects perception of surgical risk. We surveyed 1609 patients undergoing primary hip or knee replacement surgery. Relevant covariates including demographic data, body mass index (BMI), sex, comorbidities, education, and ethnicity were recorded. Pain and joint functional status were assessed at baseline and at 1-year followup with the Western Ontario McMaster University Osteoarthritis Index (WOMAC) pain and function scores. Risk perception was assessed with 3 survey questions. Non-European patients had greater functional disability and pain prior to surgery and demonstrated significantly greater perception of risk than European patients (p < 0.001). Independent of other covariates, non-European ethnicity was an independent predictor of a greater perception of risk (p < 0.05). Patient ethnicity is an important factor to consider in understanding a patient's perception of risk in joint replacement surgery.

Analysis of fluid film lubrication in artificial hip joint replacements with surfaces of high elastic modulus.

PubMed

Jin, Z M; Dowson, D; Fisher, J

1997-01-01

Lubrication mechanisms and contact mechanics have been analysed for total hip joint replacements made from hard bearing surfaces such as metal-on-metal and ceramic-on-ceramic. A similar analysis for ultra-high molecular weight polyethylene (UHMWPE) against a hard bearing surface has also been carried out and used as a reference. The most important factor influencing the predicted lubrication film thickness has been found to be the radial clearance between the ball and the socket. Full fluid film lubrication may be achieved in these hard/hard bearings provided that the surface finish of the bearing surface and the radial clearance are chosen correctly and maintained. Furthermore, there is a close relation between the predicted contact half width and the predicted lubrication film thickness. Therefore, it is important to analyse the contact mechanics in artificial hip joint replacements. Practical considerations of manufacturing these bearing surfaces have also been discussed.

Implications of the Definition of an Episode of Care Used in the Comprehensive Care for Joint Replacement Model.

PubMed

Ellimoottil, Chad; Ryan, Andrew M; Hou, Hechuan; Dupree, James M; Hallstrom, Brian; Miller, David C

2017-01-01

Under the Comprehensive Care for Joint Replacement (CJR) model, hospitals are held accountable for nearly all Medicare payments that occur during the initial hospitalization until 90 days after hospital discharge (ie, the episode of care). It is not known whether unrelated expenditures resulting from this "broad" definition of an episode of care will affect participating hospitals' average episode-of-care payments. To compare the CJR program's broad definition of an episode of care with a clinically narrow definition of an episode of care. We identified Medicare claims for 23 251 patients in Michigan who were Medicare beneficiaries and who underwent joint replacement during the period from 2011 through 2013 at hospitals located in metropolitan statistical areas. Using specifications from the CJR model and the clinically narrow Hospital Compare payment measure, we constructed episodes of care and calculated 90-day episode payments. We then compared hospitals' average 90-day episode payments using the 2 definitions of an episode of care and fit linear regression models to understand whether payment differences were associated with specific hospital characteristics (average Centers for Medicare & Medicaid Services-hierarchical condition categories risk score, rural hospital status, joint replacement volume, percentage of Medicaid discharges, teaching hospital status, number of beds, percentage of joint replacements performed on African American patients, and median income of the hospital's county). We performed analyses from July 1 through October 1, 2015. The correlation and difference between average 90-day episode payments using the broad definition of an episode of care in the CJR model and the clinically narrow Hospital Compare definition of an episode of care. We identified 23 251 joint replacements (ie, episodes of care). The 90-day episode payments using the broad definition of the CJR model ranged from $17 349 to $29 465 (mean [SD] payment, $22 122 [$2600]). Episode payments were slightly lower (mean payment, $21 670) when the Hospital Compare definition was used. Both methods were strongly correlated (r = 0.99, P < .001). The average payment difference between these 2 types of episodes of care was small (mean [SD], $452 [$177]; range, $73-$1006). In our multivariable analysis, we found that the hospital characteristics examined had a minimal impact or no impact on the payment differential. The average 90-day episode payments determined by both definitions of an episode of care were strongly correlated, and there was a small payment differential for most hospitals. In the context of joint replacement bundled payments, these data suggest that hospital performance will be consistent whether a broad or clinically narrow definition of an episode of care is used.

A Computational Modeling Approach for Investigating Soft Tissue Balancing in Bicruciate Retaining Knee Arthroplasty

PubMed Central

Amiri, Shahram; Wilson, David R.

2012-01-01

Bicruciate retaining knee arthroplasty, although has shown improved functions and patient satisfaction compared to other designs of total knee replacement, remains a technically demanding option for treating severe cases of arthritic knees. One of the main challenges in bicruciate retaining arthroplasty is proper balancing of the soft tissue during the surgery. In this study biomechanics of soft tissue balancing was investigated using a validated computational model of the knee joint with high fidelity definitions of the soft tissue structures along with a Taguchi method for design of experiments. The model was used to simulate intraoperative balancing of soft tissue structures following the combinations suggested by an orthogonal array design. The results were used to quantify the corresponding effects on the laxity of the joint under anterior-posterior, internal-external, and varus-valgus loads. These effects were ranked for each ligament bundle to identify the components of laxity which were most sensitive to the corresponding surgical modifications. The resulting map of sensitivity for all the ligament bundles determined the components of laxity most suitable for examination during intraoperative balancing of the soft tissue. Ultimately, a sequence for intraoperative soft tissue balancing was suggested for a bicruciate retaining knee arthroplasty. PMID:23082090

Fracture toughness in Mode I (GIC) for ductile adhesives

NASA Astrophysics Data System (ADS)

Gálvez, P.; Carbas, RJC; Campilho, RDSG; Abenojar, J.; Martínez, MA; Silva LFM, da

2017-05-01

Works carried out in this publication belong to a project that seeks the replacement of welded joints by adhesive joints at stress concentration nodes in bus structures. Fracture toughness in Mode I (GIC) has been measured for two different ductile adhesives, SikaTack Drive and SikaForce 7720. SikaTack Drive is a single-component polyurethane adhesive with high viscoelasticity (more than 100%), whose main use is the car-glass joining and SikaForce 7720 is double-component structural polyurethane adhesive. Experimental works have been carried out from the test called Double Cantilever Beam (DCB), using two steel beams as adherents and an adhesive thickness according to the problem posed in the Project, of 2 and 3 mm for SikaForce 7720 and SikaTack Drive, respectively. Three different methods have been used for measuring the fracture toughness in mode I (GIC) from the values obtained in the experimental DCB procedure for each adhesive: Corrected Beam Theory (CBT), Compliance Calibration Method (CCM) and Compliance Based Beam Method (CBBM). Four DCB specimens have been tested for each adhesive. Dispersion of each GIC calculation method for each adhesive has been studied. Likewise variations between the three different methods have been also studied for each adhesive.

[Rehabilitation of the patients following the endoprosthetic replacement of the joints of the lower extremities].

PubMed

Rud, I M; Melnikova, E A; Rassulova, M A; Razumov, A N; Gorelikov, A E

2017-12-28

The present article is the analytical review of the literature pertaining to the problem of rehabilitation of the patients following the endoprosthetic replacement of joints of the lower extremities. The relevance of the problem of interest for medical rehabilitation is beyond any doubt. The traditional methods for the rehabilitation of the patients do not always lead to the desired results. The authors discuss in detail the need for and the contemporary approaches to the rehabilitation of the patients who had undergone reconstructive surgery and arthroplasty of the joints of the lower extremities. The pathogenetically-based three-stage algorithm for medical rehabilitation is proposed.

Influence factors of multicomponent mixtures containing reactive chemicals and their joint effects.

PubMed

Tian, Dayong; Lin, Zhifen; Yu, Jianqiao; Yin, Daqiang

2012-08-01

Organic chemicals usually coexist as a mixture in the environment, and the mixture toxicity of organic chemicals has received increased attention. However, research regarding the joint effects of reactive chemicals is lacking. In this study, we examined two kinds of reactive chemicals, cyanogenic toxicants and aldehydes and determined their joint effects on Photobacterium phosphoreum. Three factors were found to influence the joint effects of multicomponent mixtures containing reactive chemicals, including the number of components, the dominating components and the toxic ratios. With an increased number of components, the synergistic or antagonistic effects (interactions) will weaken to the additive effects (non-interactions) if the added component cannot yield a much stronger joint effect with an existing component. Contrarily, the joint effect of the mixture may become stronger instead of weaker if the added components can yield a much stronger joint effect than the existing joint effect of the multicomponent mixture. The components that yield the strongest interactions in their binary mixture can be considered the dominating components. These components contribute more to the interactions of multicomponent mixtures than other components. Moreover, the toxic ratios also influence the joint effects of the mixtures. This study provides an insight into what are the main factors and how they influence the joint effects of multicomponent mixtures containing reactive chemicals, and thus, the findings are beneficial to the study of mixture toxicology. Copyright © 2012 Elsevier Ltd. All rights reserved.

Peak Stress Intensity Factor Governs Crack Propagation Velocity In Crosslinked UHMWPE

PubMed Central

Sirimamilla, P. Abhiram; Furmanski, Jevan; Rimnac, Clare

2013-01-01

Ultra high molecular weight polyethylene (UHMWPE) has been successfully used as a bearing material in total joint replacement components. However, these bearing materials can fail as a result of in vivo static and cyclic loads. Crack propagation behavior in this material has been considered using the Paris relationship which relates fatigue crack growth rate, da/dN (mm/cycle) versus the stress intensity factor range, ΔK (Kmax-Kmin, MPa√m). However, recent work suggests that the crack propagation velocity of conventional UHMWPE is driven by the peak stress intensity (Kmax), not ΔK. The hypothesis of this study is that the crack propagation velocity of highly crosslinked and remelted UHMWPE is also driven by the peak stress intensity, Kmax, during cyclic loading, rather than by ΔK. To test this hypothesis, two highly crosslinked (65 kGy and 100 kGy) and remelted UHMWPE materials were examined. Frequency, waveform and R-ratio were varied between test conditions to determine the governing factor for fatigue crack propagation. It was found that the crack propagation velocity in crosslinked UHMWPE is also driven by Kmax and not ΔK, and is dependent on loading waveform and frequency in a predictable quasi-static manner. The current study supports that crack growth in crosslinked UHMWPE materials, even under cyclic loading conditions, can be described by a relationship between the velocity of crack growth, da/dt and the peak stress intensity, Kmax. The findings suggest that stable crack propagation can occur as a result of static loading only and this should be taken into consideration in design of UHMWPE total joint replacement components. PMID:23165898

Influence of gamma-irradiation sterilization and temperature on the fracture toughness of ultra-high-molecular-weight polyethylene.

PubMed

Pascaud, R S; Evans, W T; McCullagh, P J; FitzPatrick, D P

1997-05-01

Surface damage of the tibial plateau components of knee prostheses made from medical grade ultra-high-molecular-weight polyethylene (UHMW-PE) has been attributed to delamination wear caused by a fatigue fracture mechanism. It has been proposed that factors such as component design and method of sterilization contribute to such failure mechanisms. Understanding the fracture behaviour of UHMW-PE is therefore critical in optimizing the in vivo life-span of total joint components. The elastic-plastic fracture toughness parameter J was consequently determined for a commercial UHMW-PE at ambient and body temperatures, before and after gamma-irradiation sterilization in air at a minimum dose of 29 kGy. Both ductile stability theory and experimental data suggest that cracks propagate in a stable manner, although stability is affected by the sterilization process. Sterilization with gamma-irradiation results in a loss in fracture toughness JIc of 50% and a decrease in tearing modulus (Tm) of 30%. This dramatic reduction could result in a 50% decrease in the residual strength of the components, maximum permissible crack size under service loading and service life (assuming flaws such as fusion defects exist). The time required for a crack to grow from its original size to the maximum permissible size could be decreased by 30%, resulting in earlier failure. In terms of the design of joint replacement components the critical factor to envisage is the design stress level, which should be halved to account for the irradiation process. A scanning electron microscope study reveals that the material fails in layers parallel to the fracture surface.

Taking care of your new knee joint

MedlinePlus

Knee arthroplasty - precautions; Knee replacement - precautions ... After you have knee replacement surgery , you will need to be careful about how you move your knee, especially for the first few ...

Shoulder replacement

MedlinePlus

... the opening at the end of the shoulder blade, called the socket. This type of joint allows ... head. The socket part (glenoid) of your shoulder blade will be replaced with a smooth plastic shell ( ...

Patient Use of Cost and Quality Data When Choosing a Joint Replacement Provider in the Context of Reference Pricing

PubMed Central

Mehrotra, Ateev; DeVries, Andrea; Wu, Sze-jung; SooHoo, Nelson F.; Martsolf, Grant R.

2015-01-01

Health plans are encouraging consumerism among joint replacement patients by reporting information on hospital costs and quality. Little is known about how the proliferation of such initiatives impacts patients’ selection of a surgeon and hospital. We performed a qualitative analysis of semistructured interviews with 13 patients who recently received a hip or knee replacement surgery. Patients focused on the choice of a surgeon as opposed to a hospital, and the surgeon choice was primarily made based on reputation. Most patients had long-standing relationships with an orthopedic surgeon and tended to stay with that surgeon for their replacement. Despite growing availability of cost and quality information, patients almost never used such information to make a decision. PMID:28462261

Quantifying opportunities for hospital cost control: medical device purchasing and patient discharge planning.

PubMed

Robinson, James C; Brown, Timothy T

2014-09-01

To quantify the potential reduction in hospital costs from adoption of best local practices in supply chain management and discharge planning. We performed multivariate statistical analyses of the association between total variable cost per procedure and medical device price and length of stay, controlling for patient and hospital characteristics. Ten hospitals in 1 major metropolitan area supplied patient-level administrative data on 9778 patients undergoing joint replacement, spine fusion, or cardiac rhythm management (CRM) procedures in 2008 and 2010. The impact on each hospital of matching lowest local market device prices and lowest patient length of stay (LOS) was calculated using multivariate regression analysis controlling for patient demographics, diagnoses, comorbidities, and implications. Average variable costs ranged from $11,315 for joint replacement to $16,087 for CRM and $18,413 for spine fusion. Implantable medical devices accounted for a large share of each procedure's variable costs: 44% for joint replacement, 39% for spine fusion, and 59% for CRM. Device prices and patient length-of-stay exhibited wide variation across hospitals. Total potential hospital cost savings from achieving best local practices in device prices and patient length of stay are 14.5% for joint replacement, 18.8% for spine fusion;,and 29.1% for CRM. Hospitals have opportunities for cost reduction from adoption of best local practices in supply chain management and discharge planning.

Endoscopic or arthroscopic iliopsoas tenotomy for iliopsoas impingement following total hip replacement. A prospective multicenter 64-case series.

PubMed

Guicherd, W; Bonin, N; Gicquel, T; Gedouin, J E; Flecher, X; Wettstein, M; Thaunat, M; Prevost, N; Ollier, E; May, O

2017-12-01

Impingement between the acetabular component and the iliopsoas tendon is a cause of anterior pain after total hip replacement (THR). Treatment can be non-operative, endoscopic or arthroscopic, or by open revision of the acetabular component. Few studies have assessed these options. The present study hypothesis was that endo/arthroscopic treatment provides rapid pain relief with a low rate of complications. A prospective multicenter study included 64 endoscopic or arthroscopic tenotomies for impingement between the acetabular component and the iliopsoas tendon, performed in 8 centers. Mean follow-up was 8months, with a minimum of 6months and no loss to follow-up. Oxford score, patient satisfaction, anterior pain and iliopsoas strength were assessed at last follow-up. Complications and revision procedures were collated. Forty-four percent of patients underwent rehabilitation. At last follow-up, 92% of patients reported pain alleviation. Oxford score, muscle strength and pain in hip flexion showed significant improvement. The complications rate was 3.2%, with complete resolution. Mean hospital stay was 0.8 nights. In 2 cases, arthroscopy revealed metallosis, indicating revision of the acetabular component. The only predictive factor was acetabular projection on oblique view. Rehabilitation significantly improved muscle strength. Endoscopic or arthroscopic tenotomy for impingement between the acetabular component and the iliopsoas tendon following THR significantly alleviated anterior pain in more than 92% of cases. The low complications rate makes this the treatment of choice in case of failure of non-operative management. Arthroscopy also reorients diagnosis in case of associated joint pathology. Projection of the acetabular component on preoperative oblique view is the most predictive criterion, guiding treatment. Copyright © 2017. Published by Elsevier Masson SAS.

Joint Optimization of Vertical Component Gravity and Seismic P-wave First Arrivals by Simulated Annealing

NASA Astrophysics Data System (ADS)

Louie, J. N.; Basler-Reeder, K.; Kent, G. M.; Pullammanappallil, S. K.

2015-12-01

Simultaneous joint seismic-gravity optimization improves P-wave velocity models in areas with sharp lateral velocity contrasts. Optimization is achieved using simulated annealing, a metaheuristic global optimization algorithm that does not require an accurate initial model. Balancing the seismic-gravity objective function is accomplished by a novel approach based on analysis of Pareto charts. Gravity modeling uses a newly developed convolution algorithm, while seismic modeling utilizes the highly efficient Vidale eikonal equation traveltime generation technique. Synthetic tests show that joint optimization improves velocity model accuracy and provides velocity control below the deepest headwave raypath. Detailed first arrival picking followed by trial velocity modeling remediates inconsistent data. We use a set of highly refined first arrival picks to compare results of a convergent joint seismic-gravity optimization to the Plotrefa™ and SeisOpt® Pro™ velocity modeling packages. Plotrefa™ uses a nonlinear least squares approach that is initial model dependent and produces shallow velocity artifacts. SeisOpt® Pro™ utilizes the simulated annealing algorithm and is limited to depths above the deepest raypath. Joint optimization increases the depth of constrained velocities, improving reflector coherency at depth. Kirchoff prestack depth migrations reveal that joint optimization ameliorates shallow velocity artifacts caused by limitations in refraction ray coverage. Seismic and gravity data from the San Emidio Geothermal field of the northwest Basin and Range province demonstrate that joint optimization changes interpretation outcomes. The prior shallow-valley interpretation gives way to a deep valley model, while shallow antiformal reflectors that could have been interpreted as antiformal folds are flattened. Furthermore, joint optimization provides a clearer image of the rangefront fault. This technique can readily be applied to existing datasets and could replace the existing strategy of forward modeling to match gravity data.

Surgery and survival in birth cohorts with severe haemophilia and differences in access to replacement therapy: The Malmö experience.

PubMed

Osooli, M; Steen Carlsson, K; Astermark, J; Berntorp, E

2017-09-01

Persons with severe haemophilia require lifelong replacement therapy, prophylaxis, to prevent bleeding. Data describing long-term outcomes of prophylactic treatment are scarce. The aim of this study was to investigate joint surgery and survival among persons with severe haemophilia with special attention to access to prophylaxis in the early years of life. Eligible participants had severe haemophilia A or B and were treated at the Malmö centre from the 1960s onward. Time from birth until joint surgery was analysed for participants negative for factor inhibitor and alive in 2000. We compared survival among the entire cohort with severe haemophilia treated at the Malmö centre with the general male population of Sweden and a sample of persons with severe haemophilia from the United Kingdom (UK). Overall, 167 participants were included, 106 (63.5%) of whom had complete data on joint surgery. Among those born before 1970, 1970-1979 and ≥1980 approximately 37%, 21% and 0% had their first joint surgery by age 30, respectively. There were no second joint surgeries reported in cohorts born ≥1970. Persons with severe haemophilia and negative for HIV treated in Malmö have attained approximately similar survival to that of the general male population in Sweden and live slightly longer than persons with severe haemophilia from the UK. Prophylaxis in Sweden, although costly, has markedly improved survival and joint outcomes for persons with severe haemophilia. This study highlights the importance of early start of replacement therapy to prevent or postpone serious joint damage. © 2017 John Wiley & Sons Ltd.

Measurement Uncertainty Relations for Discrete Observables: Relative Entropy Formulation

NASA Astrophysics Data System (ADS)

Barchielli, Alberto; Gregoratti, Matteo; Toigo, Alessandro

2018-02-01

We introduce a new information-theoretic formulation of quantum measurement uncertainty relations, based on the notion of relative entropy between measurement probabilities. In the case of a finite-dimensional system and for any approximate joint measurement of two target discrete observables, we define the entropic divergence as the maximal total loss of information occurring in the approximation at hand. For fixed target observables, we study the joint measurements minimizing the entropic divergence, and we prove the general properties of its minimum value. Such a minimum is our uncertainty lower bound: the total information lost by replacing the target observables with their optimal approximations, evaluated at the worst possible state. The bound turns out to be also an entropic incompatibility degree, that is, a good information-theoretic measure of incompatibility: indeed, it vanishes if and only if the target observables are compatible, it is state-independent, and it enjoys all the invariance properties which are desirable for such a measure. In this context, we point out the difference between general approximate joint measurements and sequential approximate joint measurements; to do this, we introduce a separate index for the tradeoff between the error of the first measurement and the disturbance of the second one. By exploiting the symmetry properties of the target observables, exact values, lower bounds and optimal approximations are evaluated in two different concrete examples: (1) a couple of spin-1/2 components (not necessarily orthogonal); (2) two Fourier conjugate mutually unbiased bases in prime power dimension. Finally, the entropic incompatibility degree straightforwardly generalizes to the case of many observables, still maintaining all its relevant properties; we explicitly compute it for three orthogonal spin-1/2 components.

A prospective study on the risk of glove fingertip contamination during draping in joint replacement surgery

PubMed Central

Deierl, K; Pandit, A; Trakru, S

2014-01-01

Introduction The aim of this prospective study was to investigate the risk of contamination of surgical gloves during preparation and draping in joint replacement surgery. Methods During 46 hip and knee replacement procedures, the gloves of orthopaedic consultants (n=5) and registrars (n=3) were assessed for contamination immediately after draping by impression of gloved fingers on blood agar. Contamination was evaluated by the surgeon’s grade, the type of procedure, the role of the assistant and the dominance of the hand. Results A total of 125 pairs of top gloves were examined (79 pairs from registrars and 46 pairs from consultants). Bacterial contamination was isolated on 19 pairs (15.2%) (16 pairs from registrars and 3 pairs from consultants, p=0.04). Coagulase negative staphylococci were the main isolates and contamination was considered low in all cases (1–5 colonies). Contamination was seen more on the dominant hand (16 gloves from dominant hands and 6 from non-dominant hands, p=0.04), on the index finger and thumb. More contaminated gloves were seen in hip arthroplasty procedures (16 pairs from total hip replacements vs 3 pairs from total knee replacements, p=0.02). Conclusions Contamination of glove fingertips during draping in joint replacement procedures is more likely to occur among junior surgeons, in hip rather than knee arthroplasty procedures and on the dominant hand. It is therefore essential that surgeons of different grades replace gloves used in draping to avoid exposing patients to the risk of infection. PMID:25198974

Analysis on Sealing Reliability of Bolted Joint Ball Head Component of Satellite Propulsion System

NASA Astrophysics Data System (ADS)

Guo, Tao; Fan, Yougao; Gao, Feng; Gu, Shixin; Wang, Wei

2018-01-01

Propulsion system is one of the important subsystems of satellite, and its performance directly affects the service life, attitude control and reliability of the satellite. The Paper analyzes the sealing principle of bolted joint ball head component of satellite propulsion system and discuss from the compatibility of hydrazine anhydrous and bolted joint ball head component, influence of ground environment on the sealing performance of bolted joint ball heads, and material failure caused by environment, showing that the sealing reliability of bolted joint ball head component is good and the influence of above three aspects on sealing of bolted joint ball head component can be ignored.

Social support and actual versus expected length of stay in inpatient rehabilitation facilities

PubMed Central

Lewis, Zakkoyya H.; Hay, Catherine Cooper; Graham, James E.; Lin, Yu-Li; Karmarkar, Amol M.; Ottenbacher, Kenneth J.

2016-01-01

Objectives Describe impairment-specific patterns in shorter- and longer-than-expected lengths of stay in inpatient rehabilitation and examine the independent effects of social support on deviations from expected lengths of stay. Design Retrospective cohort study. Setting Inpatient rehabilitation facilities across the United States. Participants Medicare fee-for-service beneficiaries (N=119,437) who were discharged from inpatient rehabilitation facilities in 2012 following stroke, lower extremity fracture, or lower extremity joint replacement. Intervention Not applicable. Main Outcome Measure Relative length of stay (actual – expected). The Centers for Medicare and Medicaid Services posts annual expected lengths of stay based on patients’ clinical profiles at admission. We created a 3-category outcome variable: short, expected, long. Our primary independent variable (social support) also included 3 categories: family/friends, paid/other, none. Results Mean (SD) actual lengths of stay for joint replacement, fracture, and stroke were 9.8 (3.6), 13.8 (4.5), and 15.8 (7.3) days, respectively; relative lengths of stay were −1.2 (3.1), −1.6 (3.7), and −1.7 (5.2) days. Nearly half of patients (47–48%) were discharged more than 1 day earlier than expected in all 3 groups, whereas 14% of joint replacement, 15% of fracture, and 20% of stroke patients were discharged more than 1 day later than expected. In multinomial regression analysis, using family/friends as the reference group, paid/other support was associated (p<.05) with higher odds of long stays in joint replacement. No social support was associated with lower odds of short stays in all 3 impairment groups and higher odds of long stays in fracture and joint replacement. Conclusion Inpatient rehabilitation experiences and outcomes can be substantially impacted by a patient’s level of social support. More research is needed to better understand these relationships and possible unintended consequences in terms of patient access issues and provider-level quality measures. PMID:27373747

Strength Variation of Parachute Joints

NASA Technical Reports Server (NTRS)

Mollmann, Catherine

2017-01-01

A parachute joint is defined as a location where a component is sewn or connected to another component. During the design and developmental phase of a parachute system, the joints for each structural component are isolated and tested through a process called seam and joint testing. The objective of seam and joint testing is to determine the degradation on a single component due to interaction with other components; this data is then used when calculating the margin of safety for that component. During the engineering developmental phase of CPAS (Capsule Parachute Assembly System), the parachute system for the NASA Orion Crew Module, testing was completed for every joint of the six subsystems: the four parachutes (main, drogue, pilot, and FBCP [forward bay cover parachute]), the retention release bridle, and the retention panels. The number of joint tests for these subsystems totaled 92, which provides a plethora of data and results for further analysis. In this paper, the data and results of these seam and joint tests are examined to determine the effects, if any, of different operators and sewing machines on the strength of parachute joints. Other variables are also studied to determine their effect on joint strength, such as joint complexity, joint strength magnitude, material type, and material construction. Findings reveal that an optimally-run seam and joint test program could result in an increased understanding of the structure of the parachute; this should lead to a parachute built with optimal components, potentially saving system weight and volume.

21 CFR 888.5 - Resurfacing technique.

Code of Federal Regulations, 2014 CFR

2014-04-01

... techniques, certain joint prostheses require far less bone resection than other devices intended to repair or replace the same joint. The amount of bone resection may or may not affect the safety and effectiveness of...

21 CFR 888.5 - Resurfacing technique.

Code of Federal Regulations, 2011 CFR

2011-04-01

... techniques, certain joint prostheses require far less bone resection than other devices intended to repair or replace the same joint. The amount of bone resection may or may not affect the safety and effectiveness of...

21 CFR 888.5 - Resurfacing technique.

Code of Federal Regulations, 2013 CFR

2013-04-01

... techniques, certain joint prostheses require far less bone resection than other devices intended to repair or replace the same joint. The amount of bone resection may or may not affect the safety and effectiveness of...

21 CFR 888.5 - Resurfacing technique.

Code of Federal Regulations, 2010 CFR

2010-04-01

... techniques, certain joint prostheses require far less bone resection than other devices intended to repair or replace the same joint. The amount of bone resection may or may not affect the safety and effectiveness of...

21 CFR 888.5 - Resurfacing technique.

Code of Federal Regulations, 2012 CFR

2012-04-01

... techniques, certain joint prostheses require far less bone resection than other devices intended to repair or replace the same joint. The amount of bone resection may or may not affect the safety and effectiveness of...

How weak values emerge in joint measurements on cloned quantum systems.

PubMed

Hofmann, Holger F

2012-07-13

A statistical analysis of optimal universal cloning shows that it is possible to identify an ideal (but nonpositive) copying process that faithfully maps all properties of the original Hilbert space onto two separate quantum systems, resulting in perfect correlations for all observables. The joint probabilities for noncommuting measurements on separate clones then correspond to the real parts of the complex joint probabilities observed in weak measurements on a single system, where the measurements on the two clones replace the corresponding sequence of weak measurement and postselection. The imaginary parts of weak measurement statics can be obtained by replacing the cloning process with a partial swap operation. A controlled-swap operation combines both processes, making the complete weak measurement statistics accessible as a well-defined contribution to the joint probabilities of fully resolved projective measurements on the two output systems.

Release of zirconia nanoparticles at the metal stem-bone cement interface in implant loosening of total hip replacements.

PubMed

Schunck, Antje; Kronz, Andreas; Fischer, Cornelius; Buchhorn, Gottfried Hans

2016-02-01

In a previous failure analysis performed on femoral components of cemented total hip replacements, we determined high volumes of abraded bone cement. Here, we describe the topography of the polished surface of polymethyl methacrylate (PMMA) bone cement containing zirconia radiopacifier, analyzed by scanning electron microscopy and vertical scanning interferometry. Zirconia spikes protruded about 300nm from the PMMA matrix, with pits of former crystal deposition measuring about 400nm in depth. We deduced that the characteristically mulberry-shaped agglomerates of zirconia crystals are ground and truncated into flat surfaces and finally torn out of the PMMA matrix. Additionally, evaluation of in vitro PMMA-on-PMMA articulation confirmed that crystal agglomerations of zirconia were exposed to grain pullout, fatigue, and abrasion. In great quantities, micron-sized PMMA wear and zirconia nanoparticles accumulate in the cement-bone interface and capsular tissues, thereby contributing to osteolysis. Dissemination of nanoparticles to distant lymph nodes and organs of storage has been reported. As sufficient information is lacking, foreign body reactions to accumulated nanosized zirconia in places of long-term storage should be investigated. The production of wear particles of PMMA bone cement in the interface to joint replacement devices, presents a local challenge. The presence of zirconia particles results in frustrated digestion attempts by macrophages, liberation of inflammatory mediators, and necrosis leading to aseptic inflammation and osteolyses. Attempts to minimize wear of articulating joints reduced the attention to the deterioration of cement cuffs. We therefore investigated polished surfaces of retrieved cuffs to demonstrate their morphology and to measure surface roughness. Industrially admixed agglomerates of the radiopacifier are abraded to micron and nano-meter sized particles. The dissemination of zirconia particles in the reticulo-endothelial system to storage organs is a possible burden. Research to replace the actual contrast media by non-particulate material deserves more attention. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Older Person's Guide to Joint Replacement

MedlinePlus

... he or she will refer you to an orthopedic surgeon who does hip and knee replacement surgery. ... The Arthritis Foundation Web The American Academy of Orthopedic Surgeons ' The American Association of Knee and Hip ...

Deciding to have knee or hip replacement

MedlinePlus

... joint replacement surgery References Harkess JW, Crockarell JR. Arthroplasty of the hip. In: Azar FM, Beaty JH, ... Philadelphia, PA: Elsevier; 2017:chap 3. Mihalko WM. Arthroplasty of the knee. In: Azar FM, Beaty JH, ...

Hip Replacement: MedlinePlus Health Topic

MedlinePlus

... damage. The most common cause of damage is osteoarthritis . Osteoarthritis causes pain, swelling, and reduced motion in your ... Food and Drug Administration) Genetics Genetics Home Reference: osteoarthritis (National Library of Medicine) Images Hip joint replacement - ...

Aircrew Sizing Survey 2011

DTIC Science & Technology

2014-10-01

Resource JSF Joint Strike Fighter JPATS Joint Primary Aircraft Training System USMC United States Marine Corps USAF United States Air Force LIST...Surface Anthropometry Resource (CAESAR) was developed for the Joint Strike Fighter (JSF) program. The ACSS was intended to replace the JSF-CAESAR...an aircrew sample was made in 2003 by Hudson et al. They extracted a subset, named JSF CAESAR (Joint Strike Fighter), from the Civilian American and

Evaluation of total alloplastic temporo-mandibular joint replacement with two different types of prostheses: A three-year prospective study.

PubMed

Gonzalez-Perez, L-M; Gonzalez-Perez-Somarriba, B; Centeno, G; Vallellano, C; Montes-Carmona, J-F

2016-11-01

Temporo-Mandibular Joint (TMJ) replacement has been used clinically for years. The objective of this study was to evaluate outcomes achieved in patients with two different categories of TMJ prostheses. All patients who had a TMJ replacement (TMJR) implanted during the study period from 2006 through 2012 were included in this 3-year prospective study. All procedures were performed using the Biomet Microfixation TMJ Replacement System, and all involved replacing both the skull base component (glenoid fossa) and the mandibular condyle. Fifty-seven patients (38 females and 19 males), involving 75 TMJs with severe disease requiring reconstruction (39 unilateral, 18 bilateral) were operated on consecutively, and 68 stock prostheses and 7 custom-made prostheses were implanted. The mean age at surgery was 52.6±11.5 years in the stock group and 51.8±11.7 years in the custom-made group. In the stock group, after three years of TMJR, results showed a reduction in pain intensity from 6.4±1.4 to 1.6±1.2 (p<0.001), and an improvement in jaw opening from 2.7±0.9 cm to 4.2±0.7 cm (p<0.001). In the custom-made group, after three years of TMJR, results showed a reduction in pain intensity from 6.0±1.6 to 2.2±0.4 (p<0.001), and an improvement in jaw opening from 1.5±0.5 cm to 4.3±0.6 cm (p<0.001). No statistically significant differences between two groups were detected. The results of this three-year prospective study support the surgical placement of TMJ prostheses (stock prosthetic, and custom-made systems), and show that the approach is efficacious and safe, reduces pain, and improves maximum mouth opening movement, with few complications. As such, TMJR represents a viable technique and a stable long-term solution for cranio-mandibular reconstruction in patients with irreversible end-stage TMJ disease. Comparing stock and custom-made groups, no statistically significant differences were detected with respect to pain intensity reduction and maximum mouth opening improvement.

Corrosion behaviour and mechanical properties of functionally gradient materials developed for possible hard-tissue applications.

PubMed

Becker, B S; Bolton, J D

1997-12-01

Artificial hip joints have an average lifetime of 10 years due to aseptic loosening of the femoral stem attributed to polymeric wear debris; however, there is a steadily increasing demand from younger osteoarthritis patients aged between 15 and 40 year for a longer lasting joint of 25 years or more. Compliant layers incorporated into the acetabular cup generate elastohydrodynamic lubrication conditions between the bearing surfaces, reduce joint friction coefficients and wear debris production and could increase the average life of total hip replacements, and other human load-bearing joint replacements, i.e. total knee replacements. Poor adhesion between a fully dense substrate and the compliant layer has so far prevented any further exploitation. This work investigated the possibility of producing porous metallic, functionally gradient type acetabular cups using powder metallurgy techniques - where a porous surface was supported by a denser core - into which the compliant layers could be incorporated. The corrosion behaviour and mechanical properties of three biomedically approved alloys containing two levels of total porosity (>30% and <10%) were established, resulting in Ti-6Al-4V being identified as the most promising biocompatible functionally graded material, not only for this application but for other hard-tissue implants.

Novel biological strategies for treatment of wear particle-induced periprosthetic osteolysis of orthopaedic implants for joint replacement

PubMed Central

Goodman, S. B.; Gibon, E.; Pajarinen, J.; Lin, T.-H.; Keeney, M.; Ren, P.-G.; Nich, C.; Yao, Z.; Egashira, K.; Yang, F.; Konttinen, Y. T.

2014-01-01

Wear particles and by-products from joint replacements and other orthopaedic implants may result in a local chronic inflammatory and foreign body reaction. This may lead to persistent synovitis resulting in joint pain and swelling, periprosthetic osteolysis, implant loosening and pathologic fracture. Strategies to modulate the adverse effects of wear debris may improve the function and longevity of joint replacements and other orthopaedic implants, potentially delaying or avoiding complex revision surgical procedures. Three novel biological strategies to mitigate the chronic inflammatory reaction to orthopaedic wear particles are reported. These include (i) interference with systemic macrophage trafficking to the local implant site, (ii) modulation of macrophages from an M1 (pro-inflammatory) to an M2 (anti-inflammatory, pro-tissue healing) phenotype in the periprosthetic tissues, and (iii) local inhibition of the transcription factor nuclear factor kappa B (NF-κB) by delivery of an NF-κB decoy oligodeoxynucleotide, thereby interfering with the production of pro-inflammatory mediators. These three approaches have been shown to be viable strategies for mitigating the undesirable effects of wear particles in preclinical studies. Targeted local delivery of specific biologics may potentially extend the lifetime of orthopaedic implants. PMID:24478281

Current concepts and future perspectives in computer-assisted navigated total knee replacement.

PubMed

Matsumoto, Tomoyuki; Nakano, Naoki; Lawrence, John E; Khanduja, Vikas

2018-05-12

Total knee replacements (TKR) aim to restore stability of the tibiofemoral and patella-femoral joints and provide relief of pain and improved quality of life for the patient. In recent years, computer-assisted navigation systems have been developed with the aim of reducing human error in joint alignment and improving patient outcomes. We examined the current body of evidence surrounding the use of navigation systems and discussed their current and future role in TKR. The current body of evidence shows that the use of computer navigation systems for TKR significantly reduces outliers in the mechanical axis and coronal prosthetic position. Also, navigation systems offer an objective assessment of soft tissue balancing that had previously not been available. Although these benefits represent a technical superiority to conventional TKR techniques, there is limited evidence to show long-term clinical benefit with the use of navigation systems, with only a small number of studies showing improvement in outcome scores at short-term follow-up. Because of the increased costs and operative time associated with their use as well as the emergence of more affordable and patient-specific technologies, it is unlikely for navigation systems to become more widely used in the near future. Whilst this technology helps surgeons to achieve improved component positioning, it is important to consider the clinical and functional implications, as well as the added costs and potential learning curve associated with adopting new technology.

Cross-Shear Implementation in Sliding-Distance-Coupled Finite Element Analysis of Wear in Metal-on-Polyethylene Total Joint Arthroplasty: Intervertebral Total Disc Replacement as an Illustrative Application

PubMed Central

Goreham-Voss, Curtis M.; Hyde, Philip J.; Hall, Richard M.; Fisher, John; Brown, Thomas D.

2010-01-01

Computational simulations of wear of orthopaedic total joint replacement implants have proven to valuably complement laboratory physical simulators, for pre-clinical estimation of abrasive/adhesive wear propensity. This class of numerical formulations has primarily involved implementation of the Archard/Lancaster relationship, with local wear computed as the product of (finite element) contact stress, sliding speed, and a bearing-couple-dependent wear factor. The present study introduces an augmentation, whereby the influence of interface cross-shearing motion transverse to the prevailing molecular orientation of the polyethylene articular surface is taken into account in assigning the instantaneous local wear factor. The formulation augment is implemented within a widely-utilized commercial finite element software environment (ABAQUS). Using a contemporary metal-on-polyethylene total disc replacement (ProDisc-L) as an illustrative implant, physically validated computational results are presented to document the role of cross-shearing effects in alternative laboratory consensus testing protocols. Going forward, this formulation permits systematically accounting for cross-shear effects in parametric computational wear studies of metal-on-polyethylene joint replacements, heretofore a substantial limitation of such analyses. PMID:20399432

Joint Venture Health Plans May Give ACOs a Run for Their Money.

PubMed

Reinke, Thomas

2016-12-01

Joint venture plans are starting to demonstrate their ability to implement clinical management and financial management reforms. A JV health plan replaces the offloading of financial risk by health plans to ill-equipped providers with an executive-level cost management committee stated jointly by the hospital and payer.

Effect of Structured Touch and Guided Imagery for Pain and Anxiety in Elective Joint Replacement Patients--A Randomized Controlled Trial: M-TIJRP.

PubMed

Forward, John Brent; Greuter, Nancy Elizabeth; Crisall, Santa J; Lester, Houston F

2015-01-01

Postoperative management of pain after total joint arthroplasty remains a challenge despite advancements in analgesics. Evidence shows that complementary modalities with mind-body and tactile-based approaches are valid and effective adjuncts to reduce pain and anxiety postoperatively. To investigate the effectiveness of the "M" Technique (M), a registered method of structured touch using a set sequence and number of strokes, and a consistent level of pressure on hands and feet, compared with guided imagery and usual care, for the reduction of pain and anxiety in patients undergoing elective total knee or hip replacement surgery. Randomized controlled trial: M-TIJRP (MiTechnique and guided Imagery in Joint Replacement Patients [Mighty Junior P]). At a community hospital, 225 male and female patients, aged 38 to 90 years, undergoing elective total hip or knee replacement were randomly assigned to 1 of 3 groups (75 patients in each): M, guided imagery, or usual care. They were blinded to their assignment until the intervention. Reduction of pain and anxiety postoperatively. Secondary outcomes measured use of pain medication and patient satisfaction. This study yielded positive findings for the management of pain and anxiety in patients undergoing elective joint replacement using M and guided imagery for 18 to 20 minutes compared with usual care. M showed the largest predicted decreases in both pain and anxiety between groups. There was no significant difference in narcotic pain medication use between groups. Patient satisfaction survey ratings were highest for M, followed by guided imagery. The benefit of M may be because of the specifically structured sequence of touch by competent caring, trained providers.

Effect of Structured Touch and Guided Imagery for Pain and Anxiety in Elective Joint Replacement Patients—A Randomized Controlled Trial: M-TIJRP

PubMed Central

Forward, John Brent; Greuter, Nancy Elizabeth; Crisall, Santa J; Lester, Houston F

2015-01-01

Context: Postoperative management of pain after total joint arthroplasty remains a challenge despite advancements in analgesics. Evidence shows that complementary modalities with mind-body and tactile-based approaches are valid and effective adjuncts to reduce pain and anxiety postoperatively. Objective: To investigate the effectiveness of the “M” Technique (M), a registered method of structured touch using a set sequence and number of strokes, and a consistent level of pressure on hands and feet, compared with guided imagery and usual care, for the reduction of pain and anxiety in patients undergoing elective total knee or hip replacement surgery. Methods: Randomized controlled trial: M-TIJRP (MiTechnique and guided Imagery in Joint Replacement Patients [Mighty Junior P]). At a community hospital, 225 male and female patients, aged 38 to 90 years, undergoing elective total hip or knee replacement were randomly assigned to 1 of 3 groups (75 patients in each): M, guided imagery, or usual care. They were blinded to their assignment until the intervention. Main Outcome Measures: Reduction of pain and anxiety postoperatively. Secondary outcomes measured use of pain medication and patient satisfaction. Results: This study yielded positive findings for the management of pain and anxiety in patients undergoing elective joint replacement using M and guided imagery for 18 to 20 minutes compared with usual care. M showed the largest predicted decreases in both pain and anxiety between groups. There was no significant difference in narcotic pain medication use between groups. Patient satisfaction survey ratings were highest for M, followed by guided imagery. Conclusion: The benefit of M may be because of the specifically structured sequence of touch by competent caring, trained providers. PMID:26222093

Ranges of motion after reverse shoulder arthroplasty improve significantly the first year after surgery in patients with rheumatoid arthritis.

PubMed

Tiusanen, Hannu; Sarantsin, Pjotor; Stenholm, Miika; Mattie, Ryan; Saltychev, Mikhail

2016-07-01

To evaluate the trajectory of the change in range of motion after reverse shoulder joint replacement during 3-year follow-up among patients with rheumatoid arthritis. Retrospective cohort longitudinal study of 76 shoulder replacements performed in a university clinic. The range of shoulder motion was assessed by a physiotherapist using a manual goniometer with 5-degree precision before the surgery and 1, 3, 6, 12, and 36 months postoperatively. The shapes of the regression curves suggest that the improvement or decline observed in joint motion was happening mostly during the first year after surgery. After 1 year, the trajectories become flat and they remained unchanged until the end of follow-up. After shoulder joint replacement, the range of shoulder motion showed substantial changes during the first year only. This should be taken into account when scheduling control visits, planning rehabilitation, and predicting the use of community services after the surgery.

Assessment of the Patient-Centered and Family-Centered Care Experience of Total Joint Replacement Patients Using a Shadowing Technique.

PubMed

Marcus-Aiyeku, Ulanda; DeBari, Margaret; Salmond, Susan

2015-01-01

In 2030, when baby boomers reach 65 years of age and represent 18% of the population, it is anticipated that 67 million adults will have a diagnosis of arthritis increasing the demand for total hip and knee arthroplasty. With the growing emphasis on patient- and family-centered care, the aim of this project was to assess the patient experience of patients and families throughout the entire spectrum of the total joint replacement service line care at a university regional trauma hospital. A shadowing methodology as defined by the Institute for Health Improvement was utilized. Eight patient/family groups undergoing total joint replacements were shadowed. The mapped care experience included time, caregiver, activity, shadower observations, and impressions. Findings revealed inconsistencies in the delivery of patient- and family-centered care. Communication and interactions were predominantly provider-centric, with a focus on care routines versus the patient and family, and anticipation that care would be medically directed.

Wormhole Formation in RSRM Nozzle Joint Backfill

NASA Technical Reports Server (NTRS)

Stevens, J.

2000-01-01

The RSRM nozzle uses a barrier of RTV rubber upstream of the nozzle O-ring seals. Post flight inspection of the RSRM nozzle continues to reveal occurrence of "wormholes" into the RTV backfill. The term "wormholes", sometimes called "gas paths", indicates a gas flow path not caused by pre-existing voids, but by a little-understood internal failure mode of the material during motor operation. Fundamental understanding of the mechanics of the RSRM nozzle joints during motor operation, nonlinear viscoelastic characterization of the RTV backfill material, identification of the conditions that predispose the RTV to form wormholes, and screening of candidate replacement materials is being pursued by a joint effort between Thiokol Propulsion, NASA, and the Army Propulsion & Structures Directorate at Redstone Arsenal. The performance of the RTV backfill in the joint is controlled by the joint environment. Joint movement, which applies a tension and shear load on the material, coupled with the introduction of high pressure gas in combination create an environment that exceeds the capability of the material to withstand the wormhole effect. Little data exists to evaluate why the material fails under the modeled joint conditions, so an effort to characterize and evaluate the material under these conditions was undertaken. Viscoelastic property data from characterization testing will anchor structural analysis models. Data over a range of temperatures, environmental pressures, and strain rates was used to develop a nonlinear viscoelastic model to predict material performance, develop criteria for replacement materials, and quantify material properties influencing wormhole growth. Three joint simulation analogs were developed to analyze and validate joint thermal barrier (backfill) material performance. Two exploratory tests focus on detection of wormhole failure under specific motor operating conditions. A "validation" test system provides data to "validate" computer models and predictions. Finally, two candidate replacement materials are being screened and "validated" using the developed test systems.

Current Risk Adjustment and Comorbidity Index Underperformance in Predicting Post-Acute Utilization and Hospital Readmissions After Joint Replacements: Implications for Comprehensive Care for Joint Replacement Model.

PubMed

Kumar, Amit; Karmarkar, Amol; Downer, Brian; Vashist, Amit; Adhikari, Deepak; Al Snih, Soham; Ottenbacher, Kenneth

2017-11-01

To compare the performances of 3 comorbidity indices, the Charlson Comorbidity Index, the Elixhauser Comorbidity Index, and the Centers for Medicare & Medicaid Services (CMS) risk adjustment model, Hierarchical Condition Category (HCC), in predicting post-acute discharge settings and hospital readmission for patients after joint replacement. A retrospective study of Medicare beneficiaries with total knee replacement (TKR) or total hip replacement (THR) discharged from hospitals in 2009-2011 (n = 607,349) was performed. Study outcomes were post-acute discharge setting and unplanned 30-, 60-, and 90-day hospital readmissions. Logistic regression models were built to compare the performance of the 3 comorbidity indices using C statistics. The base model included patient demographics and hospital use. Subsequent models included 1 of the 3 comorbidity indices. Additional multivariable logistic regression models were built to identify individual comorbid conditions associated with high risk of hospital readmissions. The 30-, 60-, and 90-day unplanned hospital readmission rates were 5.3%, 7.2%, and 8.5%, respectively. Patients were most frequently discharged to home health (46.3%), followed by skilled nursing facility (40.9%) and inpatient rehabilitation facility (12.7%). The C statistics for the base model in predicting post-acute discharge setting and 30-, 60-, and 90-day readmission in TKR and THR were between 0.63 and 0.67. Adding the Charlson Comorbidity Index, the Elixhauser Comorbidity Index, or HCC increased the C statistic minimally from the base model for predicting both discharge settings and hospital readmission. The health conditions most frequently associated with hospital readmission were diabetes mellitus, pulmonary disease, arrhythmias, and heart disease. The comorbidity indices and CMS-HCC demonstrated weak discriminatory ability to predict post-acute discharge settings and hospital readmission following joint replacement. © 2017, American College of Rheumatology.

Genetic association studies in osteoarthritis: is it fairytale?

PubMed

Warner, Sophie C; Valdes, Ana M

2017-01-01

Osteoarthritis is a common complex disorder with a strong genetic component. Other identified risk factors such as increasing age and overweight do not fully explain the risk of osteoarthritis. Here, we highlight the main findings from genetic association studies on osteoarthritis to date. Currently, genetic association studies have identified 21 independent susceptibility loci for osteoarthritis. Studies have focused on hip, knee and hand osteoarthritis, as well as posttotal joint replacement and minimum joint space width, a proxy for cartilage thickness. Four distinct loci have recently been identified in a genome-wide association scan on minimum joint space width. The role of mitochondrial DNA variants has been the focus of a recent meta-analysis. Findings have previously been mixed, however, this study suggests a plausible involvement of mitochondrial DNA in the progression of radiographic knee osteoarthritis. Identifying genetic locations of interest provides a framework upon which to base future studies, for example replication analysis and functional work. Genetic association studies have shaped and will continue to shape research in this field. Improving the understanding of osteoarthritis could improve the diagnosis and treatment of the disease and improve quality of life for many individuals.

Determination of Parachute Joint Factors using Seam and Joint Testing

NASA Technical Reports Server (NTRS)

Mollmann, Catherine

2015-01-01

This paper details the methodology for determining the joint factor for all parachute components. This method has been successfully implemented on the Capsule Parachute Assembly System (CPAS) for the NASA Orion crew module for use in determining the margin of safety for each component under peak loads. Also discussed are concepts behind the joint factor and what drives the loss of material strength at joints. The joint factor is defined as a "loss in joint strength...relative to the basic material strength" that occurs when "textiles are connected to each other or to metals." During the CPAS engineering development phase, a conservative joint factor of 0.80 was assumed for each parachute component. In order to refine this factor and eliminate excess conservatism, a seam and joint testing program was implemented as part of the structural validation. This method split each of the parachute structural joints into discrete tensile tests designed to duplicate the loading of each joint. Breaking strength data collected from destructive pull testing was then used to calculate the joint factor in the form of an efficiency. Joint efficiency is the percentage of the base material strength that remains after degradation due to sewing or interaction with other components; it is used interchangeably with joint factor in this paper. Parachute materials vary in type-mainly cord, tape, webbing, and cloth -which require different test fixtures and joint sample construction methods. This paper defines guidelines for designing and testing samples based on materials and test goals. Using the test methodology and analysis approach detailed in this paper, the minimum joint factor for each parachute component can be formulated. The joint factors can then be used to calculate the design factor and margin of safety for that component, a critical part of the design verification process.

A Systematic Review of Different Implants and Approaches for Proximal Interphalangeal Joint Arthroplasty

PubMed Central

Yamamoto, Michiro; Malay, Sunitha; Fujihara, Yuki; Zhong, Lin; Chung, Kevin C.

2016-01-01

Background Outcomes after implant arthroplasty for primary degenerative and posttraumatic osteoarthritis (OA) of proximal interphalangeal (PIP) joint were different according to the implant design and surgical approach. The purpose of this systematic review was to evaluate outcomes of various types of implant arthroplasty for PIP joint OA with emphasis on different surgical approaches. Methods The authors searched all available literature in the PubMed and EMBASE databases for articles reporting on outcomes of implant arthroplasty for PIP joint OA. Data collection included active arc of motion (AOM), extension lag, and complications. We combined the data of various types of surface replacement arthroplasty into one group to compare with silicone arthroplasty. Results A total of 849 articles were screened, yielding 40 studies for final review. The mean postoperative AOM and the mean gain in AOM of silicone implant with volar approach were 58° and 17° respectively which was greater than surface replacement implant with dorsal approach as 51° and 8°, respectively. The mean postoperative extension lag of silicone implant with volar approach and surface replacement with dorsal approach was 5° and 14° respectively. The revision rate of silicone implant with volar approach and surface replacement with dorsal approach was 6% and 18% at the mean follow-up period of 41.2 and 51 months, respectively. Conclusions Silicone implant with volar approach showed the best AOM with less extension lag and fewer complications after surgery among all the implant designs and surgical approaches. PMID:28445369

CONICAL, RADIOGRAPHIC, AND PATIENT-REPORTED RESULTS OF SURFACE REPLACING PROXIMAL INTERPHALANGEAL JOINT ARTHROPLASTY OF THE HAND

PubMed Central

Amirtharajah, Mohana; Fufa, Duretti; Lightdale, Nina; Weiland, Andew

2011-01-01

The purpose of this study was to evaluate the one-year clinical, radiologic and patient-reported results of surface-replacing proximal interphalangeal joint arthroplasty (SR-PIP) of the hand. Fifteen patients with 18 joints underwent the procedure, and nine patients with 11 joints had follow-up of at least one year's duration. Of these joints, six had a diagnosis of osteoarthritis with no history of trauma, three had post-traumatic arthritis, one had psoriatic arthritis, and one had erosive arthritis. The mean clinical follow-up was at 3.3 years, and the mean radiographic follow-up was at 3.1 years. The average post-operative gain in range of motion at the PIP joint was 28 degrees and was statistically significant. Six patients completed self-reported questionnaires at a mean of 4.8 years post-operatively. The mean Disabilities of the Arm, Shoulder and Hand (DASH) score post-operatively was 17, and the Michigan Hand Questionnaire (MHQ) score for overall satisfaction was 70. There were three complications but only one reoperation. Seven of 11 joints showed some evidence of subsidence on follow-up radiographic examination. However, no joints were revised sec-ondary to loosening. Longer follow-up is needed to determine if this observable radiologic subsidence leads to symptomatic loosening of the implant PMID:22096433

Joint Replacement (Finger and Wrist Joints)

MedlinePlus

... Lawnmower Safety Snowblower safety Pumpkin Carving Gardening Safety Turkey Carving Removing a Ring Fireworks Safety Español Artritis ... Lawnmower Safety Snowblower safety Pumpkin Carving Gardening Safety Turkey Carving Removing a Ring Fireworks Safety Español Artritis ...

Integrating dynamic stereo-radiography and surface-based motion data for subject-specific musculoskeletal dynamic modeling.

PubMed

Zheng, Liying; Li, Kang; Shetye, Snehal; Zhang, Xudong

2014-09-22

This manuscript presents a new subject-specific musculoskeletal dynamic modeling approach that integrates high-accuracy dynamic stereo-radiography (DSX) joint kinematics and surface-based full-body motion data. We illustrate this approach by building a model in OpenSim for a patient who participated in a meniscus transplantation efficacy study, incorporating DSX data of the tibiofemoral joint kinematics. We compared this DSX-incorporated (DSXI) model to a default OpenSim model built using surface-measured data alone. The architectures and parameters of the two models were identical, while the differences in (time-averaged) tibiofemoral kinematics were of the order of magnitude of 10° in rotation and 10mm in translation. Model-predicted tibiofemoral compressive forces and knee muscle activations were compared against literature data acquired from instrumented total knee replacement components (Fregly et al., 2012) and the patient's EMG recording. The comparison demonstrated that the incorporation of DSX data improves the veracity of musculoskeletal dynamic modeling. Copyright © 2014 Elsevier Ltd. All rights reserved.

Integrating dynamic stereo-radiography and surface-based motion data for subject-specific musculoskeletal dynamic modeling

PubMed Central

Zheng, Liying; Li, Kang; Shetye, Snehal; Zhang, Xudong

2014-01-01

This paper presents a new subject-specific musculoskeletal dynamic modeling approach that integrates high-accuracy dynamic stereo-radiography (DSX) joint kinematics and surface-based full-body motion data. We illustrate this approach by building a model in OpenSim for a patient who participated in a meniscus transplantation efficacy study, incorporating DSX data of the tibiofemoral joint kinematics. We compared this DSX-incorporated (DSXI) model to a default OpenSim model built using surface-measured data alone. The architectures and parameters of the two models were identical, while the differences in (time-averaged) tibiofemoral kinematics were of the order of magnitude of 10° in rotation and 10 mm in translation. Model-predicted tibiofemoral compressive forces and knee muscle activations were compared against literature data acquired from instrumented total knee replacement components (Fregly et al., 2012) and the patient's EMG recording. The comparison demonstrated that the incorporation of DSX data improves the veracity of musculoskeletal dynamic modeling. PMID:25169658

Marginal ambulatory teaching cost under varying levels of service utilization.

PubMed

Panton, D M; Mushlin, A I; Gavett, J W

1980-06-01

The ambulatory component of residency training jointly produces two products, namely, training and patient services. In costing educational programs of this type, two approaches are frequently taken. The first considers the total costs of the educational program, including training and patient services. These costs are usually constructed from historical accounting records. The second approach attempts to cost the joint products separately, based upon estimates of future changes in program costs, if the product in question is added to or removed from the program. The second approach relates to typical decisions facing the managers of medical centers and practices used for teaching purposes. This article reports such a study of costs in a primary-care residency training program in a hospital outpatient setting. The costs of the product, i.e., on-the-job training, are evaluated using a replacement-cost concept under different levels of patient services. The results show that the cost of the product, training, is small at full clinical utilization and is sensitive to changes in the volume of services provided.

The Unified Classification System (UCS): improving our understanding of periprosthetic fractures.

PubMed

Duncan, C P; Haddad, F S

2014-06-01

Periprosthetic fractures are an increasingly common complication following joint replacement. The principles which underpin their evaluation and treatment are common across the musculoskeletal system. The Unified Classification System proposes a rational approach to treatment, regardless of the bone that is broken or the joint involved. ©2014 The British Editorial Society of Bone & Joint Surgery.

Dynamic behavior of tripolar hip endoprostheses under physiological conditions and their effect on stability.

PubMed

Fabry, Christian; Kaehler, Michael; Herrmann, Sven; Woernle, Christoph; Bader, Rainer

2014-01-01

Tripolar systems have been implanted to reduce the risk of recurrent dislocation. However, there is little known about the dynamic behavior of tripolar hip endoprostheses under daily life conditions and achieved joint stability. Hence, the objective of this biomechanical study was to examine the in vivo dynamics and dislocation behavior of two types of tripolar systems compared to a standard total hip replacement (THR) with the same outer head diameter. Several load cases of daily life activities were applied to an eccentric and a concentric tripolar system by an industrial robot. During testing, the motion of the intermediate component was measured using a stereo camera system. Additionally, their behavior under different dislocation scenarios was investigated in comparison to a standard THR. For the eccentric tripolar system, the intermediate component demonstrated the shifting into moderate valgus-positions, regardless of the type of movement. This implant showed the highest resisting torque against dislocation in combination with a large range of motion. In contrast, the concentric tripolar system tended to remain in varus-positions and was primarily moved after stem contact. According to the results, eccentric tripolar systems can work well under in vivo conditions and increase hip joint stability in comparison to standard THRs. Copyright © 2013 IPEM. Published by Elsevier Ltd. All rights reserved.

How do gait frequency and serum-replacement interval affect polyethylene wear in knee-wear simulator tests?

PubMed

Reinders, Jörn; Sonntag, Robert; Kretzer, Jan Philippe

2014-11-01

Polyethylene wear (PE) is known to be a limiting factor in total joint replacements. However, a standardized wear test (e.g. ISO standard) can only replicate the complex in vivo loading condition in a simplified form. In this study, two different parameters were analyzed: (a) Bovine serum, as a substitute for synovial fluid, is typically replaced every 500,000 cycles. However, a continuous regeneration takes place in vivo. How does serum-replacement interval affect the wear rate of total knee replacements? (b) Patients with an artificial joint show reduced gait frequencies compared to standardized testing. What is the influence of a reduced frequency? Three knee wear tests were run: (a) reference test (ISO), (b) testing with a shortened lubricant replacement interval, (c) testing with reduced frequency. The wear behavior was determined based on gravimetric measurements and wear particle analysis. The results showed that the reduced test frequency only had a small effect on wear behavior. Testing with 1 Hz frequency is therefore a valid method for wear testing. However, testing with a shortened replacement interval nearly doubled the wear rate. Wear particle analysis revealed only small differences in wear particle size between the different tests. Wear particles were not linearly released within one replacement interval. The ISO standard should be revised to address the marked effects of lubricant replacement interval on wear rate.

[Patella fractures in knee arthroplasty].

PubMed

Roth, A; Ghanem, M; Fakler, J

2016-05-01

Periprosthetic patella fractures occur both with and without retropatellar joint replacement. A non-operative treatment yields satisfactory results with low morbidity. It can be applied in minimally displaced fractures that have an intact retropatellar component and an intact extensor mechanism, combined with an initial immobilization. The surgical treatment is associated with relatively poor results and with high complication rates. There was only minor improvement of functional results, no matter which surgical technique was used. Surgical intervention is still required in fractures with a loosening of the patellar component, considerable dislocations of fragments, and damage to or rupture of the extensor mechanism. In particular, type II fractures require repair of the extensor mechanism and the fracture or patellectomy. Type III fractures require a revision or resection of the patella, a patelloplasty or total patellectomy. In addition, early or late reconstruction using allograft to restore the extensor mechanism can be taken in consideration.

49 CFR 213.309 - Restoration or renewal of track under traffic conditions.

Code of Federal Regulations, 2014 CFR

2014-10-01

....g., as in joint bar replacement or rail replacement; (2) Any work that adversely affects the lateral or vertical stability of the track with the exception of spot tamping an isolated condition where not...

49 CFR 213.309 - Restoration or renewal of track under traffic conditions.

Code of Federal Regulations, 2011 CFR

2011-10-01

....g., as in joint bar replacement or rail replacement; (2) Any work that adversely affects the lateral or vertical stability of the track with the exception of spot tamping an isolated condition where not...

49 CFR 213.309 - Restoration or renewal of track under traffic conditions.

Code of Federal Regulations, 2012 CFR

2012-10-01

....g., as in joint bar replacement or rail replacement; (2) Any work that adversely affects the lateral or vertical stability of the track with the exception of spot tamping an isolated condition where not...

49 CFR 213.309 - Restoration or renewal of track under traffic conditions.

Code of Federal Regulations, 2013 CFR

2013-10-01

....g., as in joint bar replacement or rail replacement; (2) Any work that adversely affects the lateral or vertical stability of the track with the exception of spot tamping an isolated condition where not...

A joint-space numerical model of metabolic energy expenditure for human multibody dynamic system.

PubMed

Kim, Joo H; Roberts, Dustyn

2015-09-01

Metabolic energy expenditure (MEE) is a critical performance measure of human motion. In this study, a general joint-space numerical model of MEE is derived by integrating the laws of thermodynamics and principles of multibody system dynamics, which can evaluate MEE without the limitations inherent in experimental measurements (phase delays, steady state and task restrictions, and limited range of motion) or muscle-space models (complexities and indeterminacies from excessive DOFs, contacts and wrapping interactions, and reliance on in vitro parameters). Muscle energetic components are mapped to the joint space, in which the MEE model is formulated. A constrained multi-objective optimization algorithm is established to estimate the model parameters from experimental walking data also used for initial validation. The joint-space parameters estimated directly from active subjects provide reliable MEE estimates with a mean absolute error of 3.6 ± 3.6% relative to validation values, which can be used to evaluate MEE for complex non-periodic tasks that may not be experimentally verifiable. This model also enables real-time calculations of instantaneous MEE rate as a function of time for transient evaluations. Although experimental measurements may not be completely replaced by model evaluations, predicted quantities can be used as strong complements to increase reliability of the results and yield unique insights for various applications. Copyright © 2015 John Wiley & Sons, Ltd.

21 CFR 888.3510 - Knee joint femorotibial metal/polymer constrained cemented prosthesis.

Code of Federal Regulations, 2012 CFR

2012-04-01

...-and-socket joint located between a stemmed femoral and a stemmed tibial component and a runner and track joint between each pair of femoral and tibial condyles. The ball-and-socket joint is composed of a...-molybdenum. The ball of the tibial component is held within the socket of the femoral component by the...

21 CFR 888.3510 - Knee joint femorotibial metal/polymer constrained cemented prosthesis.

Code of Federal Regulations, 2011 CFR

2011-04-01

...-and-socket joint located between a stemmed femoral and a stemmed tibial component and a runner and track joint between each pair of femoral and tibial condyles. The ball-and-socket joint is composed of a...-molybdenum. The ball of the tibial component is held within the socket of the femoral component by the...

21 CFR 888.3510 - Knee joint femorotibial metal/polymer constrained cemented prosthesis.

Code of Federal Regulations, 2013 CFR

2013-04-01

...-and-socket joint located between a stemmed femoral and a stemmed tibial component and a runner and track joint between each pair of femoral and tibial condyles. The ball-and-socket joint is composed of a...-molybdenum. The ball of the tibial component is held within the socket of the femoral component by the...

21 CFR 888.3510 - Knee joint femorotibial metal/polymer constrained cemented prosthesis.

Code of Federal Regulations, 2014 CFR

2014-04-01

...-and-socket joint located between a stemmed femoral and a stemmed tibial component and a runner and track joint between each pair of femoral and tibial condyles. The ball-and-socket joint is composed of a...-molybdenum. The ball of the tibial component is held within the socket of the femoral component by the...

Central sensitization and neuropathic features of ongoing pain in a rat model of advanced osteoarthritis

PubMed Central

Havelin, Joshua; Imbert, Ian; Cormier, Jennifer; Allen, Joshua; Porreca, Frank; King, Tamara

2015-01-01

Osteoarthritis (OA) pain is most commonly characterized by movement-triggered joint pain. However, in advanced disease, OA pain becomes persistent, ongoing and resistant to treatment with NSAIDs. The mechanisms underlying ongoing pain in advanced OA are poorly understood. We recently showed that intra-articular (i.a.) injection of monosodium iodoacetate (MIA) into the rat knee joint produces concentration-dependent outcomes. Thus, a low dose of i.a. MIA produces NSAID-sensitive weight asymmetry without evidence of ongoing pain while a high i.a. MIA dose produces weight asymmetry and NSAID-resistant ongoing pain. In the present studies, palpation of the ipsilateral hindlimb of rats treated 14 days previously with high, but not low, doses of i.a. MIA produced FOS expression in the spinal dorsal horn. Inactivation of descending pain facilitatory pathways by microinjection of lidocaine within the rostral ventromedial medulla (RVM) induced conditioned place preference (CPP) selectively in rats treated with the high dose of MIA. CPP to intra-articular lidocaine was blocked by pretreatment with duloxetine (30 mg/kg, i.p. at −30 min). These observations are consistent with the likelihood of a neuropathic component of OA that elicits ongoing, NSAID resistant pain and central sensitization that is mediated, in part, by descending modulatory mechanisms. This model provides a basis for exploration of underlying mechanisms promoting neuropathic components of OA pain and for the identification of mechanisms that may guide drug discovery for treatment of advanced OA pain without the need for joint replacement. PMID:26694132

Joint BioEnergy Institute

ScienceCinema

Keasling, Jay; Simmons, Blake; Tartaglino, Virginia; Baidoo, Edward; Kothari, Ankita

2018-05-11

The Joint BioEnergy Institute (JBEI) is a U.S. Department of Energy (DOE) Bioenergy Research Center dedicated to developing advanced biofuels—liquid fuels derived from the solar energy stored in plant biomass that can replace gasoline, diesel and jet fuels.

Hydrogels as a Replacement Material for Damaged Articular Hyaline Cartilage

PubMed Central

Beddoes, Charlotte M.; Whitehouse, Michael R.; Briscoe, Wuge H.; Su, Bo

2016-01-01

Hyaline cartilage is a strong durable material that lubricates joint movement. Due to its avascular structure, cartilage has a poor self-healing ability, thus, a challenge in joint recovery. When severely damaged, cartilage may need to be replaced. However, currently we are unable to replicate the hyaline cartilage, and as such, alternative materials with considerably different properties are used. This results in undesirable side effects, including inadequate lubrication, wear debris, wear of the opposing articular cartilage, and weakening of the surrounding tissue. With the number of surgeries for cartilage repair increasing, a need for materials that can better mimic cartilage, and support the surrounding material in its typical function, is becoming evident. Here, we present a brief overview of the structure and properties of the hyaline cartilage and the current methods for cartilage repair. We then highlight some of the alternative materials under development as potential methods of repair; this is followed by an overview of the development of tough hydrogels. In particular, double network (DN) hydrogels are a promising replacement material, with continually improving physical properties. These hydrogels are coming closer to replicating the strength and toughness of the hyaline cartilage, while offering excellent lubrication. We conclude by highlighting several different methods of integrating replacement materials with the native joint to ensure stability and optimal behaviour. PMID:28773566

Hydrogels as a Replacement Material for Damaged Articular Hyaline Cartilage.

PubMed

Beddoes, Charlotte M; Whitehouse, Michael R; Briscoe, Wuge H; Su, Bo

2016-06-03

Hyaline cartilage is a strong durable material that lubricates joint movement. Due to its avascular structure, cartilage has a poor self-healing ability, thus, a challenge in joint recovery. When severely damaged, cartilage may need to be replaced. However, currently we are unable to replicate the hyaline cartilage, and as such, alternative materials with considerably different properties are used. This results in undesirable side effects, including inadequate lubrication, wear debris, wear of the opposing articular cartilage, and weakening of the surrounding tissue. With the number of surgeries for cartilage repair increasing, a need for materials that can better mimic cartilage, and support the surrounding material in its typical function, is becoming evident. Here, we present a brief overview of the structure and properties of the hyaline cartilage and the current methods for cartilage repair. We then highlight some of the alternative materials under development as potential methods of repair; this is followed by an overview of the development of tough hydrogels. In particular, double network (DN) hydrogels are a promising replacement material, with continually improving physical properties. These hydrogels are coming closer to replicating the strength and toughness of the hyaline cartilage, while offering excellent lubrication. We conclude by highlighting several different methods of integrating replacement materials with the native joint to ensure stability and optimal behaviour.

Transverse joint configuration development and testing for a modular bridge deck replacement system.

DOT National Transportation Integrated Search

2011-03-01

According to the 2009 Report Card for Americas Infrastructure, one in four of the nations bridges are listed as : structurally deficient of functionally obsolete, establishing a dire need for new and innovative repair and replacement : techniqu...

Measuring the ICF components of impairment, activity limitation and participation restriction: an item analysis using classical test theory and item response theory

PubMed Central

Pollard, Beth; Dixon, Diane; Dieppe, Paul; Johnston, Marie

2009-01-01

Background The International Classification of Functioning, Disability and Health (ICF) proposes three main health outcomes, Impairment (I), Activity Limitation (A) and Participation Restriction (P), but good measures of these constructs are needed The aim of this study was to use both Classical Test Theory (CTT) and Item Response Theory (IRT) methods to carry out an item analysis to improve measurement of these three components in patients having joint replacement surgery mainly for osteoarthritis (OA). Methods A geographical cohort of patients about to undergo lower limb joint replacement was invited to participate. Five hundred and twenty four patients completed ICF items that had been previously identified as measuring only a single ICF construct in patients with osteoarthritis. There were 13 I, 26 A and 20 P items. The SF-36 was used to explore the construct validity of the resultant I, A and P measures. The CTT and IRT analyses were run separately to identify items for inclusion or exclusion in the measurement of each construct. The results from both analyses were compared and contrasted. Results Overall, the item analysis resulted in the removal of 4 I items, 9 A items and 11 P items. CTT and IRT identified the same 14 items for removal, with CTT additionally excluding 3 items, and IRT a further 7 items. In a preliminary exploration of reliability and validity, the new measures appeared acceptable. Conclusion New measures were developed that reflect the ICF components of Impairment, Activity Limitation and Participation Restriction for patients with advanced arthritis. The resulting Aberdeen IAP measures (Ab-IAP) comprising I (Ab-I, 9 items), A (Ab-A, 17 items), and P (Ab-P, 9 items) met the criteria of conventional psychometric (CTT) analyses and the additional criteria (information and discrimination) of IRT. The use of both methods was more informative than the use of only one of these methods. Thus combining CTT and IRT appears to be a valuable tool in the development of measures. PMID:19422677

Efficient rehabilitation care for joint replacement patients: skilled nursing facility or inpatient rehabilitation facility?

PubMed

Tian, Wenqiang; DeJong, Gerben; Horn, Susan D; Putman, Koen; Hsieh, Ching-Hui; DaVanzo, Joan E

2012-01-01

There has been lengthy debate as to which setting, skilled nursing facility (SNF) or inpatient rehabilitation facility (IRF), is more efficient in treating joint replacement patients. This study aims to determine the efficiency of rehabilitation care provided by SNF and IRF to joint replacement patients with respect to both payment and length of stay (LOS). This study used a prospective multisite observational cohort design. Tobit models were used to examine the association between setting of care and efficiency. The study enrolled 948 knee replacement patients and 618 hip replacement patients from 11 IRFs and 7 SNFs between February 2006 and February 2007. Output was measured by motor functional independence measure (FIM) score at discharge. Efficiency was measured in 3 ways: payment efficiency, LOS efficiency, and stochastic frontier analysis efficiency. IRF patients incurred higher expenditures per case but also achieved larger motor FIM gains in shorter LOS than did SNF patients. Setting of care was not a strong predictor of overall efficiency of rehabilitation care. Great variation in characteristics existed within IRFs or SNFs and severity groups. Medium-volume facilities among both SNFs and IRFs were most efficient. Early rehabilitation was consistently predictive of efficient treatment. The advantage of either setting is not clear-cut. Definition of efficiency depends in part on preference between cost and time. SNFs are more payment efficient; IRFs are more LOS efficient. Variation within SNFs and IRFs blurred setting differences; a simple comparison between SNF and IRF may not be appropriate.

Behavior of single lap composite bolted joint under traction loading: Experimental investigation

NASA Astrophysics Data System (ADS)

Awadhani, L. V.; Bewoor, Anand

2018-04-01

Composite bolted joints are preferred connection in the composite structures to facilitate the dismantling for the replacements/ maintenance work. The joint behavior under tractive forces has been studied in order to understand the safety of the structure designed. The main objective of this paper is to investigate the behavior of single-lap joints in carbon fiber reinforced epoxy composites under traction loading conditions. The experiments were designed to identify the effect of bolt diameter, stacking sequence and loading rate on the properties of the joint. The experimental results show that the parameters influence the joint performance significantly.

[Reconstruction and balance of soft tissue in hemi-shoulder replacement for patients with four-part fracture of the proximal humerus].

PubMed

Wu, Xing; Lou, Lie-ming; Chen, Zheng-rong; Zhang, Guang-jian

2008-10-01

To explore the effective skills of reconstruction and balance of soft tissue in hemi-shoulder replacement for patients with four-part fracture of the proximal humerus in order to avoid postoperative complications of joint instability and great tubercle displacement. From June 2002 to June 2006, 25 patients with Neer four-part fracture of the proximal humerus were adopted in the study which included 15 females and 10 males, with the mean age of 66 years (ranged from 56 years to 80 years). They were treated with humeral head replacement and should joint reparation simultaneously by modified operation approach and reconstruction and balance skills of soft tissue. The mean duration of follow-up was 2.3 years (ranged from 1 to 4.5 years). No infection, nerve damage and prosthesis loosing were found in all cases. Two cases of infra-forward dislocation or subluxation occurred due to affected limb placed on abduction splint postoperatively. One case occurred prosthesis upward displacement due to early active abduction exercise but no complains. Neither joint instability nor displacement and malunion of great tubercle were found in other patients. According to Neer scoring system, 6 cases were rated as excellent, 15 as good and 5 as fair. The good and excellent rate was 84%. In hemi-shoulder replacement for patients with Neer four-part fracture the modified operation approach and reconstruction and balance of soft tissue skills combined with rational rehabilitation exercise can prevent postoperative shoulder joint instability and displacement and malunion of great tubercle.

Early mobilization of patients who have had a hip or knee joint replacement reduces length of stay in hospital: a systematic review.

PubMed

Guerra, Mark L; Singh, Parminder J; Taylor, Nicholas F

2015-09-01

To systematically review the effect of early mobilization after hip or knee joint replacement surgery on length of stay in an acute hospital. Randomized controlled trials were selected from electronic databases based on inclusion criterion requiring an experimental group mobilizing (sitting out of bed/walking) earlier than a comparison group post joint replacement surgery of the hip or knee in an acute hospital. Clinically homogeneous data were analyzed with meta-analysis. Five randomized controlled trials (totaling 622 participants) were included for review. A meta-analysis of 5 trials found a reduced length of stay of 1.8 days (95% confidence interval 1.1 to 2.6) in favor of the experimental group. In 4 of the 5 trials the experimental group first sat out of bed within 24 hours post operatively. In 4 of the 5 trials the experimental group first walked within 48 hours post operatively. Individual trials reported benefits in range of motion, muscle strength and health-related quality of life in favor of the experimental group. There were no differences in discharge destinations, incidence of negative outcomes or adverse events attributable to early mobilization when compared to the comparison groups. Early mobilization post hip or knee joint replacement surgery can result in a reduced length of stay of about 1.8 days. Trials that reported these positive results showed that early mobilization can be achieved within 24 hours of operation. This positive gain was achieved without an increase in negative outcomes. © The Author(s) 2014.

A Systematic Review of Different Implants and Approaches for Proximal Interphalangeal Joint Arthroplasty.

PubMed

Yamamoto, Michiro; Malay, Sunitha; Fujihara, Yuki; Zhong, Lin; Chung, Kevin C

2017-05-01

Outcomes after implant arthroplasty for primary degenerative and posttraumatic osteoarthritis of the proximal interphalangeal joint were different according to the implant design and surgical approach. The purpose of this systematic review was to evaluate outcomes of various types of implant arthroplasty for proximal interphalangeal joint osteoarthritis, with an emphasis on different surgical approaches. The authors searched all available literature in the PubMed and EMBASE databases for articles reporting on outcomes of implant arthroplasty for proximal interphalangeal joint osteoarthritis. Data collection included active arc of motion, extension lag, and complications. The authors combined the data of various types of surface replacement arthroplasty into one group for comparison with silicone arthroplasty. A total of 849 articles were screened, yielding 40 studies for final review. The mean postoperative arc of motion and the mean gain in arc of motion of silicone implant with the volar approach were 58 and 17 degrees, respectively, which was greater than surface replacement implant with the dorsal approach at 51 and 8 degrees, respectively. The mean postoperative extension lag of silicone implant with the volar approach and surface replacement with the dorsal approach was 5 and 14 degrees, respectively. The revision rate of silicone implant with the volar approach and surface replacement with the dorsal approach was 6 percent and 18 percent at a mean follow-up of 41.2 and 51 months, respectively. Silicone implant with the volar approach showed the best arc of motion, with less extension lag and fewer complications after surgery among all the implant designs and surgical approaches.

Can physical joint simulators be used to anticipate clinical wear problems of new joint replacement implants prior to market release?

PubMed

Medley, John B

2016-05-01

One of the most important mandates of physical joint simulators is to provide test results that allow the implant manufacturer to anticipate and perhaps avoid clinical wear problems with their new products. This is best done before market release. This study gives four steps to follow in conducting such wear simulator testing. Two major examples involving hip wear simulators are discussed in which attempts had been made to predict clinical wear performance prior to market release. The second one, involving the DePuy ASR implant systems, is chosen for more extensive treatment by making it an illustrative example to explore whether wear simulator testing can anticipate clinical wear problems. It is concluded that hip wear simulator testing did provide data in the academic literature that indicated some risk of clinical wear problems prior to market release of the ASR implant systems. This supports the idea that physical joint simulators have an important role in the pre-market testing of new joint replacement implants. © IMechE 2016.

Knee joint transplantation combined with surgical angiogenesis in rabbits – a new experimental model

PubMed Central

Kremer, Thomas; Giusti, Guilherme; Friedrich, Patricia F.; Willems, Wouter; Bishop, Allen T.; Giessler, Goetz A.

2012-01-01

Summary Purpose We have previously described a means to maintain bone allotransplant viability, without long-term immune modulation, replacing allogenic bone vasculature with autogenous vessels. A rabbit model for whole knee joint transplantation was developed and tested using the same methodology, initially as an autotransplant. Materials/Methods Eight New Zealand White rabbit knee joints were elevated on a popliteal vessel pedicle to evaluate limb viability in a non-survival study. Ten additional joints were elevated and replaced orthotopically in a fashion identical to allotransplantation, obviating only microsurgical repairs and immunosuppression. A superficial inferior epigastric facial (SIEF) flap and a saphenous arteriovenous (AV) bundle were introduced into the femur and tibia respectively, generating a neoangiogenic bone circulation. In allogenic transplantation, this step maintains viability after cessation of immunosuppression. Sixteen weeks later, x-rays, microangiography, histology, histomorphometry and biomechanical analysis were performed. Results Limb viability was preserved in the initial 8 animals. Both soft tissue and bone healing occurred in 10 orthotopic transplants. Surgical angiogenesis from the SIEF flap and AV bundle was always present. Bone and joint viability was maintained, with demonstrable new bone formation. Bone strength was less than the opposite side. Arthrosis and joint contractures were frequent. Conclusion We have developed a rabbit knee joint model and evaluation methods suitable for subsequent studies of whole joint allotransplantation. PMID:22113889

Rotational joint assembly and method for constructing the same

NASA Technical Reports Server (NTRS)

Bandera, Pablo (Inventor); Buchele, Paul (Inventor)

2012-01-01

A rotational joint assembly and a method for constructing a rotational joint assembly are provided. The rotational joint assembly includes a first rotational component, a second rotational component coupled to the first rotational component such that the second rotational component is rotatable relative to the first rotational component in first and second rotational directions about an axis, and a flexure member, being deflectable in first and second deflection directions, coupled to at least one of the first and second rotational components such that when the second rotational component is rotated relative to the first rotational component in each of the first and second rotational directions about the axis, the flexure member is deflected in the first deflection direction and exerts a force on the second rotational component opposing the rotation.

Lactobacillus as a rare cause of an infected total knee replacement: a case report

PubMed Central

2009-01-01

Introduction We report a rare case of an infected revision total knee replacement as a result of a Lactobacillus species infection. Lactobacillus infections have been associated with prolonged broad-spectrum antibiotic use. This can have implications in revision surgery, especially when patients have been on previous long-term suppressive antibiotic therapy. Case presentation An 81-year-old British man with a previous history of complex revision knee arthroplasty for infection presented with a hot, swollen knee joint. He had previously been on long-term suppressive antibiotic therapy. Aspiration of the knee joint yielded a culture of Lactobacillus species. Conclusion In patients undergoing revision joint arthroplasty, especially for previous infection, the presence of common and uncommon bacterial species must be excluded and eradicated before further surgical intervention. PMID:19830207

Medicare Program; Cancellation of Advancing Care Coordination Through Episode Payment and Cardiac Rehabilitation Incentive Payment Models; Changes to Comprehensive Care for Joint Replacement Payment Model: Extreme and Uncontrollable Circumstances Policy for the Comprehensive Care for Joint Replacement Payment Model. Final rule; interim final rule with comment period.

PubMed

2017-12-01

This final rule cancels the Episode Payment Models (EPMs) and Cardiac Rehabilitation (CR) Incentive Payment Model and rescinds the regulations governing these models. It also implements certain revisions to the Comprehensive Care for Joint Replacement (CJR) model, including: Giving certain hospitals selected for participation in the CJR model a one-time option to choose whether to continue their participation in the model; technical refinements and clarifications for certain payment, reconciliation and quality provisions; and a change to increase the pool of eligible clinicians that qualify as affiliated practitioners under the Advanced Alternative Payment Model (Advanced APM) track. An interim final rule with comment period is being issued in conjunction with this final rule in order to address the need for a policy to provide some flexibility in the determination of episode costs for providers located in areas impacted by extreme and uncontrollable circumstances.

The biological response to orthopedic implants for joint replacement. II: Polyethylene, ceramics, PMMA, and the foreign body reaction

PubMed Central

Gibon, Emmanuel; Córdova, Luis A.; Lu, Laura; Lin, Tzu-Hua; Yao, Zhenyu; Hamadouche, Moussa; Goodman, Stuart B.

2017-01-01

Novel evidence-based prosthetic designs and biomaterials facilitate the performance of highly successful joint replacement (JR) procedures. To achieve this goal, constructs must be durable, biomechanically sound, and avoid adverse local tissue reactions. Different biomaterials such as metals and their alloys, polymers, ceramics, and composites are currently used for JR implants. This review focuses on (1) the biological response to the different biomaterials used for TJR and (2) the chronic inflammatory and foreign-body response induced by byproducts of these biomaterials. A homeostatic state of bone and surrounding soft tissue with current biomaterials for JR can be achieved with mechanically stable, infection free and intact (as opposed to the release of particulate or ionic byproducts) implants. Adverse local tissue reactions (an acute/chronic inflammatory reaction, periprosthetic osteolysis, loosening and subsequent mechanical failure) may evolve when the latter conditions are not met. This article (Part 2 of 2) summarizes the biological response to the non-metallic materials commonly used for joint replacement including polyethylene, ceramics, and polymethylmethacrylate (PMMA), as well as the foreign body reaction to byproducts of these materials. PMID:27080740

Properties of open-cell porous metals and alloys for orthopaedic applications.

PubMed

Lewis, Gladius

2013-10-01

One shortcoming of metals and alloys used to fabricate various components of orthopaedic systems, such as the femoral stem of a total hip joint replacement and the tibial plate of a total knee joint replacement, is well-recognized. This is that the material modulus of elasticity (E') is substantially larger than that of the contiguous cancellous bone, a consequence of which is stress shielding which, in turn, has been postulated to be implicated in a cascade of events that culminates in the principal life-limiting phenomenon of these systems, namely, aseptic loosening. Thus, over the years, a host of research programs have focused on the synthesis of metallic biomaterials whose E' can be tailored to match that of cancellous bone. The present work is a review of the extant large volume of literature on these materials, which are called open-cell porous metals/alloys (or, sometimes, metal foams or cellular materials). As such, its range is wide, covering myriad aspects such as production methods, characterization studies, in vitro evaluations, and in vivo performance. The review also includes discussion of seven areas for future research, such as parametric studies of the influence of an assortment of process variables (such as the space holder material and the laser power in the space holder method and the laser-engineered net-shaping process, respectively) on various properties (notably, permeability, fatigue strength, and corrosion resistance) of a given porous metal/alloy, innovative methods of determining fatigue strength, and modeling of corrosion behavior.

Regenerative Medicine and Restoration of Joint Function

DTIC Science & Technology

2014-12-01

to resist fracture and excessive deformation under antici- pated mechanical loading conditions both during the early healing process and for longer...per sample type), the results sug- gest a correlation between percent fractured sinter neck area and mechanical properties with the lowest bending...joint replacement are used to treat a joint with an intra-articular fracture or destroyed by a combat injury. Generation of personalized, anatomically

Objective evaluation of female feet and leg joint conformation at time of selection and post first parity in swine.

PubMed

Stock, J D; Calderón Díaz, J A; Rothschild, M F; Mote, B E; Stalder, K J

2018-06-09

Feet and legs of replacement females were objectively evaluated at selection, i.e. approximately 150 days of age (n=319) and post first parity, i.e. any time after weaning of first litter and before 2nd parturition (n=277) to 1) compare feet and leg joint angle ranges between selection and post first parity; 2) identify feet and leg joint angle differences between selection and first three weeks of second gestation; 3) identify feet and leg join angle differences between farms and gestation days during second gestation; and 4) obtain genetic variance components for conformation angles for the two time points measured. Angles for carpal joint (knee), metacarpophalangeal joint (front pastern), metatarsophalangeal joint (rear pastern), tarsal joint (hock), and rear stance were measured using image analysis software. Between selection and post first parity significant differences were observed for all joints measured (P < 0.05). Knee, front and rear pastern angles were less (more flexion), and hock angles were greater (less flexion) as age progressed (P < 0.05), while the rear stance pattern was less (feet further under center) at selection than post first parity (only including measures during first three weeks of second gestation). Only using post first parity leg conformation information, farm was a significant source of variation for front and rear pasterns and rear stance angle measurements (P < 0.05). Knee angle was less (more flexion) (P < 0.05) as gestation age progressed. Heritability estimates were low to moderate (0.04 - 0.35) for all traits measured across time points. Genetic correlations between the same joints at different time points were high (> 0.8) between the front leg joints and low (<0.2) between the rear leg joints. High genetic correlations between time points indicate that the trait can be considered the same at either time point, and low genetic correlations indicate that the trait at different time points should be considered as two separate traits. Minimal change in the front leg suggests conformation traits that remain between selection and post first parity, while larger changes in rear leg indicate that rear leg conformation traits should be evaluated at multiple time periods.

Low cracking concretes for the closure pours and overlays of the Dunlap Creek Bridge : final report.

DOT National Transportation Integrated Search

2017-10-01

Joints, wide cracks, and poor-quality concretes facilitate the intrusion of chlorides, causing corrosion in bridge decks and substructures. In this study, joints were replaced with closure pours (link slabs) consisting of low permeability fiber-reinf...

Reoperations following proximal interphalangeal joint nonconstrained arthroplasties.

PubMed

Pritsch, Tamir; Rizzo, Marco

2011-09-01

To retrospectively analyze the reasons for reoperations following primary nonconstrained proximal interphalangeal (PIP) joint arthroplasty and review clinical outcomes in this group of patients with 1 or more reoperations. Between 2001 and 2009, 294 nonconstrained (203 pyrocarbon and 91 metal-plastic) PIP joint replacements were performed in our institution. A total of 76 fingers (59 patients) required reoperation (50 pyrocarbon and 26 metal-plastic). There were 40 women and 19 men with an average age of 51 years (range, 19-83 y). Primary diagnoses included osteoarthritis in 35, posttraumatic arthritis in 24, and inflammatory arthritis in 17 patients. There were 21 index, 27 middle, 18 ring, and 10 small fingers. The average number of reoperations per PIP joint was 1.6 (range, 1-4). A total of 45 joints had 1 reoperation, 19 had 2, 11 had 3, and 1 had 4. Extensor mechanism dysfunction was the most common reason for reoperation; it involved 51 of 76 fingers and was associated with Chamay or tendon-reflecting surgical approaches. Additional etiologies included component loosening in 17, collateral ligament failure in 10, and volar plate contracture in 8 cases. Inflammatory arthritis was associated with collateral ligament failure. Six fingers were eventually amputated, 9 had PIP joint arthrodeses, and 2 had resection arthroplasties. The arthrodesis and amputation rates correlated with the increased number of reoperations per finger. Clinically, most patients had no or mild pain at the most recent follow-up, and the PIP joint range-of-motion was not significantly different from preoperative values. Pain levels improved with longer follow-up. Reoperations following primary nonconstrained PIP joint arthroplasties are common. Extensor mechanism dysfunction was the most common reason for reoperation. The average reoperation rate was 1.6, and arthrodesis and amputation are associated with an increasing number of operations. Overall clinical outcomes demonstrated no significant change in range of motion, and most patients had mild or no pain. Copyright © 2011 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Laboratory studies on the tribology of hard bearing hip prostheses: ceramic on ceramic and metal on metal.

PubMed

Vassiliou, K; Scholes, S C; Unsworth, A

2007-01-01

Total hip replacements offer relief to a great many patients every year around the world. With an expected service life of around 25 years on most devices, and with younger and younger patients undergoing this surgery, it is of great importance to understand the mechanisms of their function. Tribological testing of both conventional and hard bearing joint combinations have been conducted in many centres throughout the world, and, after being initially abandoned owing to premature failures, hard bearing combinations have been revisited as viable options for joint replacements. Improved design, manufacturing procedures, and material compositions have led to improved performance over first-generation designs in both metal-on-metal and ceramic-on-ceramic hip prostheses. This paper offers a review of the work conducted in an attempt to highlight the most important factors affecting joint performance and tribology of hard bearing combinations. The tribological performance of these joints is superior to that of conventional metal- or ceramic-on-polymer designs.

Influence of hip joint simulator design and mechanics on the wear and creep of metal-on-polyethylene bearings

PubMed Central

Ali, Murat; Al-Hajjar, Mazen; Partridge, Susan; Williams, Sophie; Fisher, John; Jennings, Louise M

2016-01-01

Hip joint simulators are used extensively for preclinical testing of hip replacements. The variation in simulator design and test conditions used worldwide can affect the tribological performance of polyethylene. The aim of this study was to assess the effects of simulator mechanics and design on the wear and creep of ultra-high-molecular-weight polyethylene. In the first part of this study, an electromechanical simulator and pneumatic simulator were used to compare the wear and creep of metal-on-polyethylene components under the same standard gait conditions. In the second part of the study, the same electromechanical hip joint simulator was used to investigate the influence of kinematics on wear. Higher wear rates and penetration depths were observed from the electromechanical simulator compared with the pneumatic simulator. When adduction/abduction was introduced to the gait cycle, there was no significant difference in wear with that obtained under the gait cycle condition without adduction/abduction. This study confirmed the influence of hip simulator design and loading conditions on the wear of polyethylene, and therefore direct comparisons of absolute wear rates between different hip joint simulators should be avoided. This study also confirmed that the resulting wear path was the governing factor in obtaining clinically relevant wear rates, and this can be achieved with either two axes or three axes of rotations. However, three axes of rotation (with the inclusion of adduction/abduction) more closely replicate clinical conditions and should therefore be the design approach for newly developed hip joint simulators used for preclinical testing. PMID:27160559

Influence of hip joint simulator design and mechanics on the wear and creep of metal-on-polyethylene bearings.

PubMed

Ali, Murat; Al-Hajjar, Mazen; Partridge, Susan; Williams, Sophie; Fisher, John; Jennings, Louise M

2016-05-01

Hip joint simulators are used extensively for preclinical testing of hip replacements. The variation in simulator design and test conditions used worldwide can affect the tribological performance of polyethylene. The aim of this study was to assess the effects of simulator mechanics and design on the wear and creep of ultra-high-molecular-weight polyethylene. In the first part of this study, an electromechanical simulator and pneumatic simulator were used to compare the wear and creep of metal-on-polyethylene components under the same standard gait conditions. In the second part of the study, the same electromechanical hip joint simulator was used to investigate the influence of kinematics on wear. Higher wear rates and penetration depths were observed from the electromechanical simulator compared with the pneumatic simulator. When adduction/abduction was introduced to the gait cycle, there was no significant difference in wear with that obtained under the gait cycle condition without adduction/abduction. This study confirmed the influence of hip simulator design and loading conditions on the wear of polyethylene, and therefore direct comparisons of absolute wear rates between different hip joint simulators should be avoided. This study also confirmed that the resulting wear path was the governing factor in obtaining clinically relevant wear rates, and this can be achieved with either two axes or three axes of rotations. However, three axes of rotation (with the inclusion of adduction/abduction) more closely replicate clinical conditions and should therefore be the design approach for newly developed hip joint simulators used for preclinical testing. © IMechE 2016.

Effect of leisure time physical activity on severe knee or hip osteoarthritis leading to total joint replacement: a population-based prospective cohort study

PubMed Central

2012-01-01

Background Studies on leisure time physical activity as risk factor or protective factor for knee or hip osteoarthritis (OA) show divergent results. Longitudinal prospective studies are needed to clarify the association of physical activity with future OA. The aim was to explore in a prospective population-based cohort study the influence of leisure time physical activity on severe knee or hip OA, defined as knee or hip replacement due to OA. Methods Leisure time physical activity was reported by 28320 participants (mean age 58 years (SD 7.6), 60% women) at baseline. An overall leisure time physical activity score, taking both duration and intensity of physical activities into account, was created. The most commonly reported activities were also used for analysis. The incidence of knee or hip replacement due to OA over 11 years was monitored by linkage with the Swedish hospital discharge register. Cox’s proportional hazards model (crude and adjusted for potential confounding factors) was used to assess the incidence of total joint replacement, or osteotomy (knee), in separate analyses of leisure time physical activity. Results There was no significant overall association between leisure time physical activity and risk for knee or hip replacement due to OA over the 11-year observation time. For women only, the adjusted RR (95% CI) for hip replacement was 0.66 (0.48, 0.89) (fourth vs. first quartile), indicating a lower risk of hip replacement in those with the highest compared with the lowest physical activity. The most commonly reported activities were walking, bicycling, using stairs, and gardening. Walking was associated with a lower risk of hip replacement (adjusted RR 0.76 (95% CI 0.61, 0.94), specifically for women (adjusted RR 0.75 (95% CI 0.57, 0.98)). Conclusions In this population-based study of middle-aged men and women, leisure time physical activity showed no consistent overall relationship with incidence of severe knee or hip OA, defined as joint replacement due to OA, over 11 years. For women, higher leisure time physical activity may have a protective role for the incidence of hip replacement. Walking may have a protective role for hip replacement, specifically for women. PMID:22595023

Finite element analysis of a condylar support prosthesis to replace the temporomandibular joint.

PubMed

Abel, Eric W; Hilgers, André; McLoughlin, Philip M

2015-04-01

This paper presents a finite element study of a temporomandibular joint (TMJ) prosthesis in which the mandibular component sits on the condyle after removal of only the diseased articular surface and minimal amount of condylar bone. The condylar support prosthesis (CSP) is customised to fit the patient and allows a large part of the joint force to be transmitted through the condyle to the ramus, rather than relying only on transfer of the load by the screws that fix the prosthesis to the ramus. The 3-dimensional structural finite element analysis compared a design of CSP with a standard commercial prosthesis and one that was modified to fit the ramus, to relate the findings to the different designs and geometrical features. The models simulated an incisal bite under high loading. In the CSP and in its fixation screws, the stresses were much lower than those in the other 2 prostheses and the bone strains were at physiological levels. The CSP gives a more physiological form of load transfer than is possible without the condylar contact, and considerably reduces the amount of strain on the bone around the screws. Copyright © 2015 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

No evidence for the use of DIR, D–D fusions, chromosome 15 open reading frames or VHreplacement in the peripheral repertoire was found on application of an improved algorithm, JointML, to 6329 human immunoglobulin H rearrangements

PubMed Central

Ohm-Laursen, Line; Nielsen, Morten; Larsen, Stine R; Barington, Torben

2006-01-01

Antibody diversity is created by imprecise joining of the variability (V), diversity (D) and joining (J) gene segments of the heavy and light chain loci. Analysis of rearrangements is complicated by somatic hypermutations and uncertainty concerning the sources of gene segments and the precise way in which they recombine. It has been suggested that D genes with irregular recombination signal sequences (DIR) and chromosome 15 open reading frames (OR15) can replace conventional D genes, that two D genes or inverted D genes may be used and that the repertoire can be further diversified by heavy chain V gene (VH) replacement. Safe conclusions require large, well-defined sequence samples and algorithms minimizing stochastic assignment of segments. Two computer programs were developed for analysis of heavy chain joints. JointHMM is a profile hidden Markow model, while JointML is a maximum-likelihood-based method taking the lengths of the joint and the mutational status of the VH gene into account. The programs were applied to a set of 6329 clonally unrelated rearrangements. A conventional D gene was found in 80% of unmutated sequences and 64% of mutated sequences, while D-gene assignment was kept below 5% in artificial (randomly permutated) rearrangements. No evidence for the use of DIR, OR15, multiple D genes or VH replacements was found, while inverted D genes were used in less than 1‰ of the sequences. JointML was shown to have a higher predictive performance for D-gene assignment in mutated and unmutated sequences than four other publicly available programs. An online version 1·0 of JointML is available at http://www.cbs.dtu.dk/services/VDJsolver. PMID:17005006

QM-8 field joint protection system, volume 7

NASA Technical Reports Server (NTRS)

Hale, Elgie

1989-01-01

The pre-launch functioning data of the Field Joint Protection System (JPS) used on QM-8 are presented. Also included is the post fire condition of the JPS components following the test firing of the motor. The JPS components are: field joint heaters; field joint sensors; field joint moisture seal; moisture seal kevlar retaining straps; field joint external extruded cork insulation; vent valve; power cables; and igniter heater.

Aircraft to Medicine

NASA Technical Reports Server (NTRS)

1991-01-01

This video discusses how the technology of computer modeling can improve the design and durability of artificial joints for human joint replacement surgery. Also, ultrasound, originally used to detect structural flaws in aircraft, can also be used to quickly assess the severity of a burn patient's injuries, thus aiding the healing process.

JPSS CGS Evolution

NASA Astrophysics Data System (ADS)

Miller, S. W.; Grant, K. D.; Jamilkowski, M. L.

2012-12-01

The National Oceanic and Atmospheric Administration (NOAA) and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation civilian weather and environmental satellite system: the Joint Polar Satellite System (JPSS). JPSS will contribute the afternoon orbit component and ground processing system. As such, the Joint Polar Satellite System replaces the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA. It also replaces the ground processing component of both Polar-orbiting Operational Environmental Satellites, as well as components of the Defense Meteorological Satellite Program (DMSP) replacement, previously known as the Defense Weather Satellite System (DWSS), managed by the Department of Defense (DoD). The JPSS satellites will carry a suite of sensors designed to collect meteorological, oceanographic, climatological and solar-geophysical observations of the earth, atmosphere and space. The ground processing system for JPSS is known as the JPSS Common Ground System (JPSS CGS), which consists of a Command, Control and Communications Segment (C3S) and an Interface Data Processing Segment (IDPS). Both segments are developed by Raytheon Intelligence and Information Systems (IIS). The C3S is currently flying the Suomi National Polar Partnership (Suomi NPP) satellite and transfers mission data from Suomi NPP and between the ground facilities. The IDPS processes Suomi NPP satellite data to provide Environmental Data Records (EDRs) to NOAA and DoD processing centers operated by the United States government. When the JPSS-1 satellite is launched in early 2017, the responsibilities of the C3S and the IDPS will be expanded to support both Suomi NPP and JPSS-1. The CGS also employs its ground stations at Svalbard, Norway and McMurdo Station, Antarctica, along with a global fiber communications network, to provide data acquisition and routing for multiple additional missions. These include POES, DMSP, NASA Space Communications and Navigation (SCaN, which includes the Earth Observing System [EOS]), Metop for the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), Coriolis/WindSat for the DoD, as well as research activities of the National Science Foundation (NSF). The CGS architecture is evolving over the next few years for several key reasons: 1. "Operationalizing" Suomi NPP, which had originally been intended as a risk reduction mission 2. Leveraging lessons learned to date in multi-mission support 3. Taking advantage of newer, more reliable and efficient technologies 4. Satisfying new requirements and constraints due to the continually evolving budgetary environment Three key aspects of the CGS architecture are being prototyped as part of the path to improve operations in the 2015 timeframe. First, the front end architecture for mission data transport is being re-architected to improve reliability and address the incorporation of new ground stations. Second, the IDPS is undergoing a decoupling process to enhance its flexibility and modularity for supporting an array of potential new missions beyond those listed above. Finally, a solution for complete situational awareness across the CGS is being developed, to facilitate quicker and more efficient identification and resolution of system anomalies. This paper discusses the evolution of the CGS architecture to address these future mission needs.

Tribochemical Characterization and Tribocorrosive Behavior of CoCrMo Alloys: A Review

PubMed Central

Toh, Wei Quan; Liu, Erjia; Tor, Shu Beng

2017-01-01

Orthopedic implants first started out as an all-metal hip joint replacement. However, poor design and machinability as well as unsatisfactory surface finish subjected the all-metal joint replacement to being superseded by a polyethylene bearing. Continued improvement in manufacturing techniques together with the reality that polyethylene wear debris can cause hazardous reactions in the human body has brought about the revival of metal-on-metal (MOM) hip joints in recent years. This has also led to a relatively new research area that links tribology and corrosion together. This article aims at reviewing the commonly used tribochemical methods adopted in the analysis of tribocorrosion and putting forward some of the models and environmental factors affecting the tribocorrosive behavior of CoCrMo alloys, a widely-used class of biomaterial for orthopedic implants. PMID:29278375

The trivector approach for minimally invasive total knee arthroplasty: a technical note.

PubMed

Benazzo, Francesco; Rossi, Stefano Marco Paolo

2012-09-01

One of the main criticisms of minimally invasive approaches in total knee arthroplasty has been their poor adaptability in cases of major deformity or stiffness of the knee joint. When they are used in such cases, excessive soft-tissue tension is needed to provide appropriate joint exposure. Here, we describe the "mini trivector approach," which has become our standard approach for total knee replacement because it permits us to enlarge the indication for minimally or less invasive total knee replacement to many knees where quad sparing, a subvastus approach, or a mini quad or mini midvastus snip may not be sufficient to achieve correct exposure. It consists of a limited double snip of the VMO and the quadriceps tendon that reduces tension on the extensor mechanism and allows easier verticalization of the patella as well as good joint exposure.

Tribochemical Characterization and Tribocorrosive Behavior of CoCrMo Alloys: A Review.

PubMed

Toh, Wei Quan; Tan, Xipeng; Bhowmik, Ayan; Liu, Erjia; Tor, Shu Beng

2017-12-26

Orthopedic implants first started out as an all-metal hip joint replacement. However, poor design and machinability as well as unsatisfactory surface finish subjected the all-metal joint replacement to being superseded by a polyethylene bearing. Continued improvement in manufacturing techniques together with the reality that polyethylene wear debris can cause hazardous reactions in the human body has brought about the revival of metal-on-metal (MOM) hip joints in recent years. This has also led to a relatively new research area that links tribology and corrosion together. This article aims at reviewing the commonly used tribochemical methods adopted in the analysis of tribocorrosion and putting forward some of the models and environmental factors affecting the tribocorrosive behavior of CoCrMo alloys, a widely-used class of biomaterial for orthopedic implants.

Late Streptococcus bovis infection of total knee replacement complicated by infective endocarditis and associated with colonic ulcers

PubMed Central

Nagy, Mathias Thomas; Hla, Sann Minn; Keys, Graham Watson

2013-01-01

Streptococcus bovis is rare cause of late infections after total knee replacement (TKR). This report presents a case of confirmed late septic arthritis following TKR caused by S bovis that was further complicated with infective endocarditis resulting in aortic valve insufficiency in an immunecompetent patient. As an association between S bovis and gastrointestinal malignancies is suggested, a workup for such malignancies was performed that revealed non-malignant ulcers in patient's ascending colon. The patient is currently recovering from his aortic valve replacement surgery and is scheduled to have annual colonoscopies. His knee joint has improved; however, he developed constant pain because of underlying chronic infection in the affected joint and has difficulties mobilising. Therefore, a revision TKR is considered but postponed until he fully recovers from his heart valve surgery. PMID:23744853

Trapezium Bone Density-A Comparison of Measurements by DXA and CT.

PubMed

Breddam Mosegaard, Sebastian; Breddam Mosegaard, Kamille; Bouteldja, Nadia; Bæk Hansen, Torben; Stilling, Maiken

2018-01-18

Bone density may influence the primary fixation of cementless implants, and poor bone density may increase the risk of implant failure. Before deciding on using total joint replacement as treatment in osteoarthritis of the trapeziometacarpal joint, it is valuable to determine the trapezium bone density. The aim of this study was to: (1) determine the correlation between measurements of bone mineral density of the trapezium obtained by dual-energy X-ray absorptiometry (DXA) scans by a circumference method and a new inner-ellipse method; and (2) to compare those to measurements of bone density obtained by computerized tomography (CT)-scans in Hounsfield units (HU). We included 71 hands from 59 patients with a mean age of 59 years (43-77). All patients had Eaton-Glickel stage II-IV trapeziometacarpal (TM) joint osteoarthritis, were under evaluation for trapeziometacarpal total joint replacement, and underwent DXA and CT wrist scans. There was an excellent correlation (r = 0.94) between DXA bone mineral density measures using the circumference and the inner-ellipse method. There was a moderate correlation between bone density measures obtained by DXA- and CT-scans with (r = 0.49) for the circumference method, and (r = 0.55) for the inner-ellipse method. DXA may be used in pre-operative evaluation of the trapezium bone quality, and the simpler DXA inner-ellipse measurement method can replace the DXA circumference method in estimation of bone density of the trapezium.

76 FR 13928 - Amendment to the International Traffic in Arms Regulations: Replacement Parts/Components and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-15

... International Traffic in Arms Regulations: Replacement Parts/Components and Incorporated Articles AGENCY... incorporated articles. DATES: The Department of State will accept comments on this proposed rule until April 14... Controls Policy, Attn: Regulatory Changes--Replacement Parts/Components and Incorporated Articles, Bureau...

Patterns of Ninety-Day Readmissions Following Total Joint Replacement in a Bundled Payment Initiative.

PubMed

Behery, Omar A; Kester, Benjamin S; Williams, Jarrett; Bosco, Joseph A; Slover, James D; Iorio, Richard; Schwarzkopf, Ran

2017-04-01

Alternative payment models aim to improve quality and decrease costs associated with total joint replacement. Postoperative readmissions within 90 days are of interest to clinicians and administrators as there is no additional reimbursement beyond the episode bundled payment target price. The aim of this study is to improve the understanding of the patterns of readmission which would better guide perioperative patient management affecting readmissions. We hypothesize that readmissions have different timing, location, and patient health profile patterns based on whether the readmission is related to a medical or surgical diagnosis. A retrospective cohort of 80 readmissions out of 1412 total joint replacement patients reimbursed through a bundled payment plan was analyzed. Patients were grouped by readmission diagnosis (surgical or medical) and the main variables analyzed were time to readmission, location of readmission, and baseline Perioperative Orthopaedic Surgical Home and American Society of Anesthesiologists scores capturing pre-existing state of health. Nonparametric tests and multivariable regressions were used to test associations. Surgical readmissions occurred earlier than medical readmissions (mean 18 vs 33 days, P = .011), and were more likely to occur at the hospital where the surgery was performed (P = .035). Perioperative Orthopaedic Surgical Home and American Society of Anesthesiologists scores did not predict medical vs surgical readmissions (P = .466 and .879) after adjusting for confounding variables. Readmissions appear to follow different patterns depending on whether they are surgical or medical. Surgical readmissions occur earlier than medical readmissions, and more often at the hospital where the surgery was performed. The results of this study suggest that these 2 types of readmissions have different patterns with different implications toward perioperative care and follow-up after total joint replacement. Copyright © 2016 Elsevier Inc. All rights reserved.

Exploring the relationships between International Classification of Functioning, Disability and Health (ICF) constructs of Impairment, Activity Limitation and Participation Restriction in people with osteoarthritis prior to joint replacement.

PubMed

Pollard, Beth; Johnston, Marie; Dieppe, Paul

2011-05-16

The International Classification of Functioning, Disability and Health (ICF) proposes three main constructs, impairment (I), activity limitation (A) and participation restriction (P). The ICF model allows for all paths between the constructs to be explored, with significant paths likely to vary for different conditions. The relationships between I, A and P have been explored in some conditions but not previously in people with osteoarthritis prior to joint replacement. The aim of this paper is to examine these relationships using separate measures of each construct and structural equation modelling. A geographical cohort of 413 patients with osteoarthritis about to undergo hip and knee joint replacement completed the Aberdeen measures of Impairment, Activity Limitation and Participation Restriction (Ab-IAP). Confirmatory factor analysis was used to test the three factor (I, A, P) measurement model. Structural equation modelling was used to explore the I, A and P pathways in the ICF model. There was support from confirmatory factor analysis for the three factor I, A, P measurement model. The structural equation model had good fit [S-B Chi-square = 439.45, df = 149, CFI robust = 0.91, RMSEA robust = 0.07] and indicated significant pathways between I and A (standardised coefficient = 0.76 p < 0.0001) and between A and P (standardised coefficient = 0.75 p < 0.0001). However, the path between I and P was not significant (standardised coefficient = 0.01). The significant pathways suggest that treatments and interventions aimed at reducing impairment, such as joint replacement, may only affect P indirectly, through A, however, longitudinal data would be needed to establish this.

Modeling the Potential Economic Impact of the Medicare Comprehensive Care for Joint Replacement Episode-Based Payment Model.

PubMed

Maniya, Omar Z; Mather, Richard C; Attarian, David E; Mistry, Bipin; Chopra, Aneesh; Strickland, Matt; Schulman, Kevin A

2017-11-01

The Medicare program has initiated Comprehensive Care for Joint Replacement (CJR), a bundled payment mandate for lower extremity joint replacements. We sought to determine the degree to which hospitals will invest in care redesign in response to CJR, and to project its economic impacts. We defined 4 potential hospital management strategies to address CJR: no action, light care management, heavy care management, and heavy care management with contracting. For each of 798 hospitals included in CJR, we used hospital-specific volume, cost, and quality data to determine the hospital's economically dominant strategy. We aggregated data to assess the percentage of hospitals pursuing each strategy; savings to the health care system; and costs and percentages of CJR-derived revenues gained or lost for Medicare, hospitals, and postacute care facilities. In the model, 83.1% of hospitals (range 55.0%-100.0%) were expected to take no action in response to CJR, and 16.1% of hospitals (range 0.0%-45.0%) were expected to pursue heavy care management with contracting. Overall, CJR is projected to reduce health care expenditures by 0.5% (range 0.0%-4.1%) or $14 million (range $0-$119 million). Medicare is expected to save 2.2% (range 2.2%-2.2%), hospitals are projected to lose 3.7% (range 4.7% loss to 3.8% gain), and postacute care facilities are expected to lose 6.5% (range 0.0%-12.8%). Hospital administrative costs are projected to increase by $63 million (range $0-$148 million). CJR is projected to have a negligible impact on total health care expenditures for lower extremity joint replacements. Further research will be required to assess the actual care management strategies adopted by CJR hospitals. Copyright © 2017 Elsevier Inc. All rights reserved.

Comparison of a self-administered foot evaluation questionnaire (SAFE-Q) between joint-preserving arthroplasty and resection-replacement arthroplasty in forefoot surgery for patients with rheumatoid arthritis.

PubMed

Ebina, Kosuke; Hirao, Makoto; Hashimoto, Jun; Nampei, Akihide; Shi, Kenrin; Tomita, Tetsuya; Futai, Kazuma; Kunugiza, Yasuo; Noguchi, Takaaki; Yoshikawa, Hideki

2017-09-01

To clarify the difference of patient-based outcome between joint-preserving arthroplasty and resection-replacement arthroplasty in forefoot surgery for patients with rheumatoid arthritis (RA). A total of 63 feet of 49 RA patients who underwent forefoot surgery were asked to answer pre-operative and post-operative self-administered foot evaluation questionnaire (SAFE-Q). Patients were treated with either (1) metatarsal head resection-replacement arthroplasty (28 feet, post-operative mean age 63.8 years, follow-up 4.2 years, DAS28-CRP 2.2) or (2) metatarsophalangeal joint-preserving arthroplasty (35 feet, post-operative mean age 63.1 years, follow-up 3.6 years, DAS28-CRP 2.1) at each surgeon's discretion. Mean pre-operative and post-operative subscale scores of SAFE-Q of group (1) and (2) were as follows. Pain and pain-related [(1) pre-op 36.8 to post-op 75.0 vs. (2) pre-op 42.2 to post-op 82.6], physical functioning and daily-living [(1) 43.2-68.8 vs. (2) 52.778.1], social functioning [(1) 44.3-72.0 vs. (2) 52.5-81.9], general health and well-being [(1) 48.4-68.4 vs. (2) 45.5-84.4], and shoe-related [(1) 30.1-50.3 vs. (2) 30.6-64.4]. Both general health and well-being subscale scores (p < 0.05) and shoe-related subscale scores (p < 0.05) were significantly more improved in group (2) compared with group (1). Joint-preserving arthroplasty resulted in better patient-based outcomes than resection-replacement arthroplasty.

RSA and registries: the quest for phased introduction of new implants.

PubMed

Nelissen, Rob G H H; Pijls, Bart G; Kärrholm, Johan; Malchau, Henrik; Nieuwenhuijse, Marc J; Valstar, Edward R

2011-12-21

Although the overall survival of knee and hip prostheses at ten years averages 90%, recent problems with several hip and knee prostheses have illustrated that the orthopaedic community, industry, and regulators can still further improve patient safety. Given the early predictive properties of roentgen stereophotogrammetric analysis (RSA) and the meticulous follow-up of national joint registries, these two methods are ideal tools for such a phased clinical introduction. In this paper, we elaborate on the predictive power of RSA within a two-year follow-up after arthroplasty and its relationship to national joint registries. The association between RSA prosthesis-migration data and registry data is evaluated. The five-year rate of revision of RSA-tested total knee replacements was compared with that of non-RSA-tested total knee replacements. Data were extracted from the published results of the national joint registries of Sweden, Australia, and New Zealand. There was a 22% to 35% reduction in the number of revisions of RSA-tested total knee replacements as compared with non-RSA-tested total knee replacements in the national joint registries. Assuming that the total cost of total knee arthroplasty is $37,000 in the United States, a 22% to 35% reduction in the number of revisions (currently close to 55,000 annually) could lead to an estimated annual savings of over $400 million to the health-care system. The phased clinical introduction of new prostheses with two-year RSA results as a qualitative tool could lead to better patient care and could reduce the costs associated with revision total knee arthroplasty. Follow-up in registries is necessary to substantiate these results and to improve post-market surveillance.

Defense Acquisitions: Assessments of Selected Weapon Programs

DTIC Science & Technology

2016-03-01

Increment 3 81 Indirect Fire Protection Capability Increment 2-Intercept Block 1 (IFPC Inc 2-I Block 1) 83 Improved Turbine Engine Program (ITEP...ITEP Improved Turbine Engine Program JAGM Joint Air-to-Ground Missile JLTV Joint Light Tactical Vehicle JSTARS Recap Joint Surveillance Target...Attack Radar System Recap 09/2017 —-   Improved Turbine Engine Program 06/2018 O O O Amphibious Ship Replacement 09/2018 O O Advanced Pilot

Second-site prosthetic joint infection in patients with multiple prosthetic joints.

PubMed

Clesham, Kevin; Hughes, Andrew J; O' hEireamhoin, Sven; Fleming, Catherine; Murphy, Colin G

2018-04-10

Prosthetic joint infections (PJIs) are among the most serious complications in arthroplasty. A second-site PJI in patients with multiple prosthetic joints increases morbidity, with many requiring further revision procedures. We aimed to establish why some patients with multiple joints develop second-site infections. Our institution's arthroplasty database was reviewed from 2004 to 2017. All PJIs were identified, and all patients with more than one prosthetic joint in situ were included. We recorded risk factors, causative organisms, number of procedures and length of stay. Forty-four patients meeting the criteria were identified. Four patients (9.1%) developed second-site infection. Eight patients (18.2%) developed re-infection of the primary PJI. Positive MRSA carrier status and PJI of a total knee replacement were associated with an increased risk of a second episode of infection. Patients who developed further infection had more frequent admission and longer lengths of stay than isolated PJIs. Higher morbidity and use of hospital resources are associated with this cohort of patients. PJIs in total knee replacements and positive MRSA status are associated with higher rates of second infection. Identifying this vulnerable cohort of patients at an early stage is critical to ensure measures are taken to reduce the risks of further infection.

Bonded repair of composite aircraft structures: A review of scientific challenges and opportunities

NASA Astrophysics Data System (ADS)

Katnam, K. B.; Da Silva, L. F. M.; Young, T. M.

2013-08-01

Advanced composite materials have gained popularity in high-performance structural designs such as aerospace applications that require lightweight components with superior mechanical properties in order to perform in demanding service conditions as well as provide energy efficiency. However, one of the major challenges that the aerospace industry faces with advanced composites - because of their inherent complex damage behaviour - is structural repair. Composite materials are primarily damaged by mechanical loads and/or environmental conditions. If material damage is not extensive, structural repair is the only feasible solution as replacing the entire component is not cost-effective in many cases. Bonded composite repairs (e.g. scarf patches) are generally preferred as they provide enhanced stress transfer mechanisms, joint efficiencies and aerodynamic performance. With an increased usage of advanced composites in primary and secondary aerospace structural components, it is thus essential to have robust, reliable and repeatable structural bonded repair procedures to restore damaged composite components. But structural bonded repairs, especially with primary structures, pose several scientific challenges with the current existing repair technologies. In this regard, the area of structural bonded repair of composites is broadly reviewed - starting from damage assessment to automation - to identify current scientific challenges and future opportunities.

Prevalence of Total Hip and Knee Replacement in the United States.

PubMed

Maradit Kremers, Hilal; Larson, Dirk R; Crowson, Cynthia S; Kremers, Walter K; Washington, Raynard E; Steiner, Claudia A; Jiranek, William A; Berry, Daniel J

2015-09-02

Descriptive epidemiology of total joint replacement procedures is limited to annual procedure volumes (incidence). The prevalence of the growing number of individuals living with a total hip or total knee replacement is currently unknown. Our objective was to estimate the prevalence of total hip and total knee replacement in the United States. Prevalence was estimated using the counting method by combining historical incidence data from the National Hospital Discharge Survey and the Healthcare Cost and Utilization Project (HCUP) State Inpatient Databases from 1969 to 2010 with general population census and mortality counts. We accounted for relative differences in mortality rates between those who have had total hip or knee replacement and the general population. The 2010 prevalence of total hip and total knee replacement in the total U.S. population was 0.83% and 1.52%, respectively. Prevalence was higher among women than among men and increased with age, reaching 5.26% for total hip replacement and 10.38% for total knee replacement at eighty years. These estimates corresponded to 2.5 million individuals (1.4 million women and 1.1 million men) with total hip replacement and 4.7 million individuals (3.0 million women and 1.7 million men) with total knee replacement in 2010. Secular trends indicated a substantial rise in prevalence over time and a shift to younger ages. Around 7 million Americans are living with a hip or knee replacement, and consequently, in most cases, are mobile, despite advanced arthritis. These numbers underscore the substantial public health impact of total hip and knee arthroplasties. Copyright © 2015 by The Journal of Bone and Joint Surgery, Incorporated.

Brazing graphite to graphite

DOEpatents

Peterson, George R.

1976-01-01

Graphite is joined to graphite by employing both fine molybdenum powder as the brazing material and an annealing step that together produce a virtually metal-free joint exhibiting properties similar to those found in the parent graphite. Molybdenum powder is placed between the faying surfaces of two graphite parts and melted to form molybdenum carbide. The joint area is thereafter subjected to an annealing operation which diffuses the carbide away from the joint and into the graphite parts. Graphite dissolved by the dispersed molybdenum carbide precipitates into the joint area, replacing the molybdenum carbide to provide a joint of virtually graphite.

Influence of Total Knee Arthroplasty on Gait Mechanics of the Replaced and Non-Replaced Limb During Stair Negotiation.

PubMed

Standifird, Tyler W; Saxton, Arnold M; Coe, Dawn P; Cates, Harold E; Reinbolt, Jeffrey A; Zhang, Songning

2016-01-01

This study compared biomechanics during stair ascent in replaced and non-replaced limbs of total knee arthroplasty (TKA) patients with control limbs of healthy participants. Thirteen TKA patients and fifteen controls performed stair ascent. Replaced and non-replaced knees of TKA patients were less flexed at contact compared to controls. The loading response peak knee extension moment was greater in control and non-replaced knees compared with replaced. The push-off peak knee abduction moment was elevated in replaced limbs compared to controls. Loading and push-off peak hip abduction moments were greater in replaced limbs compared to controls. The push-off peak hip abduction moment was greater in non-replaced limbs compared to controls. Future rehabilitation protocols should consider the replaced knee and also the non-replaced knee and surrounding joints. Copyright © 2016 Elsevier Inc. All rights reserved.

Intra-articular Enzyme Replacement Therapy with rhIDUA is Safe, Well-Tolerated, and Reduces Articular GAG Storage in the Canine Model of Mucopolysaccharidosis Type I

PubMed Central

Wang, Raymond Y; Aminian, Afshin; McEntee, Michael F; Kan, Shih-Hsin; Simonaro, Calogera M; Lamanna, William; Lawrence, Roger; Ellinwood, N. Matthew; Guerra, Catalina; Le, Steven Q; Dickson, Patricia I; Esko, Jeffrey D

2014-01-01

Background Treatment with intravenous enzyme replacement therapy and hematopoietic stem cell transplantation for mucopolysaccharidosis (MPS) type I does not address joint disease, resulting in persistent orthopedic complications and impaired quality of life. A proof-of-concept study was conducted to determine the safety, tolerability, and efficacy of intra-articular recombinant human iduronidase (IA-rhIDUA) enzyme replacement therapy in the canine MPS I model. Methods Four MPS I dogs underwent monthly rhIDUA injections (0.58 mg/joint) into the right elbow and knee for six months. Contralateral elbows and knees concurrently received normal saline. No intravenous rhIDUA therapy was administered. Monthly blood counts, chemistries, anti-rhIDUA antibody titers, and synovial fluid cell counts were measured. Lysosomal storage of synoviocytes and chondrocytes, synovial macrophages and plasma cells were scored at baseline and one month following the final injection. Results All injections were well-tolerated without adverse reactions. One animal required prednisone for spinal cord compression. There were no clinically significant abnormalities in blood counts or chemistries. Circulating anti-rhIDUA antibody titers gradually increased in all dogs except the prednisone-treated dog; plasma cells, which were absent in all baseline synovial specimens, were predominantly found in synovium of rhIDUA-treated joints at study-end. Lysosomal storage in synoviocytes and chondrocytes following 6 months of IA-rhIDUA demonstrated significant reduction compared to tissues at baseline, and saline-treated tissues at study-end. Mean joint synovial GAG levels in IA-rhIDUA joints was 8.62±5.86 μg/mg dry weight and 21.6±10.4 μg/mg dry weight in control joints (60% reduction). Cartilage heparan sulfate was also reduced in the IA-rhIDUA joints (113±39.5 ng/g wet weight) compared to saline-treated joints (142±56.4 ng/g wet weight). Synovial macrophage infiltration, which was present in all joints at baseline, was abolished in rhIDUA-treated joints only. Conclusions Intra-articular rhIDUA is well-tolerated and safe in the canine MPS I animal model. Qualitative and quantitative assessments indicate that IA-rhIDUA successfully reduces tissue and cellular GAG storage in synovium and articular cartilage, including cartilage deep to the articular surface, and eliminates inflammatory macrophages from synovial tissue. PMID:24951454

Development of a patient-specific temporomandibular joint prosthesis according to the Groningen principle through a cadaver test series.

PubMed

Kraeima, J; Merema, B J; Witjes, M J H; Spijkervet, F K L

2018-05-01

Patients suffering from osteoarthritis, ankylosis (e.g. post-trauma or tumour) in the temporomandibular joint (TMJ) can present with symptoms such as severely restricted mouth opening, pain or other dynamic restrictions of the mandible. To alleviate the symptoms, a total joint prosthesis can be indicated, such as the Groningen TMJ prosthesis. This was developed as a stock device with a lowered centre of rotation for improved translational and opening capacity. This study aimed to improve the design of the prosthesis, and produce a workflow for a customized Groningen TMJ prosthesis, in order to make it more accurate and predictable. The fossa and mandibular components of the Groningen TMJ prosthesis were customized. A series of five human cadavers was operated and bilateral TMJ prostheses were placed using custom cutting and drilling guides. Placement accuracy was evaluated based on post-operative CT data. A total of N = 10 prostheses were placed and analysed. The average Euclidean distance deviation from planned to actual position was 0.81 mm (SD 0.21). All prostheses were placed according to the routine surgical approaches and had an excellent alignment with the bony structures. The newly developed custom Groningen TMJ prosthesis can be placed with great accuracy and is the first step for improving TMJ total joint replacement surgery. Copyright © 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Effects of tibial plateau angle and spacer thickness applied during in vitro canine total knee replacement on three-dimensional kinematics and collateral ligament strain.

PubMed

Baker, Katherine M; Foutz, Timothy L; Johnsen, Kyle J; Budsberg, Steven C

2014-09-01

To quantify the 3-D kinematics and collateral ligament strain of stifle joints in cadaveric canine limbs before and after cranial cruciate ligament transection followed by total knee replacement (TKR) involving various tibial plateau angles and spacer thicknesses. 6 hemi-pelvises collected from clinically normal nonchondrodystrophic dogs (weight range, 25 to 35 kg). Hemi-pelvises were mounted on a modified Oxford knee rig that allowed 6 degrees of freedom of the stifle joint but prevented mechanical movement of the hip and tarsal joints. Kinematics and collateral ligament strain were measured continuously while stifle joints were flexed. Data were again collected after cranial cruciate ligament transection and TKR with combinations of 3 plateau angles (0°, 4°, and 8°) and spacer thicknesses (5, 7, and 9 mm). Presurgical (ie, normal) stifle joint rotations were comparable to those previously documented for live dogs. After TKR, kinematics recorded for the 8°, 5-mm implant most closely resembled those of unaltered stifle joints. Decreasing the plateau angle and increasing spacer thickness altered stifle joint adduction, internal rotation, and medial translation. Medial collateral ligament strain was minimal in unaltered stifle joints and was unaffected by TKR. Lateral collateral ligament strain decreased with steeper plateau angles but returned to a presurgical level at the flattest plateau angle. Among the constructs tested, greatest normalization of canine stifle joint kinematics in vitro was achieved with the steepest plateau angle paired with the thinnest spacer. Furthermore, results indicated that strain to the collateral ligaments was not negatively affected by TKR.

21 CFR 888.6 - Degree of constraint.

Code of Federal Regulations, 2010 CFR

2010-04-01

... replacement and prevents dislocation of the prosthesis in more than one anatomic plane and consists of either... translation and rotation of the prosthesis in one or more planes via the geometry of its articulating surfaces... total joint replacement and restricts minimally prosthesis movement in one or more planes. Its...

Experimental Investigation on Strengthening of Bolted Connections in Transmission/Communication Towers

NASA Astrophysics Data System (ADS)

Balagopal, R.; Prasad Rao, N.; Rokade, R. P.; Umesha, P. K.

2018-06-01

Due to increase in demand for power supply and increase in bandwidth for communication industry, the existing transmission line (TL) and communication towers needs to be strengthened. The strengthening of existing tower is economical rather than installation of new towers due to constraints in acquisition of land. The size of conductors have to be increased or additional number of antenna needs to be installed in existing TL/communication tower respectively. The compression and tension capacity of members in the existing towers have to be increased to sustain the additional loads due to wind and self-weight of these components. The tension capacity enhancement of existing angle sections in live line condition without power shut-down is a challenging task. In the present study, the use of Glass Fiber Reinforced Plastic (GFRP) plate/angle sections is explored to strengthen existing bolted connections in TL/communication towers. Experimental investigation conducted at component level on strengthening of existing two types of single cover steel butt joint, one made of steel plate and another joint made of steel angle sections respectively. First series of experiment conducted on strengthening the connection using GFRP plate/cleat angle sections. The second series of strengthening experiment is conducted using steel plate/angle sections to replace GFRP sections. The load sharing behaviour of strengthened GFRP and steel section is compared and suitable recommendations are given.

Experimental Investigation on Strengthening of Bolted Connections in Transmission/Communication Towers

NASA Astrophysics Data System (ADS)

Balagopal, R.; Prasad Rao, N.; Rokade, R. P.; Umesha, P. K.

2018-02-01

Due to increase in demand for power supply and increase in bandwidth for communication industry, the existing transmission line (TL) and communication towers needs to be strengthened. The strengthening of existing tower is economical rather than installation of new towers due to constraints in acquisition of land. The size of conductors have to be increased or additional number of antenna needs to be installed in existing TL/communication tower respectively. The compression and tension capacity of members in the existing towers have to be increased to sustain the additional loads due to wind and self-weight of these components. The tension capacity enhancement of existing angle sections in live line condition without power shut-down is a challenging task. In the present study, the use of Glass Fiber Reinforced Plastic (GFRP) plate/angle sections is explored to strengthen existing bolted connections in TL/communication towers. Experimental investigation conducted at component level on strengthening of existing two types of single cover steel butt joint, one made of steel plate and another joint made of steel angle sections respectively. First series of experiment conducted on strengthening the connection using GFRP plate/cleat angle sections. The second series of strengthening experiment is conducted using steel plate/angle sections to replace GFRP sections. The load sharing behaviour of strengthened GFRP and steel section is compared and suitable recommendations are given.

MEMS-based power generation techniques for implantable biosensing applications.

PubMed

Lueke, Jonathan; Moussa, Walied A

2011-01-01

Implantable biosensing is attractive for both medical monitoring and diagnostic applications. It is possible to monitor phenomena such as physical loads on joints or implants, vital signs, or osseointegration in vivo and in real time. Microelectromechanical (MEMS)-based generation techniques can allow for the autonomous operation of implantable biosensors by generating electrical power to replace or supplement existing battery-based power systems. By supplementing existing battery-based power systems for implantable biosensors, the operational lifetime of the sensor is increased. In addition, the potential for a greater amount of available power allows additional components to be added to the biosensing module, such as computational and wireless and components, improving functionality and performance of the biosensor. Photovoltaic, thermovoltaic, micro fuel cell, electrostatic, electromagnetic, and piezoelectric based generation schemes are evaluated in this paper for applicability for implantable biosensing. MEMS-based generation techniques that harvest ambient energy, such as vibration, are much better suited for implantable biosensing applications than fuel-based approaches, producing up to milliwatts of electrical power. High power density MEMS-based approaches, such as piezoelectric and electromagnetic schemes, allow for supplemental and replacement power schemes for biosensing applications to improve device capabilities and performance. In addition, this may allow for the biosensor to be further miniaturized, reducing the need for relatively large batteries with respect to device size. This would cause the implanted biosensor to be less invasive, increasing the quality of care received by the patient.

Two-Stage Revision for Infected Total Knee Arthroplasty: Based on Autoclaving the Recycled Femoral Component and Intraoperative Molding Using Antibiotic-Impregnated Cement on the Tibial Side.

PubMed

Lee, Byoung-Joo; Kyung, Hee-Soo; Yoon, Seong-Dae

2015-09-01

The purpose of this study was to determine the degree of infection control and postoperative function for new articulating metal-on-cement spacer. A retrospective study of 19 patients (20 cases), who underwent a two-stage revision arthroplasty using mobile cement prosthesis, were followed for a minimum of 2 years. This series consisted of 16 women and 3 men, having an overall mean age of 71 years. During the first stage of revision, the femoral implant and all the adherent cement was removed, after which it was autoclaved before replacement. The tibial component was removed and a doughy state, antibiotic-impregnated cement was inserted on the tibial side. To achieve joint congruency, intraoperative molding was performed by flexing and extending the knee joint. Each patient was evaluated clinically and radiologically. The clinical assessments included range of motion, and the patients were scored as per the Hospital for Special Surgery (HSS) and Knee Society (KS) criteria. The mean range of knee joint motion was 70° prior to the first stage operation and 72° prior to the second stage revision arthroplasty; following revision arthroplasty, it was 113° at the final follow-up. The mean HSS score and KS knee and function scores were 86, 82, and 54, respectively, at the final follow-up. The success rate in terms of infection eradication was 95% (19/20 knees). No patient experienced soft tissue contracture requiring a quadriceps snip. This novel technique provides excellent radiological and clinical outcomes. It offers a high surface area of antibiotic-impregnated cement, a good range of motion between first and second stage revision surgery for the treatment of chronic infection after total knee arthroplasty, and is of a reasonable cost.

Low Resolution Picture Transmission (LRPT) Demonstration System. Phase II; 1.0

NASA Technical Reports Server (NTRS)

Fong, Wai; Yeh, Pen-Shu; Duran, Steve; Sank, Victor; Nyugen, Xuan; Xia, Wei; Day, John H. (Technical Monitor)

2002-01-01

Low-Resolution Picture Transmission (LRPT) is a proposed standard for direct broadcast transmission of satellite weather images. This standard is a joint effort by the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT) and NOAA. As a digital transmission scheme, its purpose is to replace the current analog Automatic Picture Transmission (APT) system for use in the Meteorological Operational (METOP) satellites. GSFC has been tasked to build an LRPT Demonstration System (LDS). Its main objective is to develop or demonstrate the feasibility of a low-cost receiver utilizing a PC as the primary processing component and determine the performance of the protocol in the simulated Radio Frequency (RF) environment. The approach would consist of two phases.

[Total and unicompartmental knee replacement. Patient-specific Instrumentation].

PubMed

Köster, G; Biró, C

2016-04-01

The objective of patient-specific instrumentation (PSI Zimmer®) technology is to optimize positioning and selection of components as well as surgical procedure in uni- and bicompartimental knee replacement. The article contains a description of the planning and surgical technique and evaluates the method based on own results and literature. Using MRI or CT scans a virtual 3D model of the joint is created in order to simulate and plan the implant positioning. According to these data, pin placement and/or cutting guides are produced, which enable the surgeon to transfer the planning to the surgical procedure. In a prospective comparative study 88 patients (44 per each of the two techniques) were operated by one surgeon receiving the same TKA using either MRI-based PSI or a conventional technique. The number of surgical trays, operating time, intraoperative changes and frontal alignment using a full leg x‑ray (70 cases) were compared. In 17 patients the method was applied with unicondylar knee replacement. Anatomical abnormalities could be detected preoperatively and considered during the operation. With PSI the number of trays could be reduced and predictability of the component size was more precise. Intraoperative changes became necessary only for distal femoral (25 %) and proximal tibial (36 %) resection and tibial rotation (40 %). Alignment was more precise in the PSI cases PSI using the applied technique proved to be practicable and reliable. The advantages of precise planning became obvious. Results concerning alignment are inconsistent in the literature. Soft tissue balancing has only been included in the technique to a limited degree so far. PSI is still in an early stage of development and further development opportunities should be exploited before final assessment.

Scandinavian Total Ankle Replacement: 15-Year Follow-up.

PubMed

Palanca, Ariel; Mann, Roger A; Mann, Jeffrey A; Haskell, Andrew

2018-02-01

Over the past decade, total ankle arthroplasty (TAA) has become a mainstay in the treatment of end-stage ankle arthritis. Currently in its fourth generation, the Scandanavian Total Ankle Replacement (STAR) is the only 3-piece mobile bearing ankle prosthesis available in the United States. Our current study reports implant survivorship at 15 years and patient outcomes for a subset of these survivors available for study. Eighty-four TAAs were performed between 1998 and 2000. Metal component survivorship at 15 years was calculated with a Kaplan-Meier curve. Twenty-four (29%) of 84 patients were available for participation with a minimum 15-year follow-up. Any radiographic changes were documented. All additional procedures and complications were recorded. Clinical findings, self-reported performance and pain evaluations, and AOFAS ankle/hindfoot scores were noted. Metal implant survival was 73% at 15 years. Of the 24 patients available for clinical evaluation, 18 of 24 patients (70.7%) had no change in prosthetic alignment from the immediate postoperative radiograph. Only 1 subtalar fusion was required for symptomatic adjacent joint arthritis. Three patients sustained a broken polyethylene component. AOFAS scores improved from an average of 39.6 points preoperatively, to an average of 71.6. More than half (52.4%) of patients with retained implants required an additional surgical procedure; 3 required 2 additional procedures. The average time to subsequent procedure was 10.2 years. Our small cohort demonstrated STAR ankles with retention at 9 years were highly likely to survive to 15 years, and patients continued to have significant improvement in pain relief and minimal decrease in function. At 15 years from TAA, metal survivorship was 73%. As with all ankle replacements, supplementary procedures were common. Level IV, case series.

Electron gun with a transmission photocathode for the Joint Institute for Nuclear Research photoinjector

NASA Astrophysics Data System (ADS)

Balalykin, N. I.; Minashkin, V. F.; Nozdrin, M. A.; Shirkov, G. D.; Zelenogorskii, V. V.; Gacheva, E. I.; Potemkin, A. K.; Huran, J.

2017-10-01

Photocathode electron guns are key to the generation of high-quality electron bunches, which are currently the primary source of electrons for linear electron accelerators. The photogun test bench built at the Joint Institute for Nuclear Research (JINR) is currently being used to further develop the hollow (backside irradiated) photocathode concept. A major achievement was the replacement of the hollow photocathode by a technologically more feasible transmission photocathode made from a metal mesh that serves as a substrate for films of various photomaterials. A number of thin-film cathodes on quartz glass substrates are fabricated by photolithography. The vectorial photoeffect (related to the surface-normal component of the wave electric field) is observed and found to significantly affect the quantum efficiency. The dependence of the quantum efficiency of diamond-like carbon photocathodes on the manufacturing technology is investigated. The Rutherford backscattering and elastic recoil detection techniques are combined to carry out an elemental analysis of the films. An estimate of the emittance of a 400 pC electron beam is obtained using the cross-section method.

Early Results of Medicare's Bundled Payment Initiative for a 90-Day Total Joint Arthroplasty Episode of Care.

PubMed

Iorio, Richard; Clair, Andrew J; Inneh, Ifeoma A; Slover, James D; Bosco, Joseph A; Zuckerman, Joseph D

2016-02-01

In 2011 Medicare initiated a Bundled Payment for Care Improvement (BPCI) program with the goal of introducing a payment model that would "lead to higher quality, more coordinated care at a lower cost to Medicare." A Model 2 bundled payment initiative for Total Joint Replacement (TJR) was implemented at a large, tertiary, urban academic medical center. The episode of care includes all costs through 90 days following discharge. After one year, data on 721 Medicare primary TJR patients were available for analysis. Average length of stay (LOS) was decreased from 4.27 days to 3.58 days (Median LOS 3 days). Discharges to inpatient facilities decreased from 71% to 44%. Readmissions occurred in 80 patients (11%), which is slightly lower than before implementation. The hospital has seen cost reduction in the inpatient component over baseline. Early results from the implementation of a Medicare BPCI Model 2 primary TJR program at this medical center demonstrate cost-savings. IV economic and decision analyses-developing an economic or decision model. Copyright © 2016 Elsevier Inc. All rights reserved.

Comprehensive Care for Joint Replacement Model (CJR); Delay of Effective Date. Final rule; delay of effective date.

PubMed

2017-05-19

This final rule finalizes May 20, 2017 as the effective date of the final rule titled "Advancing Care Coordination Through Episode Payment Models (EPMs); Cardiac Rehabilitation Incentive Payment Model; and Changes to the Comprehensive Care for Joint Replacement Model (CJR)" originally published in the January 3, 2017 Federal Register. This final rule also finalizes a delay of the applicability date of the regulations at 42 CFR part 512 from July 1, 2017 to January 1, 2018 and delays the effective date of the specific CJR regulations listed in the DATES section from July 1, 2017 to January 1, 2018.

Comparison of radiographic joint space width and magnetic resonance imaging for prediction of knee replacement: A longitudinal case-control study from the Osteoarthritis Initiative.

PubMed

Eckstein, Felix; Boudreau, Robert; Wang, Zhijie; Hannon, Michael J; Duryea, Jeff; Wirth, Wolfgang; Cotofana, Sebastian; Guermazi, Ali; Roemer, Frank; Nevitt, Michael; John, Markus R; Ladel, Christoph; Sharma, Leena; Hunter, David J; Kwoh, C Kent

2016-06-01

To evaluate whether change in fixed-location measures of radiographic joint space width (JSW) and cartilage thickness by MRI predict knee replacement. Knees replaced between 36 and 60 months' follow-up in the Osteoarthritis Initiative were each matched with one control by age, sex and radiographic status. Radiographic JSW was determined from fixed flexion radiographs and subregional femorotibial cartilage thickness from 3 T MRI. Changes between the annual visit before replacement (T0) and 2 years before T0 (T-2) were compared using conditional logistic regression. One hundred and nineteen knees from 102 participants (55.5 % women; age 64.2 ± 8.7 [mean ± SD] years) were studied. Fixed-location JSW change at 22.5 % from medial to lateral differed more between replaced and control knees (case-control [cc] OR = 1.57; 95 % CI: 1.23-2.01) than minimum medial JSW change (ccOR = 1.38; 95 % CI: 1.11-1.71). Medial femorotibial cartilage loss displayed discrimination similar to minimum JSW, and central tibial cartilage loss similar to fixed-location JSW. Location-independent thinning and thickening scores were elevated prior to knee replacement. Discrimination of structural progression between knee pre-placement cases versus controls was stronger for fixed-location than minimum radiographic JSW. MRI displayed similar discrimination to radiography and suggested greater simultaneous cartilage thickening and loss prior to knee replacement. • Fixed-location JSW predicts surgical knee replacement more strongly than minimum JSW. • MRI predicts knee replacement with similar accuracy to radiographic JSW. • MRI reveals greater cartilage thinning and thickening prior to knee replacement.

A computational parametric study on edge loading in ceramic-on-ceramic total hip joint replacements.

PubMed

Liu, Feng; Feng, Li; Wang, Junyuan

2018-07-01

Edge loading in ceramic-on-ceramic total hip joint replacement is an adverse condition that occurs as the result of a direct contact between the head and the cup rim. It has been associated with translational mismatch in the centres of rotation of the cup and head, and found to cause severe wear and early failure of the implants. Edge loading has been considered in particular in relation to dynamic separation of the cup and head centres during a gait cycle. Research has been carried out both experimentally and computationally to understand the mechanism including the influence of bearing component positioning on the occurrence and severity of edge loading. However, it is experimentally difficult to measure both the load magnitude and duration of edge loading as it occurs as a short impact within the tight space of hip joints. Computationally, a dynamic contact model, for example, developed using the MSC ADAMS software for a multi-body dynamics simulation can be particularly useful for calculating the loads and characterising the edge loading. The aim of the present study was to further develop the computational model, and improve the predictions of contact force and the understanding of mechanism in order to provide guidance on design and surgical factors to avoid or to reduce edge loading and wear. The results have shown that edge loading can be avoided for a low range of translational mismatch in the centres of rotation of the cup and head during gait at the level of approximately 1.0 mm for a cup at 45° inclination, keeping a correct cup inclination at 45° is important to reduce the edge loading severity, and edge loading can be avoided for a certain range of translational mismatch of the cup and head centres with an increased swing phase load. Copyright © 2018 Elsevier Ltd. All rights reserved.

Biomechanics of the natural, arthritic, and replaced human ankle joint

PubMed Central

2014-01-01

The human ankle joint complex plays a fundamental role in gait and other activities of daily living. At the same time, it is a very complicated anatomical system but the large literature of experimental and modelling studies has not fully described the coupled joint motion, position and orientation of the joint axis of rotation, stress and strain in the ligaments and their role in guiding and stabilizing joint motion, conformity and congruence of the articular surfaces, patterns of contact at the articular surfaces, patterns of rolling and sliding at the joint surfaces, and muscle lever arm lengths. The present review article addresses these issues as described in the literature, reporting the most recent relevant findings. PMID:24499639

Evaluation of musculoskeletal sepsis with indium-111 white blood cell imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ouzounian, T.J.; Thompson, L.; Grogan, T.J.

The detection of musculoskeletal sepsis, especially following joint replacement, continues to be a challenging problem. Often, even with invasive diagnostic evaluation, the diagnosis of infection remains uncertain. This is a report on the first 55 Indium-111 white blood cell (WBC) images performed in 39 patients for the evaluation of musculoskeletal sepsis. There were 40 negative and 15 positive Indium-111 WBC images. These were correlated with operative culture and tissue pathology, aspiration culture, and clinical findings. Thirty-eight images were performed for the evaluation of possible total joint sepsis (8 positive and 30 negative images); 17 for the evaluation of nonarthroplasty-related musculoskeletalmore » sepsis (7 positive and 10 negative images). Overall, there were 13 true-positive, 39 true-negative, two false-positive, and one false-negative images. Indium-111 WBC imaging is a sensitive and specific means of evaluating musculoskeletal sepsis, especially following total joint replacement.« less

Outcomes of a Joint Replacement Surgical Home Model Clinical Pathway

PubMed Central

Chaurasia, Avinash; Garson, Leslie; Kain, Zeev L.; Schwarzkopf, Ran

2014-01-01

Optimizing perioperative care to provide maximum benefit at minimum cost may be best achieved using a perioperative clinical pathway (PCP). Using our joint replacement surgical home (JSH) model PCP, we examined length of stay (LOS) following total joint arthroplasty (TJA) to evaluate patient care optimization. We reviewed a spectrum of clinical measurements in 190 consecutive patients who underwent TJA. Patients who had surgery earlier in the week and who were earlier cases of the day had a significantly lower LOS than patients whose cases started both later in the week and later in the day. Patients discharged home had significantly lower LOS than those discharged to a secondary care facility. Patients who received regional versus general anesthesia had a significantly lower LOS. Scheduling patients discharged to home and who will likely receive regional anesthesia for the earliest morning slot and earlier in the week may help decrease overall LOS. PMID:25025045

Estimation of wear in total hip replacement using a ten station hip simulator.

PubMed

Brummitt, K; Hardaker, C S

1996-01-01

The results of hip simulator tests on a total of 16 total hip joints, all of them 22.25 mm Charnley designs, are presented. Wear at up to 6.75 million cycles was assessed by using a coordinate measuring machine. The results gave good agreement with clinical estimates of wear rate on the same design of joint replacement from a number of sources. Good agreement was also obtained when comparison was made with the published results from more sophisticated simulators. The major source of variation in the results was found to occur in the first million cycles where creep predominates. The results of this study support the use of this type of simplified simulator for estimating wear in a total hip prosthesis. The capability to test a significant number of joints simultaneously may make this mechanism preferable to more complex machines in many cases.

Bundled Payments in Total Joint Replacement: Keeping Our Care Affordable and High in Quality.

PubMed

McLawhorn, Alexander S; Buller, Leonard T

2017-09-01

The purpose of this review was to evaluate the literature regarding bundle payment reimbursement models for total joint arthroplasty (TJA). From an economic standpoint, TJA are cost-effective, but they represent a substantial expense to the Centers for Medicare & Medicaid Services (CMS). Historically, fee-for-service payment models resulted in highly variable cost and quality. CMS introduced Bundled Payments for Care Improvement (BPCI) in 2012 and subsequently the Comprehensive Care for Joint Replacement (CJR) reimbursement model in 2016 to improve the value of TJA from the perspectives of both CMS and patients, by improving quality via cost control. Early results of bundled payments are promising, but preserving access to care for patients with high comorbidity burdens and those requiring more complex care is a lingering concern. Hospitals, regardless of current participation in bundled payments, should develop care pathways for TJA to maximize efficiency and patient safety.

[Custom-made implant for complex facial reconstruction: A case of total replacement of temporo-mandibular joint, zygomatic arch and malar bone].

PubMed

Guillier, D; Moris, V; See, L-A; Girodon, M; Wajszczak, B-L; Zwetyenga, N

2017-02-01

Total prosthetic replacement of the temporo-mandibular joint (TMJ) has become a common procedure, but it is usually limited to the TMJ itself. We report about one case of complex prosthetic joint reconstruction extending to the neighbouring bony structures. A 57-year-old patient, operated several times for a cranio-facial fibrous dysplasia, presented with a recurring TMJ ankylosis and a complexe latero-facial bone loss on the right side. We performed a reconstruction procedure including the TMJ, the zygomatic arch and the malar bone by mean of custom made composite prosthesis (chrome-cobalt-molybdenum-titanium and polyethylene). Five years postoperatively, mouth opening, nutrition, pain and oral hygiene were significantly improved. Nowadays technical possibilities allow for complex facial alloplastic reconstructions with good medium term results. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Measurement of installation deformation of the acetabulum during prosthetic replacement of a hip joint using digital image correlation

NASA Astrophysics Data System (ADS)

Lei, Dong; Bai, Pengxiang; Zhu, Feipeng

2018-01-01

Nowadays, acetabulum prosthesis replacement is widely used in clinical medicine. However, there is no efficient way to evaluate the implantation effect of the prosthesis. Based on a modern photomechanics technique called digital image correlation (DIC), the evaluation method of the installation effect of the acetabulum was established during a prosthetic replacement of a hip joint. The DIC method determines strain field by comparing the speckle images between the undeformed sample and the deformed counterpart. Three groups of experiments were carried out to verify the feasibility of the DIC method on the acetabulum installation deformation test. Experimental results indicate that the installation deformation of acetabulum generally includes elastic deformation (corresponding to the principal strain of about 1.2%) and plastic deformation. When the installation angle is ideal, the plastic deformation can be effectively reduced, which could prolong the service life of acetabulum prostheses.

Flight Set 360L002 (STS-27) field joint protection system, volume 7

NASA Technical Reports Server (NTRS)

Hale, Elgie

1989-01-01

This report contains the pre-launch functioning data of the Field Joint Protection System (JPS) used on STS-27. Also included is the post flight condition of the JPS components following the launch and recovery of the two redesigned solid rocket motors (RSRM) boosters. The JPS components are: (1) field joint heaters; (2) field joint sensors; (3) field joint moisture seal; (4) moisture seal Kevlar retaining straps; (5) field joint external insulation; (6) vent valve; (7) power cables; and (8) igniter heater.

Dynamics of quiet human stance: computer simulations of a triple inverted pendulum model.

PubMed

Günther, Michael; Wagner, Heiko

2016-01-01

For decades, the biomechanical description of quiet human stance has been dominated by the single inverted pendulum (SIP) paradigm. However, in the past few years, the SIP model family has been falsified as an explanatory approach. Double inverted pendulum models have recently proven to be inappropriate. Human topology with three major leg joints suggests in a natural way to examine triple inverted pendulum (TIP) models as an appropriate approach. In this study, we focused on formulating a TIP model that can synthesise stable balancing attractors based on minimalistic sensor information and actuation complexity. The simulated TIP oscillation amplitudes are realistic in vertical direction. Along with the horizontal ankle, knee and hip positions, though, all simulated joint angle amplitudes still exceed the measured ones about threefold. It is likely that they could be eventually brought down to the physiological range by using more sensor information. The TIP systems' eigenfrequency spectra come out as another major result. The eigenfrequencies spread across about 0.1 Hz...20 Hz. Our main result is that joint stiffnesses can be reduced even below statically required values by using an active hip torque balancing strategy. When reducing mono- and bi-articular stiffnesses further down to levels threatening dynamic stability, the spectra indicate a change from torus-like (stable) to strange (chaotic) attractors. Spectra of measured ground reaction forces appear to be strange-attractor-like. We would conclude that TIP models are a suitable starting point to examine more deeply the dynamic character of and the essential structural properties behind quiet human stance. Abbreviations and technical terms Inverted pendulum body exposed to gravity and pivoting in a joint around position of unstable equilibrium (operating point) SIP single inverted pendulum: one rigid body pivoting around fixation to the ground (external joint) DIP double inverted pendulum: two bodies; external and internal joint operate around instability TIP triple inverted pendulum: three bodies; external and both internal joints operate around instability QIP quadruple inverted pendulum: four bodies, foot replaces external joint; all three internal joints operate around instability Eigenfrequency characteristic frequency that a physical system is oscillating at when externally excited at a limited energy level DOF degree of freedom; in mechanics: linear displacement or angle or combination thereof Mono-articular stiffness: coefficient of proportionality between mechanical displacement of a DOF and restoring force/torque component in the respective DOF Bi-articular stiffness coefficient of proportionality between mechanical displacement of a DOF and restoring force/torque component in another DOF GRF ground reaction force HAT segment including head, arms and trunk COM centre of mass COP centre of pressure in the plane of the force platform surface.

Static and Fatigue Strength Evaluations for Bolted Composite/Steel Joints for Heavy Vehicle Chassis Components

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Xin; Stephens, Elizabeth V.; Herling, Darrell R.

2004-09-14

In May 2003, ORNL and PNNL began collaboration on a four year research effort focused on developing joining techniques to overcome the technical issues associated with joining lightweight materials in heavy vehicles. The initial focus of research is the development and validation of joint designs for a composite structural member attached to a metal member that satisfy the structural requirements both economically and reliably. Huck-bolting is a common joining method currently used in heavy truck chassis structures. The initial round of testing was conducted to establish a performance benchmark by evaluating the static and fatigue behavior of an existing steel/steelmore » chassis joint at the single huck-bolt level. Both tension and shear loading conditions were considered, and the resulting static and fatigue strengths will be used to guide the joint design for a replacement composite/steel joint. A commercially available, pultruded composite material was chosen to study the generic issues related to composite/steel joints. Extren is produced by STRONGWELL, and it is a combination of fiberglass reinforcement and thermosetting polyester or vinyl ester resin systems. Extren sheets of 3.2 mm thick were joined to 1.4 mm SAE1008 steel sheets with a standard grade 5 bolt with 6.35 mm diameter. Both tension and shear loading modes were considered for the single hybrid joint under static and fatigue loading conditions. Since fiberglass reinforced thermoset polymer composites are a non-homogenous material, their strengths and behavior are dependent upon the design of the composite and reinforcement. The Extren sheet stock was cut along the longitudinal direction to achieve maximum net-section strength. The effects of various manufacturing factors and operational conditions on the static and fatigue strength of the hybrid joint were modeled and experimentally verified. It was found that loading mode and washer size have significant influence on the static and fatigue strength of the hybrid joint. The effect of different fatigue test frequencies on the sample temperature and the resulting fatigue life was also examined.« less

21 CFR 888.3320 - Hip joint metal/metal semi-constrained, with a cemented acetabular component, prosthesis.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hip joint metal/metal semi-constrained, with a... Devices § 888.3320 Hip joint metal/metal semi-constrained, with a cemented acetabular component, prosthesis. (a) Identification. A hip joint metal/metal semi-constrained, with a cemented acetabular...

21 CFR 888.3320 - Hip joint metal/metal semi-constrained, with a cemented acetabular component, prosthesis.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Hip joint metal/metal semi-constrained, with a... Devices § 888.3320 Hip joint metal/metal semi-constrained, with a cemented acetabular component, prosthesis. (a) Identification. A hip joint metal/metal semi-constrained, with a cemented acetabular...

Functional anatomy of the temporomandibular joint (I).

PubMed

Sava, Anca; Scutariu, Mihaela Monica

2012-01-01

Jaw movement is analyzed as the action between two rigid components jointed together in a particular way, the movable mandible against the stabilized cranium. Jaw articulation distinguishes form most other synovial joints of the body by the coincidence of certain characteristic features. Its articular surfaces are not covered by hyaline cartilage as elsewhere. The two jointed components carry teeth the shape, position and occlusion of which having a unique influence on specific positions and movements within the joint. A fibrocartilaginous disc is interposed between upper and lower articular surfaces; this disc compensates for the incongruities in opposing parts and allows sliding, pivoting, and rotating movements between the bony components. These are the reasons for our review of the functional anatomy of the temporomandibular joint.

Tribology and total hip joint replacement: current concepts in mechanical simulation.

PubMed

Affatato, S; Spinelli, M; Zavalloni, M; Mazzega-Fabbro, C; Viceconti, M

2008-12-01

Interest in the rheology and effects of interacting surfaces is as ancient as man. This subject can be represented by a recently coined word: tribology. This term is derived from the Greek word "tribos" and means the "science of rubbing". Friction, lubrication, and wear mechanism in the common English language means the precise field of interest of tribology. Wear of total hip prosthesis is a significant clinical problem that involves, nowadays, a too high a number of patients. In order to acquire further knowledge on the tribological phenomena that involve hip prosthesis wear tests are conducted on employed materials to extend lifetime of orthopaedic implants. The most basic type of test device is the material wear machine, however, a more advanced one may more accurately reproduce some of the in vivo conditions. Typically, these apparatus are called simulators, and, while there is no absolute definition of a joint simulator, its description as a mechanical rig used to test a joint replacement, under conditions approximating those occurring in the human body, is acceptable. Simulator tests, moreover, can be used to conduct accelerated protocols that replicate/simulate particularly extreme conditions, thus establishing the limits of performance for the material. Simulators vary in their level of sophistication and the international literature reveals many interpretations of the design of machines used for joint replacement testing. This paper aims to review the current state of the art of the hip joint simulators worldwide. This is specified through a schematic overview by describing, in particular, constructive solutions adopted to reproduce in vivo conditions. An exhaustive commentary on the evolution and actually existing simulation standards is proposed by the authors. The need of a shared protocol among research laboratories all over the world could lead to a consensus conference.

Position of the prosthesis and the incidence of dislocation following total hip replacement.

PubMed

He, Rong-xin; Yan, Shi-gui; Wu, Li-dong; Wang, Xiang-hua; Dai, Xue-song

2007-07-05

Dislocation is the second most common complication of hip replacement surgery, and impact of the prosthesis is believed to be the fundamental reason. The present study employed Solidworks 2003 and MSC-Nastran software to analyze the three dimensional variables in order to investigate how to prevent dislocation following hip replacement surgery. Computed tomography (CT) imaging was used to collect femoral outline data and Solidworks 2003 software was used to construct the cup model with variabilities. Nastran software was used to evaluate dislocation at different prosthesis positions and different geometrical shapes. Three dimensional movement and results from finite element method were analyzed and the values of dislocation resistance index (DRI), range of motion to impingement (ROM-I), range of motion to dislocation (ROM-D) and peak resisting moment (PRM) were determined. Computer simulation was used to evaluate the range of motion of the hip joint at different prosthesis positions. Finite element analysis showed: (1) Increasing the ratio of head/neck increased the ROM-I values and moderately increased ROM-D and PRM values. Increasing the head size significantly increased PRM and to some extent ROM-I and ROM-D values, which suggested that there would be a greater likelihood of dislocation. (2) Increasing the anteversion angle increased the ROM-I, ROM-D, PRM, energy required for dislocation (ENERGY-D) and DRI values, which would increase the stability of the joint. (3) As the chamber angle was increased, ROM-I, ROM-D, PRM, Energy-D and DRI values were increased, resulting in improved joint stability. Chamber angles exceeding 55 degrees resulted in increases in ROM-I and ROM-D values, but decreases in PRM, Energy-D, and DRI values, which, in turn, increased the likelihood of dislocation. (4) The cup, which was reduced posteriorly, reduced ROM-I values (2.1 -- 5.3 degrees ) and increased the DRI value (0.073). This suggested that the posterior high side had the effect of 10 degrees anteversion angle. Increasing the head/neck ratio increases joint stability. Posterior high side reduced the range of motion of the joint but increased joint stability; Increasing the anteversion angle increases DRI values and thus improve joint stability; Increasing the chamber angle increases DRI values and improves joint stability. However, at angles exceeding 55 degrees , further increases in the chamber angle result in decreased DRI values and reduce the stability of the joint.

Clinical characteristics, microbiology, and outcomes of prosthetic joint infection in Taiwan.

PubMed

Tsai, Jen-Chih; Sheng, Wang-Huei; Lo, Wan-Yu; Jiang, Ching-Chuan; Chang, Shan-Chwen

2015-04-01

Prosthetic joint infection (PJI) after total knee or hip replacement is a devastating complication associated with substantial morbidity and economic cost. The incidence of prosthetic joint infection is increasing as the use of mechanical joint replacement increases. The treatment approach to prosthetic joint infection is based on different clinical situations such as a patient's comorbidities, epidemic microbiology data, and surgical procedures. The aim of our study was to understand clinical characteristics of prosthetic joint infection, the microbiology of the prosthetic joint infection, and the outcomes of different treatment strategies during 2006-2011. We retrospectively collected cases of prosthetic joint infection in the National Taiwan University Hospital between January 1, 2006 and December 31, 2011. The patients' characteristics, microbiology, outcomes, and factors associated with treatment success were recorded. One hundred and forty-four patients were identified as having PJI. Of these, 92 patients were entered into per-protocol analysis. Staphylococcus aureus was the most common causative organism (29.9%), followed by coagulase-negative Staphylococci (16.7%), and Enterococci (9.7%). The overall treatment success rate was 50%. Patients who received a two-stage revision had a better outcome, compared to patients who underwent other types of surgeries (70% vs. 32.7%, respectively; p < 0.001). In multivariate analysis, the two-stage revision was significantly associated with treatment success (odds ratio = 3.923, 95% confidence interval = 1.53-10.04). Our study demonstrates that Staphylococcus aureus was the most common causative organisms in PJI. Performing two-stage revisions was significantly associated with a better outcome. Copyright © 2013. Published by Elsevier B.V.

Comparison of Multisegmental Foot and Ankle Motion Between Total Ankle Replacement and Ankle Arthrodesis in Adults.

PubMed

Seo, Sang Gyo; Kim, Eo Jin; Lee, Doo Jae; Bae, Kee Jeong; Lee, Kyoung Min; Lee, Dong Yeon

2017-09-01

Total ankle replacement (TAR) and ankle arthrodesis (AA) are usually performed for severe ankle arthritis. We compared postoperative foot segmental motion during gait in patients treated with TAR and AA. Gait analysis was performed in 17 and 7 patients undergoing TAR and AA, respectively. Subjects were evaluated using a 3-dimensional multisegmental foot model with 15 markers. Temporal gait parameters were calculated. The maximum and minimum values and the differences in hallux, forefoot, hindfoot, and arch in 3 planes (sagittal, coronal, transverse) were compared between the 2 groups. One hundred healthy adults were evaluated as a control. Gait speed was faster in the TAR ( P = .028). On analysis of foot and ankle segmental motion, the range of hindfoot sagittal motion was significantly greater in the TAR (15.1 vs 10.2 degrees in AA; P = .004). The main component of motion increase was hindfoot dorsiflexion (12.3 and 8.6 degrees). The range of forefoot sagittal motion was greater in the TAR (9.3 vs 5.8 degrees in AA; P = .004). Maximum ankle power in the TAR (1.16) was significantly higher than 0.32 in AA; P = .008). However, the range of hindfoot and forefoot sagittal motion was decreased in both TAR and AA compared with the control group ( P = .000). Although biomechanical results of TAR and AA were not similar to those in the normal controls, joint motions in the TAR more closely matched normal values. Treatment decision making should involve considerations of the effect of surgery on the adjacent joints. Level III, case-control study.

Frontal plane stability following UKA in a biomechanical study.

PubMed

Heyse, Thomas J; Tucker, Scott M; Rajak, Yogesh; Kia, Mohammad; Lipman, Joseph D; Imhauser, Carl W; Westrich, Geoffrey H

2015-06-01

Function and kinematics following unicondylar knee arthroplasty (UKA) have been reported to be close to the native knee. Gait, stair climbing and activities of daily living expose the knee joint to a combination of varus and valgus moments. Replacement of the medial compartment via UKA is likely to change the physiologic knee stability and its ability to respond to varus and valgus moments. It was hypothesized that UKA implantation would stiffen the knee and decrease range of motion in the frontal plane. Six fresh frozen cadaver knees were prepared and mounted in a six-degrees-of-freedom robot. An axial load of 200 N was applied with the knee in 15°, 45° and 90° of flexion. Varus and valgus moments were added, respectively, before and after implantation of medial UKA. Tests were than redone with a thicker polyethylene inlay to simulate overstuffing of the medial compartment. Range of motion in the frontal plane and the tibial response to moments were recorded via the industrial robot. The range of motion in the frontal plane was decreased with both, balanced and overstuffed UKA and shifted towards valgus. When exposed to valgus moments, knees following UKA were stiffer in comparison with the native knee. The effect was even more pronounced with medial overstuffing. In UKA, the compressive anatomy is replaced by much stiffer components. This lack of medial compression and relative overstuffing leads to a tighter medial collateral ligament. This drives the trend towards a stiffer joint as documented by a decrease in frontal plane range of motion. Overstuffing should strictly be avoided when performing UKA.

The influence of simulator input conditions on the wear of total knee replacements: An experimental and computational study

PubMed Central

Brockett, Claire L; Abdelgaied, Abdellatif; Haythornthwaite, Tony; Hardaker, Catherine; Fisher, John; Jennings, Louise M

2016-01-01

Advancements in knee replacement design, material and sterilisation processes have provided improved clinical results. However, surface wear of the polyethylene leading to osteolysis is still considered the longer-term risk factor. Experimental wear simulation is an established method for evaluating the wear performance of total joint replacements. The aim of this study was to investigate the influence of simulation input conditions, specifically input kinematic magnitudes, waveforms and directions of motion and position of the femoral centre of rotation, on the wear performance of a fixed-bearing total knee replacement through a combined experimental and computational approach. Studies were completed using conventional and moderately cross-linked polyethylene to determine whether the influence of these simulation input conditions varied with material. The position of the femoral centre of rotation and the input kinematics were shown to have a significant influence on the wear rates. Similar trends were shown for both the conventional and moderately cross-linked polyethylene materials, although lower wear rates were found for the moderately cross-linked polyethylene due to the higher level of cross-linking. The most important factor influencing the wear was the position of the relative contact point at the femoral component and tibial insert interface. This was dependent on the combination of input displacement magnitudes, waveforms, direction of motion and femoral centre of rotation. This study provides further evidence that in order to study variables such as design and material in total knee replacement, it is important to carefully control knee simulation conditions. This can be more effectively achieved through the use of displacement control simulation. PMID:27160561

Geographic region, socioeconomic position and the utilisation of primary total joint replacement for hip or knee osteoarthritis across western Victoria: a cross-sectional multilevel study of the Australian Orthopaedic Association National Joint Replacement Registry.

PubMed

Brennan-Olsen, Sharon; Vogrin, Sara; Holloway, Kara L; Page, Richard S; Sajjad, Muhammad A; Kotowicz, Mark A; Livingston, Patricia M; Khasraw, Mustafa; Hakkennes, Sharon; Dunning, Trish L; Brumby, Susan; Pedler, Daryl; Sutherland, Alasdair; Venkatesh, Svetha; Williams, Lana J; Duque, Gustavo; Pasco, Julie A

2017-11-06

Compared to urban residents, those in rural/regional areas often experience inequitable healthcare from specialist service providers. Independent of small between-area differences in utilisation, socially advantaged groups had the greatest uptake of joint replacement. These data suggest low correlation between 'need' vs. 'uptake' of surgery in rural/regional areas. Compared to urban residents, those in rural and regional areas often experience inequitable healthcare from specialist service providers, often due to geographical issues. We investigated associations between socioeconomic position (SEP), region of residence and utilisation of primary total knee replacement (TKR) and/or total hip replacement (THR) for osteoarthritis. As part of the Ageing, Chronic Disease and Injury study, we extracted data from the Australian Orthopaedic Association National Joint Replacement Registry (2011-2013) for adults that utilised primary TKR (n = 4179; 56% female) and/or THR (n = 3120; 54% female). Residential addresses were matched with the Australian Bureau of Statistics (ABS) 2011 census data: region of residence was defined according to local government areas (LGAs), and area-level SEP (quintiles) defined using an ABS-derived composite index. The ABS-determined control population (n = 591,265; 51% female) excluded individuals identified as cases. We performed multilevel logistic regression modelling using a stratified two-stage cluster design. TKR was higher for those aged 70-79 years (AOR 1.4 95%CI 1.3-1.5; referent = 60-69 years) and in the most advantaged SEP quintile (AOR 2.1, 95%CI 1.8-2.3; referent = SEP quintile 3); results were similar for THR (70-79 years = AOR 1.7, 95%CI 1.5-1.8; SEP quintile 5 = AOR 2.5, 95%CI 2.2-2.8). Total variances contributed by the variance in LGAs were 2% (SD random effects ± 0.28) and 3% (SD ± 0.32), respectively. Independent of small between-LGA differences in utilisation, and in contrast to the expected greater prevalence of osteoarthritis in disadvantaged populations, we report greater TKR and THR in more advantaged groups. Further research should investigate whether more advantaged populations may be over-serviced.

The Greenland Telescope (GLT): antenna status and future plans

NASA Astrophysics Data System (ADS)

Raffin, Philippe; Algaba-Marcosa, Juan Carlos; Asada, Keiichi; Blundell, Raymond; Burgos, Roberto; Chang, Chih-Cheng; Chen, Ming-Tang; Christensen, Robert; Grimes, Paul K.; Han, C. C.; Ho, Paul T. P.; Huang, Yau-De; Inoue, Makoto; Koch, Patrick M.; Kubo, Derek; Leiker, Steve; Liu, Ching-Tang; Martin-Cocher, Pierre; Matsushita, Satoki; Nakamura, Masanori; Nishioka, Hiroaki; Nystrom, George; Paine, Scott N.; Patel, Nimesh A.; Pradel, Nicolas; Pu, Hung-Yi; Shen, H.-Y.; Snow, William; Sridharan, Tirupati K.; Srinivasan, Ranjani; Tong, Edward; Wang, Jackie

2014-07-01

The ALMA North America Prototype Antenna was awarded to the Smithsonian Astrophysical Observatory (SAO) in 2011. SAO and the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA), SAO's main partner for this project, are working jointly to relocate the antenna to Greenland to carry out millimeter and submillimeter VLBI observations. This paper presents the work carried out on upgrading the antenna to enable operation in the Arctic climate by the GLT Team to make this challenging project possible, with an emphasis on the unexpected telescope components that had to be either redesigned or changed. Five-years of inactivity, with the antenna laying idle in the desert of New Mexico, coupled with the extreme weather conditions of the selected site in Greenland have it necessary to significantly refurbish the antenna. We found that many components did need to be replaced, such as the antenna support cone, the azimuth bearing, the carbon fiber quadrupod, the hexapod, the HVAC, the tiltmeters, the antenna electronic enclosures housing servo and other drive components, and the cables. We selected Vertex, the original antenna manufacturer, for the main design work, which is in progress. The next coming months will see the major antenna components and subsystems shipped to a site of the US East Coast for test-fitting the major antenna components, which have been retrofitted. The following step will be to ship the components to Greenland to carry out VLBI

The impact of obesity on the outcome of total ankle replacement.

PubMed

Bouchard, Maryse; Amin, Amit; Pinsker, Ellie; Khan, Ryan; Deda, Erisa; Daniels, Timothy R

2015-06-03

Obese patients have a slightly higher proportion of revision and infection following knee or hip replacement, but functional improvement is equivalent to that of normal-weight patients. We compared outcomes of total ankle replacement for end-stage ankle arthritis in obese and normal-weight patients. This retrospective cohort study compared thirty-nine obese patients (those with a body mass index of ≥30 kg/m(2)) at a mean follow-up time of 3.76 years and forty-eight non-obese patients (those with a body mass index of <30 kg/m(2)) at a mean follow-up time of 3.92 years after total ankle replacement. Outcome measure scores (Ankle Osteoarthritis Scale [AOS] and Short-Form 36 [SF-36]) were collected preoperatively and at least two years postoperatively. Complication and revision data were collected by manual chart audits. Statistical analyses were performed with use of t tests, Wilcoxon signed-rank tests, and Mann-Whitney U tests. Survival analysis was conducted with use of the Kaplan-Meier method. The two cohorts had similar demographic characteristics. Ten (26%) of thirty-nine patients in the obese group were morbidly obese (having a body mass index of >40 kg/m(2)). There were thirty-nine patients in the obese group and forty-eight patients in the non-obese group. The mean body mass index (and standard deviation) was 36.28 ± 5.43 kg/m(2) for the obese group and 25.84 ± 3.00 kg/m(2) for the non-obese group. The obese group had significantly worse preoperative SF-36 Physical Component Summary scores (p = 0.01) than the non-obese group. Preoperatively to postoperatively, both obese and non-obese patients demonstrated significant improvements (p < 0.001) in AOS pain, AOS disability, and SF-36 Physical Component Summary scores, and the changes in these scores were similar for both groups. The SF-36 Mental Component Summary scores did not change significantly (p = 0.30) in either group. There was no significant difference (p = 0.48) in the proportion of complications or revisions between the groups. Although obese patients had increased disability and worse function preoperatively, total ankle replacement significantly and similarly improved pain and disability scores in both obese and non-obese patients, with no significant difference in the proportion of complications. We therefore maintain that total ankle replacement is a reliable treatment option for patients with end-stage ankle arthritis, including those who are obese. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence. Copyright © 2015 by The Journal of Bone and Joint Surgery, Incorporated.

Converging flow joint insert system at an intersection between adjacent transitions extending between a combustor and a turbine assembly in a gas turbine engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wiebe, David J.; Carlson, Andrew; Stoker, Kyle C.

A transition duct system for routing a gas flow in a combustion turbine engine is provided. The transition duct system includes one or more converging flow joint inserts forming a trailing edge at an intersection between adjacent transition ducts. The converging flow joint insert may be contained within a converging flow joint insert receiver and may be disconnected from the transition duct bodies by which the converging flow joint insert is positioned. Being disconnected eliminates stress formation within the converging flow joint insert, thereby enhancing the life of the insert. The converging flow joint insert may be removable such thatmore » the insert can be replaced once worn beyond design limits.« less

An introduction to tribology.

PubMed

Norris, James A; Stabile, Kathryne J; Jinnah, Riyaz H

2008-01-01

Tribology is the study of friction, wear, lubrication mechanisms, and their interrelationships. Biotribiology focuses on understanding diarthrodial joints and has been a branch of tribology since 1973. Since then, biotribology has played a prominent role in the evaluation and development of joint prostheses, contributing to reduced wear and increased longevity. Total joint replacements are now common for arthritic patients and are also used in treating a variety of other orthopaedic conditions. For this reason, a complete understanding of the joint lubrication and microstructure that exists in nature is crucial. A subfield of biotribology, biomimetic tribology, has been formed with this goal in mind. This review covers the basic concepts of tribology, provides a brief historical perspective on joint prostheses, and presents the application of tribology in understanding diarthrodial and prosthetic joints.

Intra-articular enzyme replacement therapy with rhIDUA is safe, well-tolerated, and reduces articular GAG storage in the canine model of mucopolysaccharidosis type I.

PubMed

Wang, Raymond Y; Aminian, Afshin; McEntee, Michael F; Kan, Shih-Hsin; Simonaro, Calogera M; Lamanna, William C; Lawrence, Roger; Ellinwood, N Matthew; Guerra, Catalina; Le, Steven Q; Dickson, Patricia I; Esko, Jeffrey D

2014-08-01

Treatment with intravenous enzyme replacement therapy and hematopoietic stem cell transplantation for mucopolysaccharidosis (MPS) type I does not address joint disease, resulting in persistent orthopedic complications and impaired quality of life. A proof-of-concept study was conducted to determine the safety, tolerability, and efficacy of intra-articular recombinant human iduronidase (IA-rhIDUA) enzyme replacement therapy in the canine MPS I model. Four MPS I dogs underwent monthly rhIDUA injections (0.58 mg/joint) into the right elbow and knee for 6 months. Contralateral elbows and knees concurrently received normal saline. No intravenous rhIDUA therapy was administered. Monthly blood counts, chemistries, anti-rhIDUA antibody titers, and synovial fluid cell counts were measured. Lysosomal storage of synoviocytes and chondrocytes, synovial macrophages and plasma cells were scored at baseline and 1 month following the final injection. All injections were well-tolerated without adverse reactions. One animal required prednisone for spinal cord compression. There were no clinically significant abnormalities in blood counts or chemistries. Circulating anti-rhIDUA antibody titers gradually increased in all dogs except the prednisone-treated dog; plasma cells, which were absent in all baseline synovial specimens, were predominantly found in synovium of rhIDUA-treated joints at study-end. Lysosomal storage in synoviocytes and chondrocytes following 6 months of IA-rhIDUA demonstrated significant reduction compared to tissues at baseline, and saline-treated tissues at study-end. Mean joint synovial GAG levels in IA-rhIDUA joints were 8.62 ± 5.86 μg/mg dry weight and 21.6 ± 10.4 μg/mg dry weight in control joints (60% reduction). Cartilage heparan sulfate was also reduced in the IA-rhIDUA joints (113 ± 39.5 ng/g wet weight) compared to saline-treated joints (142 ± 56.4 ng/g wet weight). Synovial macrophage infiltration, which was present in all joints at baseline, was abolished in rhIDUA-treated joints only. Intra-articular rhIDUA is well-tolerated and safe in the canine MPS I animal model. Qualitative and quantitative assessments indicate that IA-rhIDUA successfully reduces tissue and cellular GAG storage in synovium and articular cartilage, including cartilage deep to the articular surface, and eliminates inflammatory macrophages from synovial tissue. The MPS I canine IA-rhIDUA results suggest that clinical studies should be performed to determine if IA-rhIDUA is a viable approach to ameliorating refractory orthopedic disease in human MPS I. Copyright © 2014 Elsevier Inc. All rights reserved.

21 CFR 888.3540 - Knee joint patellofemoral polymer/metal semi-constrained cemented prosthesis.

Code of Federal Regulations, 2011 CFR

2011-04-01

..., DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices... Medical Devices—Part I: Evaluation and Testing,’ ” (ii) “510(k) Sterility Review Guidance of 2/12/90 (K90... device intended to be implanted to replace part of a knee joint in the treatment of primary...

Flexible connector

DOEpatents

Savage, Mark E.; Simpson, Walter W.

1999-01-01

An electrical connector accommodates high current, is not labor intensive to assemble and disassemble, and allows a wide range of motion to accommodate mechanical variations and movement of connected components. The connector comprises several parts with joints therebetween, wherein each joint provides electrical connection between and allows relative motion of the joined parts. The combination of parts and joints maintains electrical connection between two electrical components even if the components are misaligned or move after connection.

Evaluation of Rock Joint Coefficients

NASA Astrophysics Data System (ADS)

Audy, Ondřej; Ficker, Tomáš

2017-10-01

A computer method for evaluation of rock joint coefficients is described and several applications are presented. The method is based on two absolute numerical indicators that are formed by means of the Fourier replicas of rock joint profiles. The first indicator quantifies the vertical depth of profiles and the second indicator classifies wavy character of profiles. The absolute indicators have replaced the formerly used relative indicators that showed some artificial behavior in some cases. This contribution is focused on practical computations testing the functionality of the newly introduced indicators.

Revision Rates after Primary Hip and Knee Replacement in England between 2003 and 2006

PubMed Central

Sibanda, Nokuthaba; Copley, Lynn P; Lewsey, Jim D; Borroff, Mick; Gregg, Paul; MacGregor, Alex J; Pickford, Martin; Porter, Martyn; Tucker, Keith; van der Meulen, Jan H

2008-01-01

Background Hip and knee replacement are some of the most frequently performed surgical procedures in the world. Resurfacing of the hip and unicondylar knee replacement are increasingly being used. There is relatively little evidence on their performance. To study performance of joint replacement in England, we investigated revision rates in the first 3 y after hip or knee replacement according to prosthesis type. Methods and Findings We linked records of the National Joint Registry for England and Wales and the Hospital Episode Statistics for patients with a primary hip or knee replacement in the National Health Service in England between April 2003 and September 2006. Hospital Episode Statistics records of succeeding admissions were used to identify revisions for any reason. 76,576 patients with a primary hip replacement and 80,697 with a primary knee replacement were included (51% of all primary hip and knee replacements done in the English National Health Service). In hip patients, 3-y revision rates were 0.9% (95% confidence interval [CI] 0.8%–1.1%) with cemented, 2.0% (1.7%–2.3%) with cementless, 1.5% (1.1%–2.0% CI) with “hybrid” prostheses, and 2.6% (2.1%–3.1%) with hip resurfacing (p < 0.0001). Revision rates after hip resurfacing were increased especially in women. In knee patients, 3-y revision rates were 1.4% (1.2%–1.5% CI) with cemented, 1.5% (1.1%–2.1% CI) with cementless, and 2.8% (1.8%–4.5% CI) with unicondylar prostheses (p < 0.0001). Revision rates after knee replacement strongly decreased with age. Interpretation Overall, about one in 75 patients needed a revision of their prosthesis within 3 y. On the basis of our data, consideration should be given to using hip resurfacing only in male patients and unicondylar knee replacement only in elderly patients. PMID:18767900

The biological response to orthopedic implants for joint replacement. II: Polyethylene, ceramics, PMMA, and the foreign body reaction.

PubMed

Gibon, Emmanuel; Córdova, Luis A; Lu, Laura; Lin, Tzu-Hua; Yao, Zhenyu; Hamadouche, Moussa; Goodman, Stuart B

2017-08-01

Novel evidence-based prosthetic designs and biomaterials facilitate the performance of highly successful joint replacement (JR) procedures. To achieve this goal, constructs must be durable, biomechanically sound, and avoid adverse local tissue reactions. Different biomaterials such as metals and their alloys, polymers, ceramics, and composites are currently used for JR implants. This review focuses on (1) the biological response to the different biomaterials used for TJR and (2) the chronic inflammatory and foreign-body response induced by byproducts of these biomaterials. A homeostatic state of bone and surrounding soft tissue with current biomaterials for JR can be achieved with mechanically stable, infection free and intact (as opposed to the release of particulate or ionic byproducts) implants. Adverse local tissue reactions (an acute/chronic inflammatory reaction, periprosthetic osteolysis, loosening and subsequent mechanical failure) may evolve when the latter conditions are not met. This article (Part 2 of 2) summarizes the biological response to the non-metallic materials commonly used for joint replacement including polyethylene, ceramics, and polymethylmethacrylate (PMMA), as well as the foreign body reaction to byproducts of these materials. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1685-1691, 2017. © 2016 Wiley Periodicals, Inc.

Shoulder Arthroplasty, from Indications to Complications: What the Radiologist Needs to Know.

PubMed

Lin, Dana J; Wong, Tony T; Kazam, Jonathan K

2016-01-01

The replaced shoulder is increasingly encountered by the radiologist, both on a dedicated and incidental basis, in this era of the growing population of aging patients wishing to preserve their mobility and function. Knowledge of the normal biomechanics of the glenohumeral joint-particularly the function of the rotator cuff and the unique relationship of the humeral head to the glenoid-is essential for understanding the need for shoulder replacement and its subsequent complications, because the intent of shoulder arthroplasty is to approximate the normal joint as closely as possible. The most common indications for shoulder arthroplasty are osteoarthritis, inflammatory arthritis, proximal humerus fractures, irreparable rotator cuff tears, rotator cuff arthropathy, and avascular necrosis of the humeral head. Knowledge of the key imaging features of these indications helps facilitate a correlative understanding between the initial diagnosis and the choice of which type of arthroplasty is used-total shoulder arthroplasty, reverse total shoulder arthroplasty, or partial joint replacement (humeral head resurfacing arthroplasty or hemiarthroplasty). The preoperative requirements and usual postoperative appearance of each arthroplasty type are summarized, as well as the complications of shoulder arthroplasty, including those unique to or closely associated with each type of arthroplasty and those that can be encountered with any type of shoulder arthroplasty. ©RSNA, 2016.

A Qualitative Study of Factors Underlying Decision Making for Joint Replacement among African Americans and Latinos with Osteoarthritis

PubMed Central

Parks, Michael L.; Hebert-Beirne, Jennifer; Rojas, Mary; Tuzzio, Leah; Nelson, Charles L.; Boutin-Foster, Carla

2015-01-01

To support patients in making decisions that align with their unique cultural beliefs, an understanding of factors underlying patient preferences is needed. We sought to identify psychosocial factors that influenced decision making among African-American and Hispanic patients referred for knee or hip arthroplasty. Thirty-six participants deciding on surgery were interviewed. Responses were audio-taped, transcribed, and read. Codes were assigned to the raw data and then clustered into categories that were analyzed to yield overarching themes. This process was repeated independently by two corroborators. Six categories described the mental calculations made in patients' decision-making processes: 1) self-assessment of ft for surgery based on age and comorbidity, 2) research and development of mental report cards of their surgeons, 3) reliving of social network experiences, 4) reliance on faith and spirituality for guidance, 5) acknowledgment of fear and anxiety, and 6) setting expectations for recovery. This study advanced the understanding of how decisions about joint replacement are constructed and identified cultural levers that can be targeted for intervention. Developing culturally tailored health information that addresses some of our findings and disseminating messages through social networks may reduce the underutilization of joint replacement among racial and ethnic minority populations. PMID:25272219

A qualitative study of factors underlying decision making for joint replacement among African Americans and Latinos with osteoarthritis.

PubMed

Parks, Michael L; Hebert-Beirne, Jennifer; Rojas, Mary; Tuzzio, Leah; Nelson, Charles L; Boutin-Foster, Carla

2014-01-01

To support patients in making decisions that align with their unique cultural beliefs, an understanding of factors underlying patient preferences is needed. We sought to identify psychosocial factors that influenced decision making among African-American and Hispanic patients referred for knee or hip arthroplasty. Thirty-six participants deciding on surgery were interviewed. Responses were audio-taped, transcribed, and read. Codes were assigned to the raw data and then clustered into categories that were analyzed to yield overarching themes. This process was repeated independently by two corroborators. Six categories described the mental calculations made in patients' decision-making processes: 1) self-assessment of fit for surgery based on age and comorbidity, 2) research and development of mental report cards of their surgeons, 3) reliving of social network experiences, 4) reliance on faith and spirituality for guidance, 5) acknowledgment of fear and anxiety, and 6) setting expectations for recovery. This study advanced the understanding of how decisions about joint replacement are constructed and identified cultural levers that can be targeted for intervention. Developing culturally tailored health information that addresses some of our findings and disseminating messages through social networks may reduce the underutilization of joint replacement among racial and ethnic minority populations.

Obesity & osteoarthritis

PubMed Central

King, Lauren K.; March, Lyn; Anandacoomarasamy, Ananthila

2013-01-01

The most significant impact of obesity on the musculoskeletal system is associated with osteoarthritis (OA), a disabling degenerative joint disorder characterized by pain, decreased mobility and negative impact on quality of life. OA pathogenesis relates to both excessive joint loading and altered biomechanical patterns together with hormonal and cytokine dysregulation. Obesity is associated with the incidence and progression of OA of both weight-bearing and non weight-bearing joints, to rate of joint replacements as well as operative complications. Weight loss in OA can impart clinically significant improvements in pain and delay progression of joint structural damage. Further work is required to determine the relative contributions of mechanical and metabolic factors in the pathogenesis of OA. PMID:24056594

Tribological performance of the biological components of synovial fluid in artificial joint implants

NASA Astrophysics Data System (ADS)

Ghosh, Subir; Choudhury, Dipankar; Roy, Taposh; Moradi, Ali; Masjuki, H. H.; Pingguan-Murphy, Belinda

2015-08-01

The concentration of biological components of synovial fluid (such as albumin, globulin, hyaluronic acid, and lubricin) varies between healthy persons and osteoarthritis (OA) patients. The aim of the present study is to compare the effects of such variation on tribological performance in a simulated hip joint model. The study was carried out experimentally by utilizing a pin-on-disk simulator on ceramic-on-ceramic (CoC) and ceramic-on-polyethylene (CoP) hip joint implants. The experimental results show that both friction and wear of artificial joints fluctuate with the concentration level of biological components. Moreover, the performance also varies between material combinations. Wear debris sizes and shapes produced by ceramic and polyethylene were diverse. We conclude that the biological components of synovial fluid and their concentrations should be considered in order to select an artificial hip joint to best suit that patient.

Multiple fault separation and detection by joint subspace learning for the health assessment of wind turbine gearboxes

NASA Astrophysics Data System (ADS)

Du, Zhaohui; Chen, Xuefeng; Zhang, Han; Zi, Yanyang; Yan, Ruqiang

2017-09-01

The gearbox of a wind turbine (WT) has dominant failure rates and highest downtime loss among all WT subsystems. Thus, gearbox health assessment for maintenance cost reduction is of paramount importance. The concurrence of multiple faults in gearbox components is a common phenomenon due to fault induction mechanism. This problem should be considered before planning to replace the components of the WT gearbox. Therefore, the key fault patterns should be reliably identified from noisy observation data for the development of an effective maintenance strategy. However, most of the existing studies focusing on multiple fault diagnosis always suffer from inappropriate division of fault information in order to satisfy various rigorous decomposition principles or statistical assumptions, such as the smooth envelope principle of ensemble empirical mode decomposition and the mutual independence assumption of independent component analysis. Thus, this paper presents a joint subspace learning-based multiple fault detection (JSL-MFD) technique to construct different subspaces adaptively for different fault patterns. Its main advantage is its capability to learn multiple fault subspaces directly from the observation signal itself. It can also sparsely concentrate the feature information into a few dominant subspace coefficients. Furthermore, it can eliminate noise by simply performing coefficient shrinkage operations. Consequently, multiple fault patterns are reliably identified by utilizing the maximum fault information criterion. The superiority of JSL-MFD in multiple fault separation and detection is comprehensively investigated and verified by the analysis of a data set of a 750 kW WT gearbox. Results show that JSL-MFD is superior to a state-of-the-art technique in detecting hidden fault patterns and enhancing detection accuracy.

A prospective 24 months follow-up of a three component press-fit prosthesis for hallux rigidus.

PubMed

Wassink, S; Burger, B J; Saragas, N P; Asunción Márquez, J; Trtik, L; Harlaar, J

2017-09-01

The aim of this study was to evaluate the results following total first metatarsophalangeal (FMTP) joint replacement arthroplasty using a modular three component press fit prosthesis at two year follow up. All patient data was collected in a prospective way in four study centres. Both preoperative and postoperative evaluation consisted of an assessment using the AOFAS-HMI score, visual analogue scale for pain, evaluation of the range of motion and patient satisfaction scores. Postoperative X-rays were reviewed for loosening and radiolucency up to two years. Fifty-five feet were available for analysis at 24 months. Two implants were removed during the study. Six more feet had additional surgery due to stiffness or malalignment. Postoperative AOFAS-HMI scores improved significantly by 32.4 points at two year follow-up (p<0.001). The visual analogue scale for pain improved significantly from 6.8 (std 1,6) preoperatively to 1.6 (std 1,9) postoperatively (p<0.0001). Mean dorsiflexion improved from 12.6 (std 10,1) degrees preoperatively to 31.2 (std 16,8) degrees postoperatively. Eighty-seven percent of patients were moderately to well satisfied with the end result. Eighteen prostheses showed radiolucency at 24 months. Implantation of a Metis ® modular three component press fit prosthesis for the metatarsophalangeal joint in hallux rigidus shows significant improvement in AOFAS-HMI scores and a decrease in pain. Concerns remain with regard to early reoperation rate (14.5%) and long term survival of the implant. Future studies will have to address these aspects. Copyright © 2016 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

Breast carcinoma with a predominant duct-replacing component and chondroid matrix production.

PubMed

Tajima, Shogo; Koda, Kenji

2016-12-01

Breast carcinomas that produce chondroid matrix are extremely rare. If the carcinoma is invasive, it is classified as a matrix-producing carcinoma (MPC). Herein, we present a case of a breast carcinoma, which showed duct-replacing growth with chondroid matrix production. A 63-year-old woman underwent fine needle aspiration cytology for suspected malignancy, based on radiological findings. Cellular components showed sufficient atypia to allow a diagnosis of malignancy. A partial mastectomy was performed, and no mass-forming lesion was apparent in the surgically resected specimen. Histopathological examination showed that the carcinoma produced chondroid matrix and grew replacing ducts, which were associated with a small amount of an obvious invasive component without matrix production. Some parts of the duct-replacing component might take the form of expansile invasion due to the absence of residual duct-lining myoepithelial cells; it is difficult to decide whether the duct-replacing component is invasive or not. However, regarding a few tumor nests, they would be recognized as MPC-like intraductal components because of the focal presence of myoepithelial cells around them. Hence, this carcinoma could not be definitely diagnosed as a MPC, even though we believe they are closely related. This is the first reported case of a breast carcinoma displaying duct-replacing growth with chondroid matrix production.

Cyclic steady state stress-strain behavior of UHMW polyethylene.

PubMed

Krzypow, D J; Rimnac, C M

2000-10-01

To increase the long-term performance of total joint replacements, finite element analyses of ultra high molecular weight polyethylene (UHMWPE) components have been conducted to predict the effect of load on the stress and strain distributions occurring on and within these components. Early models incorporated the monotonic behavior of UHMWPE without considering the unloading and cyclic loading behavior. However, UHMWPE components undergo cyclic loading during use and at least two wear damage modes (pitting and delamination) are thought to be associated with the fatigue fracture properties of UHMWPE. The objective of this study was to examine the fully reversed uniaxial tension/compression cyclic steady state stress-strain behavior of UHMWPE as a first step towards developing a cyclic constitutive relationship for UHMWPE. The hypothesis that cycling results in a permanent change in the stress-strain relationship, that is, that the cyclic steady state represents a new cyclically stabilized state, was examined. It was found that, like other ductile polymers, UHMWPE substantially cyclically softens under fully reversed uniaxial straining. More cyclic softening occurred in tension than in compression. Furthermore, cyclic steady state was attained, but not cyclic stability. It is suggested that it may be more appropriate to base a material constitutive relationship for UHMWPE for finite element analyses of components upon a cyclically modified stress-strain relationship.

The Need for an Implant Identification Card at Airport Security Check

PubMed Central

Kosuge, Dennis; MacDowell, Andrew

2017-01-01

Background Joint replacement surgery is having an increasing demand as national healthcare systems confront an ever ageing population. Surgical complications associated with lower limb arthroplasty are well known but less investigation has been performed examining its effect on air travel, more specifically, unwanted and significant inconvenience caused to travelers going through airport security. Methods In lower limb arthroplasty clinics, 50 patients who met our selection criteria were given questionnaires. Ten airport security officers from 4 international airports (London Stansted, London Gatwick, London Heathrow, and Amsterdam Schiphol International Airport) were also given a separate questionnaire. The opinion of the Civil Aviation Authority was also sought. Results All 50 patients (mean age, 70.4 years; range, 55 to 84 years) who were presenting in lower limb arthroplasty clinics and who met our selection criteria volunteered to enter the study. Twenty-eight of these patients were female (mean age, 69.1 years; range, 55 to 84 years) and 22 were male (mean age, 71.2 years; range, 58 to 81 years). Of the patients, 14% stated that their joint replacements did not set off the airport security alarm. Responses were received from 10 airport security officers as well. Six airport security officers were male and 4 were female. All of the airport officers were aware of some form of implant identification card with 90% stating that these were useful to them at airport security. Eight-four percent of the patients stated that an implant identification card outlining what joint replacement they possessed and when this had been done would be very useful. Sixteen percent of the patients did not think a card would be beneficial since all of them had set off the airport alarm system only once or less in their lifetime. Conclusions It is the opinion of airport security officers and patients that joint replacement implant identification cards streamline airport security checks and decrease the need for more invasive searches at airport security. PMID:28567216

The Need for an Implant Identification Card at Airport Security Check.

PubMed

Ali, Erden; Kosuge, Dennis; MacDowell, Andrew

2017-06-01

Joint replacement surgery is having an increasing demand as national healthcare systems confront an ever ageing population. Surgical complications associated with lower limb arthroplasty are well known but less investigation has been performed examining its effect on air travel, more specifically, unwanted and significant inconvenience caused to travelers going through airport security. In lower limb arthroplasty clinics, 50 patients who met our selection criteria were given questionnaires. Ten airport security officers from 4 international airports (London Stansted, London Gatwick, London Heathrow, and Amsterdam Schiphol International Airport) were also given a separate questionnaire. The opinion of the Civil Aviation Authority was also sought. All 50 patients (mean age, 70.4 years; range, 55 to 84 years) who were presenting in lower limb arthroplasty clinics and who met our selection criteria volunteered to enter the study. Twenty-eight of these patients were female (mean age, 69.1 years; range, 55 to 84 years) and 22 were male (mean age, 71.2 years; range, 58 to 81 years). Of the patients, 14% stated that their joint replacements did not set off the airport security alarm. Responses were received from 10 airport security officers as well. Six airport security officers were male and 4 were female. All of the airport officers were aware of some form of implant identification card with 90% stating that these were useful to them at airport security. Eight-four percent of the patients stated that an implant identification card outlining what joint replacement they possessed and when this had been done would be very useful. Sixteen percent of the patients did not think a card would be beneficial since all of them had set off the airport alarm system only once or less in their lifetime. It is the opinion of airport security officers and patients that joint replacement implant identification cards streamline airport security checks and decrease the need for more invasive searches at airport security.

Flexible connector

DOEpatents

Savage, M.E.; Simpson, W.W.

1999-07-27

An electrical connector accommodates high current, is not labor intensive to assemble and disassemble, and allows a wide range of motion to accommodate mechanical variations and movement of connected components. The connector comprises several parts with joints therebetween, wherein each joint provides electrical connection between and allows relative motion of the joined parts. The combination of parts and joints maintains electrical connection between two electrical components even if the components are misaligned or move after connection. 6 figs.

Joint health and functional ability in children with haemophilia who receive intensive replacement therapy.

PubMed

Groen, W; van der Net, J; Bos, K; Abad, A; Bergstrom, B-M; Blanchette, V S; Feldman, B M; Funk, S; Helders, P; Hilliard, P; Manco-Johnson, M; Petrini, P; Zourikian, N; Fischer, K

2011-09-01

Joint physical examination is an important outcome in haemophilia; however its relationship with functional ability is not well established in children with intensive replacement therapy. Boys aged 4-16 years were recruited from two European and three North American treatment centres. Joint physical structure and function was measured with the Haemophilia Joint Health Score (HJHS) while functional ability was measured with the revised Childhood Health Assessment Questionnaire (CHAQ₃₈. Two haemophilia-specific domains were created by selecting items of the CHAQ₃₈ that cover haemophilia-specific problems. Associations between CHAQ, HJHS, cumulative number of haemarthroses and age were assessed. A total of 226 subjects - mean 10.8 years old (SD 3.8) - participated; the majority (68%) had severe haemophilia. Most severe patients (91%) were on prophylactic treatment. Lifetime number of haemarthroses [median=5; interquartile range (IQR)=1-12] and total HJHS (median = 5; IQR=1-12) correlated strongly (ρ = 0.51). Total HJHS did not correlate with age and only weakly (ρ=-0.19) with functional ability scores (median=0; IQR=-0.06-0). Overall, haemarthroses were reported most frequently in the ankles. Detailed analysis of ankle joint health scores revealed moderate associations (ρ=0.3-0.5) of strength, gait and atrophy with lower extremity tasks (e.g. stair climbing). In this population, HJHS summating six joints did not perform as well as individual joint scores, however, certain elements of ankle impairment, specifically muscle strength, atrophy and gait associated significantly with functional loss in lower extremity activities. Mild abnormalities in ankle assessment by HJHS may lead to functional loss. Therefore, ankle joints may warrant special attention in the follow up of these children. © 2011 Blackwell Publishing Ltd.

Fabrication and Assembly of High-Precision Hinge and Latch Joints for Deployable Optical Instruments

NASA Technical Reports Server (NTRS)

Phelps, James E.

1999-01-01

Descriptions are presented of high-precision hinge and latch joints that have been co-developed, for application to deployable optical instruments, by NASA Langley Research Center and Nyma/ADF. Page-sized versions of engineering drawings are included in two appendices to describe all mechanical components of both joints. Procedures for assembling the mechanical components of both joints are also presented. The information herein is intended to facilitate the fabrication and assembly of the high-precision hinge and latch joints, and enable the incorporation of these joints into the design of deployable optical instrument systems.

Public priorities for joint pain research: results from a general population survey

PubMed Central

Carter, Pam; Ong, Bie Nio; Bedson, John; Jordan, Kelvin P.; Jinks, Clare

2012-01-01

Objective. We aimed to identify the priorities for joint pain research from a large general population survey and identify characteristics associated with these priorities. Methods. A question about research priorities was developed in collaboration with the Arthritis Research UK Primary Care Centre’s Research Users’ Group. The question was embedded in a postal survey to an existing cohort of adults with self-reported joint pain, aged ≥56 years, in North Staffordshire. Respondents were asked to rank their top three priorities for research. Factor mixture modelling was used to determine subgroups of priorities. Results. In all, 1756 (88%) people responded to the survey. Of these, 1356 (77%) gave three priorities for research. Keeping active was rated the top priority by 38%, followed by research around joint replacement (9%) and diet/weight loss (9%). Two clusters of people were identified: 62% preferred lifestyle/self-management topics (e.g. keeping active, weight loss) and 38% preferred medical intervention topics (e.g. joint replacement, tablets). Those who preferred the medical options tended to be older and have hip or foot pain. Conclusion. This study has provided population data on priorities for joint pain research expressed by a large cohort of older people who report joint pain. The most popular topics for research were linked to lifestyle and self-management opportunities. Pharmaceutical and invasive interventions, despite being common topics of research, are of less importance to these respondents than non-medical topics. Specific research questions will be generated from this study with collaboration of the patient’s group. PMID:22886341

Joint Procrustes Analysis for Simultaneous Nonsingular Transformation of Component Score and Loading Matrices

ERIC Educational Resources Information Center

Adachi, Kohei

2009-01-01

In component analysis solutions, post-multiplying a component score matrix by a nonsingular matrix can be compensated by applying its inverse to the corresponding loading matrix. To eliminate this indeterminacy on nonsingular transformation, we propose Joint Procrustes Analysis (JPA) in which component score and loading matrices are simultaneously…

Cost-Effectiveness of Total Hip and Knee Replacements for the Australian Population with Osteoarthritis: Discrete-Event Simulation Model

PubMed Central

Higashi, Hideki; Barendregt, Jan J.

2011-01-01

Background Osteoarthritis constitutes a major musculoskeletal burden for the aged Australians. Hip and knee replacement surgeries are effective interventions once all conservative therapies to manage the symptoms have been exhausted. This study aims to evaluate the cost-effectiveness of hip and knee replacements in Australia. To our best knowledge, the study is the first attempt to account for the dual nature of hip and knee osteoarthritis in modelling the severities of right and left joints separately. Methodology/Principal Findings We developed a discrete-event simulation model that follows up the individuals with osteoarthritis over their lifetimes. The model defines separate attributes for right and left joints and accounts for several repeat replacements. The Australian population with osteoarthritis who were 40 years of age or older in 2003 were followed up until extinct. Intervention effects were modelled by means of disability-adjusted life-years (DALYs) averted. Both hip and knee replacements are highly cost effective (AUD 5,000 per DALY and AUD 12,000 per DALY respectively) under an AUD 50,000/DALY threshold level. The exclusion of cost offsets, and inclusion of future unrelated health care costs in extended years of life, did not change the findings that the interventions are cost-effective (AUD 17,000 per DALY and AUD 26,000 per DALY respectively). However, there was a substantial difference between hip and knee replacements where surgeries administered for hips were more cost-effective than for knees. Conclusions/Significance Both hip and knee replacements are cost-effective interventions to improve the quality of life of people with osteoarthritis. It was also shown that the dual nature of hip and knee OA should be taken into account to provide more accurate estimation on the cost-effectiveness of hip and knee replacements. PMID:21966520

MEMS-Based Power Generation Techniques for Implantable Biosensing Applications

PubMed Central

Lueke, Jonathan; Moussa, Walied A.

2011-01-01

Implantable biosensing is attractive for both medical monitoring and diagnostic applications. It is possible to monitor phenomena such as physical loads on joints or implants, vital signs, or osseointegration in vivo and in real time. Microelectromechanical (MEMS)-based generation techniques can allow for the autonomous operation of implantable biosensors by generating electrical power to replace or supplement existing battery-based power systems. By supplementing existing battery-based power systems for implantable biosensors, the operational lifetime of the sensor is increased. In addition, the potential for a greater amount of available power allows additional components to be added to the biosensing module, such as computational and wireless and components, improving functionality and performance of the biosensor. Photovoltaic, thermovoltaic, micro fuel cell, electrostatic, electromagnetic, and piezoelectric based generation schemes are evaluated in this paper for applicability for implantable biosensing. MEMS-based generation techniques that harvest ambient energy, such as vibration, are much better suited for implantable biosensing applications than fuel-based approaches, producing up to milliwatts of electrical power. High power density MEMS-based approaches, such as piezoelectric and electromagnetic schemes, allow for supplemental and replacement power schemes for biosensing applications to improve device capabilities and performance. In addition, this may allow for the biosensor to be further miniaturized, reducing the need for relatively large batteries with respect to device size. This would cause the implanted biosensor to be less invasive, increasing the quality of care received by the patient. PMID:22319362

JOURNEY II XR Safety and Effectiveness PMCF

ClinicalTrials.gov

2018-04-19

Rheumatoid Vasculitis With Rheumatoid Arthritis of Knee; Unilateral Post-Traumatic Osteoarthritis of Knee; Knee Osteoarthritis; Degenerative Arthritis Peripheral Joint; Failed Osteotomies; Failed Unicompartmental Replacement

How to define responders in osteoarthritis

PubMed Central

Cooper, Cyrus; Adachi, Jonathan D.; Bardin, Thomas; Berenbaum, Francis; Flamion, Bruno; Jonsson, Helgi; Kanis, John A.; Pelousse, Franz; Lems, Willem F.; Pelletier, Jean-Pierre; Martel-Pelletier, Johanne; Reiter, Susanne; Reginster, Jean-Yves; Rizzoli, René; Bruyère, Olivier

2013-01-01

Background Osteoarthritis is a clinical syndrome of failure of the joint accompanied by varying degrees of joint pain, functional limitation, and reduced quality of life due to deterioration of articular cartilage and involvement of other joint structures. Scope Regulatory agencies require relevant clinical benefit on symptoms and structure modification for registration of a new therapy as a disease-modifying osteoarthritis drug (DMOAD). An international Working Group of the European Society on Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO) and International Osteoporosis Foundation was convened to explore the current burden of osteoarthritis, review current regulatory guidelines for the conduct of clinical trials, and examine the concept of responder analyses for improving drug evaluation in osteoarthritis. Findings The ESCEO considers that the major challenges in DMOAD development are the absence of a precise definition of the disease, particularly in the early stages, and the lack of consensus on how to detect structural changes and link them to clinically meaningful endpoints. Responder criteria should help identify progression of disease and be clinically meaningful. The ideal criterion should be sensitive to change over time and should predict disease progression and outcomes such as joint replacement. Conclusion The ESCEO considers that, for knee osteoarthritis, clinical trial data indicate that radiographic joint space narrowing >0.5 mm over 2 or 3 years might be a reliable surrogate measure for total joint replacement. On-going research using techniques such as magnetic resonance imaging and biochemical markers may allow the identification of these patients earlier in the disease process. PMID:23557069

Comparison of air exhausts for surgical body suits (space suits) and the potential for periprosthetic joint infection.

PubMed

Ling, F; Halabi, S; Jones, C

2018-07-01

Periprosthetic joint infection is a major complication of total joint replacement surgery and is associated with significant morbidity, mortality and financial burden. Surgical body suits (space suits), originally designed to reduce the incidence of infection, have paradoxically been implicated in increased periprosthetic joint infection rates recently. Air exhausted from space suits may contribute to this increased rate of periprosthetic joint infection. To investigate the flow of air exhausted from space suits commonly used in modern operating theatres. The exhaust airflow patterns of four commercially available space suit systems were compared using a fog machine and serial still photographs. The space suit systems tested all air exhausted into the operating room. The single fan systems with a standard surgical gown exhausted air laterally from the posterior gown fold at approximately the level of the surgical field. The single fan system with a dedicated zippered suit exhausted air at a level below the surgical field. The dual fan system exhausted air out of the top of the helmet at a level above the surgical field. Space suit systems currently in use in joint replacement surgery differ significantly from traditional body exhaust systems; rather than removing contaminated air from the operating environment, modern systems exhaust this air into the operating room, in some cases potentially towards the sterile instrument tray and the surgical field. Copyright © 2018 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Applying the Hájek Approach in Formula-Based Variance Estimation. Research Report. ETS RR-17-24

ERIC Educational Resources Information Center

Qian, Jiahe

2017-01-01

The variance formula derived for a two-stage sampling design without replacement employs the joint inclusion probabilities in the first-stage selection of clusters. One of the difficulties encountered in data analysis is the lack of information about such joint inclusion probabilities. One way to solve this issue is by applying Hájek's…

Photovoltaic Roofs

NASA Technical Reports Server (NTRS)

Drummond, R. W., Jr.; Shepard, N. F., Jr.

1984-01-01

Solar cells perform two functions: waterproofing roof and generating electricity. Sections through horizontal and slanting joints show overlapping modules sealed by L-section rubber strips and side-by-side modules sealed by P-section strips. Water seeping through seals of slanting joints drains along channels. Rooftop photovoltaic array used watertight south facing roof, replacing shingles, tar, and gravel. Concept reduces cost of residential solar-cell array.

Haemophilia and joint disease: pathophysiology, evaluation, and management

PubMed Central

Knobe, Karin; Berntorp, Erik

2011-01-01

In patients with haemophilia, regular replacement therapy with clotting factor concentrates (prophylaxis) is effective in preventing recurrent bleeding episodes into joints and muscles. However, despite this success, intra-articular and intramuscular bleeding is still a major clinical manifestation of the disease. Bleeding most commonly occurs in the knees, elbows, and ankles, and is often evident from early childhood. The pathogenesis of haemophilic arthropathy is multifactorial, with changes occurring in the synovium, bone, cartilage, and blood vessels. Recurrent joint bleeding causes synovial proliferation and inflammation (haemophilic synovitis) that contribute to end-stage degeneration (haemophilic arthropathy); with pain and limitation of motion severely affecting patients’ quality of life. If joint bleeding is not treated adequately, it tends to recur, resulting in a vicious cycle that must be broken to prevent the development of chronic synovitis and degenerative arthritis. Effective prevention and management of haemophilic arthropathy includes the use of early, aggressive prophylaxis with factor replacement therapies, as well as elective procedures, including restorative physical therapy, analgesia, aspiration, synovectomy, and orthopaedic surgery. Optimal treatment of patients with haemophilia requires a multidisciplinary team comprising a haematologist, physiotherapist, orthopaedic practitioner, rehabilitation physician, occupational therapist, psychologist, social workers, and nurses. Journal of Comorbidity 2011;1:51–59 PMID:29090136

NextGen Weather Processor Architecture Study

DTIC Science & Technology

2010-03-09

achieved in a staged fashion , ideally with new components coming on-line in time to replace existing capabilities prior to their end-of-life dates... fashion , ideally with new components coming on-line in time to replace existing capabilities prior to their end-of-life dates. As part of NWP Segment...weather capabilities. These objectives are to be achieved in a staged fashion , ideally with new components coming on-line in time to replace existing

Hemophilia A Pseudoaneurysm in a Patient with High Responding Inhibitors Complicating Total Knee Arthroplasty: Embolization: A Cost-Reducing Alternative to Medical Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kickuth, Ralph, E-mail: ralph.kickuth@insel.ch; Anderson, Suzanne; Peter-Salonen, Kristiina

2006-12-15

Joint hemorrhages are very common in patients with severe hemophilia. Inhibitors in patients with hemophilia are allo-antibodies that neutralize the activity of the clotting factor. After total knee replacement, rare intra-articular bleeding complications might occur that do not respond to clotting factor replacement. We report a 40-year-old male with severe hemophilia A and high responding inhibitors presenting with recurrent knee joint hemorrhage after bilateral knee prosthetic surgery despite adequate clotting factor treatment. There were two episodes of marked postoperative hemarthrosis requiring extensive use of subsititution therapy. Eleven days postoperatively, there was further hemorrhage into the right knee. Digital subtraction angiographymore » diagnosed a complicating pseudoaneurysm of the inferior lateral geniculate artery and embolization was successfully performed. Because clotting factor replacement therapy has proved to be excessively expensive and prolonged, especially in patients with inhibitors, we recommend the use of cost-effective early angiographic embolization.« less

[Efficacy of health education on patients with hip replacement based on the Internet].

PubMed

Zhou, Yang; Yang, Tubao; Li, Yinglan; Yu, Jie; Zeng, Biyun

2015-03-01

To evaluate the efficacy of health education on patients with hip replacement based on the Internet, and to establish a new health education model through modern technology. A total of 300 patients with hip replacement from March to August, 2015 were enrolled in this study. The participants were divided into a control group and an experimental group according to months surgeries performed. Traditional education was applied in the control group while the multimedia source material plus the Internet platform of Joint Registration System were applied in the experimental group. Levels of anxiety, degree of satisfaction, and postoperative complications were analyzed. The levels of knowledge, attitude and behavior compliance in the patients of the experimental group were significantly improved, while the levels of postoperative anxiety were decreased compared with those in the control group (P<0.05). Education based on the Internet platform of Joint Registration System and the computer video could improve patients' knowledge, attitude, and behavior, which is worthy of clinical spread.

Extravehicular activity compatibility evaluation of developmental hardware for assembly and repair of precision reflectors

NASA Technical Reports Server (NTRS)

Heard, Walter L., Jr.; Lake, Mark S.; Bush, Harold G.; Jensen, J. Kermit; Phelps, James E.; Wallsom, Richard E.

1992-01-01

This report presents results of tests performed in neutral buoyancy by two pressure-suited test subjects to simulate Extravehicular Activity (EVA) tasks associated with the on-orbit construction and repair of a precision reflector spacecraft. Two complete neutral buoyancy assemblies of the test article (tetrahedral truss with three attached reflector panels) were performed. Truss joint hardware, two different panel attachment hardware concepts, and a panel replacement tool were evaluated. The test subjects found the operation and size of the truss joint hardware to be acceptable. Both panel attachment concepts were found to be EVA compatible, although one concept was judged by the test subjects to be considerably easier to operate. The average time to install a panel from a position within arm's reach of the test subjects was 1 min 14 sec. The panel replacement tool was used successfully to demonstrate the removal and replacement of a damaged reflector panel in 10 min 25 sec.

Selection of contact bearing couple materials for hip prosthesis using finite element analysis under static conditions

NASA Astrophysics Data System (ADS)

Arirajan, K. A.; Chockalingam, K.; Vignesh, C.

2018-04-01

Implants are the artificial parts to replace the missing bones or joints in human anatomy to give mechanical support. Hip joint replacement is an important issue in orthopaedic surgery. The main concern limiting the long-run success of the total hip replacement is the limited service life. Hip replacement technique is widely used in replacing the femur head and acetabular cup by materials that are highly biocompatible. The success of the artificial hip replacement depends upon proper material selection, structure, and shape of the hip prosthesis. Many orthopaedic analyses have been tried with different materials, but ended with partial success on the application side. It is a critical task for selecting the best material pair in the hip prosthesis design. This work develops the finite element analysis of an artificial hip implant to study highest von Mises stress, contact pressure and elastic strain occurs for the dissimilar material combination. The different bearing couple considered for the analysis are Metal on Metal, Metal on Plastic, Metal on Ceramic, Ceramic on Plastic, Ceramic on Ceramic combinations. The analysis is carried out at different static positions of a human (i.e) standing, sitting. The results reveals that the combination with metal in contact with plastic (i.e) Titanium femoral head paired with Ultra High Molecular Weight Poly Ethylene acetabular cup reduces maximum von Mises stress and also it gives lowest contact pressure than other combination of bearing couples.

[Endoprosthesis Infections - Guidelines for Antibiotic Therapy Common Guidelines of the Czech Society for Orthopaedics and Traumatology and the Society for Infectious Diseases of the Czech Medical Association of J. E. Purkyně].

PubMed

Musil, D; Balejová, M; Horníková, M; Chrdle, A; Mallátová, N; Nyč, O; Chmelík, V; Gallo, J; Jahoda, D; Stehlík, J

2017-01-01

PURPOSE OF THE STUDY This study aims to articulate regional guidelines for curative and suppressive antibiotic therapy of total joint replacement infections. MATERIAL AND METHODS When developing the standard, used as source materials were the published foreign guidelines for antibiotic therapy of prosthetic joint infections, the analysis of resistance of bacterial strains conducted in the Hospital in České Budějovice, a.s. and the assessment of strain resistance for the Czech Republic published by the European Antimicrobial Resistance Surveillance Network (EARS-Net). Considered was also the availability of individual antibiotics in the Czech Republic and restricted prescription according to the Summary of Product Characteristics as specified in the State Institute for Drug Control marketing authorisation. The expert group composed of orthopaedists, microbiologists and infectious disease specialists elaborated the basic antibiotic guideline for choosing an appropriate antibiotic/antifungal drug based on the usual susceptibility, its dose and dosage interval for initial and continuation therapy. The comments of individual specialists were gradually incorporated therein and in case of doubts majority rule was applied. The drafted document was sent for peer reviews to clinical orthopaedic, infectious disease and microbiological centres, whose comments were also incorporated and the finalised document was submitted for evaluation to specialised medical societies. RESULTS The outcome is the submitted guideline for antibiotic curative and suppressive therapy suitable for managing the prosthetic joint infections, which was approved by the committee of the Czech Society for Orthopaedics and Traumatology andthe Society for Infectious Diseases of the Czech Medical Association of J. E. Purkyně. DISCUSION Curative therapy of total joint replacement infections consists primarily in surgical treatment and has to be accompanied by adequate antibiotic therapy administered initially intravenously and later orally over a sufficient period of time. Bearing in mind the wide spectrum of pathogens that can cause infections of a joint replacement and their capacity to form a biofilm on foreign materials, the correct choice of an antibiotic, its dose and dosage interval are essential for successful treatment. Such standard should respect regional availability of antibiotics, regional pathogen resistance/susceptibility and ensure the achievement of sufficiently high concentrations at the requested location including anti-biofilm activity. CONCLUSIONS The submitted guideline is not the only treatment option for joint total replacement infections, but it makes the decisionmaking easier when treating these complications in the form of infections. The final choice of an antibiotic, its dose and duration of therapy shall be based on a critical assessment of results of microbiological (blood culture and molecular genetic) tests and reflect the patient s clinical condition. Since these are multidisciplinary issues, we consider useful for this guideline to be commented upon and approved by the committee of both the Society for Orthopaedics and Infectious Diseases so that it can become the starting point for treatment. Key words: total joint replacement infection, TEP, ATB, antibiotic therapy, consensus meeting, guideline.

The transverse force experienced by the radial head during axial loading of the forearm: A cadaveric study.

PubMed

Orbay, Jorge L; Mijares, Michael R; Berriz, Cecilia G

2016-01-01

When designing a radial head replacement, the magnitude and direction of forces applied across the proximal radio-ulnar joint (PRUJ) and the radiocapitellar joint must be included. These designs often focus on axial loads transmitted to the radial head by the capitellum; however, the radial head also bears a significant transverse force at the PRUJ. Load transmission by the central band of the interosseous ligament induces a force component in a lateral direction perpendicular to the axis of the limb, which is borne by the articular surfaces of the proximal and distal radio-ulnar joints. The objective of this study is to establish the relationship between distally applied axial forces and proximal transverse reaction forces. Five cadaveric, human forearms with intact interosseous membranes were used to measure the magnitude of transversely-directed forces experienced by the radial head during axial loading of the forearm at the lunate fossa. A Mark-10 test stand applied a gradual and continuous axial load on the articular surface of the distal radius. A Mark-10 force gauge measured the resultant transverse force experienced by the radial head in the proximal radioulnar joint. Classical mechanics and static force analysis were applied in order to predict lateral force values that would occur when the interosseous ligament is treated as the major load transmitter between the radius and ulna. Acquired data show that the radial head bears a force in the transverse direction that averages 18% (SD 3.89%) in magnitude of the axial force applied at the wrist. This figure is in close accordance with the predicted value of 22% that was calculated by way of free-body plotting. Physiologic forearm loading results in a clinically significant transverse force component transmitted through the interosseous ligament complex. The existence of transverse forces in the human forearm may explain clinical problems seen after radial head resection and suggest that radial head implants be designed to sustain substantial transverse forces. Basic science study, anatomical. Copyright © 2015 Elsevier Ltd. All rights reserved.

The effect of dynamic hip motion on the micromotion of press-fit acetabular cups in six degrees of freedom.

PubMed

Crosnier, Emilie A; Keogh, Patrick S; Miles, Anthony W

2016-08-01

The hip joint is subjected to cyclic loading and motion during activities of daily living and this can induce micromotions at the bone-implant interface of cementless total hip replacements. Initial stability has been identified as a crucial factor to achieve osseointegration and long-term survival. Whilst fixation of femoral stems achieves good clinical results, the fixation of acetabular components remains a challenge. In vitro methods assessing cup stability keep the hip joint in a fixed position, overlooking the effect of hip motion. The effect of hip motion on cup micromotion using a hip motion simulator replicating hip flexion-extension and a six degrees of freedom measurement system was investigated. The results show an increase in cup micromotion under dynamic hip motion compared to Static Flexion. This highlights the need to incorporate hip motion and measure all degrees of freedom when assessing cup micromotion. In addition, comparison of two press-fit acetabular cups with different surface coatings suggested similar stability between the two cups. This new method provides a basis for a more representative protocol for future pre-clinical evaluation of different cup designs. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

Acoustic emissions (AE) monitoring of large-scale composite bridge components

NASA Astrophysics Data System (ADS)

Velazquez, E.; Klein, D. J.; Robinson, M. J.; Kosmatka, J. B.

2008-03-01

Acoustic Emissions (AE) has been successfully used with composite structures to both locate and give a measure of damage accumulation. The current experimental study uses AE to monitor large-scale composite modular bridge components. The components consist of a carbon/epoxy beam structure as well as a composite to metallic bonded/bolted joint. The bonded joints consist of double lap aluminum splice plates bonded and bolted to carbon/epoxy laminates representing the tension rail of a beam. The AE system is used to monitor the bridge component during failure loading to assess the failure progression and using time of arrival to give insight into the origins of the failures. Also, a feature in the AE data called Cumulative Acoustic Emission counts (CAE) is used to give an estimate of the severity and rate of damage accumulation. For the bolted/bonded joints, the AE data is used to interpret the source and location of damage that induced failure in the joint. These results are used to investigate the use of bolts in conjunction with the bonded joint. A description of each of the components (beam and joint) is given with AE results. A summary of lessons learned for AE testing of large composite structures as well as insight into failure progression and location is presented.

Knee Joint Loads and Surrounding Muscle Forces during Stair Ascent in Patients with Total Knee Replacement

PubMed Central

Rasnick, Robert; Standifird, Tyler; Reinbolt, Jeffrey A.; Cates, Harold E.

2016-01-01

Total knee replacement (TKR) is commonly used to correct end-stage knee osteoarthritis. Unfortunately, difficulty with stair climbing often persists and prolongs the challenges of TKR patents. Complete understanding of loading at the knee is of great interest in order to aid patient populations, implant manufacturers, rehabilitation, and future healthcare research. Musculoskeletal modeling and simulation approximates joint loading and corresponding muscle forces during a movement. The purpose of this study was to determine if knee joint loadings following TKR are recovered to the level of healthy individuals, and determine the differences in muscle forces causing those loadings. Data from five healthy and five TKR patients were selected for musculoskeletal simulation. Variables of interest included knee joint reaction forces (JRF) and the corresponding muscle forces. A paired samples t-test was used to detect differences between groups for each variable of interest (p<0.05). No differences were observed for peak joint compressive forces between groups. Some muscle force compensatory strategies appear to be present in both the loading and push-off phases. Evidence from knee extension moment and muscle forces during the loading response phase indicates the presence of deficits in TKR in quadriceps muscle force production during stair ascent. This result combined with greater flexor muscle forces resulted in similar compressive JRF during loading response between groups. PMID:27258086

Surface characteristics of bioactive Ti fabricated by chemical treatment for cartilaginous-integration.

PubMed

Miyajima, Hiroyuki; Ozer, Fusun; Imazato, Satoshi; Mante, Francis K

2017-09-01

Artificial hip joints are generally expected to fail due to wear after approximately 15years and then have to be replaced by revision surgery. If articular cartilage can be integrated onto the articular surfaces of artificial joints in the same way as osseo-integration of titanium dental implants, the wear of joint implants may be reduced or prevented. However, very few studies have focused on the relationship between Ti surface and cartilage. To explore the possibility of cartilaginous-integration, we fabricated chemically treated Ti surfaces with H 2 O 2 /HCl, collagen type II and SBF, respectively. Then, we evaluated surface characteristics of the prepared Ti samples and assessed the cartilage formation by culturing chondrocytes on the Ti samples. When oxidized Ti was immersed in SBF for 7days, apatite was formed on the Ti surface. The surface characteristics of Ti indicated that the wettability was increased by all chemical treatments compared to untreated Ti, and that H 2 O 2 /HCl treated surface had significantly higher roughness compared to the other three groups. Chondrocytes produced significantly more cartilage matrix on all chemically treated Ti surfaces compared to untreated Ti. Thus, to realize cartilaginous-integration and to prevent wear of the implants in joints, application of bioactive Ti formed by chemical treatment would be a promising and effective strategy to improve durability of joint replacement. Copyright © 2017 Elsevier B.V. All rights reserved.

Motion at the Tibial and Polyethylene Component Interface in a Mobile-Bearing Total Ankle Replacement.

PubMed

Lundeen, Gregory A; Clanton, Thomas O; Dunaway, Linda J; Lu, Minggen

2016-08-01

Normal biomechanics of the ankle joint includes sagittal as well as axial rotation. Current understanding of mobile-bearing motion at the tibial-polyethylene interface in total ankle arthroplasty (TAA) is limited to anterior-posterior (AP) motion of the polyethylene component. The purpose of our study was to define the motion of the polyethylene component in relation to the tibial component in a mobile-bearing TAA in both the sagittal and axial planes in postoperative patients. Patients who were a minimum of 12 months postoperative from a third-generation mobile-bearing TAA were identified. AP images were saved at maximum internal and external rotation, and the lateral images were saved in maximum plantarflexion and dorsiflexion. Sagittal range of motion and AP translation of the polyethylene component were measured from the lateral images. Axial rotation was determined by measuring the relative position of the 2 wires within the polyethylene component on AP internal and external rotation imaging. This relationship was compared to a table developed from fluoroscopic images taken at standardized degrees of axial rotation of a nonimplanted polyethylene with the associated length relationship of the 2 imbedded wires. Sixteen patients were included in this investigation, 9 (56%) were male and average age was 68 (range, 49-80) years. Time from surgery averaged 25 (range, 12-38) months. Total sagittal range of motion averaged 23±9 (range, 9-33) degrees. Axial motion for total internal and external rotation of the polyethylene component on the tibial component averaged 6±5 (range, 0-18) degrees. AP translation of the polyethylene component relative to the tibial component averaged 1±1 (range, 0-3) mm. There was no relationship between axial rotation or AP translation of the polyethylene component and ankle joint range of motion (P > .05). To our knowledge, this is the first investigation to measure axial and sagittal motion of the polyethylene component at the tibial implant interface in patients following a mobile-bearing TAA. Based on outcome scores and range-of-motion measurements, we believe the patients in this study are a representative cross section of subjects compared to other TAA research results. The results from this investigation indicate the potential for a mobile-bearing TAA to fall within the parameters of normal polyaxial ankle motion. The multiplanar articulation in a mobile-bearing TAA may reduce excessively high peak pressures during the complex dynamic tibial and talar motion, which may have a positive influence on gait pattern, polyethylene wear, and implant longevity. Level IV, case series. © The Author(s) 2016.

Knee joint motion and muscle activation patterns are altered during gait in individuals with moderate hip osteoarthritis compared to asymptomatic cohort.

PubMed

Rutherford, Derek; Moreside, Janice; Wong, Ivan

2015-07-01

Knee replacements are common after hip replacement for end stage osteoarthritis. Whether abnormal knee mechanics exist in moderate hip osteoarthritis remains undetermined and has implications for understanding early osteoarthritis joint mechanics. The purpose of this study was to determine whether three-dimensional (3D) knee motion and muscle activation patterns in individuals with moderate hip osteoarthritis differ from an asymptomatic cohort and whether these features differ between contra- and ipsilateral knees. 3D motions and medial and lateral quadriceps and hamstring surface electromyography were recorded on 20 asymptomatic individuals and 20 individuals with moderate hip osteoarthritis during treadmill walking, using standardized collection and processing procedures. Principal component analysis was used to derive electromyographic amplitude and temporal waveform features. 3D stance-phase range of motion was calculated. A 2-factor repeated analysis of variance determined significant within-group leg and muscle differences. Student's t-tests identified between group differences, with Bonferroni corrections where applicable (α=0.05). Lower sagittal plane motion between early and mid/late stance (5°, P=0.004, effect size: 0.96) and greater mid-stance quadriceps activity was found in the osteoarthritis group (P=0.01). Compared to the ipsilateral knee, a borderline significant increase in mid-stance hamstring activity was found in the contra-lateral knee of the hip osteoarthritis group (P=0.018). Bilateral knee mechanics were altered, suggesting potentially increased loads and knee muscle fatigue. There was no indication that one knee is more susceptible to osteoarthritis than the other, thus clinicians should include bilateral knee analysis when treating patients with hip osteoarthritis. Copyright © 2015 Elsevier Ltd. All rights reserved.

A review of typical thermal fatigue failure models for solder joints of electronic components

NASA Astrophysics Data System (ADS)

Li, Xiaoyan; Sun, Ruifeng; Wang, Yongdong

2017-09-01

For electronic components, cyclic plastic strain makes it easier to accumulate fatigue damage than elastic strain. When the solder joints undertake thermal expansion or cold contraction, different thermal strain of the electronic component and its corresponding substrate is caused by the different coefficient of thermal expansion of the electronic component and its corresponding substrate, leading to the phenomenon of stress concentration. So repeatedly, cracks began to sprout and gradually extend [1]. In this paper, the typical thermal fatigue failure models of solder joints of electronic components are classified and the methods of obtaining the parameters in the model are summarized based on domestic and foreign literature research.

Achieving Consensus on Total Joint Replacement Trial Outcome Reporting Using the OMERACT Filter: Endorsement of the Final Core Domain Set for Total Hip and Total Knee Replacement Trials for Endstage Arthritis.

PubMed

Singh, Jasvinder A; Dowsey, Michelle M; Dohm, Michael; Goodman, Susan M; Leong, Amye L; Scholte Voshaar, Marieke M J H; Choong, Peter F

2017-11-01

Discussion and endorsement of the OMERACT total joint replacement (TJR) core domain set for total hip replacement (THR) and total knee replacement (TKR) for endstage arthritis; and next steps for selection of instruments. The OMERACT TJR working group met at the 2016 meeting at Whistler, British Columbia, Canada. We summarized the previous systematic reviews, the preliminary OMERACT TJR core domain set and results from previous surveys. We discussed preliminary core domains for TJR clinical trials, made modifications, and identified challenges with domain measurement. Working group participants (n = 26) reviewed, clarified, and endorsed each of the inner and middle circle domains and added a range of motion domain to the research agenda. TJR were limited to THR and TKR but included all endstage hip and knee arthritis refractory to medical treatment. Participants overwhelmingly endorsed identification and evaluation of top instruments mapping to the core domains (100%) and use of subscales of validated multidimensional instruments to measure core domains for the TJR clinical trial core measurement set (92%). An OMERACT core domain set for hip/knee TJR trials has been defined and we are selecting instruments to develop the TJR clinical trial core measurement set to serve as a common foundation for harmonizing measures in TJR clinical trials.

Meniscal tears, repairs and replacement: their relevance to osteoarthritis of the knee.

PubMed

McDermott, Ian

2011-04-01

The menisci of the knee are important load sharers and shock absorbers in the joint. Meniscal tears are common, and whenever possible meniscal tears should be surgically repaired. Meniscectomy leads to a significant increased risk of osteoarthritis, and various options now exist for replacing missing menisci, including the use of meniscal scaffolds or the replacement of the entire meniscus by meniscal allograft transplantation. The field of meniscal surgery continues to develop apace, and the future may lie in growing new menisci by tissue engineering techniques.

Taking care of your new hip joint

MedlinePlus

Hip arthroplasty - precautions; Hip replacement - precautions; Osteoarthritis - hip; Osteoarthritis - knee ... Saunders; 2015:chap 61. Harkess JW, Crockarell JR. Arthroplasty of the hip. In: Azar FM, Beaty JH, ...

Is There a Need For a Joint Reserve Components Command?

DTIC Science & Technology

2013-03-01

Bravo Zulu ”. If these words were heard by a Soldier, it might be interpreted as poor performance. By having one organization as a single source for...Commander, Joint Reserve Components Command. Creation of the JRCC would, in time, strengthen partnerships between the reserve components of each

Biomechanical benefits of anterior offsetting of humeral head component in posteriorly unstable total shoulder arthroplasty: A cadaveric study.

PubMed

Kim, Hyun-Min Mike; Chacon, Alexander C; Andrews, Seth H; Roush, Evan P; Cho, Edward; Conaway, William K; Kunselman, Allen R; Lewis, Gregory S

2016-04-01

Restoration of joint stability during total shoulder arthroplasty can be challenging in the face of severe glenoid retroversion. A novel technique of humeral head component anterior-offsetting has been proposed to address posterior instability. We evaluated the biomechanical benefits of this technique in cadaveric specimens. Total shoulder arthroplasty was performed in 14 cadaveric shoulders from 7 donors. Complementary shoulders were assigned to either 10° or 20° glenoid retroversion, with retroversion created by eccentric reaming. Two humeral head component offset positions were tested in each specimen: The anatomic (posterior) and anterior (reverse). With loads applied to the rotator cuff and deltoid, joint contact pressures and the force and energy required for posterior humeral head translation were measured. The force and energy required to displace the humeral head posteriorly increased significantly with the anterior offset position compared to the anatomic offset position. The joint contact pressures were significantly shifted anteriorly, and the joint contact area significantly increased with the anterior offset position. Anterior offsetting of the humeral head component increased the resistance to posterior humeral head translation, shifted joint contact pressures anteriorly, and increased joint contact area, thus, potentially increasing the joint stability in total shoulder arthroplasty with simulated glenoid retroversion. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Does the person's context influence engagement in life activities following primary knee replacement? Results from a Canadian prospective cohort study.

PubMed

Davis, Aileen M; Venkataramanan, Viji; Bytautas-Sillanpää, Jessica; Perruccio, Anthony V; Wong, Rosalind; Carlesso, Lisa; Webster, Fiona

2017-08-18

The impact of the context of a person's life on recovery from surgical interventions is not well understood. This study evaluated if people's social, environmental and biomedical context was associated with change in frequency in engagement in life activities after total knee replacement (TKR). 418 people aged 30+ years who had TKR were followed presurgery to 1 year postsurgery. The outcome was change in frequency in engagement in life activities measured by the Late Life Disability Index (LLDI). Predictor variables of interest evaluated in multivariable linear regression analysis were positive and negative life events (Life Experiences Survey), development of a new comorbidity, another joint replacement and complications after TKR surgery. Mean age was 65 years, 36% were male; 22% and 21% had no comorbidity presurgery and postsurgery. Presurgery LLDI frequency was 69.6 (±11.4) and the mean change was 6.1 (±10.2). Thirty-four per cent and 65% reported at least one positive or negative life event. Seven per cent developed hypertension, 6% cardiovascular disease, 2% lung disease and 2% diabetes. Eleven per cent had a complication and 9% another hip or knee replaced. Smaller changes in LLDI frequency were associated with more negative life events (beta=-0.56; 95% CI -0.92 to-0.18) and complications (beta=-4.01; 95% CI -6.63 to -1.38) after adjusting for age, sex, education, body mass index, comorbidities presurgery, number of symptomatic joints and knee-specific pain and function, LLDI limitations and depression. A new comorbidity or another joint replacement was not associated with outcome in unadjusted or adjusted analysis. Multifaceted life experiences shape the context of peoples' lives impacting their engagement in activities important for healthy living post-TKR. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Joint Tactical Radio System Handheld, Manpack, and Small Form Fit Radios (JTRS HMS)

DTIC Science & Technology

2013-12-01

requisitions through the Standard Army Supply System ( SASS ). All radios procured under the Full Rate Production (FRP) phase that become unserviceable...will be turned-in to TYAD through the SASS . Radios will be returned to the original equipment manufacturer vendor for warranty repair, or replacement...procure sustainment spares to replace unserviceable radios and ancillary items requisitioned through SASS , operations, maintenance, training

The volume of the human knee joint.

PubMed

Matziolis, Georg; Roehner, Eric; Windisch, Christoph; Wagner, Andreas

2015-10-01

Despite its clinical relevance, particularly in septic knee surgery, the volume of the human knee joint has not been established to date. Therefore, the objective of this study was to determine knee joint volume and whether or not it is dependent on sex or body height. Sixty-one consecutive patients (joints) who were due to undergo endoprosthetic joint replacement were enrolled in this prospective study. During the operation, the joint volume was determined by injecting saline solution until a pressure of 200 mmHg was achieved in the joint. The average volume of all knee joints was 131 ± 53 (40-290) ml. The volume was not found to be dependent on sex, but it was dependent on the patients' height (R = 0.312, p = 0.014). This enabled an estimation of the joint volume according to V = 1.6 height - 135. The considerable inter-individual variance of the knee joint volume would suggest that it should be determined or at least estimated according to body height if the joint volume has consequences for the diagnostics or therapy of knee disorders.

A small punch test technique for characterizing the elastic modulus and fracture behavior of PMMA bone cement used in total joint replacement.

PubMed

Giddings, V L; Kurtz, S M; Jewett, C W; Foulds, J R; Edidin, A A

2001-07-01

Polymethylmethacrylate (PMMA) bone cement is used in total joint replacements to anchor implants to the underlying bone. Establishing and maintaining the integrity of bone cement is thus of critical importance to the long-term outcome of joint replacement surgery. The goal of the present study was to evaluate the suitability of a novel testing technique, the small punch or miniaturized disk bend test, to characterize the elastic modulus and fracture behavior of PMMA. We investigated the hypothesis that the crack initiation behavior of PMMA during the small punch test was sensitive to the test temperature. Miniature disk-shaped specimens, 0.5 mm thick and 6.4 mm in diameter, were prepared from PMMA and Simplex-P bone cement according to manufacturers' instructions. Testing was conducted at ambient and body temperatures, and the effect of test temperature on the elastic modulus and fracture behavior was statistically evaluated using analysis of variance. For both PMMA materials, the test temperature had a significant effect on elastic modulus and crack initiation behavior. At body temperature, the specimens exhibited "ductile" crack initiation, whereas at room temperature "brittle" crack initiation was observed. The small punch test was found to be a sensitive and repeatable test method for evaluating the mechanical behavior of PMMA. In light of the results of this study, future small punch testing should be conducted at body temperature.

Forced-air warming and ultra-clean ventilation do not mix: an investigation of theatre ventilation, patient warming and joint replacement infection in orthopaedics.

PubMed

McGovern, P D; Albrecht, M; Belani, K G; Nachtsheim, C; Partington, P F; Carluke, I; Reed, M R

2011-11-01

We investigated the capacity of patient warming devices to disrupt the ultra-clean airflow system. We compared the effects of two patient warming technologies, forced-air and conductive fabric, on operating theatre ventilation during simulated hip replacement and lumbar spinal procedures using a mannequin as a patient. Infection data were reviewed to determine whether joint infection rates were associated with the type of patient warming device that was used. Neutral-buoyancy detergent bubbles were released adjacent to the mannequin's head and at floor level to assess the movement of non-sterile air into the clean airflow over the surgical site. During simulated hip replacement, bubble counts over the surgical site were greater for forced-air than for conductive fabric warming when the anaesthesia/surgery drape was laid down (p = 0.010) and at half-height (p < 0.001). For lumbar surgery, forced-air warming generated convection currents that mobilised floor air into the surgical site area. Conductive fabric warming had no such effect. A significant increase in deep joint infection, as demonstrated by an elevated infection odds ratio (3.8, p = 0.024), was identified during a period when forced-air warming was used compared to a period when conductive fabric warming was used. Air-free warming is, therefore, recommended over forced-air warming for orthopaedic procedures.

Meniscus tear surgery and meniscus replacement

PubMed Central

Vaquero, Javier; Forriol, Francisco

2016-01-01

Summary Objective the menisci are easily injured and difficult to repair. The aim of this study was to analyze the current state of meniscal surgery aimed at preserving morphology and conserving the biomechanics of the knee to prevent joint degeneration. Methodology a search of the electronic medical literature database Medline was conducted, from http://www.ncbi.nlm.nih.gov/pubmed. The search was not limited by language. Candidate articles were identified by searching for those that included the keywords meniscus, surgery, suture, implant, allograft. The limits were included for clinical research and clinical trials. Basic research was not included. The studies selected were evaluated and classified in three different categories: basic science, reconstruction (suture and meniscectomy) and implants (scaffolds and allograft). Results the consequences of meniscectomy performed at a young age can lead to a joint cartilage degeneration twenty years later. There are few surgical options for the repair of meniscal injuries in order both to preserve the meniscus and to ensure the long term survival of the knee joint, meniscectomy, repair, suturing the tear, or reconstruction, when a meniscal allograft or synthetic substitute is used to replace the meniscus, but the biomechanical properties of the native meniscus are not reproduced entirely by the scaffolds that exist today. Conclusion therapies that successfully repair or replace the meniscus are therefore likely to prevent or delay osteoarthritis progression. PMID:27331034

What is the impact of a clinically related readmission measure on the assessment of hospital performance?

PubMed

Khouri, Roger K; Hou, Hechuan; Dhir, Apoorv; Andino, Juan J; Dupree, James M; Miller, David C; Ellimoottil, Chad

2017-11-28

The Hospital Readmission Reduction Program (HRRP) penalizes hospitals for high all-cause unplanned readmission rates. Many have expressed concern that hospitals serving patient populations with more comorbidities, lower incomes, and worse self-reported health status may be disproportionately penalized by readmissions that are not clinically related to the index admission. The impact of including clinically unrelated readmissions on hospital performance is largely unknown. We sought to determine if a clinically related readmission measure would significantly alter the assessment of hospital performance. We analyzed Medicare claims for beneficiaries in Michigan admitted for pneumonia and joint replacement from 2011 to 2013. We compared each hospital's 30-day readmission rate using specifications from the HRRP's all-cause unplanned readmission measure to values calculated using a clinically related readmission measure. We found that the mean 30-day readmission rates were lower when calculated using the clinically related readmission measure (joint replacement: all-cause 5.8%, clinically related 4.9%, p < 0.001; pneumonia: all cause 12.5%, clinically related 11.3%, p < 0.001)). The correlation of hospital ranks using both methods was strong (joint replacement: 0.95 (p < 0.001), pneumonia: 0.90 (p < 0.001)). Our findings suggest that, while greater specificity may be achieved with a clinically related measure, clinically unrelated readmissions may not impact hospital performance in the HRRP.

Knee joint replacement - slideshow

MedlinePlus

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Experimental validation of finite element modelling of a modular metal-on-polyethylene total hip replacement.

PubMed

Hua, Xijin; Wang, Ling; Al-Hajjar, Mazen; Jin, Zhongmin; Wilcox, Ruth K; Fisher, John

2014-07-01

Finite element models are becoming increasingly useful tools to conduct parametric analysis, design optimisation and pre-clinical testing for hip joint replacements. However, the verification of the finite element model is critically important. The purposes of this study were to develop a three-dimensional anatomic finite element model for a modular metal-on-polyethylene total hip replacement for predicting its contact mechanics and to conduct experimental validation for a simple finite element model which was simplified from the anatomic finite element model. An anatomic modular metal-on-polyethylene total hip replacement model (anatomic model) was first developed and then simplified with reasonable accuracy to a simple modular total hip replacement model (simplified model) for validation. The contact areas on the articulating surface of three polyethylene liners of modular metal-on-polyethylene total hip replacement bearings with different clearances were measured experimentally in the Leeds ProSim hip joint simulator under a series of loading conditions and different cup inclination angles. The contact areas predicted from the simplified model were then compared with that measured experimentally under the same conditions. The results showed that the simplification made for the anatomic model did not change the predictions of contact mechanics of the modular metal-on-polyethylene total hip replacement substantially (less than 12% for contact stresses and contact areas). Good agreements of contact areas between the finite element predictions from the simplified model and experimental measurements were obtained, with maximum difference of 14% across all conditions considered. This indicated that the simplification and assumptions made in the anatomic model were reasonable and the finite element predictions from the simplified model were valid. © IMechE 2014.

Design, Fabrication and Characterization of High Temperature Joints in Ceramic Composites

NASA Technical Reports Server (NTRS)

Singh, M.

1999-01-01

Ceramic joining has been recognized as one of the enabling technologies for the successful utilization of ceramic components in a number of demanding, high temperature applications. Various joint design philosophies and design issues have been discussed along with an affordable, robust ceramic joining technology (ARCJoinT). A wide variety of silicon carbide-based composite materials, in different shapes and sizes, have been joined using this technology. This technique is capable of producing joints with tailorable thickness and composition. The room and high temperature mechanical properties and fractography of ceramic joints have been reported. These joints maintain their mechanical strength up to 1200 C in air. This technology is suitable for the joining of large and complex shaped ceramic composite components and with certain modifications, can be applied to repair of ceramic components damaged in service.

Design, Fabrication, and Characterization of High Temperature Joints in Ceramic Composites

NASA Technical Reports Server (NTRS)

Singh, M.

1999-01-01

Ceramic joining has been recognized as one of the enabling technologies for the successful utilization of ceramic components in a number of demanding, high temperature applications. Various joint design philosophies and design issues have been discussed along with an affordable, robust ceramic joining technology (ARCJoinT). A wide variety of silicon carbide-based composite materials, in different shapes and sizes, have been joined using this technology. This technique is capable of producing joints with tailorable thickness and composition. The room and high temperature mechanical properties and fractography of ceramic joints have been reported. These joints maintain their mechanical strength up to 1200C in air. This technology is suitable for the joining of large and complex shaped ceramic composite components and with certain modifications, can be applied to repair of ceramic components damaged in service.

Perioperative mortality after hemiarthroplasty related to fixation method.

PubMed

Costain, Darren J; Whitehouse, Sarah L; Pratt, Nicole L; Graves, Stephen E; Ryan, Philip; Crawford, Ross W

2011-06-01

The appropriate fixation method for hemiarthroplasty of the hip as it relates to implant survivorship and patient mortality is a matter of ongoing debate. We examined the influence of fixation method on revision rate and mortality. We analyzed approximately 25,000 hemiarthroplasty cases from the AOA National Joint Replacement Registry. Deaths at 1 day, 1 week, 1 month, and 1 year were compared for all patients and among subgroups based on implant type. Patients treated with cemented monoblock hemiarthroplasty had a 1.7-times higher day-1 mortality compared to uncemented monoblock components (p < 0.001). This finding was reversed by 1 week, 1 month, and 1 year after surgery (p < 0.001). Modular hemiarthroplasties did not reveal a difference in mortality between fixation methods at any time point. This study shows lower (or similar) overall mortality with cemented hemiarthroplasty of the hip.

Concepts and effects of damping in isolators

NASA Technical Reports Server (NTRS)

Kerley, J.

1984-01-01

A series of innovative designs and inventions which led to the solution of many aerospace vibration and shock problems through damping techniques is presented. The design of damped airborne structures has presented a need for such creative innovation. The primary concern was to discover what concepts were necessary for good structural damping. Once these concepts are determined and converted into basic principles, the design of hardware follows. The following hardware and techniques were developed in support of aerospace program requirements: shipping containers, alignment cables for precision mechanisms, isolation of small components such as relays and flight instruments, isolation for heavy flight equipment, coupling devices, universal joints, use of wire mesh to replace cable, isolation of 16-dB, 5000 lb horn, and compound damping devices to get better isolation from shock and vibration in a high steady environment.

Detailed description of the Mayo/IBM PACS

NASA Astrophysics Data System (ADS)

Gehring, Dale G.; Persons, Kenneth R.; Rothman, Melvyn L.; Salutz, James R.; Morin, Richard L.

1991-07-01

The Mayo Clinic and IBM/Rochester have jointly developed a picture archiving system (PACS) for use with Mayo's MRI and Neuro-CT imaging modalities. The system was developed to replace the imaging system's vendor-supplied magnetic tape archiving capability. The system consists of seven MR imagers and nine CT scanners, each interfaced to the PACS via IBM Personal System/2(tm) (PS/2) computers, which act as gateways from the imaging modality to the PACS network. The PAC system operates on the token-ring component of Mayo's city-wide local area network. Also on the PACS network are four optical storage subsystems used for image archival, three optical subsystems used for image retrieval, an IBM Application System/400(tm) (AS/400) computer used for database management and multiple PS/2-based image display systems and their image servers.

Analysis of polyethylene wear debris using micro-Raman spectroscopy: a report on the presence of beta-carotene.

PubMed

Hahn, D W; Wolfarth, D L; Parks, N L

1997-04-01

This paper describes micro-Raman spectroscopy of ultra-high molecular weight polyethylene wear debris isolated from revised knee replacements. The novel application of micro-Raman spectroscopy to the analysis of in vivo-generated wear debris was used to evaluate the chemical nature of individual, retrieved polyethylene particles. The analysis revealed the presence of beta-carotene on particles from both synovial fluid and tissue samples. Raman analysis of retrieved polyethylene tibial inserts also revealed localized beta-carotene signals within the primary wear region. In this paper, a mechanism is suggested that may account for the coupling of beta-carotene and polyethylene wear debris. We also discuss the origin of beta-carotene within the implanted joint and the implications that beta-carotene, an anti-oxidant, has for the overall host response to polyethylene orthopedic components.

Polyethylene damage and deformation on fixed-bearing, non-conforming unicondylar knee replacements corresponding to progressive changes in alignment and fixation.

PubMed

Harman, Melinda K; Schmitt, Sabine; Rössing, Sven; Banks, Scott A; Sharf, Hans-Peter; Viceconti, Marco; Hodge, W Andrew

2010-07-01

Deviations from nominal alignment of unicondylar knee replacements impact knee biomechanics, including the load and stress distribution at the articular contact surfaces. This study characterizes relationships between the biomechanical environment, distinguished by progressive changes in alignment and fixation, and articular damage and deformation in a consecutive series of retrieved unicondylar knee replacements. Twenty seven fixed-bearing, non-conforming unicondylar knee replacements of one design were retrieved after 2 to 13 years of in vivo function. The in vivo biomechanical environment was characterized by grading component migration measured from full-length radiographs and grading component fixation based on intraoperative manual palpation. Articular damage patterns and linear deformation on the polyethylene inserts were measured using optical photogrammetry and contact point digitization. Articular damage patterns and surface deformation on the explanted polyethylene inserts corresponded to progressive changes in component alignment and fixation. Component migration produced higher deformation rates, whereas loosening contributed to larger damage areas but lower deformation rates. Migration and loosening of the femoral component, but not the tibial component, were factors contributing to large regions of abrasion concentrated on the articular periphery. Classifying component migration and fixation at revision proved useful for distinguishing common biomechanical conditions associated with the varied polyethylene damage patterns and linear deformation for this fixed-bearing, non-conforming design. Pre-clinical evaluations of unicondylar knee replacements that are capable of reproducing variations in clinical alignment and predicting the observed wear mechanisms are necessary to better understand the impact of knee biomechanics and design on unicondylar knee replacement longevity. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Metal-on-metal hip joint tribology.

PubMed

Dowson, D; Jin, Z M

2006-02-01

The basic tribological features of metal-on-metal total hip replacements have been reviewed to facilitate an understanding of the engineering science underpinning the renaissance of these hard-on-hard joints. Metal-on-polymer hip replacements operate in the boundary lubrication regime, thus leading to the design guidance to reduce the femoral head diameter as much as is feasible to minimize frictional torque and volumetric wear. This explains why the gold-standard implant of this form from the past half-century had a diameter of only 22.225 mm (7/8 in). Metal-on-metal implants can operate in the mild mixed lubrication regime in which much of the applied load is supported by elastohydrodynamic films. Correct tribological design leads to remarkably low steady state wear rates. Promotion of the most effective elastohydrodynamic films calls for the largest possible head diameters and the smallest clearances that can reasonably be adopted, consistent with fine surface finishes, good sphericity and minimal structural elastic deformation of the cup on its foundations. This guidance, which is opposite in form to that developed for metal-on-polymer joints, is equally valid for solid (monolithic) metallic heads on metallic femoral stems and surface replacement femoral shells. Laboratory measurements of friction and wear in metal-on-metal joints have confirmed their potential to achieve a very mild form of mixed lubrication. The key lies in the generation of effective elastohydrodynamic lubricating films of adequate thickness compared with the composite roughness of the head and cup. The calculation of the film thickness is by no means easy, but the full procedure is outlined and the use of an empirical formula that displays good agreement with calculations based upon the full numerical solutions is explained. The representation of the lambda ratio, lambda, embracing both film thickness and composite roughness, is described.

Cross-sectional analysis of association between socioeconomic status and utilization of primary total hip joint replacements 2006-7: Australian Orthopaedic Association National Joint Replacement Registry.

PubMed

Brennan, Sharon L; Stanford, Tyman; Wluka, Anita E; Henry, Margaret J; Page, Richard S; Graves, Stephen E; Kotowicz, Mark A; Nicholson, Geoffrey C; Pasco, Julie A

2012-04-30

The utilization of total hip replacement (THR) surgery is rapidly increasing, however few data examine whether these procedures are associated with socioeconomic status (SES) within Australia. This study examined primary THR across SES for both genders for the Barwon Statistical Division (BSD) of Victoria, Australia. Using the Australian Orthopaedic Association National Joint Replacement Registry data for 2006-7, primary THR with a diagnosis of osteoarthritis (OA) among residents of the BSD was ascertained. The Index of Relative Socioeconomic Disadvantage was used to measure SES; determined by matching residential addresses with Australian Bureau of Statistics census data. The data were categorised into quintiles; quintile 1 indicating the most disadvantaged. Age- and sex-specific rates of primary THR per 1,000 person years were reported for 10-year age bands using the total population at risk. Females accounted for 46.9% of the 642 primary THR performed during 2006-7. THR utilization per 1,000 person years was 1.9 for males and 1.5 for females. The highest utilization of primary THR was observed in those aged 70-79 years (males 6.1, and females 5.4 per 1,000 person years). Overall, the U-shaped pattern of THR across SES gave the appearance of bimodality for both males and females, whereby rates were greater for both the most disadvantaged and least disadvantaged groups. Further work on a larger scale is required to determine whether relationships between SES and THR utilization for the diagnosis of OA is attributable to lifestyle factors related to SES, or alternatively reflects geographic and health system biases. Identifying contributing factors associated with SES may enhance resource planning and enable more effective and focussed preventive strategies for hip OA.

Joint Polar Satellite System (JPSS) Common Ground System (CGS) Current Technical Performance Measures

NASA Astrophysics Data System (ADS)

Cochran, S.; Panas, M.; Jamilkowski, M. L.; Miller, S. W.

2015-12-01

ABSTRACT The National Oceanic and Atmospheric Administration (NOAA) and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation civilian weather and environmental satellite system: the Joint Polar Satellite System (JPSS). The Joint Polar Satellite System will replace the afternoon orbit component and ground processing system of the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA. The JPSS satellites will carry a suite of sensors designed to collect meteorological, oceanographic, climatological and geophysical observations of the Earth. The ground processing system for JPSS is known as the JPSS Common Ground System (JPSS CGS). Developed and maintained by Raytheon Intelligence, Information and Services (IIS), the CGS is a multi-mission enterprise system serving NOAA, NASA and their national and international partners. The CGS has demonstrated its scalability and flexibility to incorporate multiple missions efficiently and with minimal cost, schedule and risk, while strengthening global partnerships in weather and environmental monitoring. The CGS architecture is being upgraded to Block 2.0 in 2015 to "operationalize" S-NPP, leverage lessons learned to date in multi-mission support, take advantage of more reliable and efficient technologies, and satisfy new requirements and constraints in the continually evolving budgetary environment. To ensure the CGS meets these needs, we have developed 49 Technical Performance Measures (TPMs) across 10 categories, such as data latency, operational availability and scalability. This paper will provide an overview of the CGS Block 2.0 architecture, with particular focus on the 10 TPM categories listed above. We will provide updates on how we ensure the deployed architecture meets these TPMs to satisfy our multi-mission objectives with the deployment of Block 2.0.

High pressure ceramic joint

DOEpatents

Ward, M.E.; Harkins, B.D.

1993-11-30

Many recuperators have components which react to corrosive gases and are used in applications where the donor fluid includes highly corrosive gases. These recuperators have suffered reduced life, increased service or maintenance, and resulted in increased cost. The present joint when used with recuperators increases the use of ceramic components which do not react to highly corrosive gases. Thus, the present joint used with the present recuperator increases the life, reduces the service and maintenance, and reduces the increased cost associated with corrosive action of components used to manufacture recuperators. The present joint is comprised of a first ceramic member, a second ceramic member, a mechanical locking device having a groove defined in one of the first ceramic member and the second ceramic member. The joint and the mechanical locking device is further comprised of a refractory material disposed in the groove and contacting the first ceramic member and the second ceramic member. The present joint mechanically provides a high strength load bearing joint having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures. 4 figures.

High pressure ceramic joint

DOEpatents

Ward, Michael E.; Harkins, Bruce D.

1993-01-01

Many recuperators have components which react to corrosive gases and are used in applications where the donor fluid includes highly corrosive gases. These recuperators have suffered reduced life, increased service or maintenance, and resulted in increased cost. The present joint when used with recuperators increases the use of ceramic components which do not react to highly corrosive gases. Thus, the present joint used with the present recuperator increases the life, reduces the service and maintenance, and reduces the increased cost associated with corrosive action of components used to manufacture recuperators. The present joint is comprised of a first ceramic member, a second ceramic member, a mechanical locking device having a groove defined in one of the first ceramic member and the second ceramic member. The joint and the mechanical locking device is further comprised of a refractory material disposed in the groove and contacting the first ceramic member and the second ceramic member. The present joint mechanically provides a high strength load bearing joint having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures.

Evaluating the contribution of a neural component of ankle joint resistive torque in patients with stroke using a manual device.

PubMed

Kobayashi, Toshiki; Leung, Aaron K L; Akazawa, Yasushi; Hutchins, Stephen W

2011-01-01

To investigate the methodology using a manual ankle joint resistive torque measurement device to evaluate the contribution of the neural component of ankle joint resistive torque in patients with stroke. Within-subject comparison to compare the ankle joint resistive torque between fast and slow stretching conditions. Ten patients with stroke participated in this study. The incremental ratio of ankle joint resistive torque at the ankle angular position of 5degrees dorsiflexion under the fast stretching condition in comparison to the slow one was calculated in each patient. A significant increase (p<0.01) in the ankle joint resistive torque was demonstrated under the fast stretching condition in comparison to the slow one in all patients and the mean ankle joint resistive torque was 4.6 (SD=1.7) Nm under the slow stretching condition, while it was 8.4 (SD=4.1) Nm under the fast stretching condition at the ankle angular position of 5 degrees dorsiflexion. The incremental ratio ranged from 9.4-139.3% among the patients. The results of this study demonstrated the potential advantage of the device to evaluate the contribution of the neural component of ankle joint resistive torque.

The POP Program: the patient education advantage.

PubMed

Claeys, M; Mosher, C; Reesman, D

1998-01-01

In 1992, a preoperative education program was developed for total joint replacement patients in a small community hospital. The goals of the program were to increase educational opportunities for the joint replacement patients, prepare patients for hospitalization, plan for discharge needs, and increase efficiency of the orthopaedic program. Since 1992, approximately 600 patients have attended the education program. Outcomes have included positive responses from patients regarding their preparedness for surgery, increased participation in their plan of care, coordinated discharge planning, decreased length of stay, and progression across the continuum of care. A multidisciplinary approach to preparing patients for surgery allows for a comprehensive and efficient education program. Marketing of successful programs can enhance an institution's competitive advantage and help ensure the hospital's viability in the current health care arena.

Low-Friction, Low-Profile, High-Moment Two-Axis Joint

NASA Technical Reports Server (NTRS)

Lewis, James L.; Le, Thang; Carroll, Monty B.

2010-01-01

The two-axis joint is a mechanical device that provides two-degrees-of-freedom motion between connected components. A compact, moment-resistant, two-axis joint is used to connect an electromechanical actuator to its driven structural members. Due to the requirements of the overall mechanism, the joint has a low profile to fit within the allowable space, low friction, and high moment-reacting capability. The mechanical arrangement of this joint can withstand high moments when loads are applied. These features allow the joint to be used in tight spaces where a high load capability is required, as well as in applications where penetrating the mounting surface is not an option or where surface mounting is required. The joint consists of one base, one clevis, one cap, two needle bearings, and a circular shim. The base of the joint is the housing (the base and the cap together), and is connected to the grounding structure via fasteners and a bolt pattern. Captive within the housing, between the base and the cap, are the rotating clevis and the needle bearings. The clevis is attached to the mechanical system (linear actuator) via a pin. This pin, and the rotational movement of the clevis with respect to the housing, provides two rotational degrees of freedom. The larger diameter flange of the clevis is sandwiched between a pair of needle bearings, one on each side of the flange. During the assembly of the two-axis joint, the circular shims are used to adjust the amount of preload that is applied to the needle bearings. The above arrangement enables the joint to handle high moments with minimal friction. To achieve the high-moment capability within a low-profile joint, the use of depth of engagement (like that of a conventional rotating shaft) to react moment is replaced with planar engagement parallel to the mounting surface. The needle bearings with the clevis flange provide the surface area to react the clevis loads/moments into the joint housing while providing minimal friction during rotation. The diameter of the flange and the bearings can be increased to react higher loads and still maintain a compact surface mounting capability. This type of joint can be used in a wide variety of mechanisms and mechanical systems. It is especially effective where precise, smooth, continuous motion is required. For example, the joint can be used at the end of a linear actuator that is required to extend and rotate simultaneously. The current design application is for use in a spacecraft docking-system capture mechanism. Other applications might include industrial robotic or assembly line apparatuses, positioning systems, or in the motion-based simulator industry that employs complex, multi-axis manipulators for various types of motions.

Mixed models approaches for joint modeling of different types of responses.

PubMed

Ivanova, Anna; Molenberghs, Geert; Verbeke, Geert

2016-01-01

In many biomedical studies, one jointly collects longitudinal continuous, binary, and survival outcomes, possibly with some observations missing. Random-effects models, sometimes called shared-parameter models or frailty models, received a lot of attention. In such models, the corresponding variance components can be employed to capture the association between the various sequences. In some cases, random effects are considered common to various sequences, perhaps up to a scaling factor; in others, there are different but correlated random effects. Even though a variety of data types has been considered in the literature, less attention has been devoted to ordinal data. For univariate longitudinal or hierarchical data, the proportional odds mixed model (POMM) is an instance of the generalized linear mixed model (GLMM; Breslow and Clayton, 1993). Ordinal data are conveniently replaced by a parsimonious set of dummies, which in the longitudinal setting leads to a repeated set of dummies. When ordinal longitudinal data are part of a joint model, the complexity increases further. This is the setting considered in this paper. We formulate a random-effects based model that, in addition, allows for overdispersion. Using two case studies, it is shown that the combination of random effects to capture association with further correction for overdispersion can improve the model's fit considerably and that the resulting models allow to answer research questions that could not be addressed otherwise. Parameters can be estimated in a fairly straightforward way, using the SAS procedure NLMIXED.

Program for life extension and preserving existing resources for motor control center components [nuclear plants

NASA Astrophysics Data System (ADS)

Sanwarwalla, M. H.; Alsammarae, A. J.

1995-08-01

Many nuclear power plants have motor control centers (MCCs) installed in a harsh, radiation only, environment. Procurement of safety-related replacement devices for these MCCs is an economic burden for the stations if these MCCs have become obsolete. Identical replacement components for many MCCs installed in older plants (ITE Gould, Allis-Chalmers, Klockner-Moeller, Cutler-Hammer, etc.) are no longer available. Plants are left with the option of either retrofitting these MCCs or finding ways to extend the qualified lives of the safety-related components to minimize replacement costs. ComEd nuclear station has embarked on a program to minimize the economic burden for the replacement of Klockner-Moeller (K-M) MCC components. This paper discusses the program adopted by this station and its economic benefits to ComEd.

Hypothyroidism presenting as destructive arthropathy of the fingers.

PubMed Central

Gerster, J. C.; Quadri, P.; Saudan, Y.

1985-01-01

A patient presenting with destructive arthropathy of the proximal interphalangeal (PIP) joints of the hands is described. She was initially believed to have rheumatoid arthritis but non-steroidal anti-inflammatory drugs were of no help. The patient was subsequently found to have hypothyroidism and erosive osteoarthritis of the fingers. Joint swelling, pain and stiffness responded dramatically to thyroid hormone substitution. The PIP joint spaces reappeared on the radiographs within 9 months. This case suggest that hypothyroidism may induce destructive arthropathy of the finger joints. As thyroxine replacement may reverse the rheumatic complaints, hypothyroidism should be considered in the differential diagnosis of a destructive arthropathy of unclear aetiology. Images Figure 1 Figure 2 PMID:3983045

[Displacement and tissue remodeling of temporomandibular joint disc].

PubMed

Wang, M Q

2017-03-09

Sounding takes the highest prevalence of the signs of temporomandibular disorders (TMD). The well accepted theory of the mechanism for temporomandibular joint (TMJ) sounding is the internal derangement typically characterized by disc displacement. However, according to literature, there are approximately one third of asymptomatic joints in population had disc displacement, and, on the other hand, there are one fourth of TMJ sounding patients had not signs or very limited signs of disc displacement. Replacing the displaced disc to the normal position via methods like surgical operation did not achieve satisfactory long-term outcomes. In this review, we discuss and analyze the possible remodeling of the joint disc displacement diagnosed with imaging based on the anatomy and pathophysiology.

Physician trust and depression influence adherence to factor replacement: a single-centre cross-sectional study.

PubMed

Tran, D Q; Barry, V; Antun, A; Ribeiro, M; Stein, S; Kempton, C L

2017-01-01

Poor adherence to factor replacement therapy among patients with haemophilia can lead to joint bleeding and eventual disability. The aim of this study was to determine patient-related characteristics associated with adherence to factor replacement in adults with haemophilia. Adults with haemophilia were recruited to participate in this cross-sectional study. Adherence was measured using either the Validated Hemophilia Regimen Treatment Adherence Scale (VERITAS)-Pro or the VERITAS-PRN questionnaire. Simple and multiple regression analyses that controlled for confounding were performed to determine the association between patient-related characteristics and adherence to factor replacement therapy. Of the 99 subjects enrolled, all were men; 91% had haemophilia A and 78% had severe disease. Age ranged from 18 to 62 years. Most (95%) had functional health literacy; but only 23% were numerate. Mean adherence scores were 45.6 (SD 18) and 51.0 (SD 15) for those on a prophylactic and those on an episodic regimen, respectively, with a lower score indicating better adherence. On multivariable analysis, being on any chronic medication, longer duration followed at our haemophilia treatment centre, higher physician trust and better quality of life were associated with higher adherence. A history of depression was associated with lower adherence. Two potentially modifiable characteristics, physician trust and depression, were identified as motivator and barrier to adherence to factor replacement therapy. Promoting a high level of trust between the patient and the healthcare team as well as identifying and treating depression may impact adherence to factor replacement therapy and accordingly reduce joint destruction. © 2016 John Wiley & Sons Ltd.

Contact stresses, pressure and area in a fixed-bearing total ankle replacement: a finite element analysis.

PubMed

Martinelli, Nicolo; Baretta, Silvia; Pagano, Jenny; Bianchi, Alberto; Villa, Tomaso; Casaroli, Gloria; Galbusera, Fabio

2017-11-25

Mobile-bearing ankle implants with good clinical results continued to increase the popularity of total ankle arthroplasty to address endstage ankle osteoarthritis preserving joint movement. Alternative solutions used fixed-bearing designs, which increase stability and reduce the risk of bearing dislocation, but with a theoretical increase of contact stresses leading to a higher polyethylene wear. The purpose of this study was to investigate the contact stresses, pressure and area in the polyethylene component of a new total ankle replacement with a fixed-bearing design, using 3D finite element analysis. A three-dimensional finite element model of the Zimmer Trabecular Metal Total Ankle was developed and assembled based on computed tomography images. Three different sizes of the polyethylene insert were modeled, and a finite element analysis was conducted to investigate the contact pressure, the von Mises stresses and the contact area of the polyethylene component during the stance phase of the gait cycle. The peak value of pressure was found in the anterior region of the articulating surface, where it reached 19.8 MPa at 40% of the gait cycle. The average contact pressure during the stance phase was 6.9 MPa. The maximum von Mises stress of 14.1 MPa was reached at 40% of the gait cycle in the anterior section. In the central section, the maximum von Mises stress of 10.8 MPa was reached at 37% of the gait cycle, whereas in the posterior section the maximum stress of 5.4 MPa was reached at the end of the stance phase. The new fixed-bearing total ankle replacement showed a safe mechanical behavior and many clinical advantages. However, advanced models to quantitatively estimate the wear are need. To the light of the clinical advantages, we conclude that the presented prosthesis is a good alternative to the other products present in the market.

The association between radiographic severity and pre-operative function in patients undergoing primary knee replacement for osteoarthritis.

PubMed

Dowsey, Michelle M; Dieppe, Paul; Lohmander, Stefan; Castle, David; Liew, Danny; Choong, Peter F M

2012-12-01

To determine the association between radiographic osteoarthritis (OA) and pre-operative function in patients undergoing primary knee replacement. Single centre study examining pre-operative outcomes in a consecutive series of 525 patients who underwent primary knee replacement for OA between January 2006 and December 2007. Pre-operative data included: demographics, American Society of Anaesthesiologists (ASA) status and OA in the contralateral knee. The International Knee Society (IKS) rating and Short Form-12 (SF-12) were recorded for each patient. Pre-operative radiographs were read by a single observer for Kellgren and Lawrence (K&L) grading and Osteoarthritis Research Society International (OARSI) atlas features. Multiple linear regression was used to assess the strength of associations between radiographic OA severity and function, adjusting for clinically relevant variables. Lateral tibiofemoral osteophyte grade was an independent predictor of pre-operative function as determined by the functional sub-scale of the IKS in patients undergoing primary knee replacement (coefficient=2.58, p=0.033). No associations were evident between pre-operative function and modified K&L, joint space narrowing, Ahlbäck attrition and coronal plane deformity. Other statistically significant predictors of poorer pre-operative function included: advancing age, female gender, knee pain and poorer SF-12 mental component summary scores which including osteophyte grade accounted for 24.6% of the variation in functional scores, (r=0.496). Osteophytes in the lateral compartment of the knee were associated with pre-operative function in patients with advanced knee OA. Further studies are required which examine individual radiographic features specifically in patients with advanced knee OA to determine their relationship to pre-operative pain and function. Copyright © 2012 Elsevier B.V. All rights reserved.

Recrystallization Behavior in Mixed Solder Joints of BGA Components during Thermal Shock

NASA Astrophysics Data System (ADS)

Tan, Shihai; Han, Jing; Guo, Fu

2018-03-01

Sn-37Pb and Sn-3.0Ag-0.5Cu solder pastes printed onto a board were attached to ball grid array (BGA) samples using Sn-3.0Ag-0.5Cu solder balls. Before thermal shock, the initial grain orientations on the cross-section were obtained by scanning electron microscopy equipped with an electron backscattered diffraction system. Three mixed solder joints (two from the corner and another from the middle of the BGA component) and three lead-free solder joints (at the same positions) were selected to investigate the recrystallization behavior under thermal shock (TS) cycling conditions. All of the mixed and lead-free solder joints were initially single crystal. The results showed that recrystallization occurred in both the mixed and lead-free solder joints after 200 TS. For the mixed solder joints, more recrystallization was observed and the location of samples had a significant influence on their recrystallization behavior, while location was not as important for the lead-free samples after 200 TS in this study. Both the mixed and lead-free solder joints at the corner of BGA components showed the poorest reliability. According to misorientation distribution maps and subgrain rotation behaviors, the reliability of mixed solder joints was much poorer than that of lead-free solder joints.

Astronaut tool development: An orbital replaceable unit-portable handhold

NASA Technical Reports Server (NTRS)

Redmon, John W., Jr.

1989-01-01

A tool to be used during astronaut Extra-Vehicular Activity (EVA) replacement of spent or defective electrical/electronic component boxes is described. The generation of requirements and design philosophies are detailed, as well as specifics relating to mechanical development, interface verifications, testing, and astronaut feedback. Findings are presented in the form of: (1) a design which is universally applicable to spacecraft component replacement, and (2) guidelines that the designer of orbital replacement units might incorporate to enhance spacecraft on-orbit maintainability and EVA mission safety.

Three-Dimensional Biomechanical Analysis of Rearfoot and Forefoot Running.

PubMed

Knorz, Sebastian; Kluge, Felix; Gelse, Kolja; Schulz-Drost, Stefan; Hotfiel, Thilo; Lochmann, Matthias; Eskofier, Björn; Krinner, Sebastian

2017-07-01

In the running community, a forefoot strike (FFS) pattern is increasingly preferred compared with a rearfoot strike (RFS) pattern. However, it has not been fully understood which strike pattern may better reduce adverse joint forces within the different joints of the lower extremity. To analyze the 3-dimensional (3D) stress pattern in the ankle, knee, and hip joint in runners with either a FFS or RFS pattern. Descriptive laboratory study. In 22 runners (11 habitual rearfoot strikers, 11 habitual forefoot strikers), RFS and FFS patterns were compared at 3.0 m/s (6.7 mph) on a treadmill with integrated force plates and a 3D motion capture analysis system. This combined analysis allowed characterization of the 3D biomechanical forces differentiated for the ankle, knee, and hip joint. The maximum peak force (MPF) and maximum loading rate (LR) were determined in their 3 ordinal components: vertical, anterior-posterior (AP), and medial-lateral (ML). For both strike patterns, the vertical components of the MPF and LR were significantly greater than their AP or ML components. In the vertical axis, FFS was generally associated with a greater MPF but significantly lower LR in all 3 joints. The AP components of MPF and LR were significantly lower for FFS in the knee joint but significantly greater in the ankle and hip joints. The ML components of MPF and LR tended to be greater for FFS but mostly did not reach a level of significance. FFS and RFS were associated with different 3D stress patterns in the ankle, knee, and hip joint, although there was no global advantage of one strike pattern over the other. The multimodal individual assessment for the different anatomic regions demonstrated that FFS seems favorable for patients with unstable knee joints in the AP axis and RFS may be recommended for runners with unstable ankle joints. Different strike patterns show different 3D stress in joints of the lower extremity. Due to either rehabilitation after injuries or training in running sports, rearfoot or forefoot running should be preferred to prevent further damage or injuries caused by inadequate biomechanical load. Runners with a history of knee joint injuries may benefit from FFS whereas RFS may be favorable for runners with a history of ankle joint injuries.

Three-Dimensional Biomechanical Analysis of Rearfoot and Forefoot Running

PubMed Central

Knorz, Sebastian; Kluge, Felix; Gelse, Kolja; Schulz-Drost, Stefan; Hotfiel, Thilo; Lochmann, Matthias; Eskofier, Björn; Krinner, Sebastian

2017-01-01

Background: In the running community, a forefoot strike (FFS) pattern is increasingly preferred compared with a rearfoot strike (RFS) pattern. However, it has not been fully understood which strike pattern may better reduce adverse joint forces within the different joints of the lower extremity. Purpose: To analyze the 3-dimensional (3D) stress pattern in the ankle, knee, and hip joint in runners with either a FFS or RFS pattern. Study Design: Descriptive laboratory study. Methods: In 22 runners (11 habitual rearfoot strikers, 11 habitual forefoot strikers), RFS and FFS patterns were compared at 3.0 m/s (6.7 mph) on a treadmill with integrated force plates and a 3D motion capture analysis system. This combined analysis allowed characterization of the 3D biomechanical forces differentiated for the ankle, knee, and hip joint. The maximum peak force (MPF) and maximum loading rate (LR) were determined in their 3 ordinal components: vertical, anterior-posterior (AP), and medial-lateral (ML). Results: For both strike patterns, the vertical components of the MPF and LR were significantly greater than their AP or ML components. In the vertical axis, FFS was generally associated with a greater MPF but significantly lower LR in all 3 joints. The AP components of MPF and LR were significantly lower for FFS in the knee joint but significantly greater in the ankle and hip joints. The ML components of MPF and LR tended to be greater for FFS but mostly did not reach a level of significance. Conclusion: FFS and RFS were associated with different 3D stress patterns in the ankle, knee, and hip joint, although there was no global advantage of one strike pattern over the other. The multimodal individual assessment for the different anatomic regions demonstrated that FFS seems favorable for patients with unstable knee joints in the AP axis and RFS may be recommended for runners with unstable ankle joints. Clinical Relevance: Different strike patterns show different 3D stress in joints of the lower extremity. Due to either rehabilitation after injuries or training in running sports, rearfoot or forefoot running should be preferred to prevent further damage or injuries caused by inadequate biomechanical load. Runners with a history of knee joint injuries may benefit from FFS whereas RFS may be favorable for runners with a history of ankle joint injuries. PMID:28812039

The Effect on Long-Term Survivorship of Surgeon Preference for Posterior-Stabilized or Minimally Stabilized Total Knee Replacement: An Analysis of 63,416 Prostheses from the Australian Orthopaedic Association National Joint Replacement Registry.

PubMed

Vertullo, Christopher J; Lewis, Peter L; Lorimer, Michelle; Graves, Stephen E

2017-07-05

Controversy still exists as to the optimum management of the posterior cruciate ligament (PCL) in total knee arthroplasty. Surgeons can choose to kinematically substitute the PCL with a posterior-stabilized total knee replacement or alternatively to utilize a cruciate-retaining, also known as minimally stabilized, total knee replacement. Proponents of posterior-stabilized total knee replacement propose that the reported lower survivorship in registries when directly compared with minimally stabilized total knee replacement is due to confounders such as selection bias because of the preferential usage of posterior-stabilized total knee replacement in more complex or severe cases. In this study, we aimed to eliminate these possible confounders by performing an instrumental variable analysis based on surgeon preference to choose either posterior-stabilized or minimally stabilized total knee replacement, rather than the actual prosthesis received. Cumulative percent revision, hazard ratio (HR), and revision diagnosis data were obtained from the Australian Orthopaedic Association National Joint Replacement Registry from September 1, 1999, to December 31, 2014, for 2 cohorts of patients, those treated by high-volume surgeons who preferred minimally stabilized replacements and those treated by high-volume surgeons who preferred posterior-stabilized replacements. All patients had a diagnosis of osteoarthritis and underwent fixed-bearing total knee replacement with patellar resurfacing. At 13 years, the cumulative percent revision was 5.0% (95% confidence interval [CI], 4.0% to 6.2%) for the surgeons who preferred the minimally stabilized replacements compared with 6.0% (95% CI, 4.2% to 8.5%) for the surgeons who preferred the posterior-stabilized replacements. The revision risk for the surgeons who preferred posterior-stabilized replacements was significantly higher for all causes (HR = 1.45 [95% CI, 1.30 to 1.63]; p < 0.001), for loosening or lysis (HR = 1.93 [95% CI, 1.58 to 2.37]; p < 0.001), and for infection (HR = 1.51 [95% CI, 1.25 to 1.82]; p < 0.001). This finding was irrespective of patient age and was evident with cemented fixation and with both cross-linked polyethylene and non-cross-linked polyethylene. However, the higher revision risk was only evident in male patients. There was a 45% higher risk of revision for the patients of surgeons who preferred a posterior-stabilized total knee replacement compared with the patients of surgeons who preferred a minimally stabilized total knee replacement. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Adaptive Postural Control for Joint Immobilization during Multitask Performance

PubMed Central

Hsu, Wei-Li

2014-01-01

Motor abundance is an essential feature of adaptive control. The range of joint combinations enabled by motor abundance provides the body with the necessary freedom to adopt different positions, configurations, and movements that allow for exploratory postural behavior. This study investigated the adaptation of postural control to joint immobilization during multi-task performance. Twelve healthy volunteers (6 males and 6 females; 21–29 yr) without any known neurological deficits, musculoskeletal conditions, or balance disorders participated in this study. The participants executed a targeting task, alone or combined with a ball-balancing task, while standing with free or restricted joint motions. The effects of joint configuration variability on center of mass (COM) stability were examined using uncontrolled manifold (UCM) analysis. The UCM method separates joint variability into two components: the first is consistent with the use of motor abundance, which does not affect COM position (VUCM); the second leads to COM position variability (VORT). The analysis showed that joints were coordinated such that their variability had a minimal effect on COM position. However, the component of joint variability that reflects the use of motor abundance to stabilize COM (VUCM) was significant decreased when the participants performed the combined task with immobilized joints. The component of joint variability that leads to COM variability (VORT) tended to increase with a reduction in joint degrees of freedom. The results suggested that joint immobilization increases the difficulty of stabilizing COM when multiple tasks are performed simultaneously. These findings are important for developing rehabilitation approaches for patients with limited joint movements. PMID:25329477

Brandon Research, Inc. Orthopedic Implant Cooperative Research and Development Agreement (CRADA) Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Freeman, W.R.

1999-04-22

The project was a joint research effort between the U. S. Department of Energy's (DOE) Kansas City Plant (KCP) and Brandon Research, Inc. to develop ways to improve implants used for orthopedic surgery for joint replacement. The primary product produced by this study is design information, which may be used to develop implants that will improve long-term fixation and durability in the host bone environment.

Security Cooperation and Professional Military Education: Developing Better Theater Campaign Planners

DTIC Science & Technology

2012-05-22

publication of the Security Cooperation Guidance ( SCG ), 32 U.S. Joint Chiefs of Staff, Joint Operation...format and content of the plans themselves. 2 The 2003 release of the classified SCG , which replaced TEPs with TSCPs, rendered CJCSM 3113.01 obsolete...interests while providing the SecDef increased visibility on and control over security cooperation activities, but the SCG was not as explicit in its

Glenoid wear after shoulder hemiarthroplasty: quantitative radiographic analysis.

PubMed

Parsons, I M; Millett, Peter J; Warner, Jon J P

2004-04-01

Symptomatic glenoid arthrosis may limit the long-term success of shoulder hemiarthroplasty in patients who are young and functionally demanding. The principal objective of the current study was to quantify glenoid wear after proximal humeral replacement in young, active subjects. Eight patients, ages 21 to 60 years (mean, 45 years), met inclusion criteria. The mean followup was 43 months. Functional scores for the cohort averaged 60% of age and gender-adjusted healthy subjects (range, 28%-84%). Glenohumeral joint space was measured on serial axillary radiographs using a Microscribe 3-DX digitizing device (measurement accuracy, 0.23 mm). Progressive glenoid wear was found in all eight patients. The mean decrease was 2 mm (range, 1.3-2.8 mm), a 68% decrease in glenohumeral joint space. Glenoid cartilage wear also was correlated with Constant and Murley scores. Patients with residual joint spaces less than 1 mm had a mean score of 50%, compared with a score of 71% for patients with joint spaces greater than 1 mm. There were no correlations between wear and mechanism of injury, duration of symptoms, and prior surgery. This study suggests that glenoid cartilage erosion can be expected routinely after humeral head replacement in young, active individuals, and that such wear may adversely affect function or necessitate conversion to total shoulder arthroplasty.

Perioperative Care of a Patient with Refractory Idiopathic Thrombocytopenic Purpura Undergoing Total Knee Arthroplasty

PubMed Central

Gudimetla, Veera; Stewart, Andrew; Luscombe, Karen L; Charalambous, Charalambos P

2012-01-01

Idiopathic thrombocytopenic purpura (ITP) is an autoimmune disorder leading to low platelet count and an increased risk of bleeding. Major joint replacement surgery in a patient with ITP can be associated with severe postoperative bleeding. We present our experience of perioperative management in a patient with severe refractory chronic idiopathic thrombocytopenic purpura who successfully underwent a cemented total knee replacement. PMID:23269964

2007 Armaments Technology Seminar and Exhibition - Joint Munitions and Lethality Life Cycle Management Command

DTIC Science & Technology

2007-06-13

MTOP APS LOS-KE TBX Ceramic Barrel Novel Energetic Materials for the Future Force Multimode HPM and Laser Induced Plasma Channel Technology T Force...in one item • Enhanced incendiary device • Replacement of environmentally unfriendly materials • Insensitive munitions compliance 12 Pyrotechnics...simulators • Pocket sized hand held signals • Replacement of environmentally unfriendly materials • Improve pyrotechnic characteristics with nanotechnologies

Application of the rapid prototyping technique to design a customized temporomandibular joint used to treat temporomandibular ankylosis

PubMed Central

Chaware, Suresh M.; Bagaria, Vaibhav; Kuthe, Abhay

2009-01-01

Anthropometric variations in humans make it difficult to replace a temporomandibular joint (TMJ), successfully using a standard “one-size-fits-all” prosthesis. The case report presents a unique concept of total TMJ replacement with customized and modified TMJ prosthesis, which is cost-effective and provides the best fit for the patient. The process involved in designing and modifications over the existing prosthesis are also described. A 12-year- old female who presented for treatment of left unilateral TMJ ankylosis underwent the surgery for total TMJ replacement. A three-dimensional computed tomography (CT) scan suggested features of bony ankylosis of left TMJ. CT images were converted to a sterolithographic model using CAD software and a rapid prototyping machine. A process of rapid manufacturing was then used to manufacture the customized prosthesis. Postoperative recovery was uneventful, with an improvement in mouth opening of 3.5 cm and painless jaw movements. Three years postsurgery, the patient is pain-free, has a mouth opening of about 4.0 cm and enjoys a normal diet. The postoperative radiographs concur with the excellent clinical results. The use of CAD/CAM technique to design the custom-made prosthesis, using orthopaedically proven structural materials, significantly improves the predictability and success rates of TMJ replacement surgery. PMID:19881026

Space Shuttle Main Engine Joint Data List Applying Today's Desktop Technologies to Facilitate Engine Processing

NASA Technical Reports Server (NTRS)

Jacobs, Kenneth; Drobnick, John; Krell, Don; Neuhart, Terry; McCool, A. (Technical Monitor)

2001-01-01

Boeing-Rocketdyne's Space Shuttle Main Engine (SSME) is the world's first large reusable liquid rocket engine. The space shuttle propulsion system has three SSMEs, each weighing 7,400 lbs and providing 470,000 lbs of thrust at 100% rated power level. To ensure required safety and reliability levels are achieved with the reusable engines, each SSME is partially disassembled, inspected, reassembled, and retested at Kennedy Space Center between each flight. Maintenance processing must be performed very carefully to replace any suspect components, maintain proper engine configuration, and avoid introduction of contaminants that could affect performance and safety. The long service life, and number, complexity, and pedigree of SSME components makes logistics functions extremely critical. One SSME logistics challenge is documenting the assembly and disassembly of the complex joint configurations. This data (joint nomenclature, seal and fastener identification and orientation, assembly sequence, fastener torques, etc.) must be available to technicians and engineers during processing. Various assembly drawings and procedures contain this information, but in this format the required (practical) joint data can be hard to find, due to the continued use of archaic engineering drawings and microfilm for field site use. Additionally, the release system must traverse 2,500 miles between design center and field site, across three time zones, which adds communication challenges and time lags for critical engine configuration data. To aid in information accessibility, a Joint Data List (JDL) was developed that allows efficient access to practical joint data. The published JDL has been a very useful logistics product, providing illustrations and information on the latest SSME configuration. The JDL identifies over 3,350 unique parts across seven fluid systems, over 300 joints, times two distinct engine configurations. The JDL system was recently converted to a web-based, navigable electronic manual that contains all the required data and illustrations in expanded view format using standard PC products (Word, Excel, PDF, Photoshop). The logistics of accurately releasing this information to field personnel was greatly enhanced via the utilization of common office products to produce a more user-friendly format than was originally developed under contract to NASA. This was done without reinventing the system, which would be cost prohibitive on a program of this maturity. The brunt of the joint part tracking is done within the logistics organization and disseminated to all field sites, without duplicating effort at each site. The JDL is easily accessible across the country via the NASA intranet directly at the SSME workstand. The advent of this logistics data product has greatly enhanced the reliability of tracking dynamic changes to the SSME and greatly reduces engineering change turnaround time and potential for errors. Since the inception of the JDL system in 1997, no discrepant parts have propagated to engine assembly operations. This presentation focuses on the challenges overcome and the techniques used to apply today's desktop technologies to an existing logistics data source.

Surgical Technical Evidence Review for Elective Total Joint Replacement Conducted for the AHRQ Safety Program for Improving Surgical Care and Recovery.

PubMed

Childers, Christopher P; Siletz, Anaar E; Singer, Emily S; Faltermeier, Claire; Hu, Q Lina; Ko, Clifford Y; Golladay, Gregory J; Kates, Stephen L; Wick, Elizabeth C; Maggard-Gibbons, Melinda

2018-01-01

Use of enhanced recovery pathways (ERPs) can improve patient outcomes, yet national implementation of these pathways remains low. The Agency for Healthcare Research and Quality (AHRQ; funder), the American College of Surgeons, and the Johns Hopkins Medicine Armstrong Institute for Patent Safety and Quality have developed the Safety Program for Improving Surgical Care and Recovery-a national effort to catalyze implementation of practices to improve perioperative care and enhance recovery of surgical patients. This review synthesizes evidence that can be used to develop a protocol for elective total knee arthroplasty (TKA) and total hip arthroplasty (THA). This review focuses on potential components of the protocol relevant to surgeons; anesthesia components are reported separately. Components were identified through review of existing pathways and from consultation with technical experts. For each, a structured review of MEDLINE identified systematic reviews, randomized trials, and observational studies that reported on these components in patients undergoing elective TKA/THA. This primary evidence review was combined with existing clinical guidelines in a narrative format. Sixteen components were reviewed. Of the 10 preoperative components, most were focused on risk factor assessment including anemia, diabetes mellitus, tobacco use, obesity, nutrition, immune-modulating therapy, and opiates. Preoperative education, venous thromboembolism (VTE) prophylaxis, and bathing/ Staphylococcus aureus decolonization were also included. The routine use of drains was the only intraoperative component evaluated. The 5 postoperative components included early mobilization, continuous passive motion, extended duration VTE prophylaxis, early oral alimentation, and discharge planning. This review synthesizes the evidence supporting potential surgical components of an ERP for elective TKA/THA. The AHRQ Safety Program for Improving Surgical Care and Recovery aims to guide hospitals and surgeons in identifying the best practices to implement in the surgical care of TKA and THA patients.

Transmission overhaul and replacement predictions using Weibull and renewel theory

NASA Technical Reports Server (NTRS)

Savage, M.; Lewicki, D. G.

1989-01-01

A method to estimate the frequency of transmission overhauls is presented. This method is based on the two-parameter Weibull statistical distribution for component life. A second method is presented to estimate the number of replacement components needed to support the transmission overhaul pattern. The second method is based on renewal theory. Confidence statistics are applied with both methods to improve the statistical estimate of sample behavior. A transmission example is also presented to illustrate the use of the methods. Transmission overhaul frequency and component replacement calculations are included in the example.

The Meniscus-Deficient Knee

PubMed Central

Rao, Allison J.; Erickson, Brandon J.; Cvetanovich, Gregory L.; Yanke, Adam B.; Bach, Bernard R.; Cole, Brian J.

2015-01-01

Meniscal tears are the most common knee injury, and partial meniscectomies are the most common orthopaedic surgical procedure. The injured meniscus has an impaired ability to distribute load and resist tibial translation. Partial or complete loss of the meniscus promotes early development of chondromalacia and osteoarthritis. The primary goal of treatment for meniscus-deficient knees is to provide symptomatic relief, ideally to delay advanced joint space narrowing, and ultimately, joint replacement. Surgical treatments, including meniscal allograft transplantation (MAT), high tibial osteotomy (HTO), and distal femoral osteotomy (DFO), are options that attempt to decrease the loads on the articular cartilage of the meniscus-deficient compartment by replacing meniscal tissue or altering joint alignment. Clinical and biomechanical studies have reported promising outcomes for MAT, HTO, and DFO in the postmeniscectomized knee. These procedures can be performed alone or in conjunction with ligament reconstruction or chondral procedures (reparative, restorative, or reconstructive) to optimize stability and longevity of the knee. Complications can include fracture, nonunion, patella baja, compartment syndrome, infection, and deep venous thrombosis. MAT, HTO, and DFO are effective options for young patients suffering from pain and functional limitations secondary to meniscal deficiency. PMID:26779547

Knee joint replacement - discharge

MedlinePlus

... such as downhill skiing or contact sports like football and soccer. But, you should be able to ... herein should not be used during any medical emergency or for the diagnosis or treatment of any ...

Architectural design of diamond-like carbon coatings for long-lasting joint replacements.

PubMed

Liu, Yujing; Zhao, Xiaoli; Zhang, Lai-Chang; Habibi, Daryoush; Xie, Zonghan

2013-07-01

Surface engineering through the application of super-hard, low-friction coatings as a potential approach for increasing the durability of metal-on-metal replacements is attracting significant attention. In this study innovative design strategies are proposed for the development of diamond-like-carbon (DLC) coatings against the damage caused by wear particles on the joint replacements. Finite element modeling is used to analyze stress distributions induced by wear particles of different sizes in the newly-designed coating in comparison to its conventional monolithic counterpart. The critical roles of architectural design in regulating stress concentrations and suppressing crack initiation within the coatings is elucidated. Notably, the introduction of multilayer structure with graded modulus is effective in modifying the stress field and reducing the magnitude and size of stress concentrations in the DLC diamond-like-carbon coatings. The new design is expected to greatly improve the load-carrying ability of surface coatings on prosthetic implants, in addition to the provision of damage tolerance through crack arrest. Copyright © 2013 Elsevier B.V. All rights reserved.

Reliability analysis of different structure parameters of PCBA under drop impact

NASA Astrophysics Data System (ADS)

Liu, P. S.; Fan, G. M.; Liu, Y. H.

2018-03-01

The establishing process of PCBA is modelled by finite element analysis software ABAQUS. Firstly, introduce the Input-G method and the fatigue life under drop impact are introduced and the mechanism of the solder joint failure in the process of drop is analysed. The main reason of solder joint failure is that the PCB component is suffering repeated tension and compression stress during the drop impact. Finally, the equivalent stress and peel stress of different solder joint and plate-level components under different impact acceleration are also analysed. The results show that the reliability of tin-silver copper joint is better than that of tin- lead solder joint, and the fatigue life of solder joint expectancy decrease as the impact pulse amplitude increases.

Management of Osseous and Soft-Tissue Ankle Equinus During Total Ankle Replacement.

PubMed

Roukis, Thomas S; Simonson, Devin C

2015-10-01

Obtaining functional alignment of a total ankle replacement, including physiologic sagittal plane range of motion, is paramount for a successful outcome. This article reviews the literature on techniques available for correction of osseous and soft-tissue equinus at the time of index total ankle replacement. These techniques include anterior tibiotalar joint cheilectomy, posterior superficial muscle compartment lengthening, posterior ankle capsule release, and release of the posterior portions of the medial and lateral collateral ligament complexes. The rationale for these procedures and the operative sequence of events for these procedures are presented. Copyright © 2015 Elsevier Inc. All rights reserved.

The Cost of Joint Replacement: Comparing Two Approaches to Evaluating Costs of Total Hip and Knee Arthroplasty.

PubMed

Palsis, John A; Brehmer, Thomas S; Pellegrini, Vincent D; Drew, Jacob M; Sachs, Barton L

2018-02-21

In an era of mandatory bundled payments for total joint replacement, accurate analysis of the cost of procedures is essential for orthopaedic surgeons and their institutions to maintain viable practices. The purpose of this study was to compare traditional accounting and time-driven activity-based costing (TDABC) methods for estimating the total costs of total hip and knee arthroplasty care cycles. We calculated the overall costs of elective primary total hip and total knee replacement care cycles at our academic medical center using traditional and TDABC accounting methods. We compared the methods with respect to the overall costs of hip and knee replacement and the costs for each major cost category. The traditional accounting method resulted in higher cost estimates. The total cost per hip replacement was $22,076 (2014 USD) using traditional accounting and was $12,957 using TDABC. The total cost per knee replacement was $29,488 using traditional accounting and was $16,981 using TDABC. With respect to cost categories, estimates using traditional accounting were greater for hip and knee replacement, respectively, by $3,432 and $5,486 for personnel, by $3,398 and $3,664 for space and equipment, and by $2,289 and $3,357 for indirect costs. Implants and consumables were derived from the actual hospital purchase price; accordingly, both methods produced equivalent results. Substantial cost differences exist between accounting methods. The focus of TDABC only on resources used directly by the patient contrasts with the allocation of all operating costs, including all indirect costs and unused capacity, with traditional accounting. We expect that the true costs of hip and knee replacement care cycles are likely somewhere between estimates derived from traditional accounting methods and TDABC. TDABC offers patient-level granular cost information that better serves in the redesign of care pathways and may lead to more strategic resource-allocation decisions to optimize actual operating margins.

Acquisition Research for Design and Service Enterprises

DTIC Science & Technology

2014-02-02

better than refurbishment.  Replacement: Replacing a component means to swap in a new component. Consequently, the efficiency after replacement is...objectives are fueled by anticipation of future gains; and transaction encapsulates the reluctance to change currencies /investments because of the fixed...those for holding currency . It can be argued that the exception is when goods are held in reserve to meet uncertain demands, with the objective of

Mechanics of Suture Joints

NASA Astrophysics Data System (ADS)

Li, Yaning; Song, Juha; Ortiz, Christine; Boyce, Mary; Ortiz Group/DMSE/MIT Team; Boyce Group/ME/MIT Team

2011-03-01

Biological sutures are joints which connect two stiff skeletal or skeletal-like components. These joints possess a wavy geometry with a thin organic layer providing adhesion. Examples of biological sutures include mammalian skulls, the pelvic assembly of the armored fish Gasterosteus aculeatus (the three-spined stickleback), and the suture joints in the shell of the red-eared slider turtle. Biological sutures allow for movement and compliance, control stress concentrations, transmit loads, reduce fatigue stress and absorb energy. In this investigation, the mechanics of the role of suture geometry in providing a naturally optimized joint is explored. In particular, analytical and numerical micromechanical models of the suture joint are constructed. The anisotropic mechanical stiffness and strength are studied as a function of suture wavelength, amplitude and the material properties of the skeletal and organic components, revealing key insights into the optimized nature of these ubiquitous natural joints.

Comparison of high‐intensity sound and mechanical vibration for cleaning porous titanium cylinders fabricated using selective laser melting

PubMed Central

Seiffert, Gary; Sutcliffe, Chris

2015-01-01

Abstract Orthopedic components, such as the acetabular cup in total hip joint replacement, can be fabricated using porous metals, such as titanium, and a number of processes, such as selective laser melting. The issue of how to effectively remove loose powder from the pores (residual powder) of such components has not been addressed in the literature. In this work, we investigated the feasibility of two processes, acoustic cleaning using high‐intensity sound inside acoustic horns and mechanical vibration, to remove residual titanium powder from selective laser melting‐fabricated cylinders. With acoustic cleaning, the amount of residual powder removed was not influenced by either the fundamental frequency of the horn used (75 vs. 230 Hz) or, for a given horn, the number of soundings (between 1 and 20). With mechanical vibration, the amount of residual powder removed was not influenced by the application time (10 vs. 20 s). Acoustic cleaning was found to be more reliable and effective in removal of residual powder than cleaning with mechanical vibration. It is concluded that acoustic cleaning using high‐intensity sound has significant potential for use in the final preparation stages of porous metal orthopedic components. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 117–123, 2017. PMID:26426906

Micro friction stir lap welding of AISI 430 ferritic stainless steel: a study on the mechanical properties, microstructure, texture and magnetic properties

NASA Astrophysics Data System (ADS)

Mostaan, Hossein; Safari, Mehdi; Bakhtiari, Arash

2018-04-01

In this study, the effect of friction stir welding of AISI 430 (X6Cr17, material number 1.4016) ferritic stainless steel is examined. Two thin sheets with dimensions of 0.4 × 50 × 200 mm3 are joined in lap configuration. Optical microscopy and field emission electron microscopy were used in order to microstructural evaluations and fracture analysis, respectively. Tensile test and microhardness measurements are employed in order to study the mechanical behaviors of welds. Also, vibrational sample magnetometry (VSM) is employed for characterizing magnetic properties of welded samples. Texture analysis is carried out in order to clarify the change mechanism of magnetic properties in the welded area. The results show that AISI 430 sheets are successfully joined considering both, the appearance of the welding bead and the strength of the welded joint. It is found that by friction stir welding of AISI 430 sheets, texture components with easy axes magnetization have been replaced by texture components with harder magnetization axes. VSM analysis showed that friction stir welding leads to increase in residual induction (Br) and coercivity (Hc). This increase is attributed to the grain refining due the friction stir welding and formation of texture components with harder axes of magnetizations.

Dynamic analysis of clamp band joint system subjected to axial vibration

NASA Astrophysics Data System (ADS)

Qin, Z. Y.; Yan, S. Z.; Chu, F. L.

2010-10-01

Clamp band joints are commonly used for connecting circular components together in industry. Some of the systems jointed by clamp band are subjected to dynamic load. However, very little research on the dynamic characteristics for this kind of joint can be found in the literature. In this paper, a dynamic model for clamp band joint system is developed. Contact and frictional slip between the components are accommodated in this model. Nonlinear finite element analysis is conducted to identify the model parameters. Then static experiments are carried out on a scaled model of the clamp band joint to validate the joint model. Finally, the model is adopted to study the dynamic characteristics of the clamp band joint system subjected to axial harmonic excitation and the effects of the wedge angle of the clamp band joint and the preload on the response. The model proposed in this paper can represent the nonlinearity of the clamp band joint and be used conveniently to investigate the effects of the structural and loading parameters on the dynamic characteristics of this type of joint system.

21 CFR 888.3480 - Knee joint femorotibial metallic constrained cemented prosthesis.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint femorotibial metallic constrained... Knee joint femorotibial metallic constrained cemented prosthesis. (a) Identification. A knee joint... knee joint. The device prevents dislocation in more than one anatomic plane and has components that are...

Structural optimization of an alternate design for the Space Shuttle solid rocket booster field joint

NASA Technical Reports Server (NTRS)

Barthelemy, Jean-Francois M.; Rogers, James L., Jr.; Chang, Kwan J.

1987-01-01

A structural optimization procedure is used to determine the shape of an alternate design for the Shuttle's solid rocket booster field joint. In contrast to the tang and clevis design of the existing joint, this alternate design consists of two flanges bolted together. Configurations with 150 studs of 1 1/8 in diameter and 135 studs of 1 3/16 in diameter are considered. Using a nonlinear programming procedure, the joint weight is minimized under constraints on either von Mises or maximum normal stresses, joint opening and geometry. The procedure solves the design problem by replacing it by a sequence of approximate (convex) subproblems; the pattern of contact between the joint halves is determined every few cycles by a nonlinear displacement analysis. The minimum weight design has 135 studs of 1 3/16 in diameter and is designed under constraints on normal stresses. It weighs 1144 lb per joint more than the current tang and clevis design.

Skilled nursing facilities after joint replacement

MedlinePlus

... able to: Safely get around using a cane, walker, or crutches. Get in and out of a ... climb steps, keep your balance, and use a walker, cane, or crutches. Occupational therapists will teach you ...

Patients' journeys through total joint replacement: patterns of medication use.

PubMed

Johnson, Emma C; Horwood, Jeremy; Gooberman-Hill, Rachael

2014-06-01

Medication is used to manage pain that results from both osteoarthritis and total joint replacement (TJR). Research has provided insight into how people living with osteoarthritis use pain relief medication. However, it is not known whether elective TJR affects existing attitudes and behaviours with regard to pain medications. Using qualitative methods, the present study explored patterns of pain relief use around the time of TJR. In-depth face-to-face qualitative interviews were carried out with 24 patients two to four weeks after they had undergone TJR for hip or knee osteoarthritis. Participants were asked to reflect on their use of pain medication pre-surgery, while in hospital and while recovering from their operation at home. Transcripts of the audio-recorded interviews were imported into Atlas.ti® and thematic analysis was used. Attitudes to pain relief medication and their use are not static. Many participants change their use of pain medication around the time of surgery. This shift was influenced by interactions with health professionals and changing views on the acceptability, necessity and value of pain relief in helping to manage an altered pain experience. Understanding reasons for medication-taking behaviour during the journey through joint replacement may be helpful to health professionals. Health professionals have a fundamental role to play in challenging or reinforcing different treatment beliefs, which is the basis for effective use of pain relief over the pre- to postoperative period. © 2013 John Wiley & Sons, Ltd.

[Partial replacement of the knee joint with patient-specific instruments and implants (ConforMIS iUni, iDuo)].

PubMed

Beckmann, J; Steinert, A; Zilkens, C; Zeh, A; Schnurr, C; Schmitt-Sody, M; Gebauer, M

2016-04-01

Knee arthroplasty is a successful standard procedure in orthopedic surgery; however, approximately 20 % of patients are dissatisfied with the clinical results as they suffer pain and can no longer achieve the presurgery level of activity. According to the literature the reasons are inexact fitting of the prosthesis or too few anatomically formed implants resulting in less physiological kinematics of the knee joint. Reducing the number of dissatisfied patients and the corresponding number of revisions is an important goal considering the increasing need for artificial joints. In this context, patient-specific knee implants are an obvious alternative to conventional implants. For the first time implants are now matched to the individual bone and not vice versa to achieve the best possible individual situation and geometry and more structures (e.g. ligaments and bone) are preserved or only those structures are replaced which were actually destroyed by arthrosis. According to the authors view, this represents an optimal and pioneering addition to conventional implants. Patient-specific implants and the instruments needed for correct alignment and fitting can be manufactured by virtual 3D reconstruction and 3D printing based on computed tomography (CT) scans. The portfolio covers medial as well as lateral unicondylar implants, medial as well as lateral bicompartmental implants (femorotibial and patellofemoral compartments) and cruciate ligament-preserving as well as cruciate ligament-substituting total knee replacements; however, it must be explicitly emphasized that the literature is sparse and no long-term data are available.

Navy Columbia Class (Ohio Replacement) Ballistic Missile Submarine (SSBN[X]) Program: Background and Issues for Congress

DTIC Science & Technology

2016-08-18

of UK design and manufacture . 12 For more on the arrangement for jointly building Virginia- class boats, see CRS Report RL32418, Navy Virginia (SSN...schedule reduction in Missile Tube Module manufacturing for the OR Class . This schedule reduction, on a potential critical path assembly, would reduce...Navy Columbia Class (Ohio Replacement) Ballistic Missile Submarine (SSBN[X]) Program: Background and Issues for Congress Ronald O’Rourke

Statement of the American Psychological Association in response to the "joint principles: integrating behavioral health care into the patient-centered medical home".

PubMed

Anderson, Norman B; Belar, Cynthia D; Cubic, Barbara A; Garrison, Ellen G; Johnson, Suzanne Bennett; Kaslow, Nadine J

2014-06-01

Comments on the article "Joint principles: Integrating behavioral health care into the patient-centered medical home" (see record 2014-24217-011), presented by the Working Party Group on Integrated Behavioral Healthcare. The American Psychological Association (APA) shares concerns about the lack of reference to behavioral health care in the original 2007 Joint Principles of the Patient-Centered Medical Home for which this new document is intended to supplement but not replace. The decision to support the supplemental Joint Principles was not an easy one for APA, as there is one area of significant concern. That concern is related to the use of the term "physician-directed medical practice"

[Compensatory joints at the pelvis (author's transl)].

PubMed

Schumacher, G; Weber, M

1980-10-01

An osteochondrosis ischio-pubica represents a "testing site" for the integrity of the pelvis not only during child age but in adults as well. If all naturally available compensatory mechanisms have been exhausted especially following a change of range of motion in the pelvis ring structure, fatigue fractures or zones in transformation in the area typical of osteochondrosis ischio-pubica may appear. These fractures or transformation zones respectively to our mind have joint character, because they are capable of temporarily replacing lost mobility of physiological joints. Healing is achieved through rest, muscular balance and a specific physiotherapy. The purpose of this muscular training is to cushion all unphysiological motions in the pelvis and to support and boost the function of those joints still well preserved.

78 FR 21924 - Alabama Power Company; Notice of Application for Amendment of License and Soliciting Comments...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-12

... approval to replace the Unit 4 turbine at the Jordan Dam Project. Specifically, the licensee proposes the following work: complete turbine replacement, wicket gate system rehabilitation or replacement, gate stem bushing replacement, turbine and generator bearing refurbishment, and related component replacement. The...

Incidence of revision after primary implantation of the Agility™ total ankle replacement system: a systematic review.

PubMed

Roukis, Thomas S

2012-01-01

Revision of failed total ankle replacement remains a challenge with limited information available to guide treatment options. I undertook a systematic review of electronic databases and other relevant sources to identify material relating to the incidence of revision after primary implantation of the Agility™ Total Ankle Replacement System. In an effort to procure the highest quality studies available, studies were eligible for inclusion only if they involved patients undergoing primary Agility™ Total Ankle Replacement; had evaluated patients at a mean follow-up of 12 months or longer; included details of the revision performed; and included revision etiologies of aseptic loosening, ballooning osteolysis, cystic changes, malalignment, or instability. A total of 14 studies involving 2312 ankles, with a weighted mean follow-up of 22.8 months, were included. Of the 2312 ankles, 224 (9.7%) underwent revision, of which 182 (81.3%) underwent implant component replacement, 34 (15.2%) underwent arthrodesis, and 8 (3.6%) underwent below-knee amputation. No significant effect from the surgeon's learning curve on the incidence of revision or the type of revision surgery performed was identified. However, excluding the inventor increased the incidence of revision twofold, from 6.6% to 12.2%, and skewed the type of revision away from arthrodesis and toward implant component replacement or below-knee amputation. Regardless, the incidence of revision after primary implantation of the Agility™ Total Ankle Replacement System was less than historically reported and amenable to implant component revision more than 80% of the time. However, methodologically sound cohort studies are needed that include the outcomes after revision surgery, specifically focusing on what implant component replacement techniques are effective in enhancing survivorship of these revised implants and the role of custom-stemmed talar and tibial components have in revision of the Agility™ Total Ankle Replacement System. A direct comparison of the incidence of revision between the various contemporary total ankle replacement systems in common use is also warranted. Copyright © 2012 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Optimization of replacement and inspection decisions for multiple components on a power system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mauney, D.A.

1994-12-31

The use of optimization on the rescheduling of replacement dates provided a very proactive approach to deciding when components on individual units need to be addressed with a run/repair/replace decision. Including the effects of time value of money and taxes and unit need inside the spreadsheet model allowed the decision maker to concentrate on the effects of engineering input and replacement date decisions on the final net present value (NPV). The personal computer (PC)-based model was applied to a group of 140 forced outage critical fossil plant tube components across a power system. The estimated resulting NPV of the optimizationmore » was in the tens of millions of dollars. This PC spreadsheet model allows the interaction of inputs from structural reliability risk assessment models, plant foreman interviews, and actual failure history on a by component by unit basis across a complete power production system. This model includes not only the forced outage performance of these components caused by tube failures but, in addition, the forecasted need of the individual units on the power system and the expected cost of their replacement power if forced off line. The use of cash flow analysis techniques in the spreadsheet model results in the calculation of an NPV for a whole combination of replacement dates. This allows rapid assessments of {open_quotes}what if{close_quotes} scenarios of major maintenance projects on a systemwide basis and not just on a unit-by-unit basis.« less

[The combined laser therapy of rheumatoid arthritis].

PubMed

Sidorov, V D; Mamiliaeva, D R; Derevnina, N A; Reformatskaia, S Iu

2000-01-01

Low-intensity infrared laser radiation to the tympanic vessels was studied as one of the hemophysiotherapeutic methods and as a component of combined treatment in which it accompanies local transcutaneous laser radiation of the affected joints. It is shown that immunomodulation is feasible under noninvasive interauricular laser effect on hemostasis. Indications for both laser regimens are formulated. Joint exposure to transcutaneous laser radiation is contraindicated if the affected joints have an exudative component of inflammation.

Deciphering the Origin of Dogs: From Fossils to Genomes.

PubMed

Freedman, Adam H; Wayne, Robert K

2017-02-08

Understanding the timing and geographic context of dog origins is a crucial component for understanding human history, as well as the evolutionary context in which the morphological and behavioral divergence of dogs from wolves occurred. A substantial challenge to understanding domestication is that dogs have experienced a complicated demographic history. An initial severe bottleneck was associated with domestication followed by postdivergence gene flow between dogs and wolves, as well as population expansions, contractions, and replacements. In addition, because the domestication of dogs occurred in the relatively recent past, much of the observed polymorphism may be shared between dogs and wolves, limiting the power to distinguish between alternative models of dog history. Greater insight into the domestication process will require explicit tests of alternative models of domestication through the joint analysis of whole genomes from modern lineages and ancient wolves and dogs from across Eurasia.

Study on the friction of κ-carrageenan hydrogels in air and aqueous environments.

PubMed

Kozbial, Andrew; Li, Lei

2014-03-01

Understanding the friction mechanism of polysaccharide hydrogels, which is the key component of human cartilage that has very low friction coefficient, is critical to develop next generation artificial joint replacement materials. In this study, the friction of the polysaccharide κ-carrageenan hydrogel was investigated to elucidate the effect of external load, cross-linking density, velocity, and environment on friction. Our experimental results show that (1) coefficient of friction (COF) decreases with normal load in air and remains constant in water, (2) increasing cross-linking density concurrently increases friction and is proportional to Young's modulus, (3) COF increases with testing velocity in both air and water, and (4) friction is reduced in aqueous environment due to the lubricating effect of water. The underlying frictional mechanism is discussed on the basis of water transport from bulk to surface and a previously proposed "repulsion-adsorption" model. Copyright © 2013 Elsevier B.V. All rights reserved.

The Influence of the Heat-Affected Zone Mechanical Properties on the Behaviour of the Welding in Transverse Plate-to-Tube Joints.

PubMed

Lozano, Miguel; Serrano, Miguel A; López-Colina, Carlos; Gayarre, Fernando L; Suárez, Jesús

2018-02-09

Eurocode 3 establishes the component method to analytically characterize the structural joints between beam and columns. When one of the members involved in the joint is a hollow section (i.e., a tube) there is a lack of information for the specific components present in the joint. There are two different ways to bridge the gap: experimental testing on the actual beam column joints involving tubular sections; or numerical modelization, typically by means of finite element analysis. For this second option, it is necessary to know the actual mechanical properties of the material. As long as the joint implies a welding process, there is a concern related to how the mechanical properties in the heat-affected zone (HAZ) influence the behavior of the joint. In this work, some coupons were extracted from the HAZ of the beam-column joint. The coupons were tested and the results were implemented in the numerical model of the joint, in an attempt to bring it closer to the experimental results of the tested joints.

Forces in wingwalls from thermal expansion of skewed semi-integral bridges : executive summary report.

DOT National Transportation Integrated Search

2010-11-01

Bridges that utilize expansion joints have an overall higher maintenance cost due to leakage at the expansion joint leading to deterioration of the joint, as well as structural components beneath the joint including the superstructure and substructur...

Improved Ball-and-Socket Docking Mechanism

NASA Technical Reports Server (NTRS)

Cloyd, Richard; Bryan, Tom

2004-01-01

A proposed docking mechanism would form a ball-and-socket joint in the docked condition. The mechanism could tolerate significant initial misalignment because it would include an alignment cone that would guide the ball into the socket. Like other ball-and-socket joints, the joint would have three rotational degrees of freedom. This docking mechanism would be a successor to the one described in Passive Capture Joint With Three Degrees of Freedom (MFS-31146), NASA Tech Briefs, Vol. 22, No. 7 (July 1998), page 65. It would contain most of the components of the prior mechanism, plus some additional components that would expand its capabilities.

ISS Solar Array Alpha Rotary Joint (SARJ) Bearing Failure and Recovery: Technical and Project Management Lessons Learned

NASA Technical Reports Server (NTRS)

DellaCorte, Christopher; Krantz, Timothy L.; Dube, Michael J.

2011-01-01

The photovoltaic solar panels on the International Space Station (ISS) track the Sun through continuous rotating motion enabled by large bearings on the main truss called solar array alpha rotary joints (SARJs). In late 2007, shortly after installation, the starboard SARJ had become hard to turn and had to be shut down after exceeding drive current safety limits. The port SARJ, of the same design, had been working well for over 2 years. An exhaustive failure investigation ensued that included multiple extravehicular activities to collect information and samples for engineering forensics, detailed structural and thermal analyses, and a careful review of the build records. The ultimate root cause was determined to be kinematic design vulnerability coupled with inadequate lubrication, and manufacturing flaws; this was corroborated through ground tests, metallurgical studies, and modeling. A highly successful recovery plan was developed and implemented that included replacing worn and damaged components in orbit and applying space-compatible grease to improve lubrication. Beyond the technical aspects, however, lie several key programmatic lessons learned. These lessons, such as running ground tests to intentional failure to experimentally verify failure modes, are reviewed and discussed so they can be applied to future projects to avoid such problems.

Mechanical Behavior of CFRP Lattice Core Sandwich Bolted Corner Joints

NASA Astrophysics Data System (ADS)

Zhu, Xiaolei; Liu, Yang; Wang, Yana; Lu, Xiaofeng; Zhu, Lingxue

2017-12-01

The lattice core sandwich structures have drawn more attention for the integration of load capacity and multifunctional applications. However, the connection of carbon fibers reinforced polymer composite (CFRP) lattice core sandwich structure hinders its application. In this paper, a typical connection of two lattice core sandwich panels, named as corner joint or L-joint, was investigated by experiment and finite element method (FEM). The mechanical behavior and failure mode of the corner joints were discussed. The results showed that the main deformation pattern and failure mode of the lattice core sandwich bolted corner joints structure were the deformation of metal connector and indentation of the face sheet in the bolt holes. The metal connectors played an important role in bolted corner joints structure. In order to save the calculation resource, a continuum model of pyramid lattice core was used to replace the exact structure. The computation results were consistent with experiment, and the maximum error was 19%. The FEM demonstrated the deflection process of the bolted corner joints structure visually. So the simplified FEM can be used for further analysis of the bolted corner joints structure in engineering.

Regional dolomitization of the Waulsortian limestone in southeastern Ireland: Evidence of large-scale fluid flow driven by the Hercynian orogeny

NASA Astrophysics Data System (ADS)

Hitzman, M. W.; Allan, J. R.; Beaty, D. W.

1998-06-01

The Lower Carboniferous Waulsortian limestone has been affected by late diagenetic, regional burial dolomitization over an area of ˜7000 km2 extending 170 km northeastward from the Hercynian front. The dolostone is composed of two components: (1) a very fine crystalline replacive component, and (2) a coarse-crystalline, baroque component that fills vuggy porosity developed within the replacive dolostone. Fluid inclusions within the coarse-crystalline component of the regional dolostone indicate that the dolomitizing solutions were warm (˜100 °C) and moderately saline (10 13 wt% NaCl equivalent). The replacive dolomite displays systematic decreases in crystal size and degree of xenotopic texture northward. Both components of the regional dolostone display a regular northward increase in mean δ18O values; the replacive dolomite has 87Sr/86Sr values that decrease northward. These laterally variable characteristics suggest that regional dolomitization resulted from large-scale, north-directed fluid flow of heated brines developed in response to topographic uplift associated with collapse of the continental margin south of Ireland during the Hercynian (Variscan) orogeny.

Emergency Department Visits Following Elective Total Hip and Knee Replacement Surgery: Identifying Gaps in Continuity of Care.

PubMed

Finnegan, Micaela A; Shaffer, Robyn; Remington, Austin; Kwong, Jereen; Curtin, Catherine; Hernandez-Boussard, Tina

2017-06-21

Major joint replacement surgical procedures are common, elective procedures with a care episode that includes both inpatient readmissions and postoperative emergency department (ED) visits. Inpatient readmissions are well studied; however, to our knowledge, little is known about ED visits following these procedures. We sought to characterize 30-day ED visits following a major joint replacement surgical procedure. We used administrative records from California, Florida, and New York, from 2010 through 2012, to identify adults undergoing total knee and hip arthroplasty. Factors associated with increased risk of an ED visit were estimated using hierarchical regression models controlling for patient variables with a fixed hospital effect. The main outcome was an ED visit within 30 days of discharge. Among the 152,783 patients who underwent major joint replacement, 5,229 (3.42%) returned to the inpatient setting and 8,883 (5.81%) presented to the ED for care within 30 days. Among ED visits, 17.94% had a primary diagnosis of pain and 25.75% had both a primary and/or a secondary diagnosis of pain. Patients presenting to the ED for subsequent care had more comorbidities and were more frequently non-white with public insurance relative to those not returning to the ED (p < 0.001). There was a significantly increased risk (p < 0.05) of isolated ED visits with regard to type of insurance when patients with Medicaid (odds ratio [OR], 2.28 [95% confidence interval (CI), 2.04 to 2.55]) and those with Medicare (OR, 1.38 [95% CI, 1.29 to 1.47]) were compared with patients with private insurance and with regard to race when black patients (OR, 1.38 [95% CI, 1.25 to 1.53]) and Hispanic patients (OR, 1.12 [95% CI, 1.03 to 1.22]) were compared with white patients. These increases in risk were stronger for isolated ED visits for patients with a pain diagnosis. ED visits following an elective major joint replacement surgical procedure were numerous and most commonly for pain-related diagnoses. Medicaid patients had almost double the risk of an ED or pain-related ED visit following a surgical procedure. The future of U.S. health-care insurance coverage expansions are uncertain; however, there are ongoing attempts to improve quality across the continuum of care. It is therefore essential to ensure that all patients, particularly vulnerable populations, receive appropriate postoperative care, including pain management. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Joint Replacement Surgery: Health Information Basics for You and Your Family

MedlinePlus

... information on research progress in these diseases. Contact Us NIAMS Archive Viewers and Players Social Media Moderation Policy FOIA Privacy Statement Accessibility Disclaimer Digital Strategy Open Source Data Public Data Listing NIH... ...

Analysis of singular interface stresses in dissimilar material joints for plasma facing components

NASA Astrophysics Data System (ADS)

You, J. H.; Bolt, H.

2001-10-01

Duplex joint structures are typical material combinations for the actively cooled plasma facing components of fusion devices. The structural integrity under the incident heat loads from the plasma is one of the most crucial issues in the technology of these components. The most critical domain in a duplex joint component is the free surface edge of the bond interface between heterogeneous materials. This is due to the fact that the thermal stress usually shows a singular intensification in this region. If the plasma facing armour tile consists of a brittle material, the existence of the stress singularity can be a direct cause of failure. The present work introduces a comprehensive analytical tool to estimate the impact of the stress singularity for duplex PFC design and quantifies the relative stress intensification in various materials joints by use of a model formulated by Munz and Yang. Several candidate material combinations of plasma facing armour and metallic heat sink are analysed and the results are compared with each other.

The influence of area level social deprivation on preoperative disease severity and postoperative outcomes following unicompartmental knee joint replacement.

PubMed

Bennett, Damien; Hill, Janet; Beverland, David; Kee, Frank

2015-12-01

This study investigated the effect of socioeconomic deprivation on preoperative disease and outcome following unicompartmental knee replacement (UKR). 307 Oxford UKRs implanted between 2008 and 2013 under the care of one surgeon using the same surgical technique were analysed. Deprivation was quantified using the Northern Ireland Multiple Deprivation Measure. Preoperative disease severity and postoperative outcome were measured using the Oxford Knee Score (OKS). There was no difference in preoperative OKS between deprivation groups. Preoperative knee range of motion (ROM) was significantly reduced in more deprived patients with 10° less ROM than least deprived patients. Postoperatively there was no difference in OKS improvement between deprivation groups (p=0.46), with improvements of 19.5 and 21.0 units in the most and least deprived groups respectively. There was no significant association between deprivation and OKS improvement on unadjusted or adjusted analysis. Preoperative OKS, Short Form 12 mental component score and length of stay were significant independent predictors of OKS improvement. A significantly lower proportion of the most deprived group (15%) reported being able to walk an unlimited distance compared to the least deprived group (41%) one year postoperatively. More deprived patients can achieve similar improvements in OKS to less deprived patients following UKR. Copyright © 2015 Elsevier B.V. All rights reserved.

Wedge edge ceramic combustor tile

DOEpatents

Shaffer, J.E.; Holsapple, A.C.

1997-06-10

A multipiece combustor has a portion thereof being made of a plurality of ceramic segments. Each of the plurality of ceramic segments have an outer surface and an inner surface. Each of the plurality of ceramic segments have a generally cylindrical configuration and including a plurality of joints. The joints define joint portions, a first portion defining a surface being skewed to the outer surface and the inner surface. The joint portions have a second portion defining a surface being skewed to the outer surface and the inner surface. The joint portions further include a shoulder formed intermediate the first portion and the second portion. The joints provide a sealing interlocking joint between corresponding ones of the plurality of ceramic segments. Thus, the multipiece combustor having the plurality of ceramic segment with the plurality of joints reduces the physical size of the individual components and the degradation of the surface of the ceramic components in a tensile stress zone is generally eliminated reducing the possibility of catastrophic failures. 7 figs.

Wedge edge ceramic combustor tile

DOEpatents

Shaffer, James E.; Holsapple, Allan C.

1997-01-01

A multipiece combustor has a portion thereof being made of a plurality of ceramic segments. Each of the plurality of ceramic segments have an outer surface and an inner surface. Each of the plurality of ceramic segments have a generally cylindrical configuration and including a plurality of joints. The joints define joint portions, a first portion defining a surface being skewed to the outer surface and the inner surface. The joint portions have a second portion defining a surface being skewed to the outer surface and the inner surface. The joint portions further include a shoulder formed intermediate the first portion and the second portion. The joints provide a sealing interlocking joint between corresponding ones of the plurality of ceramic segments. Thus, the multipiece combustor having the plurality of ceramic segment with the plurality of joints reduces the physical size of the individual components and the degradation of the surface of the ceramic components in a tensile stress zone is generally eliminated reducing the possibility of catastrophic failures.

Evaluation of a bisphosphonate enriched ultra-high molecular weight polyethylene for enhanced total joint replacement bearing surface functionality

NASA Astrophysics Data System (ADS)

Wright-Walker, Cassandra Jane

Each year in the United States there is an increasing trend of patients receiving total joint replacement (TJR) procedures. Approximately a half million total knee replacements (TKRs) are performed annually in the United States with increasing prevalence attributed to baby-boomers, obesity, older, and younger patients. This trend is also seen for total hip replacements (THRs) as well. The use of ultra high molecular weight polyethylene (UHMWPE) inserts in TJRs results in wear particle-induced osteolysis, which is the predominant cause for prosthesis failure and revision surgery. Sub-micron size particle generation is inevitable despite the numerous efforts in improving this bearing material. Work by others has shown that the use of oral and intravenous systemic bisphosphonates (BP) can significantly minimize periprosthetic osteolysis. However, the systemic delivery and the high solubility of BPs results in a predominant portion of the drug being excreted via the kidney without reaching its target, bone. This doctoral research project is focused on the development and evaluation of a novel method to administer BPs locally using the inherent wear of UHMWPE for possible use as an anti-osteolysis treatment. For new materials to be considered, they must be mechanically and tribologically comparable to the current gold standard, UHMWPE. In order to evaluate this material, mechanical, drug elution and tribological experiments were performed to allow assessment of material properties. Tensile tests showed comparable yield stress and pin-on-disk testing showed comparable wear to standard virgin UHMWPE. Further, drug elution tests have shown that BP was released from the enriched material both in static and dynamic conditions. Additionally, an aggressive 2 million cycle total knee simulator experiment has shown statistically similar wear results for the two materials. Overall, this research has provided the groundwork for further characterization and development of a new potential material for total joint replacements as an enhancement to standard UHMWPE. This material shows significant potential as an alternative bearing material to indirectly increase TJR longevity by addressing osteolysis related issues.

[Eradication of Staphylococcus aureus in carrier patients undergoing joint arthroplasty].

PubMed

Barbero Allende, José M; Romanyk Cabrera, Juan; Montero Ruiz, Eduardo; Vallés Purroy, Alfonso; Melgar Molero, Virginia; Agudo López, Rosa; Gete García, Luis; López Álvarez, Joaquín

2015-02-01

Prosthetic joint infection (PJI) is a complication with serious repercussions and its main cause is Staphylococcus aureus. The purpose of this study is to determine whether decolonization of S.aureus carriers helps to reduce the incidence of PJI by S.aureus. An S.aureus screening test was performed on nasal carriers in patients undergoing knee or hip arthroplasty between January and December 2011. Patients with a positive test were treated with intranasal mupirocin and chlorhexidine soap 5 days. The incidence of PJI was compared with patients undergoing the same surgery between January and December 2010. A total of 393 joint replacements were performed in 391 patients from the control group, with 416 joint replacements being performed in the intervention group. Colonization study was performed in 382 patients (91.8%), of which 102 were positive (26.7%) and treated. There was 2 PJI due S.aureus compared with 9 in the control group (0.5% vs 2.3%, odds ratio [OR]: 0.2, 95% confidence interval [CI]: 0.4 to 2.3, P=.04). In our study, the detection of colonization and eradication of S.aureus carriers achieved a significant decrease in PJI due to S.aureus compared to a historical group. Copyright © 2013 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

Wear-screening and joint simulation studies vs. materials selection and prosthesis design.

PubMed

Clarke, I C

1982-01-01

Satisfactory friction and wear performance of orthomedic biomaterials is an essential criterion for both hemiarthroplasty and total joint replacements. This report will chart the clinical historical experience of candidate biomaterials with their wear resistance and compare/contrast these data to experimental test predictions. The latter review will encompass publications dealing with both joint simulators and the more basic friction and wear screening devices. Special consideration will be given to the adequacy of the test protocol, the design of the experimental machines, and the accuracy of the measurement techniques. The discussion will then center on clinical reality vs. experimental adequacy and summarize current developments.

Potentiality Prediction of Electric Power Replacement Based on Power Market Development Strategy

NASA Astrophysics Data System (ADS)

Miao, Bo; Yang, Shuo; Liu, Qiang; Lin, Jingyi; Zhao, Le; Liu, Chang; Li, Bin

2017-05-01

The application of electric power replacement plays an important role in promoting the development of energy conservation and emission reduction in our country. To exploit the potentiality of regional electric power replacement, the regional GDP (gross domestic product) and energy consumption are taken as potentiality evaluation indicators. The principal component factors are extracted with PCA (principal component analysis), and the integral potentiality analysis is made to the potentiality of electric power replacement in the national various regions; a region is taken as a research object, and the potentiality of electric power replacement is defined and quantified. The analytical model for the potentiality of multi-scenario electric power replacement is developed, and prediction is made to the energy consumption with the grey prediction model. The relevant theoretical research is utilized to realize prediction analysis on the potentiality amount of multi-scenario electric power replacement.

Blood loss associated with Ring uncemented total knee replacement: comparison between continuous and intermittent suction drainage.

PubMed Central

Wittmann, F W; Ring, P A

1984-01-01

In a retrospective comparison of blood loss following uncemented total knee replacement, in which either continuous or intermittent suction drainage was used, measured blood loss was significantly greater with continuous drainage. However, a method of calculating actual blood loss demonstrated no significant difference. With intermittent drainage, more blood remains undetected around the knee joint; this technique should therefore be abandoned in favour of continuous suction drainage. PMID:6747978

Navy Columbia Class (Ohio Replacement) Ballistic Missile Submarine (SSBN[X]) Program: Background and Issues for Congress

DTIC Science & Technology

2016-10-03

of UK design and manufacture . 12 For more on the arrangement for jointly building Virginia- class boats, see CRS Report RL32418, Navy Virginia (SSN...lines would result in a cumulative one year schedule reduction in Missile Tube Module manufacturing for the OR Class . This schedule reduction, on a...Navy Columbia Class (Ohio Replacement) Ballistic Missile Submarine (SSBN[X]) Program: Background and Issues for Congress Ronald O’Rourke

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.

NATO and the Challenges of Austerity

DTIC Science & Technology

2012-01-01

Navy’s participation in operations in Libya in 2011. The The Impact of Defense Cuts on Key NATO Allies 7 elimination of the Nimrod MRA.4 maritime... Nimrod MRA. Mk2. The CSR cuts included the entire fleet of Harrier GR.9 combat aircraft. The Harrier cut has joint implications because the RAF Har- riers...overlap of its replacement. The Boeing RC-135 “Rivet Joint” signals intelligence (SIGINT) aircraft will replace the two remaining Nimrod R.1 platforms

A parametric shell analysis of the shuttle 51-L SRB AFT field joint

NASA Technical Reports Server (NTRS)

Davis, Randall C.; Bowman, Lynn M.; Hughes, Robert M., IV; Jackson, Brian J.

1990-01-01

Following the Shuttle 51-L accident, an investigation was conducted to determine the cause of the failure. Investigators at the Langley Research Center focused attention on the structural behavior of the field joints with O-ring seals in the steel solid rocket booster (SRB) cases. The shell-of-revolution computer program BOSOR4 was used to model the aft field joint of the solid rocket booster case. The shell model consisted of the SRB wall and joint geometry present during the Shuttle 51-L flight. A parametric study of the joint was performed on the geometry, including joint clearances, contact between the joint components, and on the loads, induced and applied. In addition combinations of geometry and loads were evaluated. The analytical results from the parametric study showed that contact between the joint components was a primary contributor to allowing hot gases to blow by the O-rings. Based upon understanding the original joint behavior, various proposed joint modifications are shown and analyzed in order to provide additional insight and information. Finally, experimental results from a hydro-static pressurization of a test rocket booster case to study joint motion are presented and verified analytically.

Collateral ligament strains during knee joint laxity evaluation before and after TKA.

PubMed

Delport, Hendrik; Labey, Luc; De Corte, Ronny; Innocenti, Bernardo; Vander Sloten, Jos; Bellemans, Johan

2013-08-01

Passive knee stability is provided by the soft tissue envelope. There is consensus among orthopedic surgeons that good outcome in Total Knee Arthroplasty requires equal tension in the medial/lateral compartment of the knee joint, as well as equal tension in the flexion/extension gap. The purpose of this study was to quantify the ligament laxity in the normal non-arthritic knee before and after Posterior-Stabilized Total Knee Arthroplasty. We hypothesized that the Medial/Lateral Collateral Ligament shows minimal changes in length when measured directly by extensometers in the native human knee during varus/valgus laxity testing. We also hypothesized that due to differences in material properties and surface geometry, native laxity is difficult to reconstruct using a Posterior-Stabilized Total Knee. Six specimens were used to perform this in vitro cadaver test using extensometers to provide numerical values for laxity and varus-valgus tilting in the frontal plane. This study enabled a precise measurement of varus-valgus laxity as compared with the clinical assessment. The strains in both ligaments in the replaced knee were different from those in the native knee. Both ligaments were stretched in extension, in flexion the Medial Collateral Ligament tends to relax and the Lateral Collateral Ligament remains tight. As material properties and surface geometry of the replaced knee add stiffness to the joint, we recommend to avoid overstuffing the joint, when using this type of Posterior-Stabilized Total Knee Arthroplasty, in order to obtain varus/valgus laxity close to the native joint. Copyright © 2013 Elsevier Ltd. All rights reserved.

Intra-articular laser treatment plus Platelet Rich Plasma (PRP) significantly reduces pain in many patients who had failed prior PRP treatment

NASA Astrophysics Data System (ADS)

Prodromos, Chadwick C.; Finkle, Susan; Dawes, Alexander; Dizon, Angelo

2018-02-01

INTRODUCTION: In our practice Platelet Rich Plasma (PRP) injections effectively reduce pain in most but not all arthritic patients. However, for patients who fail PRP treatment, no good alternative currently exists except total joint replacement surgery. Low level laser therapy (LLLT) on the surface of the skin has not been helpful for arthritis patients in our experience. However, we hypothesized that intra-articular laser treatment would be an effective augmentation to PRP injection and would increase its efficacy in patients who had failed prior PRP injection alone. METHODS: We offered Intra-articular Low Level Laser Therapy (IAL) treatment in conjunction with repeat PRP injection to patients who had received no benefit from PRP injection alone at our center. They were the treatment group. They were not charged for PRP or IAL. They also served as a historical control group since they had all had failed PRP treatment alone. 28 patients (30 joints) accepted treatment after informed consent. 22 knees, 4 hips, 2 shoulder glenohumeral joints and 1 first carpo-metacarpal (1st CMC) joint were treated RESULTS: All patients were followed up at 1 month and no adverse events were seen from the treatment. At 6 months post treatment 46% of patients had good outcomes, and at 1 year 17% still showed improvement after treatment. 11 patients failed treatment and went on to joint replacement. DISCUSSION: A single treatment of IAL with PRP salvaged 46% of patients who had failed PRP treatment alone, allowing avoidance of surgery and good pain control.

The Influence of Artificial Cervical Disc Prosthesis Height on the Cervical Biomechanics: A Finite Element Study.

PubMed

Yuan, Wei; Zhang, Haiping; Zhou, Xiaoshu; Wu, Weidong; Zhu, Yue

2018-05-01

Artificial cervical disc replacement is expected to maintain normal cervical biomechanics. At present, the effect of the Prestige LP prosthesis height on cervical biomechanics has not been thoroughly studied. This finite element study of the cervical biomechanics aims to predict how the parameters, like range of motion (ROM), adjacent intradiscal pressure, facet joint force, and bone-implant interface stress, are affected by different heights of Prestige LP prostheses. The finite element model of intact cervical spine (C3-C7) was obtained from our previous study, and the model was altered to implant Prestige LP prostheses at the C5-C6 level. The effects of the height of 5, 6, and 7 mm prosthesis replacement on ROM, adjacent intradiscal pressure, facet joint force, as well as the distribution of bone-implant interface stress were examined. ROM, adjacent intradiscal pressure, and facet joint force increased with the prosthesis height, whereas ROM and facet joint force decreased at C5-C6. The maximal stress on the inferior surface of the prostheses was greater than that on the superior surface, and the stresses increased with the prosthesis height. The biomechanical changes were slightly affected by the height of 5 and 6 mm prostheses, but were strongly affected by the 7-mm prosthesis. An appropriate height of the Prestige LP prosthesis can preserve normal ROM, adjacent intradiscal pressure, and facet joint force. Prostheses with a height of ≥2 mm than normal can lead to marked changes in the cervical biomechanics and bone-implant interface stress. Copyright © 2018 Elsevier Inc. All rights reserved.

Method of forming a ceramic to ceramic joint

DOEpatents

Cutler, Raymond Ashton; Hutchings, Kent Neal; Kleinlein, Brian Paul; Carolan, Michael Francis

2010-04-13

A method of joining at least two sintered bodies to form a composite structure, includes: providing a joint material between joining surfaces of first and second sintered bodies; applying pressure from 1 kP to less than 5 MPa to provide an assembly; heating the assembly to a conforming temperature sufficient to allow the joint material to conform to the joining surfaces; and further heating the assembly to a joining temperature below a minimum sintering temperature of the first and second sintered bodies. The joint material includes organic component(s) and ceramic particles. The ceramic particles constitute 40-75 vol. % of the joint material, and include at least one element of the first and/or second sintered bodies. Composite structures produced by the method are also disclosed.

Understanding recovery: changes in the relationships of the International Classification of Functioning (ICF) components over time.

PubMed

Davis, A M; Perruccio, A V; Ibrahim, S; Hogg-Johnson, S; Wong, R; Badley, E M

2012-12-01

The International Classification of Functioning, Disability and Health framework describes human functioning through body structure and function, activity and participation in the context of a person's social and physical environment. This work tested the temporal relationships of these components. Our hypotheses were: 1) there would be associations among physical impairment, activity limitations and participation restrictions within time; 2) prior status of a component would be associated with future status; 3) prior status of one component would influence status of a second component (e.g. prior activity limitations would be associated with current participation restrictions); and, 4) the magnitude of the within time relationships of the components would vary over time. Participants from Canada with primary hip or knee joint replacement (n = 931), an intervention with predictable improvement in pain and disability, completed standardized outcome measures pre-surgery and five times in the first year post-surgery. These included physical impairment (pain), activity limitations and participation restrictions. ICF component relationships were evaluated cross-sectionally and longitudinally using path analysis adjusting for age, sex, BMI, hip vs. knee, low back pain and mood. All component scores improved significantly over time. The path coefficients supported the hypotheses in that both within and across time, physical impairment was associated with activity limitation and activity limitation was associated with participation restriction; prior status and change in a component were associated with current status in another component; and, the magnitude of the path coefficients varied over time with stronger associations among components to three months post surgery than later in recovery with the exception of the association between impairment and participation restrictions which was of similar magnitude at all times. This work enhances understanding of the complexities of the ICF component relationships in evaluating disability over time. Further longitudinal studies including evaluation of contextual factors are required. Copyright © 2012 Elsevier Ltd. All rights reserved.

Improvements and Extensions for Joint Polar Satellite System Algorithms

NASA Astrophysics Data System (ADS)

Grant, K. D.

2016-12-01

The National Oceanic and Atmospheric Administration (NOAA) and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation civilian weather satellite system: the Joint Polar Satellite System (JPSS). JPSS replaced the afternoon orbit component and ground processing of the old POES system managed by NOAA. JPSS satellites carry sensors designed to collect meteorological, oceanographic, climatological, and solar-geophysical observations of the earth, atmosphere, and space. The ground processing system for JPSS is the Common Ground System (CGS), and provides command, control, and communications (C3), data processing and product delivery. CGS's data processing capability provides environmental data products (Sensor Data Records (SDRs) and Environmental Data Records (EDRs)) to the NOAA Satellite Operations Facility. The first satellite in the JPSS constellation, S-NPP, was launched in October 2011. The second satellite, JPSS-1, is scheduled for launch in January 2017. During a satellite's calibration and validation (Cal/Val) campaign, numerous algorithm updates occur. Changes identified during Cal/Val become available for implementation into the operational system for both S-NPP and JPSS-1. In addition, new capabilities, such as higher spectral and spatial resolution, will be exercised on JPSS-1. This paper will describe changes to current algorithms and products as a result of S-NPP Cal/Val and related initiatives for improved capabilities. Improvements include Cross Track Infrared Sounder high spectral processing, extended spectral and spatial ranges for Ozone Mapping and Profiler Suite ozone Total Column and Nadir Profiles, and updates to Vegetation Index, Snow Cover, Active Fires, Suspended Matter, and Ocean Color. Updates will include Sea Surface Temperature, Cloud Mask, Cloud Properties, and other improvements.

Ground System Extensibility Considerations

NASA Astrophysics Data System (ADS)

Miller, S. W.; Greene, E.

2017-12-01

The National Oceanic and Atmospheric Administration (NOAA) and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation civilian weather and environmental satellite system: the Joint Polar Satellite System (JPSS). The Joint Polar Satellite System will replace the afternoon orbit component and ground processing system of the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA. The JPSS satellites will carry a suite of sensors designed to collect meteorological, oceanographic, climatological and geophysical observations of the Earth. The ground processing system for JPSS is known as the JPSS Common Ground System (JPSS CGS). Developed and maintained by Raytheon Intelligence, Information and Services (IIS), the CGS is a multi-mission enterprise system serving NOAA, NASA and their national and international partners, such as NASA's Earth Observation System (EOS), NOAA's current POES, the Japan Aerospace Exploration Agency's (JAXA) Global Change Observation Mission - Water (GCOM-W1), and DoD's Defense Meteorological Satellite Program (DMSP). The CGS provides a wide range of support to a number of national and international missions, including command and control, mission management, data acquisition and routing, and environmental data processing and distribution. The current suite of CGS-supported missions has demonstrated the value of interagency and international partnerships to address global observation needs. With its established infrastructure and existing suite of missions, the CGS is extensible to a wider array of potential new missions. This paper will describe how the inherent scalability and extensibility of the CGS enables the addition of these new missions, with an eye on global enterprise needs in the 2020's and beyond.

Repair of massively defected hemi-joints using demineralized osteoarticular allografts with protected cartilage.

PubMed

Li, Siming; Yang, Xiaohong; Tang, Shenghui; Zhang, Xunmeng; Feng, Zhencheng; Cui, Shuliang

2015-08-01

Surgical replacement of massively defected joints necessarily relies on osteochondral grafts effective to both of bone and cartilage. Demineralized bone matrix (DBM) retains the osteoconductivity but destroys viable chondrocytes in the cartilage portion essential for successful restoration of defected joints. This study prepared osteochondral grafts of DBM with protected cartilage. Protected cartilage portions was characterized by cellular and molecular biology and the grafts were allogenically used for grafting. Protected cartilage showed similar histomorphological structure and protected proteins estimated by total proteins and cartilage specific proteins as in those of fresh controls when DBMs were generated in bone portions. Such grafts were successfully used for simultaneously repair of bone and cartilage in massively defected osteoarticular joints within 16 weeks post-surgery. These results present an allograft with clinical potential for simultaneous restoration of bone and cartilage in defected joints.

Smoking and primary total hip or knee replacement due to osteoarthritis in 54,288 elderly men and women.

PubMed

Mnatzaganian, George; Ryan, Philip; Reid, Christopher M; Davidson, David C; Hiller, Janet E

2013-09-05

The reported association of smoking with risk of undergoing a total joint replacement (TJR) due to osteoarthritis (OA) is not consistent. We evaluated the independent association between smoking and primary TJR in a large cohort. The electronic records of 54,288 men and women, who were initially recruited for the Second Australian National Blood Pressure study, were linked to the Australian Orthopaedic Association National Joint Replacement Registry to detect total hip replacement (THR) or total knee replacement (TKR) due to osteoarthritis. Competing risk regressions that accounted for the competing risk of death estimated the subhazard ratios for TJR. One-way and probabilistic sensitivity analyses were undertaken to represent uncertainty in the classification of smoking exposure and socioeconomic disadvantage scores. An independent inverse association was found between smoking and risk of THR and TKR observed in both men and women. Compared to non-smokers, male and female smokers were respectively 40% and 30% less likely to undergo a TJR. This significant association persisted after controlling for age, co-morbidities, body mass index (BMI), physical exercise, and socioeconomic disadvantage. The overweight and obese were significantly more likely to undergo TJR compared to those with normal weight. A dose-response relationship between BMI and TJR was observed (P < 0.001). Socioeconomic status was not independently associated with risk of either THR or TKR. The strengths of the inverse association between smoking and TJR, the temporal relationship of the association, together with the consistency in the findings warrant further investigation about the role of smoking in the pathogenesis of osteoarthritis causing TJR.

Long Term Survivorship of a Severely Notched Femoral Stem after Replacing the Fractured Ceramic head with a Cobalt-Chromium Head

PubMed Central

Panagopoulos, Andreas; Tatani, Irini; Megas, Panagiotis

2016-01-01

Background: Although ceramic head fracture occurs infrequently today, in the event of a fracture, the resulting revision surgery can prove very challenging, since the ceramic particles lodge into the surrounding soft tissue and can cause rapid implant failure Case Presentation: A case of long term survivorship of a severed notched femoral stem after replacing the fractured femoral head with a cobalt-chromium one is reported in a 40-year old woman with hip dysplasia who underwent an uncomplicated total hip arthroplasty. The incident of ceramic femoral head fracture occurred 14 months postoperatively without reporting any significant trauma. Intraoperative findings at revision were a multifragmented femoral head and a damaged polyethylene insert along with diffuse metallosis and excessive wear of the cone of the stem. Both the stem and the acetabular component were stable. After removal of ceramic fragments, metallotic tissue excision and careful lavage of the joint, the inlay was replaced by a similar one and a cobalt-chromium femoral head was placed to the existing notched taper of the firmly incorporated stem. At the 13th year follow up examination, the patient had no pain, used no walking aids, and had normal activity with no signs of wearing or loosening in the plain x-rays. Conclusion: Despite current recommendations of using ceramic femoral heads in cases of fracture or to revise the severely damaged stems we were able to provide a long term survivorship up to 13 years postoperatively of a cobalt-chromium femoral head applied to a severe damaged stem. PMID:28217203

Long Term Survivorship of a Severely Notched Femoral Stem after Replacing the Fractured Ceramic head with a Cobalt-Chromium Head.

PubMed

Panagopoulos, Andreas; Tatani, Irini; Megas, Panagiotis

2016-01-01

Although ceramic head fracture occurs infrequently today, in the event of a fracture, the resulting revision surgery can prove very challenging, since the ceramic particles lodge into the surrounding soft tissue and can cause rapid implant failure. A case of long term survivorship of a severed notched femoral stem after replacing the fractured femoral head with a cobalt-chromium one is reported in a 40-year old woman with hip dysplasia who underwent an uncomplicated total hip arthroplasty. The incident of ceramic femoral head fracture occurred 14 months postoperatively without reporting any significant trauma. Intraoperative findings at revision were a multifragmented femoral head and a damaged polyethylene insert along with diffuse metallosis and excessive wear of the cone of the stem. Both the stem and the acetabular component were stable. After removal of ceramic fragments, metallotic tissue excision and careful lavage of the joint, the inlay was replaced by a similar one and a cobalt-chromium femoral head was placed to the existing notched taper of the firmly incorporated stem. At the 13 th year follow up examination, the patient had no pain, used no walking aids, and had normal activity with no signs of wearing or loosening in the plain x-rays. Despite current recommendations of using ceramic femoral heads in cases of fracture or to revise the severely damaged stems we were able to provide a long term survivorship up to 13 years postoperatively of a cobalt-chromium femoral head applied to a severe damaged stem.

[The use of structural proximal tibial allografts coated with human albumin in treating extensive periprosthetic knee-joint bone deficiency and averting late complications. Case report].

PubMed

Klára, Tamás; Csönge, Lajos; Janositz, Gábor; Pap, Károly; Lacza, Zsombor

2015-01-11

The authors report the history of a 74-year-old patient who underwent surgical treatment for segmental knee-joint periprosthetic bone loss using structural proximal tibial allografts coated with serum albumin. Successful treatment of late complications which occurred in the postoperative period is also described. The authors emphasize that bone replacement with allografts is a physiological process that enables the stable positioning of the implant and the reconstruction of the soft tissues, the replacement of extensive bone loss, and also it is a less expensive operation. It has been already confirmed that treatment of lyophilised allografts with albumin improves the ability of bone marrow-derived mesenchymal stem cells to adhere and proliferate the surface of the allografts, penetrate the pores and reach deeper layers of the graft. Earlier studies have shown osteoblast activity on the surface and interior of the graft.

A new approach to knee joint arthroplasty.

PubMed

Zarychta, P

2018-04-01

The main aim of this new approach dedicated to knee arthroplasty is to provide an automated method for determining the cutting planes of both the head of femur and the head of tibia in knee replacement surgery. This paper shows a new approach differing from standard procedures associated with manual determination of the mechanical axis of the lower extremity (during surgery) and replacing them with a procedure based on the imprints (with selected cutting planes) of the two heads of bones. Both these imprints have been performed on the basis of the toposcan of the lower limb (before surgery). This methodology has been implemented in MATLAB and tested in clinical CT images of the lower limb in the coronal and transverse planes (61 studies) and in clinical MRI studies of the knee joint in coronal plane (107 studies). Correct results were obtained for about 90% cases. Copyright © 2017 Elsevier Ltd. All rights reserved.