Tibial rotation kinematics subsequent to knee arthroplasty

PubMed Central

Collins, Duane J.; Khatib, Yasser H.; Parker, David A.; Jenkin, Deanne E.; Molnar, Robert B.

2015-01-01

Background The use of computer assisted joint replacement has facilitated precise intraoperative measurement of knee kinematics. The changes in “screw home mechanism” (SHM) resulting from Total Knee Arthroplasty (TKA) with different prostheses and constraints has not yet been accurately described. Methods A pilot study was first completed. Intraoperative kinematic data was collected two groups of 15 patients receiving different prostheses. Results On average, patients lost 5.3° of ER (SD = 6.1°). There was no significant difference between the prostheses or different prosthetic constraints. Conclusions There significant loss of SHM after TKA. Further research is required to understand its impact on patient function. PMID:25829754

The Influence Of Component Alignment On The Life Of Total Knee Prostheses

NASA Astrophysics Data System (ADS)

Bugariu, Delia; Bereteu, Liviu

2012-12-01

An arthritic knee affects the patient's life by causing pain and limiting movement. If the cartilage and the bone surfaces are severely affected, the natural joint is replaced with an artificial joint. The procedure is called total knee arthroplasty (TKA). Lately, the numbers of implanted total knee prostheses grow steadily. An important factor in TKA is the perfect alignment of the total knee prosthesis (TKP) components. Component misalignment can lead to the prosthesis loss by producing wear particles. The paper proposes a study on mechanical behaviors of a TKP based on numerical analysis, using ANSYS software. The numerical analysis is based on both the normal and the changed angle of the components alignment.

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.

Microscopical analysis of synovial fluid wear debris from failing CoCr hip prostheses

NASA Astrophysics Data System (ADS)

Ward, M. B.; Brown, A. P.; Cox, A.; Curry, A.; Denton, J.

2010-07-01

Metal on metal hip joint prostheses are now commonly implanted in patients with hip problems. Although hip replacements largely go ahead problem free, some complications can arise such as infection immediately after surgery and aseptic necrosis caused by vascular complications due to surgery. A recent observation that has been made at Manchester is that some Cobalt Chromium (CoCr) implants are causing chronic pain, with the source being as yet unidentified. This form of replacement failure is independent of surgeon or hospital and so some underlying body/implant interface process is thought to be the problem. When the synovial fluid from a failed joint is examined particles of metal (wear debris) can be found. Transmission Electron Microscopy (TEM) has been used to look at fixed and sectioned samples of the synovial fluid and this has identified fine (< 100 nm) metal and metal oxide particles within the fluid. TEM EDX and Electron Energy Loss Spectroscopy (EELS) have been employed to examine the composition of the particles, showing them to be chromium rich. This gives rise to concern that the failure mechanism may be associated with the debris.

Biomechanical study of the tibia in knee replacement revision.

PubMed

Quílez, M P; Pérez, M A; Seral-García, B

2015-01-01

The best management of severe bone defects following total knee replacement is still controversial. Metal augments, tantalum cones and porous tibial sleeves could help the surgeon to manage any type of bone loss, providing a stable and durable knee joint reconstruction. Five different types of prostheses have been analysed: one prosthesis with straight stem; two prostheses with offset stem, with and without supplement, and two prostheses with sleeves, with and without stem. The purpose of this study is to report a finite element study of revision knee tibial implants. The main objective was to analyse the tibial bone density changes and Von Misses tension changes following different tibial implant designs. In all cases, the bone density decreases in the proximal epiphysis and medullary channels, with a bone density increase also being predicted in the diaphysis and at the bone around the stems tips. The highest value of Von Misses stress has been obtained for the straight tibial stem, and the lowest for the stemless metaphyseal sleeves prosthesis. Copyright © 2014 SECOT. Published by Elsevier Espana. All rights reserved.

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

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.

Finite Element Analysis of Influence of Axial Position of Center of Rotation of a Cervical Total Disc Replacement on Biomechanical Parameters: Simulated 2-Level Replacement Based on a Validated Model.

PubMed

Li, Yang; Zhang, Zhenjun; Liao, Zhenhua; Mo, Zhongjun; Liu, Weiqiang

2017-10-01

Finite element models have been widely used to predict biomechanical parameters of the cervical spine. Previous studies investigated the influence of position of rotational centers of prostheses on cervical biomechanical parameters after 1-level total disc replacement. The purpose of this study was to explore the effects of axial position of rotational centers of prostheses on cervical biomechanics after 2-level total disc replacement. A validated finite element model of C3-C7 segments and 2 prostheses, including the rotational center located at the superior endplate (SE) and inferior endplate (IE), was developed. Four total disc replacement models were used: 1) IE inserted at C4-C5 disc space and IE inserted at C5-C6 disc space (IE-IE), 2) IE-SE, 3) SE-IE, and 4) SE-SE. All models were subjected to displacement control combined with a 50 N follower load to simulate flexion and extension motions in the sagittal plane. For each case, biomechanical parameters, including predicted moments, range of rotation at each level, facet joint stress, and von Mises stress on the ultra-high-molecular-weight polyethylene core of the prostheses, were calculated. The SE-IE model resulted in significantly lower stress at the cartilage level during extension and at the ultra-high-molecular-weight polyethylene cores when compared with the SE-SE construct and did not generate hypermotion at the C4-C5 level compared with the IE-SE and IE-IE constructs. Based on the present analysis, the SE-IE construct is recommended for treating cervical disease at the C4-C6 level. This study may provide a useful model to inform clinical operations. Copyright © 2017 Elsevier Inc. All rights reserved.

Bilateral total hip arthroplasty in Morquio-Brailsford's syndrome: a report of two cases.

PubMed

Tassinari, Enrico; Boriani, Luca; Traina, Francesco; Dallari, Dante; Toni, Aldo; Giunti, Armando

2008-09-01

We report two cases of bilateral cementless total hip arthroplasty in two young women affected by Morquio-Brailsford syndrome. Morquio-Brailsford disease belongs to the mucopolysaccharidoses; it shows growth retardation with disproportional dwarfism. Usually patients are affected by a severe joint degeneration from their 2nd or 3rd decade. Young age, severe dysplasia, and joint size are the main technical problems for a total hip replacement. Accurate radiographic and CT planning allows the use of standard prostheses instead of custom-made ones.

Application of computer graphics in the design of custom orthopedic implants.

PubMed

Bechtold, J E

1986-10-01

Implementation of newly developed computer modelling techniques and computer graphics displays and software have greatly aided the orthopedic design engineer and physician in creating a custom implant with good anatomic conformity in a short turnaround time. Further advances in computerized design and manufacturing will continue to simplify the development of custom prostheses and enlarge their niche in the joint replacement market.

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.

[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.

Development of friction and wear full-scale testing for TKR prostheses with reliable low cost apparatus

NASA Astrophysics Data System (ADS)

Suwandi, Agri; Soemardi, Tresna P.; Kiswanto, Gandjar; Kusumaningsih, Widjajalaksmi; I. Gusti Agung I. G., W.

2018-02-01

Prostheses products must undergo simulation and physical testing, before clinical testing. Finite element method is a preliminary simulation for in vivo test. The method visualizes the magnitude of the compressive force and the critical location of the Total Knee Replacement (TKR) prostheses design. In vitro testing is classified as physical testing for prostheses product. The test is conducted to evaluate the potential failure of the product and the characteristics of the prostheses TKR material. Friction and wear testing are part of the in vivo test. Motion of knee joints, which results in the phenomena of extension and deflection in the femoral and tibia insert, is represented by friction and wear testing. Friction and wear tests aim to obtain an approximate lifetime in normal and extreme load patterns as characterized by the shape of the friction surface area. The lifetime estimation requires friction and wear full-scale testing equipments for TKR prostheses products. These are necessary in obtaining initial data on potential product failures and characterizing of the material based on the ASTM F2724-08 standards. Based on the testing result and statistical analysis data, the average wear rate value per year is 2.19 × 10-3 mg/MC, with a 10 % safety limit of volume and 14,400 cycles times, for 15 hours moving nonstop then the prediction of wear life of the component tibia insert is ± 10 years.

[Posturographic study of total prostheses in the leg. Apropos of 88 patients examined].

PubMed

Lord, G; Gentaz, R; Gagey, P M; Baron, J B

1976-01-01

By suppressing certain articular sensory receptors, the reconstructive surgery of joints using total prostheses modifies tonic postural activity and, by this means, alters the regulation of balance in the subjects of operation. This doubtless explains certain discrepancies between the apparently excellent results in respect of joint movement and muscle strength and poor utilisation of the joint in every day life (instability, use of sticks or failure to use the joint in walking). Drawing on the experience and basic work of specialists in posture, the authors have undertaken a study of tonic postural activity in patients who had received a total prosthesis in the lower limb, both from the clinical aspect and by graphic measurement using an electronic apparatus, the statokinesiometer. Fourteen normal subjects were tested to calibrate the apparatus and 8 patients suffering from established osteoarthritis of the hip were studied as controls. Analysis of tonic postural activity was made in 66 patients who had received total prostheses in the lower limb. The results showed significant disturbance in balance in ankle prostheses, minimal disturbance in knee prostheses and not significant disturbance in hip prostheses. Certain therapeutic implications are derived from this study.

Clinical and Radiographic Assessment of Reasons for Replacement of Metal- Ceramic Fixed Dental Prostheses in Patients Referring to Dental School.

PubMed

Al Refai, Roa'a; Saker, Samah

2018-01-01

The expected length of service and reasons for fixed dental prostheses (FDPs) replacement are a frequent inquiry by patients while the answers were mainly based on studies reports that was conducted outside the middle east region. This clinical and radiographic survey was constructed to assess and survey clinically and radiographically the reasons of replacement of metal-ceramic fixed dental prostheses, amongst patients reporting at dental school in Taibah University. Between January and May 2016, 151 patients were recruited for this study. Interview (include questions pertained to the length of service of the prosthesis, the nature of complaint as told by patient in her own words), clinical examination, intra-oral photographs, and periapical radiographs, were done by the researchers. The parameters assessed were secondary caries, open margins, loss of retention, failure of endodontic treatment of the abutment and periodontal diseases. A total number of 249 failed fixed dental prostheses were evaluated. Of which 180 (39.7%) were single crowns, 159 (35.0%) were retainers and 117 (25.8%) were pontics in 69 fixed partial denture. The most common reason for replacement of fixed restorations was periodontal diseases affecting 92.8% of all types' restorations, followed by defective margin in 90.4% of examined restoration, poor aesthetic in 88% of restorations, while periapical involvement was found in 85.5% of fixed dental prosthesis. The survival rates of fixed prostheses were not predictable, and no association was found between number of years in service and the number of restorations. The most common reasons for replacing single unit fixed dental prostheses are periodontal diseases and periapical involvement, while defective margins and poor aesthetic mainly associated with multi-unit fixed dental prostheses. Key words: Failure, Fixed dental prosthesis, Survival, Replacement.

International comparative evaluation of knee replacement with fixed or mobile-bearing posterior-stabilized prostheses.

PubMed

Graves, Stephen; Sedrakyan, Art; Baste, Valborg; Gioe, Terence J; Namba, Robert; Martínez Cruz, Olga; Stea, Susanna; Paxton, Elizabeth; Banerjee, Samprit; Isaacs, Abby J; Robertsson, Otto

2014-12-17

Posterior-stabilized total knee prostheses were introduced to address instability secondary to loss of posterior cruciate ligament function, and they have either fixed or mobile bearings. Mobile bearings were developed to improve the function and longevity of total knee prostheses. In this study, the International Consortium of Orthopaedic Registries used a distributed health data network to study a large cohort of posterior-stabilized prostheses to determine if the outcome of a posterior-stabilized total knee prosthesis differs depending on whether it has a fixed or mobile-bearing design. Aggregated registry data were collected with a distributed health data network that was developed by the International Consortium of Orthopaedic Registries to reduce barriers to participation (e.g., security, proprietary, legal, and privacy issues) that have the potential to occur with the alternate centralized data warehouse approach. A distributed health data network is a decentralized model that allows secure storage and analysis of data from different registries. Each registry provided data on mobile and fixed-bearing posterior-stabilized prostheses implanted between 2001 and 2010. Only prostheses associated with primary total knee arthroplasties performed for the treatment of osteoarthritis were included. Prostheses with all types of fixation were included except for those with the rarely used reverse hybrid (cementless tibial and cemented femoral components) fixation. The use of patellar resurfacing was reported. The outcome of interest was time to first revision (for any reason). Multivariate meta-analysis was performed with linear mixed models with survival probability as the unit of analysis. This study includes 137,616 posterior-stabilized knee prostheses; 62% were in female patients, and 17.6% had a mobile bearing. The results of the fixed-effects model indicate that in the first year the mobile-bearing posterior-stabilized prostheses had a significantly higher hazard ratio (1.86) than did the fixed-bearing posterior-stabilized prostheses (95% confidence interval, 1.28 to 2.7; p = 0.001). For all other time intervals, the mobile-bearing posterior-stabilized prostheses had higher hazard ratios; however, these differences were not significant. Mobile-bearing posterior-stabilized prostheses had an increased rate of revision compared with fixed-bearing posterior-stabilized prostheses. This difference was evident in the first year. Copyright © 2014 by The Journal of Bone and Joint Surgery, Incorporated.

Prosthetic knee design by simulation

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

Hollerbach, K; Hollister, A

1999-07-30

Although 150,000 total knee replacement surgeries are performed annually in North America, current designs of knee prostheses have mechanical problems that include a limited range of motion, abnormal gait patterns, patellofemoral joint dysfunction, implant loosening or subsidence, and excessive wear. These problems fall into three categories: failure to reproduce normal joint kinematics, which results in altered limb function; bone-implant interface failure; and material failure. Modern computer technology can be used to design, prototype, and test new total knee implants. The design team uses the full range of CAD-CAM to design and produce implant prototypes for mechanical and clinical testing. Closermore » approximation of natural knee kinematics and kinetics is essential for improved patient function and diminished implant loads. Current knee replacement designs are based on 19th Century theories that the knee moves about a variable axis of rotation. Recent research has shown, however, that knee motion occurs about two fixed, offset axes of rotation. These aces are not perpendicular to the long axes of the bones or to each other, and the axes do not intersect. Bearing surfaces of mechanisms that move about axes of rotation are surfaces of revolution of those axes which advanced CAD technology can produce. Solids with surfaces of revolution for the two axes of rotation for the knee have been made using an HP9000 workstation and Structural Ideas Master Series CAD software at ArthroMotion. The implant's CAD model should closely replicate movements of the normal knee. The knee model will have a range of flexion-extension (FE) from -5 to 120 degrees. Movements include varus, valgus, internal and external rotation, as well as flexion and extension. The patellofemoral joint is aligned perpendicular to the FE axis and replicates the natural joint more closely than those of existing prostheses. The bearing surfaces will be more congruent than current designs and should generate lower stresses in the materials.« less

Multifunctional Coatings to Simultaneously Promote Osseointegration and Prevent Infection of Orthopaedic Implants

PubMed Central

Raphel, Jordan; Holodniy, Mark; Goodman, Stuart B.; Heilshorn, Sarah C.

2016-01-01

The two leading causes of failure for joint arthroplasty prostheses are aseptic loosening and periprosthetic joint infection. With the number of primary and revision joint replacement surgeries on the rise, strategies to mitigate these failure modes have become increasingly important. Much of the recent work in this field has focused on the design of coatings either to prevent infection while ignoring bone mineralization or vice versa, to promote osseointegration while ignoring microbial susceptibility. However, both coating functions are required to achieve long-term success of the implant; therefore, these two modalities must be evaluated in parallel during the development of new orthopaedic coating strategies. In this review, we discuss recent progress and future directions for the design of multifunctional orthopaedic coatings that can inhibit microbial cells while still promoting osseointegration. PMID:26851394

Awareness, attitudes, need and demand on replacement of missing teeth among a group of partially dentate patients attending a University Dental Hospital.

PubMed

Jayasinghe, Rasika Manori; Perera, Janana; Jayasinghe, Vajira; Thilakumara, Indika P; Rasnayaka, Sumudu; Shiraz, Muhammad Hanafi Muhammad; Ranabahu, Indra; Kularatna, Sanjeewa

2017-07-27

Our objective was to assess awareness, attitudes, need and demand on replacement of missing teeth according to edentulous space, age, gender, ethnicity, educational level and socio-economical status of the patient. 76.2% of the study group was opined that the missing teeth should be replaced by prosthetic means. Majority were keen in getting them replaced mainly for the comfort in mastication. Although 77.9 and 32.9% were aware of the removable prostheses and implants respectively, only 25.2% knew about tooth supported bridges as an option of replacement of missing teeth. Participants' awareness on tooth and implant supported prostheses is at a higher level. Participants' opinion on need of regular dental visit was statistically significant when gender, ethnicity and education level were considered. The highest demand for replacement of missing teeth was observed in Kennedy class I and II situations in both upper and lower arches. Demand for fixed prostheses was significantly highest in Kennedy class II in upper and lower arches. In conclusion, although removable prosthodontic options are known to most of the patients, their awareness on tooth and implant supported prostheses is also at a higher level. The highest demand for replacement of missing teeth is by patients with Kennedy class I and II situations whereas Kennedy class II being the category with highest demand for fixed prostheses. We recommend that the location of missing teeth to be considered as a priority when educating patients on the most appropriate prosthetic treatment options. Dentists' involvement in educating patients on prosthetic options needs to be improved.

In vitro assessment of the contact mechanics of reverse-engineered distal humeral hemiarthroplasty prostheses.

PubMed

Willing, Ryan; Lapner, Michael; King, Graham J W; Johnson, James A

2014-11-01

Distal humeral hemiarthroplasty alters cartilage contact mechanics, which may predispose to osteoarthritis. Current prostheses do not replicate the native anatomy, and therefore contribute to these changes. We hypothesized that prostheses reverse-engineered from the native bone shape would provide similar contact patterns as the native articulation. Reverse-engineered hemiarthroplasty prostheses were manufactured for five cadaveric elbows based on CT images of the distal humerus. Passive flexion trials with constant muscle forces were performed with the native articulation intact while bone motions were recorded using a motion tracking system. Motion trials were then repeated after the distal humerus was replaced with a corresponding reverse-engineered prosthesis. Contact areas and patterns were reconstructed using computer models created from CT scan images combined with the motion tracker data. The total contact areas, as well as the contact area within smaller sub-regions of the ulna and radius, were analyzed for changes resulting from hemiarthroplasty using repeated-measures ANOVAs. Contact area at the ulna and radius decreased on average 42% (SD 19%, P=.008) and 41% (SD 42%, P=.096), respectively. Contact area decreases were not uniform throughout the different sub-regions, suggesting that contact patterns were also altered. Reverse-engineered prostheses did not reproduce the same contact pattern as the native joints, possibly because the thickness of the distal humerus cartilage layer was neglected when generating the prosthesis shapes or as a consequence of the increased stiffness of the metallic implants. Alternative design strategies and materials for hemiarthroplasty should be considered in future work. Copyright © 2014 Elsevier Ltd. All rights reserved.

Surface evaluation of orthopedic hip implants marketed in Brazil

NASA Astrophysics Data System (ADS)

Souza, M. M.; Trommer, R. M.; Maru, M. M.; Roesler, C. R. M.; Barros, W. S.; Dutra, M. S.

2016-07-01

One of the factors that contribute to the quality of total hip prostheses is the degree of accuracy in the manufacturing of the joint surfaces. The dimensional control of joint components is important because of its direct influence on the durability and, consequently, in the patients’ life quality. This work presents studies on the form and roughness of orthopedic hip prostheses marketed in Brazil. The results provide data for quality control of the surfaces of the femoral heads and acetabular components of hip prostheses and indicate the need of improvement in the procedures used to this control.

21 CFR 888.6 - Degree of constraint.

Code of Federal Regulations, 2013 CFR

2013-04-01

... ORTHOPEDIC DEVICES General Provisions § 888.6 Degree of constraint. Certain joint prostheses provide more... affecting the safety and effectiveness of orthopedic prostheses. FDA is defining the following standard...

21 CFR 888.6 - Degree of constraint.

Code of Federal Regulations, 2011 CFR

2011-04-01

... ORTHOPEDIC DEVICES General Provisions § 888.6 Degree of constraint. Certain joint prostheses provide more... affecting the safety and effectiveness of orthopedic prostheses. FDA is defining the following standard...

21 CFR 888.6 - Degree of constraint.

Code of Federal Regulations, 2014 CFR

2014-04-01

... ORTHOPEDIC DEVICES General Provisions § 888.6 Degree of constraint. Certain joint prostheses provide more... affecting the safety and effectiveness of orthopedic prostheses. FDA is defining the following standard...

21 CFR 888.6 - Degree of constraint.

Code of Federal Regulations, 2012 CFR

2012-04-01

... ORTHOPEDIC DEVICES General Provisions § 888.6 Degree of constraint. Certain joint prostheses provide more... affecting the safety and effectiveness of orthopedic prostheses. FDA is defining the following standard...

Detection of total hip prostheses at airport security checkpoints: how has heightened security affected patients?

PubMed

Johnson, Aaron J; Naziri, Qais; Hooper, Hasan A; Mont, Michael A

2012-04-04

The sensitivity of airport security screening measures has increased substantially during the past decade, but few reports have examined how this affects patients who have undergone hip arthroplasty. The purpose of this study was to determine the experiences of patients who had hip prostheses and who passed through airport security screenings. A consecutive series of 250 patients who presented to the office of a high-volume surgeon were asked whether they had had a hip prosthesis for at least one year and, if so, whether they had flown on a commercial airline within the past year. Patients who responded affirmatively to both questions were asked to complete a written survey that included questions about which joint(s) had been replaced, the number of encounters with airport security, the frequency and location of metal detector activation, any additional screening procedures that were utilized, whether security officials requested documentation regarding the prosthesis, the degree of inconvenience, and other relevant information. Of the 143 patients with hip replacements who traveled by air, 120 (84%) reported triggering the alarm and required wanding with a handheld detector. Twenty-five of these patients reported subsequently having to undergo further inspection, including additional wanding, being patted down, and in two cases having to undress in a private room to show the incision. Ninety-nine (69%) of the 143 patients reported that the prosthetic joint caused an inconvenience while traveling. This study provides interesting and critical information that allows physicians to understand the real-world implications of implanted orthopaedic devices for patients who are traveling where there has been heightened security since September 11, 2001. Patients should be counseled that they should expect delays and be prepared for such inconveniences, but that these are often only momentary. This information could relieve some anxiety and concerns that patients may have prior to traveling.

Total Knee Replacement

PubMed Central

2005-01-01

Executive Summary Objective The aim of this review was to assess the effectiveness, in terms of pain reduction and functional improvement, and costing of total knee replacement (TKR) for people with osteoarthritis for whom less invasive treatments (such as physiotherapy, analgesics, anti-inflammatory drugs, intra-articular steroids, hyaluronic acids, and arthroscopic surgery) have failed. Clinical Need Osteoarthritis affects an estimated 10% to 12% of Canadian adults. The therapeutic goals of osteoarthritis treatment are to improve joint mobility and reduce pain. Stepwise treatment options include exercise, weight loss, physiotherapy, analgesics, anti-inflammatory drugs, intra-articular steroids and hyaluronic acids, arthroscopic surgery, and, in severe cases, total joint replacement with follow-up rehabilitation. These treatments are delivered by a range of health care professionals, including physiotherapists, occupational therapists, family physicians, internists, rheumatologists, and orthopedic surgeons. TKR is an end-of-line treatment for patients with severe pain and functional limitations. More women than men undergo knee replacement, and most patients are between 55 and 84 years old. The Technology TKR is a surgical procedure in which an artificial joint or prosthesis replaces a damaged knee joint. The primary indication for TKR is pain, followed by functional limitation. Usually, a person’s daily activities must be substantially affected by pain and functional limitations for him or her to be considered a candidate for TKR. There are 3 different types of knee replacement prostheses. Non-constrained prostheses use the patient’s ligaments and muscles to provide the stability for the prosthesis. Semi-constrained prostheses provide some stability for the knee and do not rely entirely on the patient’s ligaments and muscles to provide the stability. Constrained prostheses are for patients whose ligaments and muscles are not able to provide stability for the knee prosthesis. The most common risks and complications associated with TKR are deep venous thrombosis, infection, stiffness, loosening, and osteolysis. To prevent deep venous thrombosis, patients are treated with heparin prophylactically and/or given support stockings to wear. Patients are also given antibiotics for 24 hours after surgery to minimize the risk of infection. Stiffness is another associated complication. In most patients, it can be avoided by keeping the knee moving in the days and weeks following surgery. The National Institutes of Health in the United States concluded that the indications for TKR should include the following: radiological evidence of joint damage, moderate to severe persistent pain that is not adequately relieved by nonsurgical management, and clinically significant functional limitation resulting in diminished quality of life. Review Strategy In March 2005, the following databases were searched: Cochrane Library International Agency for Health Technology Assessment (first quarter 2005), Cochrane Database of Systematic Reviews (first quarter 2005), Cochrane Central Register of Controlled Trials (first quarter 2005), MEDLINE (1966 to March 2005), MEDLINE In-Process and Other Non-indexed Citations (1966 to March 14, 2005), and EMBASE (1980 to 2005 week 9). The Medical Advisory Secretariat also searched Medscape on the Internet for recent reports on trials that were unpublished but that were presented at international conferences. In addition, the Web site Current Controlled Trials (www.controlled-trials.com) was searched for ongoing trials investigating TKR or unicompartmental knee replacement. No studies were identified that compared TKR to an alternative treatment. Several studies have been reported that compare preoperative measurement scores on targeted measures of functioning and pain to postoperative measurement scores in patients undergoing various TKR procedures. In order for the Medical Advisory Secretariat to measure the effectiveness of TKR and to compare the effectiveness of TKR across studies, effect sizes were calculated in studies that reported the standard deviations of the preoperative and postoperative measurement scores. Percent change was also calculated. For this review, a 20% improvement in outcome score was defined as the minimal clinically important difference. Summary of Findings Overall, patients who undergo TKR surgery for osteoarthritis have substantial improvements in terms of reduction of pain and improvement of function. A comparison of the mean effect score and the percent change in 19 studies that reported preoperative and postoperative outcome scores for patients who had TKR showed that the procedure is effective. The 19 studies included patients of various ages and used a variety of prostheses and techniques to implant the device. TKR was effective in all of the studies. The revision rates ranged from 0% to 13% in the studies that reported at least 5 years of follow-up. As for the factors that predict TKR outcomes, a variety of factors have been evaluated, including obesity, age, gender, prosthesis design, and surgical techniques; however, none of these have been shown to predict outcomes (pain or function) consistently across studies. However, the regression analyses identified accounted for only 12% to 27% of the variance, indicating that over 70% of the variance in the outcomes of TKR is unexplained. In terms of the timing of TKR surgery, 2 studies found that the severity of osteoarthritis does not predict outcome, but 1 study was found that higher functioning patients had significantly less pain and better function up to 2 years after surgery compared with lower functioning patients. It is important to note that the patients in the low and high function groups were evenly matched on comorbid conditions. Unicompartmental knee replacement surgery seems to be as effective as TKR surgery for people who meet the indications for it. This is a subset of people who have osteoarthritis of the knee, because for unicompartmental knee replacement to be indicated, only 1 (usually the medial) compartment of the knee can be affected. Patients who undergo this kind of surgery seem to have shorter hospital stays and faster recovery times than do patients who have TKR surgery. Conclusion There is substantial evidence to indicate that TKR effectively reduces pain and improves function. PMID:23074478

Late dislocation of rotating platform in New Jersey Low-Contact Stress knee prosthesis.

PubMed

Huang, Chun-Hsiung; Ma, Hon-Ming; Liau, Jiann-Jong; Ho, Fang-Yuan; Cheng, Cheng-Kung

2002-12-01

Five patients with late rotational dislocation of the rotating platform bearing in the New Jersey Low-Contact Stress total knee arthroplasty are reported. The prostheses had functioned well for 8 to 12 years before failure. Preoperative radiographs showed asymmetric femorotibial joint spaces. Entrapment of the dislocated bearing in three patients and spontaneous reduction of the dislocated bearing in another two patients were seen at revision. Femorotibial ligamentous instability was found after reduction. The retrieved polyethylene bearings showed advanced wear and cold flow deformities and the thickness was reduced. The revision arthroplasty was accomplished by replacement with a thicker bearing element. Progressive femorotibial ligament laxity and reduction of the thickness of polyethylene with wearing break down the originally well-balanced soft tissue tension of the knee. The rotational degree of the rotating platform bearing is unrestricted, which may result in late dislocation. Polyethylene wear is unavoidable in knee prostheses using metal contact with polyethylene even with a mobile-bearing design. Efforts to reduce polyethylene wear are mandatory.

Cancer risk among patients with finger and hand joint and temporo-mandibular joint prostheses in Denmark.

PubMed

Fryzek, J P; Mellemkjaer, L; McLaughlin, J K; Blot, W J; Olsen, J H

1999-05-31

The use of artificial joint implants has risen greatly over the past years. However, few investigations of the cancer risk associated with implants have been performed. We investigated cancer risk in patients with finger and hand joint and temporo-mandibular (TMJ) joint implants. A nationwide cohort in Denmark of patients with finger and hand joint prostheses (n = 858) or TMJ implants (n = 389) was followed from January 1, 1977, to December 31, 1995, to evaluate any potential cancer risks subsequent to receiving these implants. Standardized incidence ratios (SIRs) for all cancers were 1.0 (95% CI = 0.8-1.2) for the finger and hand joint cohort and 1.1 (95% CI = 0.8-1.7) for the TMJ cohort. A significant risk for non-Hodgkin's lymphoma was found in the finger and hand joint cohort (SIR = 3.8, 95% CI = 1.5-7.8). When the finger and hand joint cohort was stratified by diagnosis of rheumatoid arthritis, the excess risk was seen only in the group with rheumatoid arthritis. This is consistent with past studies, which have found an association between rheumatoid arthritis and non-Hodgkin's lymphoma. Our results provide evidence that the cancer risk for patients with finger and hand joint prostheses and TMJ implants is similar to that for the general population.

Materials testing protocol for small joint prostheses.

PubMed

Savory, K M; Hutchinson, D T; Bloebaum, R

1994-10-01

In this article, a protocol for the evaluation of new materials for small joint prostheses is introduced. The testing methods employed in the protocol were developed by reviewing reported clinical failure modes and conditions found in vivo. The methods developed quantitatively evaluates the fatigue, fatigue crack propagation, and wear resistance properties of materials. For this study, a silicone elastomer similar to Dow Corning Silastic HP100, a radiation stable polypropylene, and a copolymer of polypropylene and ethylene propylene-diene monomer (EPDM) are evaluated. None of the materials tested demonstrated the ideal properties that are sought in a self-hinging joint prostheses. The silicone elastomer had excellent wear properties; however, cracks quickly propagated, causing catastrophic failure when fatigued. Conversely, the copolymer showed excellent fatigue crack propagation resistance and less than favorable wear properties. The polypropylene did not perform well in any evaluation.

Current evaluation of hydraulics to replace the cable force transmission system for body-powered upper-limb prostheses.

PubMed

LeBlanc, M

1990-01-01

Present body-powered upper-limb prostheses use a cable control system employing World War II aircraft technology to transmit force from the body to the prosthesis for operation. The cable and associated hardware are located outside the prosthesis. Because individuals with arm amputations want prostheses that are natural looking with a smooth, soft outer surface, a design and development project was undertaken to replace the cable system with hydraulics located inside the prosthesis. Three different hydraulic transmission systems were built for evaluation, and other possibilities were explored. Results indicate that a hydraulic force transmission system remains an unmet challenge as a practical replacement for the cable system. The author was unable to develop a hydraulic system that meets the necessary dynamic requirements and is acceptable in size and appearance.

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

Wear properties of alumina/zirconia composite ceramics for joint prostheses measured with an end-face apparatus.

PubMed

Morita, Yusuke; Nakata, Kenichi; Kim, Yoon-Ho; Sekino, Tohru; Niihara, Koichi; Ikeuchi, Ken

2004-01-01

While only alumina is applied to all-ceramic joint prostheses at present, a stronger ceramic is required to prevent fracture and chipping due to impingement and stress concentration. Zirconia could be a potential substitute for alumina because it has high strength and fracture toughness. However, the wear of zirconia/zirconia combination is too high for clinical use. Although some investigations on composite ceramics revealed that mixing of different ceramics was able to improve the mechanical properties of ceramics, there are few reports about wear properties of composite ceramics for joint prosthesis. Since acetabular cup and femoral head of artificial hip joint are finished precisely, they indicate high geometric conformity. Therefore, wear test under flat contact was carried out with an end-face wear testing apparatus for four kinds of ceramics: alumina monolith, zirconia monolith, alumina-based composite ceramic, and zirconia based composite ceramic. Mean contact pressure was 10 MPa and sliding velocity was 40 mm/s. The wear test continued for 72 hours and total sliding distance was 10 km. After the test, the wear factor was calculated. Worn surfaces were observed with a scanning electron micrograph (SEM). The results of this wear test show that the wear factors of the both composite ceramics are similarly low and their mechanical properties are much better than those of the alumina monolith and the zirconia monolith. According to these results, it is predicted that joint prostheses of the composite ceramics are safer against break down and have longer lifetime compared with alumina/alumina joint prostheses.

Alternatives to amputation.

PubMed Central

Lendrum, J.

1980-01-01

Alternatives to conventional skin flap cover for limb wounds extend both the number and type of defects which can now be closed with reconstruction of both form and function for patients who might otherwise come to amputation. The old adage that where a sinus leads to dead or foreign material it can only be closed after removal of that dead or foreign material is no longer true. The number of patients coming to above-knee amputation after prosthetic replacement of the knee joint could be reduced by muscle flap cover of exposed arthroplasty prostheses. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 PMID:7377695

Access to Breast Prostheses via a Government-Funded Service in Victoria, Australia: Experience of Women and Service Providers

ERIC Educational Resources Information Center

Livingston, Patricia M.; White, Victoria; Roberts, Susan; Pritchard, Emma; Gibbs, Anne; Hill, David J.

2003-01-01

For many women, the only alternative to breast reconstruction following a mastectomy is to use external prostheses, which need replacing regularly at a cost of up to $395 per prosthesis. Commonwealth and state governments across Australia have responded to this need by providing subsidies to assist in the purchase of breast prostheses. However,…

Identification of overlengthening after replacement of the radial head with a bipolar prosthesis.

PubMed

Wegmann, K; Lamsfuss, J; Ries, C; Neiss, W F; Franklin, J; Müller, L P; Burkhart, K J

2015-12-01

Overlengthening of the radial column leads to insufficient functionality and increased capitellar wear. Methods to detect or prevent overlengthening have been described for monopolar prostheses. The aim of this study was to evaluate whether one such method described by Athwal et al. is also applicable for a bipolar prosthesis. The radial heads of six fresh frozen upper extremities were resected. A bipolar radial head prosthesis was implanted in each, and the effects of sequential overlengthening on the alignment of the radiocapitellar and ulnohumeral joint line were recorded by fluoroscopic images. Digital image analysis and estimation of overlengthening followed according to the method described by Athwal et al. Statistical analysis of the estimated and actual differences between the native state and bipolar replacement of the radial head with stepwise overlengthening of 1.5, 3, 4.5, and 6 mm showed a specificity of 86 % but consistently underestimated the amount of overlengthening with a sensitivity of only 61 %. The method described by Athwal et al. for the identification of overlengthening by a monopolar prosthesis was not found to be reliable for ruling out or quantifying overlengthening of the tested bipolar prosthesis. However, the use of the method to detect (rule in) overlengthening may be acceptable in certain circumstances. A reliable method for postoperative quantification of overlengthening by bipolar prostheses has still to be found.

An economic model to evaluate cost-effectiveness of computer assisted knee replacement surgery in Norway.

PubMed

Gøthesen, Øystein; Slover, James; Havelin, Leif; Askildsen, Jan Erik; Malchau, Henrik; Furnes, Ove

2013-07-06

The use of Computer Assisted Surgery (CAS) for knee replacements is intended to improve the alignment of knee prostheses in order to reduce the number of revision operations. Is the cost effectiveness of computer assisted surgery influenced by patient volume and age? By employing a Markov model, we analysed the cost effectiveness of computer assisted surgery versus conventional arthroplasty with respect to implant survival and operation volume in two theoretical Norwegian age cohorts. We obtained mortality and hospital cost data over a 20-year period from Norwegian registers. We presumed that the cost of an intervention would need to be below NOK 500,000 per QALY (Quality Adjusted Life Year) gained, to be considered cost effective. The added cost of computer assisted surgery, provided this has no impact on implant survival, is NOK 1037 and NOK 1414 respectively for 60 and 75-year-olds per quality-adjusted life year at a volume of 25 prostheses per year, and NOK 128 and NOK 175 respectively at a volume of 250 prostheses per year. Sensitivity analyses showed that the 10-year implant survival in cohort 1 needs to rise from 89.8% to 90.6% at 25 prostheses per year, and from 89.8 to 89.9% at 250 prostheses per year for computer assisted surgery to be considered cost effective. In cohort 2, the required improvement is a rise from 95.1% to 95.4% at 25 prostheses per year, and from 95.10% to 95.14% at 250 prostheses per year. The cost of using computer navigation for total knee replacements may be acceptable for 60-year-old as well as 75-year-old patients if the technique increases the implant survival rate just marginally, and the department has a high operation volume. A low volume department might not achieve cost-effectiveness unless computer navigation has a more significant impact on implant survival, thus may defer the investments until such data are available.

Clinical Results of 40 Consecutive Basal Thumb Prostheses and No CRPS Type I After Vitamin C Prophylaxis.

PubMed

Zollinger, Paul E; Unal, Halil; Ellis, Maarten L; Tuinebreijer, Wim E

2010-02-17

Complex regional pain syndrome (CRPS) type I may occur as complication after any type of surgery for basal joint arthritis of the thumb. We investigated prospectively in an ongoing study our results after a fully standardized treatment with a total joint prosthesis under vitamin C prophylaxis.Patients with trapeziometacarpal arthritis stage II or III according to Dell, and no benefit from conservative treatment, were selected to undergo joint replacement with a semi-constrained hydroxyapatite coated prosthesis.First web opening and visual analogue scale (VAS) scores for pain, activities of daily living (ADL) and satisfaction were taken pre and postoperatively. Vitamin C 500 mg daily was started two days prior to surgery during 50 days as prevention for CRPS. Post-operative treatment was functional.We performed 40 implantations for trapeziometacarpal arthritis in 34 patients (mean age 60.8 years; 27 females, 7 males) with a mean follow-up of 44 months. Operations were performed in day care under regional (or general) anesthesia.First web opening increased with 15.4 degrees and there was a significant improvement for pain, ADL and satisfaction as well (p = 0.000). Patient satisfaction was strongly associated with the amount of pain reduction. According to the Veldman and IASP criteria, there were no cases of CRPS.The overall complication rate for this procedure is high. Literature reports 5 cases of CRPS after 38 operations with the same implant (13%). We advise vitamin C as prophylaxis against CRPS in trapeziometacarpal joint replacement.

Design and energetic evaluation of a prosthetic knee joint actuator with a lockable parallel spring.

PubMed

Geeroms, J; Flynn, L; Jimenez-Fabian, R; Vanderborght, B; Lefeber, D

2017-02-03

There are disadvantages to existing damping knee prostheses which cause an asymmetric gait and higher metabolic cost during level walking compared to non-amputees. Most existing active knee prostheses which could benefit the amputees use a significant amount of energy and require a considerable motor. In this work, a novel semi-active actuator with a lockable parallel spring for a prosthetic knee joint has been developed and tested. This actuator is able to provide an approximation of the behavior of a healthy knee during most of the gait cycle of level walking. This actuator is expanded with a series-elastic actuator to mimic the full gait cycle and enable its use in other functional tasks like stair climbing and sit-to-stance. The proposed novel actuator reduces the energy consumption for the same trajectory with respect to a compliant or directly-driven prosthetic active knee joint and improves the approximation of healthy knee behavior during level walking compared to passive or variable damping knee prostheses.

Wear Distribution Detection of Knee Joint Prostheses by Means of 3D Optical Scanners

PubMed Central

Affatato, Saverio; Valigi, Maria Cristina; Logozzo, Silvia

2017-01-01

The objective of this study was to examine total knee polyethylene inserts from in vitro simulation to evaluate and display—using a 3D optical scanner—wear patterns and wear rates of inserts exposed to wear by means of simulators. Various sets of tibial inserts have been reconstructed by using optical scanners. With this in mind, the wear behavior of fixed and mobile bearing polyethylene knee configurations was investigated using a knee wear joint simulator. After the completion of the wear test, the polyethylene menisci were analyzed by an innovative 3D optical scanners in order to evaluate the 3D wear distribution on the prosthesis surface. This study implemented a new procedure for evaluating polyethylene bearings of joint prostheses obtained after in vitro wear tests and the proposed new approach allowed quantification of the contact zone on the geometry of total knee prostheses. The results of the present study showed that mobile TKPs (total knee prosthesis) have lower wear resistance with respect to fixed TKPs. PMID:28772725

CAD-CAM-generated hydroxyapatite scaffold to replace the mandibular condyle in sheep: preliminary results.

PubMed

Ciocca, Leonardo; Donati, Davide; Fantini, Massimiliano; Landi, Elena; Piattelli, Adriano; Iezzi, Giovanna; Tampieri, Anna; Spadari, Alessandro; Romagnoli, Noemi; Scotti, Roberto

2013-08-01

In this study, rapid CAD-CAM prototyping of pure hydroxyapatite to replace temporomandibular joint condyles was tested in sheep. Three adult animals were implanted with CAD-CAM-designed porous hydroxyapatite scaffolds as condyle substitutes. The desired scaffold shape was achieved by subtractive automated milling machining (block reduction). Custom-made surgical guides were created by direct metal laser sintering and were used to export the virtual planning of the bone cut lines into the surgical environment. Using the same technique, fixation plates were created and applied to the scaffold pre-operatively to firmly secure the condyles to the bone and to assure primary stability of the hydroxyapatite scaffolds during masticatory function. Four months post-surgery, the sheep were sacrificed. The hydroxyapatite scaffolds were explanted, and histological specimens were prepared. Different histological tissues penetrating the scaffold macropores, the sequence of bone remodeling, new apposition of bone and/or cartilage as a consequence of the different functional anatomic role, and osseointegration at the interface between the scaffold and bone were documented. This animal model was found to be appropriate for testing CAD-CAM customization and the biomechanical properties of porous, pure hydroxyapatite scaffolds used as joint prostheses.

Fiber-reinforced composite fixed dental prostheses: two clinical reports.

PubMed

Zarow, Maciej; Paisley, Carl Stuart; Krupinski, Jerzy; Brunton, Paul Anthony

2010-06-01

Various options are available in clinical practice for the replacement of a single missing tooth, ranging from conventional fixed and removable dental prostheses to a single implant-supported crown. There are situations in which a semipermanent fixed dental prosthesis may be desirable, particularly for patients who have completed orthodontic treatment but are too young to embark on implant therapy. Following advances in fiber-reinforcement technology, fiber-reinforced composite resin (FRC) now represents a lower-cost alternative to traditional metal-ceramic for the construction of resin-bonded prostheses. Two case reports illustrate the use of FRC prostheses as fixed semipermanent_restorations.

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.

Detection of occult infection following total joint arthroplasty using sequential technetium-99m HDP bone scintigraphy and indium-111 WBC imaging

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

Johnson, J.A.; Christie, M.J.; Sandler, M.P.

1988-08-01

Preoperative exclusion or confirmation of periprosthetic infection is essential for correct surgical management of patients with suspected infected joint prostheses. The sensitivity and specificity of (/sup 111/In)WBC imaging in the diagnosis of infected total joint prostheses was examined in 28 patients and compared with sequential (/sup 99m/Tc)HDP/(/sup 111/In)WBC scintigraphy and aspiration arthrography. The sensitivity of preoperative aspiration cultures was 12%, with a specificity of 81% and an accuracy of 58%. The sensitivity of (/sup 111/In)WBC imaging alone was 100%, with a specificity of 50% and an accuracy of 65%. When correlated with the bone scintigraphy and read as sequential (/supmore » 99m/Tc)HDP/(/sup 111/In)WBC imaging, the sensitivity was 88%, specificity 95%, and accuracy 93%. This study demonstrates that (/sup 111/In)WBC imaging is an extremely sensitive imaging modality for the detection of occult infection of joint prostheses. It also demonstrates the necessity of correlating (/sup 111/In)WBC images with (/sup 99m/Tc)HDP skeletal scintigraphy in the detection of occult periprosthetic infection.« less

Are critical pathways and implant standardization programs effective in reducing costs in total knee replacement operations?

PubMed

Ho, David M; Huo, Michael H

2007-07-01

Total knee replacement (TKR) operation is one of the most effective procedures, both clinically and in terms of cost. Because of increased volume and cost for this procedure during the past 3 decades, TKRs are often targeted for cost reduction. The purpose of this study was to evaluate the efficacy of two cost reducing methodologies, establishment of critical clinical pathways, and standardization of implant costs. Ninety patients (90 knees) were randomly selected from a population undergoing primary TKR during a 2-year period at a tertiary teaching hospital. Patients were assigned to three groups that corresponded to different strategies implemented during the evolution of the joint-replacement program. Medical records were reviewed for type of anesthesia, operative time, length of stay, and any perioperative complications. Financial information for each patient was compared among the three groups. Data analysis demonstrated that the institution of a critical pathway significantly shortened length of hospital stay and was effective in reducing the hospital costs by 18% (p < 0.05). In addition, standardization of surgical techniques under the care of a single surgeon substantially reduced the operative time. Selection of implants from a single vendor did not have any substantial effect in additionally reducing the costs. Standardized postoperative management protocols and critical clinical pathways can reduce costs and operative time. Future efforts must focus on lowering the costs of the prostheses, particularly with competitive bidding or capitation of prostheses costs. Although a single-vendor approach was not effective in this study, it is possible that a cost reduction could have been realized if more TKRs were performed, because the pricing contract was based on projected volume of TKRs to be done by the hospital.

What is the evidence base to guide surgical treatment of infected hip prostheses? systematic review of longitudinal studies in unselected patients

PubMed Central

2012-01-01

Background Prosthetic joint infection is an uncommon but serious complication of hip replacement. There are two main surgical treatment options, with the choice largely based on the preference of the surgeon. Evidence is required regarding the comparative effectiveness of one-stage and two-stage revision to prevent reinfection after prosthetic joint infection. Methods We conducted a systematic review to identify randomised controlled trials, systematic reviews and longitudinal studies in unselected patients with infection treated exclusively by one- or two-stage methods or by any method. The Embase, MEDLINE and Cochrane databases were searched up to March 2011. Reference lists were checked, and citations of key articles were identified by using the ISI Web of Science portal. Classification of studies and data extraction were performed independently by two reviewers. The outcome measure studied was reinfection within 2 years. Data were combined to produce pooled random-effects estimates using the Freeman-Tukey arc-sine transformation. Results We identified 62 relevant studies comprising 4,197 patients. Regardless of treatment, the overall rate of reinfection after any treatment was 10.1% (95% CI = 8.2 to 12.0). In 11 studies comprising 1,225 patients with infected hip prostheses who underwent exclusively one-stage revision, the rate of reinfection was 8.6% (95% CI = 4.5 to 13.9). After two-stage revision exclusively in 28 studies comprising 1,188 patients, the rate of reinfection was 10.2% (95% CI = 7.7 to 12.9). Conclusion Evidence of the relative effectiveness of one- and two-stage revision in preventing reinfection of hip prostheses is largely based on interpretation of longitudinal studies. There is no suggestion in the published studies that one- or two stage methods have different reinfection outcomes. Randomised trials are needed to establish optimum management strategies. PMID:22340795

Alloplastic temporomandibular joint replacement systems: a systematic review of their history.

PubMed

De Meurechy, N; Mommaerts, M Y

2018-06-01

This systematic review provides an overview of the historical evolution of the prosthetic temporomandibular joint and addresses the challenges and complications faced by engineers and surgeons, in an effort to shed light on why only a few systems remain available. A better understanding of the history of temporomandibular joint prostheses might also provide insights into the origin of the negative public opinion of the prosthesis, which is based on outdated information. A computerized search using the PubMed Central, ScienceDirect, Wiley Online, Ovid, and Cochrane Library databases was performed following the PRISMA guidelines. Out of 7122 articles identified, 41 met the inclusion criteria for this systematic review. Although several historical reviews have been published previously, none has covered such an extensive time period or has described all designs. Furthermore, besides providing a historical overview, this review discusses the rationale behind the evolution in design and biomaterials, which have largely contributed to the outcomes of the prosthetic systems. Copyright © 2018 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Development of an above-knee prosthesis equipped with a microcomputer-controlled knee joint: first test results.

PubMed

Aeyels, B; Peeraer, L; Vander Sloten, J; Van der Perre, G

1992-05-01

The shortcomings of conventional above-knee prostheses are due to their lack of adaptive control. Implementation of a microcomputer controlling the knee joint in a passive way has been suggested to enhance the patient's gait comfort, safety and cosmesis. This approach was used in the design of a new prosthetic system for the above-knee amputee, and tested on one patient. The knee joint of a conventional, modular prosthesis was replaced by a knee joint mechanism, equipped with a controllable brake on the knee joint axis. Sensors and a microcomputer were added, keeping the system self-contained. The modularity of the design permits the use of an alternative, external, PC-based control unit, emulating the self-contained one, and offering extended data monitoring and storage facilities. For both units an operating environment was written, including sensor/actuator interfacing and the implementation of a real-time interrupt, executing the control algorithm. A double finite state approach was used in the design of the control algorithm. On a higher level, the mode identification algorithm reveals the patient's intent. Within a specific mode (lower level), the relevant mode control algorithm looks for the current phase within the gait cycle. Within a particular phase, a specific simple control action with the brake replaces normal knee muscle activity. Tests were carried out with one prosthetic patient using a basic control algorithm for level walking, allowing controlled knee flexion during stance phase. The technical feasibility of such a concept is illustrated by the test results, even though only flexion during early stance phase was controlled during the trials.(ABSTRACT TRUNCATED AT 250 WORDS)

Femoro-tibial kinematics after TKA in fixed- and mobile-bearing knees in the sagittal plane.

PubMed

Daniilidis, Kiriakos; Höll, Steffen; Gosheger, Georg; Dieckmann, Ralf; Martinelli, Nicolo; Ostermeier, Sven; Tibesku, Carsten O

2013-10-01

Lack of the anterior cruciate ligament in total knee arthroplasty results in paradoxical movement of the femur as opposed to the tibia under deep flexion. Total knee arthroplasty with mobile-bearing inlays has been developed to provide increased physiological movement of the knee joint and to reduce polyethylene abrasion. The aim of this study was to perform an in vitro analysis of the kinematic movement in the sagittal plane in order to show differences between fixed- and mobile-bearing TKA in comparison with the natural knee joint. Seven knee joints of human cadaver material were used in a laboratory experiment. Fixed- and mobile-bearing inlays were tested in sequences under isokinetic extension in so-called kinemator for knee joints, which can simulate muscular traction power by the use of hydraulic cylinders, which crossover the knee joint. As a target parameter, the a.p. translation of the tibio-femoral relative movement was measured in the sagittal plane under ultrasound (Zebris) control. The results show a reduced tibial a.p. translation in relation to the femur in the bearing group compared to the natural joint. In the Z-axis, between 110° and 50° of flexion, linear movement decreases towards caudal movement under extension. Admittedly, the study did not show differences in the movement pattern between "mobile-bearing" and "fixed-bearing" prostheses. Results of this study cannot prove functional advantages of mobile-bearing prostheses for the knee joint kinematic after TKA. Both types of prostheses show typical kinematics of an anterior instability, hence they were incapable of performing physiological movement.

Haemodynamic results of replacement of mitral and aortic valves with autologous fascia lata prostheses

PubMed Central

Talavlikar, P. H.; Walbaum, P. R.; Kitchin, A. H.

1973-01-01

Twelve patients undergoing aortic and 28 undergoing mitral valve replacement with autologous fascia lata valves were studied before and six months after surgery. One aortic and 10 mitral valves were found to be significantly incompetent. Of the incompetent mitral valves, two appeared to have perivalvular leaks. Six of the remainder were associated with abnormal ventricular filling patterns. Valve failure was much less common when the design was modified to provide a loose cusp structure; out of 12 such valves none was incompetent. Transvalvular gradients persist with fascial valves though they are lower than with most mechanical prostheses. Ventricular function was greatly improved in successful aortic replacement but remained impaired in the case of mitral replacement. Valve failure appeared to be associated with, or accelerated by, haemodynamic stress rather than due to inevitable degenerative pathological processes. PMID:4731108

Biomechanics principle of elbow joint for transhumeral prostheses: comparison of normal hand, body-powered, myoelectric & air splint prostheses.

PubMed

Abd Razak, Nasrul Anuar; Abu Osman, Noor Azuan; Gholizadeh, Hossein; Ali, Sadeeq

2014-09-10

Understanding of kinematics force applied at the elbow is important in many fields, including biomechanics, biomedical engineering and rehabilitation. This paper provides a comparison of a mathematical model of elbow joint using three different types of prosthetics for transhumeral user, and characterizes the forces required to overcome the passive mechanical of the prosthetics at the residual limb. The study modeled the elbow as a universal joint with intersecting axes of x-axis and y-axis in a plain of upper arm and lower arm. The equations of force applied, torque, weight and length of different type of prosthetics and the anthropometry of prosthetics hand are discussed in this study. The study also compares the force, torque and pressure while using all three types of prosthetics with the normal hand. The result was measured from the elbow kinematics of seven amputees, using three different types of prosthetics. The F-Scan sensor used in the study is to determine the pressure applied at the residual limb while wearing different type of prostheses. These technological advances in assessment the biomechanics of an elbow joint for three different type of prosthetics with the normal hand bring the new information for the amputees and prosthetist to choose the most suitable device to be worn daily.

What are estimated reimbursements for lower extremity prostheses capable of surgical and nonsurgical lengthening?

PubMed

Henderson, Eric R; Pepper, Andrew M; Letson, G Douglas

2012-04-01

Growing prostheses accommodate skeletally immature patients with bone tumors undergoing limb-preserving surgery. Early devices required surgical procedures for lengthening; recent devices lengthen without surgery. Expenses for newer expandable devices that lengthen without surgery are more than for their predecessors but overall reimbursement amounts are not known. We sought to determine reimbursement amounts associated with lengthening of growing prostheses requiring surgical and nonsurgical lengthening. We retrospectively reviewed 17 patients with growing prostheses requiring surgical expansion and eight patients with prostheses capable of nonsurgical expansion. Insurance documents were reviewed to determine the reimbursement for implantation, lengthening, and complications. Growth data were obtained from the literature. Mean reimbursement amounts of surgical and nonsurgical lengthenings were $9950 and $272, respectively. Estimated reimbursements associated with implantation of a growing prosthesis varied depending on age, sex, and location. The largest difference was found for 4-year-old boys with distal femoral replacement where reimbursement for expansion to maturity for surgical and nonsurgical lengthening prostheses would be $379,000 and $208,000, respectively. For children requiring more than one surgical expansion, net reimbursements were lower when a noninvasive lengthening device was used. Annual per-prosthesis maintenance reimbursements to address complications for surgical and nonsurgical lengthening prostheses were $3386 and $1856, respectively. This study showed that reimbursements for lengthening of growing endoprostheses capable of nonsurgical expansion may be less expensive in younger patients, particularly male patients undergoing distal femur replacement, than endoprostheses requiring surgical lengthening. Longer outcomes studies are required to see if reimbursements for complications differ between devices. Level III, economic and decision analysis. See the Guidelines for Authors for a complete description of levels of evidence.

Dental claims in the Swedish Patient Insurance Scheme.

PubMed

René, N; Owall, B; Cronström, R

1991-06-01

The Swedish Patient Insurance Scheme covers treatment injuries and guarantees the replacement of failed removable prostheses for 1 year and fixed prostheses for 2 years after fitting. In this paper, 573 dental cases are analysed for a 3-month period in 1986, during which crowns and bridges formed the vast majority of failed treatments that were reported.

Do modern total knee replacements offer better value for money? A health economic analysis.

PubMed

Hamilton, David F; Clement, Nicholas D; Burnett, Richard; Patton, James T; Moran, Mathew; Howie, Colin R; Simpson, A H R W; Gaston, Paul

2013-11-01

Cost effectiveness is an increasingly important factor in today's healthcare environment, and selection of arthroplasty implant is not exempt from such concerns. Quality adjusted life years (QALYs) are the typical tool for this type of evaluation. Using this methodology, joint arthroplasty has been shown to be cost effective; however, studies directly comparing differing prostheses are lacking. Data was gathered in a single-centre prospective double-blind randomised controlled trial comparing the outcome of modern and traditional knee implants, using the Short Form 6 dimensional (SF-6D) score and quality adjusted life year (QALY) methodology. There was significant improvement in the SF-6D score for both groups at one year (p < 0.0001). The calculated overall life expectancy for the study cohort was 15.1 years, resulting in an overall QALY gain of 2.144 (95% CI 1.752-2.507). The modern implant group demonstrated a small improvement in SF-6D score compared to the traditional design at one year (0.141 versus 0.143, p = 0.94). This difference resulted in the modern implant costing £298 less per QALY at one year. This study demonstrates that modern implant technology does not influence the cost-effectiveness of TKA using the SF-6D and QALY methodology. This type of analysis however assesses health status, and is not sensitive to joint specific function. Evolutionary design changes in implant technology are thus unlikely to influence QALY analysis following joint replacement, which has important implications for implant procurement.

A Powered Prosthetic Intervention for Bilateral Transfemoral Amputees

PubMed Central

Lawson, Brian E.; Ruhe, Brian; Shultz, Amanda; Goldfarb, Michael

2014-01-01

This paper presents the design and validation of a control system for a pair of powered knee and ankle prostheses to be used as a prosthetic intervention for bilateral transfemoral amputees. The control system leverages communication between the prostheses for enhanced awareness and stability, along with power generation at the knee and ankle joints to better restore biomechanical functionality in level ground walking. The control methodology employed is a combination of an impedance-based framework for weight-bearing portions of gait and a trajectory-based approach for the non-weight-bearing portions. The control system was implemented on a pair of self-contained powered knee and ankle prostheses, and the ability of the prostheses and control approach to provide walking functionality was assessed in a set of experimental trials with a bilateral transfemoral amputee subject. Specifically, experimental data from these trials indicate that the powered prostheses and bilateral control architecture provide gait kinematics that reproduce healthy gait kinematics to a greater extent than the subject’s daily-use passive prostheses. PMID:25014950

[Synovial fluid from aseptically failed total hip or knee arthroplasty is not toxic to osteoblasts].

PubMed

Gallo, J; Zdařilová, A; Rajnochová Svobodová, A; Ulrichová, J; Radová, L; Smižanský, M

2010-10-01

A failure of total hip or knee artroplasty is associated with an increased production of joint fluid. This contains wear particles and host cells and proteins, and is assumed to be involved in the pathogenesis of aseptic loosening and periprosthetic osteolysis. This study investigated the effect of synovial fluid from patients with aseptically failed joint prostheses on osteoblast cultures. Synovial fluid samples were obtained from patients with failed total joint prostheses (TJP; n=36) and from control patient groups (n = 16) involving cases without TJP and osteoarthritis, without TJP but with osteoarthritis, and with stable TJP. The samples were treated in the standard manner and then cultured with the SaOS-2 cell line which shows the characteristics and behaviour of osteoblasts. Each fluid sample was also examined for the content of proteins, cells and selected cytokines (IL-1ß, TNF-α, IL-6, RANKL and OPG detected by ELISA). We tested the hypothesis assuming that the fluids from failed joints would show higher cytotoxicity to osteoblast culture and we also expected higher levels of IL-1ß, TNF-α, IL-6, and RANKL in patients with TJP failure and/ or with more severe bone loss. The statistical methods used included the Kruskal-Wallis ANOVA and Mann-Whitney U test. The fluids from failed TJPs showed the highest RANKL and the lowest OPG levels resulting in the highest RANKL/OPG ratio. However, there was no evidence suggesting that the joint fluids from failed TJPs would be more toxic to osteoblast culture than the fluids from control groups. In addition, no correlation was found between the fluid levels of molecules promoting inflammation and osteoclastic activity and the extent of bone loss in the hip (in terms of Saleh's classification) or the knee (AORI classification). In fact, the fluids from failed TJPs had higher protein levels in comparison with the controls, but the difference was not significant. The finding of high RANKL levels and low OPG concentrations is in agreement with the theory of aseptic loosening and periprosthetic osteolysis. The other cytokines, particularly TNF-α and IL-1ß, were found in low levels. This can be explained by the stage of particle disease at which the samples were taken for ELISA analysis. It is probable that the level of signal molecules reflects osteolytic process activity and is therefore not constant. The reason for no correlation found between cytokine levels and the extent of bone loss may also lie in the use of therapeutic classifications of bone defects that is apparently less sensitive to the biological activity of aseptic loosening and/or periprosthetic osteolysis. Synovial fluids from failed total hip or knee joint prostheses are not toxic to osteoblast cultures. Cytotoxicity indicators and levels of pro-inflammatory and pro-osteoclastic cytokines (IL-1ß, TNF-α, IL-6, RANKL and OPG) do not correlate well with the extent of periprosthetic bone loss. Key words: total joint replacement, arthroplasty, aseptic loosening, periprosthetic osteolysis, joint fluid, SaOS-2 cell line, cytotoxicity, cytokines, RANKL, OPG.

21 CFR 888.3535 - Knee joint femorotibial (uni-compartmental) metal/polymer porous-coated uncemented prosthesis.

Code of Federal Regulations, 2014 CFR

2014-04-01

... across-the-joint. This generic type of device is designed to achieve biological fixation to bone without the use of bone cement. This identification includes fixed-bearing knee prostheses where the ultra...

21 CFR 888.3535 - Knee joint femorotibial (uni-compartmental) metal/polymer porous-coated uncemented prosthesis.

Code of Federal Regulations, 2013 CFR

2013-04-01

... across-the-joint. This generic type of device is designed to achieve biological fixation to bone without the use of bone cement. This identification includes fixed-bearing knee prostheses where the ultra...

21 CFR 888.3535 - Knee joint femorotibial (uni-compartmental) metal/polymer porous-coated uncemented prosthesis.

Code of Federal Regulations, 2012 CFR

2012-04-01

... across-the-joint. This generic type of device is designed to achieve biological fixation to bone without the use of bone cement. This identification includes fixed-bearing knee prostheses where the ultra...

21 CFR 888.3535 - Knee joint femorotibial (uni-compartmental) metal/polymer porous-coated uncemented prosthesis.

Code of Federal Regulations, 2011 CFR

2011-04-01

... across-the-joint. This generic type of device is designed to achieve biological fixation to bone without the use of bone cement. This identification includes fixed-bearing knee prostheses where the ultra...

21 CFR 888.3535 - Knee joint femorotibial (uni-compartmental) metal/polymer porous-coated uncemented prosthesis.

Code of Federal Regulations, 2010 CFR

2010-04-01

... across-the-joint. This generic type of device is designed to achieve biological fixation to bone without the use of bone cement. This identification includes fixed-bearing knee prostheses where the ultra...

Friction in hip prostheses.

PubMed

Hall, R M; Unsworth, A

1997-08-01

Although the reduction of frictional torques was the driving force behind the design of the Charnley prosthesis, later concerns about wear and subsequent loosening of this and other hip replacements have dominated debate within the bioengineering community. To stimulate discussion on the role of friction in loosening, a review of the frictional characteristics of different prostheses was undertaken. The use of simple laboratory screening-type machines in the frictional assessment of different material combinations is discussed together with experiments performed on single axis simulators using both conventional and experimental prostheses. In particular, recent developments in the use of soft layer components are highlighted. Further, the possible link between excessively high frictional torques and loosening is discussed in the light of current results obtained from explanted prostheses.

Bone Repair and Military Readiness

DTIC Science & Technology

2012-10-25

formation. Orthopedic surgeons have had to adapt surgical techniques to account for issues with cementing total joint prostheses and subsequent total joint ...the silorane composite has the potential to support osseous integration around the cemented total joint implant and may generate less immunogenic wear...factors, and potential for osseointegration/osseoinduction, this material has potential to be used for screw augmentation, total hip/knee joint

Comparative Study Between M6-C and Mobi-C Cervical Artificial Disc Replacement: Biomechanical Outcomes and Comparison with Normative Data.

PubMed

Pham, My; Phan, Kevin; Teng, Ian; Mobbs, Ralph J

2018-05-01

Cervical spondylosis affects a huge proportion of the middle-aged population. Degenerative changes can occur in multiple regions of the cervical spine typically affecting the joints, intervertebral discs and endplates. These changes lead to compression of adjacent nervous structures, which results in radiculopathic and myelopathic pain. Various treatment modalities are currently available with non-surgical approaches the initial go to if there is no symptomatic cord compression. Anterior cervical discectomy and fusion, or arthroplasty are the two common surgical approaches if non-surgical treatments fail to relieve symptoms of the patients or there are signs of central cord compression. However, studies have shown that there is an increased risk of adjacent segment disease related to fusion. Cervical disc arthroplasty aims to restore normal range of motion (ROM) in patients with pain and disability due to degenerative disc disease resistant to conservative care. Two common disc prostheses used include M6-C and Mobi-C. Both prostheses comprise a mobile polymer segment sandwiched between two metal endplates with mechanisms resembling an actual intervertebral disc. This study aims to compare the kinematics associated with these prostheses, against the normal range of motion in the non-degenerative population. Patients who underwent M6-C or Mobi-C disc replacements by the senior author from 2012 to 2015 were identified at a single tertiary institution. Routine 3-month postoperative lateral radiographs were analyzed for flexion and extension ROM angles at the involved vertebral level by two independent authors. Data was compared to previous published studies investigating cervical spine ROM of asymptomatic patients. There was no statistical significance in the difference of overall flexion range between M6-C and Mobi-C prostheses. However, overall range of extension of Mobi-C was greater compared to M6-C (P = 0.028). At C 5-6 , the range of flexion for both implants were similar but lesser compared to asymptomatic patients (P < 0.001). Range of extension was greater in the Mobi-C group (14.2° ± 5.1°) compared to the M6-C (7.3° ± 4.6°) (P = 0.0009). At C 6-7 , there were no statistical differences in both range of flexion and extension between the two prostheses and asymptomatic patients (P > 0.05). The early results regarding restoration of ROM following cervical arthroplasty using either M6-C or Mobi-C prosthesis are encouraging. Long-term follow-up studies are necessary to observe the change in ROM over time with physiological loading and wear patterns. © 2018 Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.

The impact of surface and geometry on coefficient of friction of artificial hip joints.

PubMed

Choudhury, Dipankar; Vrbka, Martin; Mamat, Azuddin Bin; Stavness, Ian; Roy, Chanchal K; Mootanah, Rajshree; Krupka, Ivan

2017-08-01

Coefficient of friction (COF) tests were conducted on 28-mm and 36-mm-diameter hip joint prostheses for four different material combinations, with or without the presence of Ultra High Molecular Weight Polyethylene (UHMWPE) particles using a novel pendulum hip simulator. The effects of three micro dimpled arrays on femoral head against a polyethylene and a metallic cup were also investigated. Clearance played a vital role in the COF of ceramic on polyethylene and ceramic on ceramic artificial hip joints. Micro dimpled metallic femoral heads yielded higher COF against a polyethylene cup; however, with metal on metal prostheses the dimpled arrays significantly reduced the COF. In situ images revealed evidence that the dimple arrays enhanced film formation, which was the main mechanism that contributed to reduced friction. Copyright © 2017 Elsevier Ltd. All rights reserved.

Results after mitral valve replacement with cloth-covered Starr-Edwards prostheses (models 6300, 6310/6320, and 6400).

PubMed Central

Forman, R; Beck, W; Barnard, C N

1978-01-01

The actuarial survival and thromboembolic rates for the three types of cloth-covered Starr-Edwards mitral prostheses, models 6300, 6310/6320, and 6400 followed 6, 5, and 2 years, respectively, were not significantly different throughout the years they were followed. The combined cumulative survival and thromboembolic proportion at 5 years for these prostheses were 71 and 66 per cent, respectively. The thromboembolic rates were not different in the following two groups: (a) 238 patients receiving anticoagulants, and (b) 52 patients who had discontinued or who were not receiving anticoagulants. Four patients thrombosed their mitral prostheses. Another 8 per cent had class 3 symptoms after operation, which were attributed to myopathic or restrictive left ventricular dysfunction or other valvular disease. PMID:656234

Preservation of kinematics with posterior cruciate-, bicruciate- and patient-specific bicruciate-retaining prostheses in total knee arthroplasty by using computational simulation with normal knee model

PubMed Central

Koh, Y-G.; Son, J.; Kwon, S-K.; Kim, H-J.; Kang, K-T.

2017-01-01

Objectives Preservation of both anterior and posterior cruciate ligaments in total knee arthroplasty (TKA) can lead to near-normal post-operative joint mechanics and improved knee function. We hypothesised that a patient-specific bicruciate-retaining prosthesis preserves near-normal kinematics better than standard off-the-shelf posterior cruciate-retaining and bicruciate-retaining prostheses in TKA. Methods We developed the validated models to evaluate the post-operative kinematics in patient-specific bicruciate-retaining, standard off-the-shelf bicruciate-retaining and posterior cruciate-retaining TKA under gait and deep knee bend loading conditions using numerical simulation. Results Tibial posterior translation and internal rotation in patient-specific bicruciate-retaining prostheses preserved near-normal kinematics better than other standard off-the-shelf prostheses under gait loading conditions. Differences from normal kinematics were minimised for femoral rollback and internal-external rotation in patient-specific bicruciate-retaining, followed by standard off-the-shelf bicruciate-retaining and posterior cruciate-retaining TKA under deep knee bend loading conditions. Moreover, the standard off-the-shelf posterior cruciate-retaining TKA in this study showed the most abnormal performance in kinematics under gait and deep knee bend loading conditions, whereas patient-specific bicruciate-retaining TKA led to near-normal kinematics. Conclusion This study showed that restoration of the normal geometry of the knee joint in patient-specific bicruciate-retaining TKA and preservation of the anterior cruciate ligament can lead to improvement in kinematics compared with the standard off-the-shelf posterior cruciate-retaining and bicruciate-retaining TKA. Cite this article: Y-G. Koh, J. Son, S-K. Kwon, H-J. Kim, O-R. Kwon, K-T. Kang. Preservation of kinematics with posterior cruciate-, bicruciate- and patient-specific bicruciate-retaining prostheses in total knee arthroplasty by using computational simulation with normal knee model. Bone Joint Res 2017;6:557–565. DOI: 10.1302/2046-3758.69.BJR-2016-0250.R1. PMID:28947604

Limitations of titanium dioxide and aluminum oxide as ossicular replacement materials: an evaluation of the effects of porosity on ceramic prostheses.

PubMed

Trabandt, Nicolaus; Brandes, Gudrun; Wintermantel, Erich; Lenarz, Thomas; Stieve, Martin

2004-09-01

Because the performance of titanium dioxide (TiO2) has not yet been assessed in the unique environment of the middle ear, its role as an ossicular replacement prototype in the form of a total ossicular replacement prosthesis (TORP) was tested and compared with aluminum oxide (Al2O3), once considered to be a suitable implant material. Ossiculoplasty was performed by implanting TORPs into the tympanic cavities of rabbits. After an implantation period of 28, 84, or 300 days, the petrous bones were extracted, whereby the biocompatibility of the prostheses was examined using light microscopy and scanning electron microscopy to determine morphologic changes in situ. Proper implant placement and functionality was tested via manual manipulation. Mucosa was seen covering most of the implants by day 84. Inflammatory cells were not observed in any of the specimens examined. The macroporous TiO2 TORPs were subjected to osseous infiltration, material dissolution, and fragmentation, whereas the microporous TiO2 implants were subjected to an increasing frequency of fissure formations. The Al2O3 prostheses demonstrated signs of material dissolution by producing encapsulated aggregates during the experimental trial period. Neither the macroporous nor microporous oxide ceramics were able to withstand the oscillatory stress to which they were continually subjected. Although porosity allows for the rapid integration of an implant material into a biological environment, its properties are not suited to fulfill the requirements of strength and long-term stability, which are demanded of middle ear prostheses.

The development of artificial organs and prostheses worldwide and in the Ottoman Empire.

PubMed

Birdane, Leman; Cingi, Cemal; Elçioğlu, Ömür; Muluk, Nuray Bayar

2016-08-01

An artificial organ or prosthesis is a man-made device that is implanted or integrated into a human to replace a natural organ. There were many historical steps in the development of artificial organs and prostheses. New surgical techniques, the development of prosthetic materials and the creative ideas of engineers led to progress in this field. © The European Society of Cardiology 2014.

The effect of adhesive strength of hydroxyapatite coating on the stability of hydroxyapatite-coated prostheses in vivo at the early stage of implantation

PubMed Central

Duan, Yonghong; Zhu, Shu; Guo, Fei; Zhu, Jinyu; Li, Mao; Ma, Jie

2012-01-01

Introduction With the increase in joint revision surgery after arthroplasty, defects of hydroxyapatite (HA)-coated prostheses have been observed increasingly often. These defects adversely affect the prosthetic stability in vivo. This study has analyzed the potential effect of the adhesive strength of HA coating on the stability of HA-coated prostheses in vivo after its implantation. Material and methods Sixty experimental rabbits were divided into HA- and Ti-coated groups. HA-coated prostheses were implanted into the bilateral epicondyle of rabbits femurs. Ti-coated prostheses were implanted as control. At different time points(4, 9, and 15 weeks) after implantation, bone tissue samples were fetched out respectively for histomorphometric analysis. Push-out testing was used to detect the ultimate shear strength at the bone-prosthesis interface. Scanning electron microscope (SEM) observation and energy-dispersive X-ray spectroscopy (EDX) analysis were used to observe the changes in surface composition of the prostheses after the ultimate shear strength testing. The coating adhesive strength of two kinds of coatings were also examined by scratch testing. Results Hydroxyapatite coating has an obvious advantage in facilitating osteogenesis and its plays a critical role in the stability of prostheses. However, the ultimate shear strength of HA-coated prostheses is much lower than that of Ti-coated implants (p < 0.01). Further study has demonstrated that the stability of HA-coated prostheses in vivo is affected by the relatively low adhesive strength between coating and substrate. Conclusions Obvious advantage in facilitating osteogenesis around HA-coated prostheses is not the only factor that determines the stability of prostheses in vivo. PMID:22661990

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.

Is there a need for routine follow-up after primary total hip arthroplasty?

PubMed

Hacking, Craig; Weinrauch, Patrick; Whitehouse, Sarah L; Crawford, Ross W; Donnelly, William J

2010-10-01

The objective of routine outpatient assessment of well-functioning patients after primary total hip arthroplasty (THA) is to detect asymptomatic failure of prostheses to guide recommendations for early intervention. We have observed that the revision of THAs in asymptomatic patients is highly uncommon. We therefore question the need for routine follow-up of patients after THA. A prospective analysis of an orthopaedic database identified 158 patients who received 177 revision THAs over a four-year period. A retrospective chart review was conducted. Patient demographics, primary and revision surgery parameters and follow-up information were recorded and cross-referenced with Australian Orthopaedic Association National Joint Replacement Registry data. One hundred ten THAs in 104 patients (average age 70.4 (SD 9.8 years)). There were 70 (63.6%) in total, 13 (11.8%) femoral and 27 (24.5%) acetabular revisions. The indications for revision were aseptic loosening (70%), dislocation (8.2%), peri-prosthetic fracture (7.3%), osteolysis (6.4%) and infection (4.5%). Only four (3.6%) were asymptomatic revisions. A mean of 5.3 (SD 5.2 and 1.9 (SD 5.3)) follow-up appointments were required before revision in patients with and without symptoms, respectively. The average time from the primary to revision surgery was 11.8 (SD 7.23) years. We conclude that patients with prostheses with excellent long-term clinical results as validated by joint registries, routine follow-up of asymptomatic THA should be questioned and requires further investigation. Based on the work of this study, the current practice of routine follow-up of asymptomatic THA may be excessively costly and unnecessary, and a less resource-intensive review method may be more appropriate. © 2010 The Authors. ANZ Journal of Surgery © 2010 Royal Australasian College of Surgeons.

Leaflet escape in a new bileaflet mechanical valve: TRI technologies.

PubMed

Bottio, Tomaso; Casarotto, Dino; Thiene, Gaetano; Caprili, Luca; Angelini, Annalisa; Gerosa, Gino

2003-05-13

Leaflet escape is a mode of structural valve failure for mechanical prostheses. This complication previously has been reported for both monoleaflet and bileaflet valve models. We report 2 leaflet escape occurrences observed in 2 patients who underwent valve replacement with a TRI Technologies valve prosthesis. At the University of Padua, between November 2000 and February 2002, 36 TRI Technologies valve prostheses (26 aortic and 10 mitral) were implanted in 34 patients (12 women and 22 men) with a mean age of 59.9+/-10.3 years (range, 30 to 75 years). There were 5 deaths: 3 in hospital, 1 early after discharge, and 1 late. Two patients experienced a catastrophic prosthetic leaflet escape; the first patient was a 52-year-old man who died 10 days after aortic valve and ascending aorta replacement, and the second was a 58-year-old man who underwent a successful emergency reoperation 20 months after mitral valve replacement. Examination of the explanted prostheses showed in both cases a leaflet escape caused by a leaflet's pivoting system fracture. Prophylactic replacement was then successfully accomplished so far in 12 patients, without evidence of structural valve failure in any of them. Among other significant postoperative complications, we observed 3 major thromboembolisms, 1 hemorrhage, and 1 paravalvular leak. These catastrophes prompted us to interrupt the implantation program, and they cast a shadow on the durability of the TRI Technologies valve prosthesis because of its high risk of structural failure.

Wear simulation of total knee prostheses using load and kinematics waveforms from stair climbing.

PubMed

Abdel-Jaber, Sami; Belvedere, Claudio; Leardini, Alberto; Affatato, Saverio

2015-11-05

Knee wear simulators are meant to perform load cycles on knee implants under physiological conditions, matching exactly, if possible, those experienced at the replaced joint during daily living activities. Unfortunately, only conditions of low demanding level walking, specified in ISO-14243, are used conventionally during such tests. A recent study has provided a consistent knee kinematic and load data-set measured during stair climbing in patients implanted with a specific modern total knee prosthesis design. In the present study, wear simulation tests were performed for the first time using this data-set on the same prosthesis design. It was hypothesised that more demanding tasks would result in wear rates that differ from those observed in retrievals. Four prostheses for total knee arthroplasty were tested using a displacement-controlled knee wear simulator for two million cycles at 1.1 Hz, under kinematics and load conditions typical of stair climbing. After simulation, the corresponding damage scars on the bearings were qualified and compared with equivalent explanted prostheses. An average mass loss of 20.2±1.5 mg was found. Scanning digital microscopy revealed similar features, though the explant had a greater variety of damage modes, including a high prevalence of adhesive wear damage and burnishing in the overall articulating surface. This study confirmed that the results from wear simulation machines are strongly affected by kinematics and loads applied during simulations. Based on the present results for the full understanding of the current clinical failure of knee implants, a more comprehensive series of conditions are necessary for equivalent simulations in vitro. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparison of mechanical and biological prostheses when used to replace heart valves in children and adolescents with rheumatic fever.

PubMed

Travancas, Paulo R; Dorigo, Ana H; Simões, Luiz C; Fonseca, Sandra C; Bloch, Kátia V; Herdy, Gesmar V

2009-04-01

To assess the outcomes in children and adolescents with rheumatic fever of the implantation of mechanical as opposed to biological heart valves. We assessed 73 patients with rheumatic heart disease under the age of 18 years, who underwent replacement of heart valves between January, 1996, and December, 2005, at the National Institute of Cardiology in Rio de Janeiro, Brazil. Of the group, 71 patients survived, and were divided into a group of 52 receiving mechanical prostheses, and 19 with biological prostheses. We compared endpoints between the groups in terms of mortality, reoperation, haemorrhage, and stroke. Survival curves were estimated using the Kaplan-Meier method and were compared by the Mantel (log-rank) test. Overall mortality was 8.2%. In those receiving mechanical prostheses, 2 (3.8%) patients died, 5 (9.6%) underwent reoperation, 2 (3.8%) suffered severe haemorrhage, and 3 (5.8%) had strokes. In those receiving biological valves, 2 (10.5%) patients died, and 4 (21%) underwent reoperation. After 2, 4, and 8 years, overall survival was 96%, 93% and 86%, respectively, with a borderline difference between the groups (p = 0.06). The probabilities of remaining free from reoperation (p = 0.13), and from combined endpoints, showed no statistically significant difference between the groups (p = 0.28). Patients with mechanical prostheses had lower mortality and required fewer reoperations, but when all combined endpoints were considered, the groups did not differ. The biological prosthesis proved to be a good option for cardiac surgery in children and adolescents with difficulties or risks of anticoagulation.

Evaluation of a commercial multiplex PCR (Unyvero i60®) designed for the diagnosis of bone and joint infections using prosthetic-joint sonication.

PubMed

Prieto-Borja, Laura; Rodriguez-Sevilla, Graciela; Auñon, Alvaro; Pérez-Jorge, Concepción; Sandoval, Enrique; Garcia-Cañete, Joaquín; Gadea, Ignacio; Fernandez-Roblas, Ricardo; Blanco, Antonio; Esteban, Jaime

2017-04-01

The development of sonication protocols over the last few years has improved the sensitivity of conventional cultures for the diagnosis of prosthetic-joint infection (PJI). However, the development of a new, specifically designed kit for the molecular diagnosis of PJI could provide a major improvement in this field. Prostheses retrieved from patients who underwent implant removal from May 2014 to May 2015 were sent for culture, and processed according to a previously defined protocol that included sonication. Furthermore, 180 microlitres of sonication fluid were used to carry out the multiplex PCR test (Unyvero i60 system ® ). A comparison of the sensitivity, specificity, positive (PPV) and negative (NPV) predictive value, was performed. The study was approved by the Clinical Research Ethics Committee. The analysis included 88 prostheses from 68 patients (1.29 prostheses/patient). The type of prostheses studied were knee (n=55), total hip (n=26), partial hip (n=5), and shoulder (n=2). Twenty-nine patients were diagnosed with a PJI (15 delayed, 12 acute, and 2 haematogenous infections). In 24 cases, the result of the PCR was positive, all but 1 corresponding to patients with clinical criteria of PJI. Nine resistance mechanisms were detected from 5 samples. The Unyvero i60 system ® showed slightly better results than traditional culture in terms of specificity and PPV. The Unyvero i60 system ® may play a role in rapid diagnosis of PJI, due to its high specificity and PPV. However, despite these results, cultures have to be performed to detect organisms not detected by the system. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

[Total Joint Replacement and Return to Sports].

PubMed

Oehler, N; Schmidt, T; Niemeier, A

2016-12-01

Background: An increasing number of physically active patients not only need to know if they will basically be able to engage in sports after undergoing arthroplasty. They also would like to know whether or not they will be able to resume their preoperative activity levels. This article aims to provide an overview of recent data regarding the following questions on hip, knee and shoulder arthroplasty: (1) What is the impact of physical activity on an endoprosthesis? (2) What level of sports can be achieved after an arthroplasty procedure? (3) What types of sport are recommended for patients with an endoprosthesis? Methods: PubMed-based review of the literature. Narrative review focusing on current data from the years 2010 to 2016. Results: The commonly known recommendation to exercise low-impact sports such as hiking, swimming, cycling or golf at a moderate intensity remains valid for all types of prostheses in all joints. There is broad consensus that the benefits of these sports outweigh the negative effects. Having undergone total hip or knee arthroplasty, most patients with a high preoperative activity level return to sports after 3-6 months, albeit with a clear tendency to lower intensity and a shift from high-impact to low-impact sports. Some key questions have to be answered regarding the effects of low-impact sports that are exercised with high intensity, the effects resulting from high-impact sports, effects specific to different types of sport, and possibilities provided by different prosthesis types. In this context, a lot remains to be done to investigate the limits between positive and negative effects resulting from physical activity of varying intensity. New data suggests that generally a higher physical performance level may be achieved than has been traditionally recommended. Early results of unicondylar knee prostheses are far better than those achieved with bicondylar prostheses. In contrast to expert recommendations, shoulder endoprostheses show the highest postoperative activity levels after inverted arthroplasty, followed by anatomic arthroplasty, and the lowest activity level after the implantation of a hemiprosthesis. Conclusion: There is a significant discrepancy between previous expert recommendations and the actual activity levels that may be achieved after the implantation of a joint prosthesis. Future studies have to define the sports level, the type of sports and the type of prosthesis that provide a positive benefit-risk ratio using state-of-the-art low-abrasion bearing surfaces and prosthesis designs. © Georg Thieme Verlag KG Stuttgart · New York.

Sensitivity of biomechanical outcomes to independent variations of hindfoot and forefoot stiffness in foot prostheses.

PubMed

Adamczyk, Peter Gabriel; Roland, Michelle; Hahn, Michael E

2017-08-01

Many studies have reported the effects of different foot prostheses on gait, but most results cannot be generalized because the prostheses' properties are seldom reported. We varied hindfoot and forefoot stiffness in an experimental foot prosthesis, in increments of 15N/mm, and tested the parametric effects of these variations on treadmill walking in unilateral transtibial amputees, at speeds from 0.7 to 1.5m/s. We computed outcomes such as prosthesis energy return, center of mass (COM) mechanics, ground reaction forces, and joint mechanics, and computed their sensitivity to component stiffness. A stiffer hindfoot led to reduced prosthesis energy return, increased ground reaction force (GRF) loading rate, and greater stance-phase knee flexion and knee extensor moment. A stiffer forefoot resulted in reduced prosthetic-side ankle push-off and COM push-off work, and increased knee extension and knee flexor moment in late stance. The sensitivity parameters obtained from these tests may be useful in clinical prescription and further research into compensatory mechanisms of joint function. Copyright © 2017 Elsevier B.V. All rights reserved.

Titanium as a biomaterial for ossicular replacement: results after implantation in the middle ear of the rabbit.

PubMed

Schwager, K

1998-01-01

The middle ear poses unique challenges when finding suitable materials for ossicular reconstruction, primarily because of its link to the external environment via the eustachian tube and, hence, its greater exposure to infectious agents. In this study, the biocompatability of titanium was examined in the middle ear of rabbits by using light and scanning electron microscopy. Implants were placed as middle ear prostheses or as free implants. These were inspected at 28 days, 84 days, 168 days, 336 days and 504 days following implantation for mucosal coverage, percent epithelization and any sign of foreign-body reaction. After 28 days, the prostheses were covered by regular mucosa. Although a majority of the free implants took up to 336 days for complete epithelialization, some of the free implants were not epithelialized even at day 504. There were no inflammatory cells observed on the surface of the material, nor were unusual amounts of fibrous tissue seen. In addition, the titanium material exhibited an affinity toward bone. The results of this animal experiment indicate that titanium is a favorable material for ossicular replacement prostheses.

Biodeterioration of medical-grade silicone rubber used for voice prostheses: a SEM study.

PubMed

Neu, T R; Van der Mei, H C; Busscher, H J; Dijk, F; Verkerke, G J

1993-05-01

Silicone voice prostheses used for rehabilitation of speech after total laryngectomy are inserted in an non-sterile habitat. Deposits on explanted Groningen Button voice prostheses revealed a biofilm, due to heavy colonization of the silicone surface by bacteria and yeasts. Furthermore, it was demonstrated by scanning electron microscopy on sectioned explants that the silicone material was deteriorated by filamentous and vegetative yeast cells. The different explants showed a variety of sharp-edged, discrete yeast colonies. The yeasts grew just under the silicone surface and up to 700 microns into the silicone material. Finally, nine different types of defects in the silicone material created by the yeasts are described. This deterioration of the silicone by yeasts seems to be the main reason for the failure and the frequent replacement of the prostheses. The mechanisms of silicone deterioration are still hypothetical.

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.

In vitro leakage susceptibility of tracheoesophageal shunt prostheses in the absence and presence of a biofilm.

PubMed

Oosterhof, Janine J H; van der Mei, Henny C; Busscher, Henk J; Free, Rolien H; Kaper, Hans J; van Weissenbruch, Ranny; Albers, Frans W J

2005-04-01

Although leakage through a tracheoesophageal shunt prosthesis is the main cause of prosthesis failure in a laryngectomy patient, this has never been the subject of in vitro evaluation. The aim of this study was to compare three commercially available voice prostheses by comparison of their in vitro leakage patterns, in absence or presence of a biofilm. To compare in vitro leakage patterns, a model comprised of an artificial throat equipped with a single prosthesis coupled to a water reservoir was developed. By varying the height of the water reservoir, different pressures on the voice prosthesis can be obtained. Both in absence and presence of a biofilm, the Blom Singer voice prosthesis demonstrated the lowest leakage, followed by Groningen Low Resistance. The Provox2 showed significantly the most leakage, however, in presence of a biofilm the leakage of the Provox2 significantly decreased. Regular airflow during biofilm formation significantly increased leakage through the Provox2. Out of 746 clinical replacements, Provox2 showed 76% and Groningen Low Resistance 57% replacements due to leakage. The model used in this study showed significant differences in leakage of the three types of voice prostheses used. Leakage occurred more readily through Provox2 than through Groningen Low Resistance and Blom Singer prostheses, which is in line with clinical observations and enforces the model. (c) 2005 Wiley Periodicals, Inc.

[Rehabilitation by hollow obturator prosthesis immediately after total maxillectomy for malignant tumor].

PubMed

Li, Xiao-ye; Yan, Ai-hui; Hao, Shuai; Li, Wei; Jiang, Xue-jun; Lu, Li; Qin, Xing-jun; Yan, Hai-xin

2011-05-01

The feasibility and clinical effects of hollow obturator prosthesis for the repair of maxillofacial defect immediately after maxillectomy for cancer were assessed. Thirteen patients with T3-4aN0M0 maxillary neoplasm were treated by the prostheses immediately after maxillectomy. According to the 3D-CT reconstruction of nasal sinus, the 3D stereoscopic prototype was constructed before the surgery. Simulating surgery with Surgicare 5.0 software and then the prosthesis 3D stereoscopic model was shaped. The prosthesis was made quickly and precisely with methacrylate resins according to the model and the print mold before surgery, with supplementary tooth at the bottom of prosthesis. In the surgery, the prosthesis was installed instantly after maxillectomy. The patients were followed up at 1, 3 and 6 month after the surgery, respectively. The facial features and the pronunciation clarity were examined and the questionnaires were carried out in the patients, with comparation by paired t-test. The hollow obturator prosthesis would be replaced by permanent prosthesis made of methacrylate resins at 6 month after the surgery. The hollow obturator prostheses were installed accurately and maxillofacial defects were repaired immediately after maxillectomy in the 13 patients. Postoperative follow-up showed there were significant differences in eyeball sagging (t = 4.67, P < 0.05), mid-facial region collapse (t = 5.67, P < 0.05), and pronunciation clarity (t = 16.38, P < 0.05) between patients with and without prostheses. Questionnaires showed that all the patients were satisfied with the retention of prostheses, the improvement of appearance, the improvement of the symptom of water choking and speech definition. Six months after the surgery, the hollow obturator prostheses were replaced smoothly by permanent prostheses in 11 of the 13 patients. The precise and instant repair of maxillofacial defect by prosthesis after maxillectomy can improve survival quality of patient.

Tricuspid valve replacement with mechanical prostheses: Short and long-term outcomes.

PubMed

Rossello, Xavier; Muñoz-Guijosa, Christian; Mena, Elisabet; Camprecios, Marta; Mendez, Ana B; Borras, Xavier; Padro, Josep M

2017-09-01

Tricuspid valve replacement has been associated with high mortality and poor long-term outcomes. We report the preoperative risk factors associated with short and long-term outcomes following tricuspid valve replacement with mechanical prostheses. In 62 patients who underwent mechanical tricuspid valve replacement, clinical, laboratory, and echocardiographic findings were analyzed using both univariate and multivariate analyses to describe operative and long-term mortality. In our population (mean age 59 ± 9.7 years, 82.3% female), most common causes of tricuspid valve disease were rheumatic fever (69.4%) and functional regurgitation (19.4%). Operative and long-term mortality were 17.7 and 33.9%, respectively. Age, diabetes mellitus, and coronary artery disease were independently associated with increased long-term mortality. New York Heart Association (NYHA) class and right heart failure symptoms significantly improved during follow-up. In this series of mechanical tricuspid valve replacements in patients with predominately rheumatic heart disease, operative and long-term mortality were increased; however, survivors had significant improvement in their NYHA class and freedom from right heart failure symptoms. Three preoperative factors (age, diabetes mellitus, and coronary artery disease) were independently associated with long-term mortality. © 2017 Wiley Periodicals, Inc.

Influence of oral health condition on swallowing and oral intake level for patients affected by chronic stroke.

PubMed

Mituuti, Cláudia T; Bianco, Vinicius C; Bentim, Cláudia G; de Andrade, Eduardo C; Rubo, José H; Berretin-Felix, Giédre

2015-01-01

According to the literature, the occurrence of dysphagia is high in cases of stroke, and its severity can be enhanced by loss of teeth and the use of poorly fitting prostheses. To verify that the status of oral health influences the level of oral intake and the degree of swallowing dysfunction in elderly patients with stroke in chronic phase. Thirty elderly individuals affected by stroke in chronic phase participated. All subjects underwent assessment of their oral condition, with classification from the Functional Oral Intake Scale (FOIS) and nasoendoscopic swallowing assessment to classify the degree of dysphagia. The statistical analysis examined a heterogeneous group (HG, n=30) and two groups designated by the affected body part, right (RHG, n=8) and left (LHG, n=11), excluding totally dentate or edentulous individuals without rehabilitation with more than one episode of stroke. There was a negative correlation between the need for replacement prostheses and the FOIS scale for the HG (P=0.02) and RHG (P=0.01). Differences in FOIS between types of prostheses of the upper dental arch in the LHG (P=0.01) and lower dental arch in the RHG (P=0.04). A negative correlation was found between the number of teeth present and the degree of dysfunction in swallowing liquid in the LHG (P=0.05). There were differences in the performance in swallowing solids between individuals without prosthesis and those with partial prosthesis in the inferior dental arch (P=0.04) for the HG. The need for replacement prostheses, type of prostheses, and the number of teeth of elderly patients poststroke in chronic phase showed an association with the level of oral intake and the degree of oropharyngeal dysphagia.

Major trends in mobility technology research and development: overview of the results of the NSF-WTEC European study.

PubMed

Reinkensmeyer, David J; Bonato, Paolo; Boninger, Michael L; Chan, Leighton; Cowan, Rachel E; Fregly, Benjamin J; Rodgers, Mary M

2012-04-20

Mobility technologies, including wheelchairs, prostheses, joint replacements, assistive devices, and therapeutic exercise equipment help millions of people participate in desired life activities. Yet, these technologies are not yet fully transformative because many desired activities cannot be pursued or are difficult to pursue for the millions of individuals with mobility related impairments. This WTEC study, initiated and funded by the National Science Foundation, was designed to gather information on European innovations and trends in technology that might lead to greater mobility for a wider range of people. What might these transformative technologies be and how might they arise? Based on visits to leading mobility technology research labs in western Europe, the WTEC panel identified eight major trends in mobility technology research. This commentary summarizes these trends, which are then described in detail in companion papers appearing in this special issue.

Major trends in mobility technology research and development: Overview of the results of the NSF-WTEC European study

PubMed Central

2012-01-01

Mobility technologies, including wheelchairs, prostheses, joint replacements, assistive devices, and therapeutic exercise equipment help millions of people participate in desired life activities. Yet, these technologies are not yet fully transformative because many desired activities cannot be pursued or are difficult to pursue for the millions of individuals with mobility related impairments. This WTEC study, initiated and funded by the National Science Foundation, was designed to gather information on European innovations and trends in technology that might lead to greater mobility for a wider range of people. What might these transformative technologies be and how might they arise? Based on visits to leading mobility technology research labs in western Europe, the WTEC panel identified eight major trends in mobility technology research. This commentary summarizes these trends, which are then described in detail in companion papers appearing in this special issue. PMID:22520596

Childhood Cancer: Osteosarcoma

MedlinePlus

... either a bone graft (usually from a bone bank) or more often a special metal prosthesis (artificial ... risk of infection and fracture is higher with bank bone replacement and therefore metal prostheses are more ...

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.

[The long term (15 years) evolution after valvular replacement with mechanical prosthesis or bioprosthesis between the age of 60 and 70 years].

PubMed

Hanania, G; Michel, P L; Montély, J M; Warembourg, H; Nardi, O; Leguerrier, A; Agnino, A; Despins, P; Legault, B; Petit, H; Bouraindeloup, M

2004-01-01

the aim of this study was to document the choice between prosthesis and bioprosthesis in cases of valvular replacement during the seventh decade of life. a retrospective and cooperative study linking eleven cardiac surgical teams and five medical cardiology teams combined 497 subjects born between 1915 and 1925 (average age 64.4 years) who underwent aortic (313 cases) or mitral (184 cases) valvular replacement with mechanical prosthesis (259 cases) or bioprosthesis (238 cases). Information was collected at each centre during the year 2000 on the long term evolution (going back 15 years), in particular on the mortality, non-fatal complications linked to the valve, cardiac complications and extra-cardiac events. These results were subjected to statistical analysis. the operative mortality of this group was 4.8%. The 15 year survival was 46% for the aortic mechanical prostheses, 32% for the aortic bioprostheses (p=0.04). 34% for the mitral bioprostheses and 33% for the mitral mechanical prostheses. Events linked to the valve were more frequent for the mitral valvulopathies than for the aortic valves (49% vs 26%, p<0.001). The absence of events linked to the valve at 15 years was 69% for the aortic mechanical prostheses and 68% for the aortic bioprostheses. This was the case in only 57% of mitral mechanical prostheses and 36% of the mitral bioprostheses (p=0.11). Thromboembolic accidents were three times more frequent in the mitrals than in the aortics (11.5 vs 3.8%, p=0.002). Haemorrhage was four times more frequent for the mechanical prostheses than for the bioprostheses (7.7 vs 2%, p=0.01). The risk of degeneration for the aortic bioprostheses was 20% at 15 years, three times less so after 65 years of age (p=0.03). At 48% it was much higher in the mitral valves at 15 years with no significant difference before and after 65 years of age (p=0.3). the current life expectancy of subjects in their seventh decade is important. The greatly elevated risk of bioprosthesis degeneration in the mitral position does not allow this alternative to be advocated before 70 years of age. In the aortic position, this risk is elevated before 65 years of age. It is lower after 65 years old. Nevertheless, this means the risk of reoperation in certain octogenarians must be accepted, balanced with the linear risk of haemorrhagic accidents for which a future reduction is expected thanks to milder anticoagulation for aortic mechanical prostheses and anticoagulation autocontrol.

Total knee replacement with natural rollback.

PubMed

Wachowski, Martin Michael; Walde, Tim Alexander; Balcarek, Peter; Schüttrumpf, Jan Philipp; Frosch, Stephan; Stauffenberg, Caspar; Frosch, Karl-Heinz; Fiedler, Christoph; Fanghänel, Jochen; Kubein-Meesenburg, Dietmar; Nägerl, Hans

2012-03-20

A novel class of total knee replacement (AEQUOS G1) is introduced which features a unique design of the articular surfaces. Based on the anatomy of the human knee and differing from all other prostheses, the lateral tibial "plateau" is convexly curved and the lateral femoral condyle is posteriorly shifted in relation to the medial femoral condyle. Under compressive forces the configuration of the articular surfaces of human knees constrains the relative motion of femur and tibia in flexion/extension. This constrained motion is equivalent to that of a four-bar linkage, the virtual 4 pivots of which are given by the centres of curvature of the articulating surfaces. The dimensions of the four-bar linkage were optimized to the effect that constrained motion of the total knee replacement (TKR) follows the flexional motion of the human knee in close approximation, particularly during gait. In pilot studies lateral X-ray pictures have demonstrated that AEQUOS G1 can feature the natural rollback in vivo. Rollback relieves the load of the patello-femoral joint and minimizes retropatellar pressure. This mechanism should reduce the prevalence of anterior knee pain. The articulating surfaces roll predominantly in the stance phase. Consequently sliding friction is replaced by the lesser rolling friction under load. Producing rollback should minimize material wear due to friction and maximize the lifetime of the prosthesis. To definitely confirm these theses one has to wait for the long term results. Copyright © 2011 Elsevier GmbH. All rights reserved.

Estimation of appropriate lubricating film thickness in ceramic-on-ceramic hip prostheses

NASA Astrophysics Data System (ADS)

Tauviqirrahman, M.; Muchammad, Bayuseno, A. P.; Ismail, R.; Saputra, E.; Jamari, J.

2016-04-01

Artificial hip prostheses, consisting of femoral head and acetabular cup are widely used and have affected the lives of many people.However, the primary issue associated with the long term performance of hip prostheses is loosening induced by excessive wear during daily activity. Therefore, an effective lubrication is necessary to significantly decrease the wear. To help understand the lubricating performance of such typical hip joint prostheses, in the present paper a hydrodynamic lubrication model based on Reynolds equationwas introduced. The material pairs of ceramic acetabular cup against ceramic femoral head was investegated.The main aim of this study is to investigate of the effect of loading on the formation of lubricating film thickness.The model of a ball-in-socket configuration was considered assuming that the cup was stationary while the ball was to rotate at a steady angular velocityvarying loads.Based on simulation result, it was found that to promote fluid film lubrication and prevent the contacting components leading to wear, the film thickness of lubricant should be determined carefully based on the load applied. This finding may have useful implication in predicting the failure of lubricating synovial fluid film and wear generation in hip prostheses.

Incus replacement prostheses of hydroxylapatite in middle ear reconstruction.

PubMed

Wehrs, R E

1989-05-01

Hydroxylapatite is a calcium bioceramic that has the same chemical composition as living bone, Ca10 (PO4) 6 (OH) 2. Since 1970 it has been used as a material in reconstructive prostheses and augmentation of lost tissues in various surgical specialties including maxillofacial surgery, plastic surgery, otolaryngology, and orthopedics. For over 20 years the author has used autograft and homograft ossicles in tympanoplasty. These incudi have been modified into prostheses that were utilized in ossicular reconstruction. During this time two principle prostheses have evolved, the notched incus with short and long processes. The short process prosthesis is used with an intact stapes, whereas the notched incus with long process carries the sound pressure directly to the stapedial footplate. These prostheses have been successful in improving and maintaining hearing following tympanoplasty. Unfortunately, however, the use of human tissue has certain limitations: it is not readily accessible and has a limited shelf life. Furthermore, clinicians are wary of using homograft tissue as concern over the AIDS virus spreads. Therefore it was felt prudent to develop a manmade prosthesis that would as nearly as possible match the advantages of living bone. Hydroxylapetite most nearly met those qualifications.

Ankylosis of temporomandibular joints after mandibular distraction osteogenesis in patients with Nager syndrome: Report of two cases and literature review.

PubMed

Wu, Cheng Chun; Sakahara, Daisuke; Imai, Keisuke

2017-10-01

Nager syndrome, also known as Nager acrofacial dysostosis, was first described by Nager and de Reynier in 1948. The patients commonly present with micrognathia, and a preventive tracheostomy is necessary when there are symptoms of upper airway obstruction. Mandibular distraction osteogenesis is considered as an effective procedure, which not only improves micrognathia but also minimizes the chances of tracheostomy. However, mandibular distraction osteogenesis has some complications such as relapse, teeth injury, infection, and injury of the temporomandibular joints (TMJs). In this study, the author reported two patients with Nager syndrome who suffered from ankylosis of TMJs after mandibular distraction osteogenesis. In addition, a comprehensive literature review of post-distraction ankylosis of TMJs in patients with Nager syndrome was performed. Few studies demonstrated the condition of TMJs after mandibular distraction osteogenesis, and three studies were identified from the review. One study reported ankylosis of bilateral coronoid processes, in which coronoidectomies were necessary. Another study reported the use of prostheses to replace the ankylosed joints in a patient who had undergone many surgeries of the joints, such as gap arthroplasties, reconstructions with costochondral grafts, etc. One other study raised the concept of unloading the condyles during the mandibular distraction to prevent subsequent ankylosis. It seems that multiple factors are related to the ankylosis of TMJs after mandibular distraction osteogenesis in patients with Nager syndrome. Prevention of post-distraction ankylosis of the joints is important because the treatment is difficult and not always effective. We should conduct more studies about protection of the joints during mandibular distraction in the future. Copyright © 2017 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Disc erosion in Models 103 and 104 of Beall mitral valve prostheses

PubMed Central

Gómez, Ricardo; Verduras, María José; Lopez-Quintana, Alfonso; Riera, Luis; Zerolo, Ignacio; Martinez-Bordiu, Cristóbal

1981-01-01

Three cases of severe disc variance and erosion of the Teflon-disc Beall mitral valve prosthesis (Models 103 and 104) are reported. In two patients, the Beall mitral valves were excised and replaced with two Björk-Shiley mitral valves. The remaining patient did not survive, and at autopsy, the lens was found at the aortic bifurcation level. Because of this potentially lethal complication, careful follow-up of patients with Beall mitral valve prostheses (Models 103 and 104) is recommended. Images PMID:15216211

Treatment planning: implant-supported partial overdentures.

PubMed

Chee, Winston W L

2005-04-01

When multiple anterior teeth are missing, many options of replacement are available. Traditionally, the choice was between a fixed or removable prostheses. Today, with the predictability of dental implants, the options of tooth replacement range from removable partial dentures to implant-supported fixed prostheses. The choice of which restoration that will best provide occlusion and esthetics depends on multiple factors including the number and location of missing teeth, the residual ridge form in relation to the replacement teeth, the relationship of the maxillary and mandibular anterior teeth, the condition of teeth adjacent to the edentulous span, the amount of bone available for implant placement, the patients "smile line" and display of teeth, lip support, and financial constraints. When there is minimal loss of the ridge contour, restorations that emerge from the ridge are the most functional and esthetic restorations, adhesive-type fixed partial dentures, conventional fixed partial dentures, and implant-supported restorations can be indicated with the choice of restoration dependent on a risk benefit and cost benefit analysis. When there is a loss of ridge contour due to residual ridge resorption or trauma, the decision becomes more complex as not only does the tooth structure need to be replaced, the ridge form also has to be replaced. (Figures 1 and 2). This can be assessed clinically as illustrated by Figures 1 and 2 where a dis crepancy in arch form and ridge form in relation to the adjacent teeth and/or opposing arch can be observed. Other considerations are lip support and display of the teeth when smiling. This article presents a case and rationale for implant-supported par tial overdentures. Many authors have written on the merits of com plete overdentures. The complete overdenture has proven to be an improvement over conventional complete prostheses with respect to chewing efficiency, patient comfort and satisfaction. In partial edentulism, the implant-supported overdenture has several advantages, some in common with a removable partial denture.

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.

Novel valve replacement with an extracellular matrix scaffold in an infant with single ventricle physiology.

PubMed

Guariento, Alvise; Burke, Redmond; Fedrigo, Marny; Angelini, Annalisa; Maschietto, Nicola; Vida, Vladimiro; Thiene, Gaetano; Stellin, Giovanni; Padalino, Massimo

2016-01-01

Valve replacement in children with functionally univentricular hearts remains challenging. The absence of small prostheses, the lack of growth, and the need for anticoagulation limit these procedures. We describe a 1-year follow-up of an extracellular matrix scaffold tube used as systemic atrio-ventricular valve in an infant. Copyright © 2015 Elsevier Inc. All rights reserved.

The utility of international shoulder joint replacement registries and databases: a comparative analytic review of two hundred and sixty one thousand, four hundred and eighty four cases.

PubMed

Bayona, Carlos Eduardo Afanador; Somerson, Jeremy S; Matsen, Frederick A

2018-02-01

National registries are valuable tools for understanding the results of shoulder arthroplasty across populations. These databases provide an unselected view of shoulder joint replacement within geographical areas that cannot be obtained from case series or prospective studies. They can be particularly helpful in determining which diagnoses, patients, procedures, and prostheses have higher than expected rates of revision. In an attempt to determine the generalizability of registry data, we asked, 'how similar are the patients and procedures among the different national registries?' We analyzed national shoulder arthroplasty registries and databases accessed via Internet portals and through a PubMed literature search. Seven national/regional registries and five publications regarding national shoulder arthroplasty data were identified; these sources contained a combined total of 261,484 shoulder arthroplasty cases. The percentages of hemiarthroplasty, anatomic (aTSA) and reverse total shoulders (rTSA), the diagnoses leading to arthroplasty, the mean patient age, and the distribution of patient gender varied significantly among these different databases. This study indicates that the indications for and application of shoulder arthroplasty have important geographical variations and that these variations must be considered when comparing outcomes of shoulder arthroplasty from different locations. Without controlling for age, gender, diagnosis and procedure type, the results from one national registry may not be applicable to patients from a different location. In that national data provide the opportunity to reduce costs by identifying implants and procedures with higher failure rates, the funding of registries needs to be free of conflicts of interest.

Movement quality of conventional prostheses and the DEKA Arm during everyday tasks

PubMed Central

Cowley, Jeffrey; Resnik, Linda; Wilken, Jason; Walters, Lisa Smurr; Gates, Deanna

2017-01-01

Background Conventional prosthetic devices fail to restore the function and characteristic movement quality of the upper limb. The DEKA Arm is a new, advanced prosthesis featuring a compound, powered wrist and multiple grip configurations. Objectives The purpose of this study was to determine if the DEKA Arm improved the movement quality of upper limb prosthesis users compared to conventional prostheses. Study design Case series. Methods Three people with transradial amputation completed tasks of daily life with their conventional prosthesis and with the DEKA Arm. A total of 10 healthy controls completed the same tasks. The trajectory of the wrist joint center was analyzed to determine how different prostheses affected movement duration, speed, smoothness, and curvature compared to patients’ own intact limbs and controls. Results Movement quality decreased with the DEKA Arm for two participants, and increased for the third. Prosthesis users made slower, less smooth, more curved movements with the prosthetic limb compared to the intact limb and controls, particularly when grasping and manipulating objects. Conclusion The effects of one month of training with the DEKA Arm on movement quality varied with participants’ skill and experience with conventional prostheses. Future studies should examine changes in movement quality after long-term use of advanced prostheses. PMID:26932980

Fracture resistance and failure mode of posterior fixed dental prostheses fabricated with two zirconia CAD/CAM systems

PubMed Central

López-Suárez, Carlos; Gonzalo, Esther; Peláez, Jesús; Rodríguez, Verónica

2015-01-01

Background In recent years there has been an improvement of zirconia ceramic materials to replace posterior missing teeth. To date little in vitro studies has been carried out on the fracture resistance of zirconia veneered posterior fixed dental prostheses. This study investigated the fracture resistance and the failure mode of 3-unit zirconia-based posterior fixed dental prostheses fabricated with two CAD/CAM systems. Material and Methods Twenty posterior fixed dental prostheses were studied. Samples were randomly divided into two groups (n=10 each) according to the zirconia ceramic analyzed: Lava and Procera. Specimens were loaded until fracture under static load. Data were analyzed using Wilcoxon´s rank sum test and Wilcoxon´s signed-rank test (P<0.05). Results Partial fracture of the veneering porcelain occurred in 100% of the samples. Within each group, significant differences were shown between the veneering and the framework fracture resistance (P=0.002). The failure occurred in the connector cervical area in 80% of the cases. Conclusions All fracture load values of the zirconia frameworks could be considered clinically acceptable. The connector area is the weak point of the restorations. Key words:Fixed dental prostheses, zirconium-dioxide, zirconia, fracture resistance, failure mode. PMID:26155341

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.

Single stage treatment of ankylosis of the temporomandibular joint using patient-specific total joint replacement and virtual surgical planning.

PubMed

Haq, Jahrad; Patel, Nishma; Weimer, Katherine; Matthews, N Shaun

2014-04-01

Ankylosis of the temporomandibular joint (TMJ) is a debilitating condition that can result in pain, trismus, and a poor quality of life. It can be caused by injury, infection, and rheumatoid disease. Current management includes gap arthroplasty, interpositional arthroplasty, and reconstruction. Traditionally, joints are reconstructed using stock implants, or the procedure is done in two stages with an additional computed tomography (CT) scan between the resective and reconstructive procedures and use of stereolithographic models to aid the design of the definitive prostheses. We describe a technique for the resection of ankylosis and reconstruction of the joint in a single operation using virtually designed custom-made implants. Five patients with ankylosis of the TMJ had a single stage operation with reconstruction between 2010 and 2012. All had preoperative high-resolution CT with contrast angiography. During an international web-based teleconference between the surgeon and the engineer a virtual resection of the ankylosis was done using the reconstructed CT images. The bespoke cutting guides and implants were designed virtually at the same time and were then manufactured precisely using computer-aided design and manufacture (CAD-CAM) over 6 weeks. After release of the ankylosis and reconstruction, the patients underwent an exercise regimen to improve mouth opening. Follow-up was for a minimum of 6 months. Four patients had one operation, and one patient had two. Median/Mean maximum incisal opening increased from 0.6mm before operation to 25 mm afterwards (range 23-27), and there was minimal surgical morbidity. This new method effectively treats ankylosis of the TMJ in a single stage procedure. Fewer operations and hospital stays, and the maintenance of overall clinical outcome are obvious advantages. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

21 CFR 888.3390 - Hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis.

Code of Federal Regulations, 2014 CFR

2014-04-01

... includes prostheses that have a femoral component made of alloys, such as cobalt-chromium-molybdenum, and a snap-fit acetabular component made of an alloy, such as cobalt-chromium-molybdenum, and ultra-high...

21 CFR 888.3390 - Hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis.

Code of Federal Regulations, 2013 CFR

2013-04-01

... includes prostheses that have a femoral component made of alloys, such as cobalt-chromium-molybdenum, and a snap-fit acetabular component made of an alloy, such as cobalt-chromium-molybdenum, and ultra-high...

21 CFR 888.3390 - Hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis.

Code of Federal Regulations, 2011 CFR

2011-04-01

... includes prostheses that have a femoral component made of alloys, such as cobalt-chromium-molybdenum, and a snap-fit acetabular component made of an alloy, such as cobalt-chromium-molybdenum, and ultra-high...

Hereditary hemochromatosis as a risk factor for joint replacement surgery.

PubMed

Sahinbegovic, Enijad; Dallos, Tomás; Aigner, Elmar; Axmann, Roland; Engelbrecht, Matthias; Schöniger-Hekele, Maximilian; Karonitsch, Thomas; Farkas, Martin; Karger, Thomas; Willeit, Johann; Stölzel, Ulrich; Keysser, Gernot; Datz, Christian; Kiechl, Stefan; Schett, Georg; Zwerina, Jochen

2010-07-01

Hemochromatosis is an inherited disease with iron overload and joint involvement resembling osteoarthritis. To determine the rate of joint replacement surgery in patients with hemochromatosis, we performed a cross-sectional cohort study. A total of 199 individuals with hereditary hemochromatosis were included. The prevalence of joint replacement surgery in hip, knee, and ankle joints because of secondary osteoarthritis was assessed. Data were compared with 917 healthy subjects from the population-based Bruneck study. A total of 32 of 199 individuals with hemochromatosis received joint replacement surgery with a total number of 52 joints replaced. Compared with expected rates in healthy individuals, patients with hemochromatosis had a significantly higher risk for joint replacement surgery (odds ratio 9.0; confidence interval, 4.6-17.4). Joint replacement occurred significantly earlier in life in patients with hemochromatosis; 21.9% of the patients with hemochromatosis and 1.7% of healthy individuals required joint replacement before the age of 50 years (P=.0027). Moreover, patients with hemochromatosis were more likely to require multiple joint replacements (8.5%) than the control group (expected rate 0.3%; P=.0001). Hemochromatosis is a risk factor for joint replacement surgery because of severe secondary osteoarthritis. Copyright 2010 Elsevier Inc. All rights reserved.

High rate of osteolytic lesions in medium-term followup after the AES total ankle replacement.

PubMed

Kokkonen, Ari; Ikävalko, Mikko; Tiihonen, Raine; Kautiainen, Hannu; Belt, Eero A

2011-02-01

Some previous studies have shown a high percentage of early-onset and rapidly progressing osteolysis associated with total ankle arthroplasty (TAA) by the Ankle Evolutive System (AES). The purpose of our study was to analyze medium-term results at our institution. Altogether 38 TAAs using AES prostheses were carried out between 2003 and 2007. Diagnoses were rheumatoid arthritis (71%), post-traumatic and idiopathic osteoarthritis (29%). The mean age was 54 years, followup 28 months. Tibial and talar components had hydroxyapatite coating on metal (Co-Cr) components (HA-coated). Since 2005 the design was changed and components were porous coated with titanium and hydroxyapatite (dual-coated). Two-year survival was 79% (95% CI: 56 to 98). At followup 34 (89%) primary tibial and talar components were preserved. In 19 (50%) TAAs osteolysis (more than or equal to 2 mm) occurred in the periprosthetic bone area and in nine (24%) comprised large "cyst-like osteolysis''. In HA-coated prostheses radiolucent lines (less than or equal to 2 mm) or osteolysis (more than or equal to 2 mm) were detected in 11 (100%) cases and in dual-coated prostheses in 19 (74%) (p = 0.08). On the other hand there was more large "cyst-like osteolysis'' around the dual-coated prosthesis and lesions were larger (p = 0.017). In rheumatoid arthritis osteolysis was detected in 14 (52%) and large "cyst-like osteolysis'' in seven (26%) prostheses and in the group of traumatic and idiopathic osteoarthritis in six (55%) and two (18%), respectively. This study showed a high frequency of osteolysis in medium-term followup after the AES ankle replacement. The outcome was not sufficiently beneficial and we have discontinued use of this prosthesis.

In-situ electrochemical study of interaction of tribology and corrosion in artificial hip prosthesis simulators.

PubMed

Yan, Yu; Dowson, Duncan; Neville, Anne

2013-02-01

The second generation Metal-on-Metal (MoM) hip replacements have been considered as an alternative to commonly used Polyethylene-on-Metal (PoM) joint prostheses due to polyethylene wear debris induced osteolysis. However, the role of corrosion and the biofilm formed under tribological contact are still not fully understood. Enhanced metal ion concentrations have been reported widely from hair, blood and urine samples of patients who received metal hip replacements and in isolated cases when abnormally high levels have caused adverse local tissue reactions. An understanding of the origin of metal ions is really important in order to design alloys for reduced ion release. Reciprocating pin-on-plate wear tester is a standard instrument to assess the interaction of corrosion and wear. However, more realistic hip simulator can provide a better understanding of tribocorrosion process for hip implants. It is very important to instrument the conventional hip simulator to enable electrochemical measurements. In this study, simple reciprocating pin-on-plate wear tests and hip simulator tests were compared. It was found that metal ions originated from two sources: (a) a depassivation of the contacting surfaces due to tribology (rubbing) and (b) corrosion of nano-sized wear particles generated from the contacting surfaces. Copyright © 2012 Elsevier Ltd. All rights reserved.

Fatigue limits of titanium-bar joints made with the laser and the electric resistance welding techniques: microstructural characterization and hardness properties.

PubMed

Degidi, Marco; Nardi, Diego; Morri, Alessandro; Sighinolfi, Gianluca; Tebbel, Florian; Marchetti, Claudio

2017-09-01

Fatigue behavior of the titanium bars is of utmost importance for the safe and reliable operation of dental implants and prosthetic constructions based on these implants. To date, however, only few data are available on the fatigue strength of dental prostheses made with electric resistance welding and laser welding techniques. This in-vitro study highlighted that although the joints made with the laser welding approach are credited of a superior tensile strength, joints made with electric resistance welding exhibited double the minimum fatigue strength with respect to the joints made with laser welding (120 vs 60 N).

Temporomandibular Prosthetic Joint Infections Associated With Propionibacterium acnes: A Case Series, and a Review of the Literature.

PubMed

Khader, Ruba; Tingey, Joseph; Sewall, Steven

2017-12-01

The orthopedic literature has shown an increasing incidence of prosthetic joint infections (PJIs) associated with Propionibacterium acnes (P acnes). These infections present serious diagnostic and management challenges to the treating surgeons. In this review, the authors report on cases of P acnes-related temporomandibular joint (TMJ) PJIs that have been diagnosed and treated at their institution. After approval by the institutional review board, information was obtained through a retrospective chart review. Records were retrieved from clinic visits from January 1, 2010 through January 1, 2015 using appropriate International Classification of Diseases, Ninth Revision codes. Data extracted included patient demographics, prostheses details, prosthetic infection history, interventions, diagnostic procedures, and culture processing methods. Of the 7 patients who met the search criteria, 4 (1 with bilateral prostheses) had cultures positive for P acnes. For the 5 TMJ PJIs with cultures positive for P acnes, tissue cultures were obtained in the operating room and processed using mass spectrometry. Symptoms identified in these 4 patients were vague and included pain and intermittent swelling; clinical and radiographic findings were nonspecific. Treatment regimens included oral and parenteral antibiotics and operative interventions. In this case series, the authors report on the management of 4 cases of P acnes-related TMJ PJI. When patients with TMJ prostheses report vague symptoms of swelling and pain that do not fit the typical infection scenario, the surgeon should consider P acnes as a source of infection. Additional case series and retrospective reviews will be necessary before developing prospective trials that could aid in the prevention and management of this infection. Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Investigating the primary stability of the transversal support tibial plateau concept to retain both cruciate ligaments during total knee arthroplasty.

PubMed

Nowakowski, Andrej M; Stangel, Melanie; Grupp, Thomas M; Valderrabano, Victor

2012-09-27

The important roles of the anterior cruciate ligament regarding knee stability, physiologic kinematics, and proprioception are unquestioned. Thus, various efforts have been made to retain the ACL during total knee arthroplasty (TKA). Neither of the existing solutions to this problem, i.e. bicruciate retaining prostheses and implantation of two unicondylar prostheses, has been successful because of concept-specific problems as well as general difficulties with implant fixation. The new transversal support tibial plateau concept is a prosthesis of two individual joint surfaces reinforced beneath the articular line by joint surface supports and buttressed by a single transversal support. This configuration, which enables retention of both cruciate ligaments, should provide good bone fixation and ensure long-term alignment of the individual joint surfaces. In the current study, four prototypes based on this novel concept were developed and the resulting primary stability was analyzed using adapted load testing. The test set-up, with the model-loading of specially prepared Sawbones® and a sinusoidal oscillating load transmission with 25 000 cycles over 10 increasing load levels, achieved subsidence, which enabled comparison of the four different model variants regarding primary stability in view of bone anchoring. The model variant (TSmobile) that allowed transverse glide of the joint surface supports along the transversal support revealed the largest subsidence. A rigid attachment of the joint surface supports of the transversal support tibial plateau thus appears to offer increased primary stability regarding bone anchoring.

Macro-retentive replaceable veneers on crowns and fixed dental prostheses: a new approach in implant-prosthodontics.

PubMed

Schweiger, Josef; Neumeier, Peter; Stimmelmayr, Michael; Beuer, Florian; Edelhoff, Daniel

2013-04-01

Implant-supported prosthetic restorations with veneered crowns and fixed dental prostheses are a proven, scientifically accepted treatment concept in fixed prosthodontics. However, in this area of indication there is a comparatively high technical complication rate, which occurs mainly in the area of the superstructure in the form of minor or major chipping of the veneering material. Various studies have shown that purely implant-supported restorations are subjected to higher loading than those on natural abutment teeth due to the special biomechanical conditions. A possible approach to prevent technical complications is to create higher stability for the implant superstructure through the use of high-strength materials. This would, however, result in undiminished overloading being transmitted to the implant components and could cause increased technical and biological complications. This article describes a new procedure for the use of replaceable veneers made from high-performance polymer material on modified implant abutments. By storing digital datasets for the veneer section, it can be replaced easily and quickly if it becomes worn or is fractured. A reduction in the stresses for the implant components and biological structures under the polymer is also to be expected due the material properties of polymers.

Mechanical valve replacement in congenital heart disease.

PubMed

Fiane, A E; Lindberg, H L; Saatvedt, K; Svennevig, J L

1996-05-01

Mechanical valves are the prosthesis of choice in valve replacement in children. However, the problem of somatic growth leading to patient-valve mismatch remains present, and the appropriate anticoagulation regimen remains controversial. We present our experience of valve replacement in a young population over 20 years. Between 1972 and 1992, 48 patients (34 males and 14 females), mean age 11.2 years (range 0.4-27.4 years), underwent mechanical valve replacement at our institution. Aortic valve replacement was performed in 28 patients (58.3%), mitral valve replacement in 13 (27.1%), tricuspid valve replacement in six (12.5%) and pulmonary valve replacement in one patient (2.1%). The prostheses used were: St. Jude Medical (n = 2), Björk-Shiley (n = 14), Medtronic Hall (n = 16), Duromedics (n = 2) and CarboMedics (n = 14). Early mortality was 14.3%, 10.7% for aortic valve replacement and 30.8% for mitral valve replacement. Mean follow up for all patients was 8.3 years (range 0-22 years), with a total of 398 patient-years. Seven patients died during the follow up (17.1%). Survival after 10 years, including operative mortality, was 81% for aortic valve replacement, 33% for mitral valve replacement, 83% for tricuspid valve replacement and 100% for pulmonary valve replacement. All patients were anticoagulated with warfarin. In eight patients (16.7%) an antiplatelet drug (aspirin or dipyridamole) was added. Major events included paravalvular leak in six patients (1.5%/pty), valve thrombosis in five (mitral position in two, tricuspid in three) (1.3%/pty) and endocarditis in one patient (0.3%/pty). Minor thromboembolic events occurred in three patients (0.8%/pty) and minor hemorrhagic events in three (0.8%/pty). No patients developed hemolytic anemia and there was no case of structural failure. In our experience, mechanical prostheses in congenital heart disease were associated with significant morbidity and mortality, however long term survival after aortic valve replacement was good (81% at 10 years). Thromboembolic and hemorrhagic events were of minor significance. Atrio-ventricular valve replacement carried the highest risk of valve thrombosis and we now give warfarin and an antiplatelet drug to children undergoing mechanical valve implantation in this position.

All-ceramic inlay-retained fixed dental prostheses for replacing posterior missing teeth: A systematic review.

PubMed

Castillo-Oyagüe, Raquel; Sancho-Esper, Rocío; Lynch, Christopher D; Suárez-García, María-Jesús

2018-01-01

To evaluate the current status of all-ceramic inlay-retained fixed dental prostheses (CIR-FDPs) for the replacement of posterior teeth. Screening of titles and abstracts, full-text analysis for inclusion eligibility, quality assessment, data extraction and evaluation of the scientific evidence were performed independently by two reviewers. The electronic databases MEDLINE/PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and Compludoc were searched with no restriction to publication date or language. The quality of the studies was evaluated through: the original 'QDP' ('Questionnaire for selecting articles on Dental Prostheses') (for research papers); the 'Guidelines for managing overviews' of the Evidence-Based Medicine Working Group (for reviews); the Cochrane risk of bias tool; and the GRADE scale for grading scientific evidence. This review started with 4942 articles, which were narrowed down to 23 according to the selection criteria. The data was not statistically treated because of the heterogeneity of the studies. Zirconia-based CIR-FDPs may be recommended for restoring posterior single missing teeth, although the prosthesis/tooth bonded interface has yet to be improved. The addition of lateral wings to the classical inlay preparation seems promising. The weakest parts of CIR-FDPs are the connectors and retainers, while caries and endodontic problems are the most common biological complications. The fabrication of CIR-FDPs with monolithic zirconia may eliminate chipping problems. A three-unit CIR-FDP is a viable treatment option for replacing a posterior missing tooth. Appropriate case selection, abutment preparation and luting procedures may be decisive for clinical success. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Paré and prosthetics: the early history of artificial limbs.

PubMed

Thurston, Alan J

2007-12-01

There is evidence for the use of prostheses from the times of the ancient Egyptians. Prostheses were developed for function, cosmetic appearance and a psycho-spiritual sense of wholeness. Amputation was often feared more than death in some cultures. It was believed that it not only affected the amputee on earth, but also in the afterlife. The ablated limbs were buried and then disinterred and reburied at the time of the amputee's death so the amputee could be whole for eternal life. One of the earliest examples comes from the 18th dynasty of ancient Egypt in the reign of Amenhotep II in the fifteenth century bc. A mummy in the Cairo Museum has clearly had the great toe of the right foot amputated and replaced with a prosthesis manufactured from leather and wood. The first true rehabilitation aids that could be recognized as prostheses were made during the civilizations of Greece and Rome. During the Dark Ages prostheses for battle and hiding deformity were heavy, crude devices made of available materials - wood, metal and leather. Such were the materials available to Ambroise Paré who invented both upper-limb and lower-limb prostheses. His 'Le Petit Lorrain', a mechanical hand operated by catches and springs, was worn by a French Army captain in battle. Subsequent refinements in medicine, surgery and prosthetic science greatly improved amputation surgery and the function of prostheses. What began as a modified crutch with a wooden or leather cup and progressed through many metamorphoses has now developed into a highly sophisticated prosthetic limb made of space-age materials.

Economic implications of implant selection.

PubMed

DeFronzo, D J; Landsman, A S; Ghareeb, J A

1995-07-01

Numerous types of implantable biomaterials are available for a variety of applications. Although much has been written about the physical properties or biocompatibility issues, very few papers have focused on the economic feasibility of these materials. This article assesses financial factors associated with first metatarsophalangeal total joint prostheses.

In vitro investigation of a novel elastic vascular prosthesis for valve-sparing aortic root and ascending aorta replacement.

PubMed

Scharfschwerdt, Michael; Leonhard, Moritz; Lehmann, Judith; Richardt, Doreen; Goldmann, Helmut; Sievers, Hans-Hinrich

2016-05-01

Prosthetic replacement of the thoracic aorta with common Dacron prostheses impairs the aortic 'windkessel' and, in valve-sparing procedures, also aortic valve function. Elastic graft material may overcome these deficiencies. Fresh porcine aortas including the root were set up in a mock circulation before and after replacement of the ascending part with a novel vascular prosthesis providing elastic behaviours. In a first series (n = 14), haemodynamics and leaflet motions of the aortic valve were investigated and also cyclic changes of aortic dimensions at different levels of the root. In a second series (n = 7), intravascular pressure and dimensions of the proximal descending aorta were measured and the corresponding wall tension was calculated. Haemodynamics of the aortic valve remain comparable after replacement. Though the novel prosthesis does not feature such high distensibility as the native aorta, the dynamic of the root was significantly increased compared with common Dacron prostheses at the commissural level, preserving 'windkessel' function. Thus, wall tension of the residual aorta remained unchanged; nevertheless, maximum pressure-time differential dp/dt increased by 13%. The use of the novel elastic prosthesis for replacement of the ascending aorta seems to be beneficial, especially with regard to the preservation of the aortic windkessel. Further studies will be needed to clarify long-term utilization of the material in vivo. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

A computational method for comparing the behavior and possible failure of prosthetic implants

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

Nielsen, C.; Hollerbach, K.; Perfect, S.

1995-05-01

Prosthetic joint implants currently in use exhibit high Realistic computer modeling of prosthetic implants provides an opportunity for orthopedic biomechanics researchers and physicians to understand possible in vivo failure modes, without having to resort to lengthy and costly clinical trials. The research presented here is part of a larger effort to develop realistic models of implanted joint prostheses. The example used here is the thumb carpo-metacarpal (cmc) joint. The work, however, can be applied to any other human joints for which prosthetic implants have been designed. Preliminary results of prosthetic joint loading, without surrounding human tissue (i.e., simulating conditions undermore » which the prosthetic joint has not yet been implanted into the human joint), are presented, based on a three-dimensional, nonlinear finite element analysis of three different joint implant designs.« less

Visual Prostheses: The Enabling Technology to Give Sight to the Blind

PubMed Central

Maghami, Mohammad Hossein; Sodagar, Amir Masoud; Lashay, Alireza; Riazi-Esfahani, Hamid; Riazi-Esfahani, Mohammad

2014-01-01

Millions of patients are either slowly losing their vision or are already blind due to retinal degenerative diseases such as retinitis pigmentosa (RP) and age-related macular degeneration (AMD) or because of accidents or injuries. Employment of artificial means to treat extreme vision impairment has come closer to reality during the past few decades. Currently, many research groups work towards effective solutions to restore a rudimentary sense of vision to the blind. Aside from the efforts being put on replacing damaged parts of the retina by engineered living tissues or microfabricated photoreceptor arrays, implantable electronic microsystems, referred to as visual prostheses, are also sought as promising solutions to restore vision. From a functional point of view, visual prostheses receive image information from the outside world and deliver them to the natural visual system, enabling the subject to receive a meaningful perception of the image. This paper provides an overview of technical design aspects and clinical test results of visual prostheses, highlights past and recent progress in realizing chronic high-resolution visual implants as well as some technical challenges confronted when trying to enhance the functional quality of such devices. PMID:25709777

The evolution of functional hand replacement: From iron prostheses to hand transplantation

PubMed Central

Zuo, Kevin J; Olson, Jaret L

2014-01-01

The hand is an integral component of the human body, with an incredible spectrum of functionality. In addition to possessing gross and fine motor capabilities essential for physical survival, the hand is fundamental to social conventions, enabling greeting, grooming, artistic expression and syntactical communication. The loss of one or both hands is, thus, a devastating experience, requiring significant psychological support and physical rehabilitation. The majority of hand amputations occur in working-age males, most commonly as a result of work-related trauma or as casualties sustained during combat. For millennia, humans have used state-of-the-art technology to design clever devices to facilitate the reintegration of hand amputees into society. The present article provides a historical overview of the progress in replacing a missing hand, from early iron hands intended primarily for use in battle, to today’s standard body-powered and myoelectric prostheses, to revolutionary advancements in the restoration of sensorimotor control with targeted reinnervation and hand transplantation. PMID:25152647

Study of the effect of the silver content on the structural and mechanical behavior of Ag-ZrCN coatings for orthopedic prostheses.

PubMed

Ferreri, I; Lopes, V; Calderon V, S; Tavares, C J; Cavaleiro, A; Carvalho, S

2014-09-01

With the increase of elderly population and health problems that are arising nowadays, hip joint prostheses are being widely used. However, it is estimated that 20% of hip replacement surgeries simply fails after few years, mainly due to wear fatigue. Bearing this in mind, this work reports on the development of new coatings that are able to sustain long and innocuous life inside the patient, which will confer to the usual biomaterials improved physical, mechanical and tribological properties. In particular, the development of multifunctional coatings based on Ag-ZrCN, prepared by DC reactive magnetron sputtering using two targets, Zr and a modified Zr target, in an Ar+C2H2+N2 atmosphere. Silver pellets were placed in the erosion area of the alloyed Zr target in order to obtain a silver content up to 8 at.%. The structural results obtained by x-ray diffraction show that the coatings crystallize in a NaCl crystal structure typical of ZrC1-xNx. The increase of Ag content promoted the formation of an additional a-CNx amorphous phase, besides a silver crystalline phase. Hardness is decreasing, as increasing silver content. Despite the low thicknesses, adhesion values (LC3) can be considered as good. Dynamic fatigue results suggest that these coatings system can be a real asset in terms of mechanical properties, by improving the performance of usual Stainless Steel 316 L biomaterials. Copyright © 2014 Elsevier B.V. All rights reserved.

Identification of bacteria on the surface of clinically infected and non-infected prosthetic hip joints removed during revision arthroplasties by 16S rRNA gene sequencing and by microbiological culture

PubMed Central

Dempsey, Kate E; Riggio, Marcello P; Lennon, Alan; Hannah, Victoria E; Ramage, Gordon; Allan, David; Bagg, Jeremy

2007-01-01

It has been postulated that bacteria attached to the surface of prosthetic hip joints can cause localised inflammation, resulting in failure of the replacement joint. However, diagnosis of infection is difficult with traditional microbiological culture methods, and evidence exists that highly fastidious or non-cultivable organisms have a role in implant infections. The purpose of this study was to use culture and culture-independent methods to detect the bacteria present on the surface of prosthetic hip joints removed during revision arthroplasties. Ten consecutive revisions were performed by two surgeons, which were all clinically and radiologically loose. Five of the hip replacement revision surgeries were performed because of clinical infections and five because of aseptic loosening. Preoperative and perioperative specimens were obtained from each patient and subjected to routine microbiological culture. The prostheses removed from each patient were subjected to mild ultrasonication to dislodge adherent bacteria, followed by aerobic and anaerobic microbiological culture. Bacterial DNA was extracted from each sonicate and the 16S rRNA gene was amplified with the universal primer pair 27f/1387r. All 10 specimens were positive for the presence of bacteria by both culture and PCR. PCR products were then cloned, organised into groups by RFLP analysis and one clone from each group was sequenced. Bacteria were identified by comparison of the 16S rRNA gene sequences obtained with those deposited in public access sequence databases. A total of 512 clones were analysed by RFLP analysis, of which 118 were sequenced. Culture methods identified species from the genera Leifsonia (54.3%), Staphylococcus (21.7%), Proteus (8.7%), Brevundimonas (6.5%), Salibacillus (4.3%), Methylobacterium (2.2%) and Zimmermannella (2.2%). Molecular detection methods identified a more diverse microflora. The predominant genus detected was Lysobacter, representing 312 (60.9%) of 512 clones analysed. In all, 28 phylotypes were identified: Lysobacter enzymogenes was the most abundant phylotype (31.4%), followed by Lysobacter sp. C3 (28.3%), gamma proteobacterium N4-7 (6.6%), Methylobacterium SM4 (4.7%) and Staphylococcus epidermidis (4.7%); 36 clones (7.0%) represented uncultivable phylotypes. We conclude that a diverse range of bacterial species are found within biofilms on the surface of clinically infected and non-infected prosthetic hip joints removed during revision arthroplasties. PMID:17501992

Laser vibrometer measurements and middle ear prostheses

NASA Astrophysics Data System (ADS)

Flock, Stephen T.; Dornhoffer, John; Ferguson, Scott

1997-05-01

One of us has developed an improved partial ossicular replacement prosthesis that is easier to implant and, based on pilot clinical measurements, results in better high-frequency hearing as compared to patients receiving one of the alternative prostheses. It is hypothesized that the primary reason for this is because of the relatively light weight (about 25 mg) and low compliance of the prosthesis, which could conceivably result in better high frequency vibrational characteristics. The purpose of our initial work was to develop an instrument suitable for objectively testing the vibrational characteristics of prostheses. We have developed a laser based device suitable for measuring the vibrational characteristics of the oval window or other structures of the middle ear. We have tested this device using a piezoelectric transducer excited at audio frequencies, as well as on the oval window in human temporal bones harvested from cadavers. The results illustrate that it is possible to non-invasively monitor the vibrational characteristics of anatomic structures with a very inexpensive photonic device.

Dosimetric considerations for patients with HIP prostheses undergoing pelvic irradiation. Report of the AAPM Radiation Therapy Committee Task Group 63.

PubMed

Reft, Chester; Alecu, Rodica; Das, Indra J; Gerbi, Bruce J; Keall, Paul; Lief, Eugene; Mijnheer, Ben J; Papanikolaou, Nikos; Sibata, Claudio; Van Dyk, Jake

2003-06-01

This document is the report of a task group of the Radiation Therapy Committee of the AAPM and has been prepared primarily to advise hospital physicists involved in external beam treatment of patients with pelvic malignancies who have high atomic number (Z) hip prostheses. The purpose of the report is to make the radiation oncology community aware of the problems arising from the presence of these devices in the radiation beam, to quantify the dose perturbations they cause, and, finally, to provide recommendations for treatment planning and delivery. Some of the data and recommendations are also applicable to patients having implanted high-Z prosthetic devices such as pins, humeral head replacements. The scientific understanding and methodology of clinical dosimetry for these situations is still incomplete. This report is intended to reflect the current state of scientific understanding and technical methodology in clinical dosimetry for radiation oncology patients with high-Z hip prostheses.

Enhanced lubricant film formation through micro-dimpled hard-on-hard artificial hip joint: An in-situ observation of dimple shape effects.

PubMed

Choudhury, Dipankar; Rebenda, David; Sasaki, Shinya; Hekrle, Pavel; Vrbka, Martin; Zou, Min

2018-05-01

This study evaluates the impact of dimple shapes on lubricant film formation in artificial hip joints. Micro-dimples with 20-50 µm lateral size and 1 ± 0.2 µm depths were fabricated on CrCoMo hip joint femoral heads using a picosecond laser. Tribological studies were performed using a pendulum hip joint simulator to apply continuous swing flexion-extension motions. The results revealed a significantly enhanced lubricant film thickness (≥ 500 nm) with micro-dimpled prosthesis heads at equilibrium position after the lubricant film has fully developed. The average lubricant film thickness of dimpled prostheses with square- and triangular-shaped dimple arrays over time is about 3.5 that of the non-dimpled prosthesis (204 nm). Remarkably, the prosthesis with square-shaped dimple arrays showed a very fast lubricant film formation reaching their peak values within 0.5 s of pendulum movement, followed by prosthesis with triangular-shaped dimple arrays with a transition period of 42.4 s. The fully developed lubricant film thicknesses (≥ 700 nm) are significantly higher than the surface roughness (≈ 25 nm) demonstrating a hydrodynamic lubrication. Hardly any scratches appeared on the post-experimental prosthesis with square-shaped dimple array and only a few scratches were found on the post-experimental prosthesis with triangular-shaped dimple arrays. Thus, prostheses with square-shaped dimple arrays could be a potential solution for durable artificial hip joints. Copyright © 2018 Elsevier Ltd. All rights reserved.

Evaluation of a noninvasive command scheme for upper-limb prostheses in a virtual reality reach and grasp task.

PubMed

Kaliki, Rahul R; Davoodi, Rahman; Loeb, Gerald E

2013-03-01

C5/C6 tetraplegic patients and transhumeral amputees may be able to use voluntary shoulder motion as command signals for a functional electrical stimulation system or transhumeral prosthesis. Stereotyped relationships, termed "postural synergies," among the shoulder, forearm, and wrist joints emerge during goal-oriented reaching and transport movements as performed by able-bodied subjects. Thus, the posture of the shoulder can potentially be used to infer the desired posture of the elbow and forearm joints during reaching and transporting movements. We investigated how well able-bodied subjects could learn to use a noninvasive command scheme based on inferences from these postural synergies to control a simulated transhumeral prosthesis in a virtual reality task. We compared the performance of subjects using the inferential command scheme (ICS) with subjects operating the simulated prosthesis in virtual reality according to complete motion tracking of their actual arm and hand movements. Initially, subjects performed poorly with the ICS but improved rapidly with modest amounts of practice, eventually achieving performance only slightly less than subjects using complete motion tracking. Thus, inferring the desired movement of distal joints from voluntary shoulder movements appears to be an intuitive and noninvasive approach for obtaining command signals for prostheses to restore reaching and grasping functions.

10-year evaluation of the cementless low-contact- stress rotating-platform total knee arthroplasty.

PubMed

Efstathopoulos, Nikolaos; Mavrogenis, Andreas F; Lallos, Stergios; Nikolaou, Vassilios; Papagelopoulos, Panayiotis J; Savvidou, Olga D; Korres, Demetrios S

2009-01-01

We present the clinical and radiographic outcomes of the cementless low-contact-stress (LCS) rotating-platform total knee arthroplasty. Overall, 423 prostheses were implanted in 393 consecutive patients (30 patients had bilateral total knee replacement) for primary varus gonarthrosis (381 patients) and rheumatoid arthritis (12 patients). There were 81 men and 312 women with a mean age of 73 years (range, 58-85 years). Patella replacement was not performed in any case. Clinical and radiographic evaluation was performed using the Knee Society Score (KSS) and the Knee Society Assessment Form, respectively. The mean follow-up was 10 years (range, 5-15 years). Three patients were lost to follow-up. Survival of the prostheses was 98% at 10 years; three prostheses required revision for deep infection, bearing dislocation, and periprosthetic fracture. The mean KSS improved significantly, from 42 and 44 points preoperatively to 90 and 79 points, respectively, at the latest evaluation (P < 0.001); results were excellent in 278 cases, good in 106, fair in 27, and poor in nine. Radiolucent lines were observed in 80 cases; revision arthroplasty was not performed in any of these cases. Complications included deep infection in one patient, bearing dislocation in one, skin necrosis in four, and a supracondylar fracture in one. The cementless LCS rotating-platform total knee arthroplasty is associated with excellent mid- and long-term results for patients with osteoarthritis and rheumatoid arthritis of the knee.

Acute obstruction by Pannus in patients with aortic medtronic-hall valves: 30 years of experience.

PubMed

Ellensen, Vegard Skalstad; Andersen, Knut Sverre; Vitale, Nicola; Davidsen, Einar Skulstad; Segadal, Leidulf; Haaverstad, Rune

2013-12-01

Acute dysfunction of mechanical aortic valve prostheses is a life-threatening adverse event. Pannus overgrowth, which is fibroelastic hyperplasia originating from the periannular area, is one cause of dysfunction. The aim of this study was to determine the annual incidence of readmittance resulting from acute obstruction caused by pannus during 30 years of observation in patients with Medtronic-Hall aortic valve prostheses and to analyze the risk factors associated with pannus development. From 1982 to 2004, 1,187 patients in our department underwent aortic valve replacement with Medtronic-Hall mechanical monoleaflet valve prostheses. As of December 31, 2012, 27 of these patients (2.3%) had presented with acute valve dysfunction caused by pannus obstruction. The annual incidence of pannus was 0.7 per 1,000. The median time from the primary operation to prosthetic dysfunction was 11.1 years (range, 1.2 to 26.8 years). Of the 20 patients who underwent reoperation, 2 died. Seven patients died before reoperation. Women had a higher risk for the development of obstructing pannus, and patients with pannus obstruction were younger. Valve size was not an independent risk factor. Women and younger patients are at higher risk for pannus development. When acute dysfunction by pannus is suspected in a mechanical aortic valve, an immediate echocardiogram and an emergency aortic valve replacement should be carried out because of the potential of a fatal outcome. Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

On occlusal forces in dentitions with implant-supported fixed cantilever prostheses.

PubMed

Falk, H

1990-01-01

The main aims of this thesis were (1) to study the functional characteristics of dentitions with mandibular implant-supported fixed cantilever prostheses - IFCP s- occluding with complete dentures, (2) to study in detail the magnitudes and distributions of axially directed closing and chewing forces in such dentitions, (3) to study the influence of number and distribution of occlusal contacts on the magnitude and distribution of closing and chewing forces, (4) to assess the vertical bending moment and the resulting vertical bending stress in the cantilever joints and (5) to find out whether the force distribution over the cantilever beams and the resulting vertical bending stress in the cantilever joint are influenced by the type of prosthetic construction in the opposing jaw. Closing and chewing forces were registered in altogether seventeen subjects by means of miniature strain gauge transducers mounted bilaterally and symmetrically in performed matrices in prosthetic appliances. Four, six or eight transducers, evenly distributed over the tooth-arch, permitted registrations of axially directed occlusal forces in several occluding areas simultaneously. In Papers I-IV, the implant-supported prostheses were installed in the mandible and occluded with complete dentures. In Paper V, group A, the fixture-supported prostheses were installed in the maxilla and occluded with tooth-supported fixed partial dentures whereas in group B, the arrangements were analogous to those in Papers I-IV. All subjects exhibited a rhythmic chewing pattern and preferred one side for chewing although both sides were used. Most chewing sequences were terminated with swallowing with occlusal force development. The mean total forces acting over the tooth-arch varied somewhat between groups and occlusal arrangements but averaged 350 and 170 N for closing and chewing respectively. Closing and chewing forces increased distally along the cantilever beams when occluding with complete dentures and decreased distally when occluding with fixed partial dentures. The distally increasing force distribution pattern could be altered to a distally decreasing force distribution pattern by infraoccluding the second cantilever unit by as little as 100 microns. Calculated vertical bending moments and stresses in the cantilever joints of the preferred chewing sides created by closing and chewing forces were larger in dentitions where the IFCP occluded with a complete denture than in dentitions where the IFCP occluded with a tooth-supported fixed partial denture.

Effect of progressive wear on the contact mechanics of hip replacements--does the realistic surface profile matter?

PubMed

Wang, Ling; Yang, Wenjian; Peng, Xifeng; Li, Dichen; Dong, Shuangpeng; Zhang, Shu; Zhu, Jinyu; Jin, Zhongmin

2015-04-13

The contact mechanics of artificial metal-on-polyethylene hip joints are believed to affect the lubrication, wear and friction of the articulating surfaces and may lead to the joint loosening. Finite element analysis has been widely used for contact mechanics studies and good agreements have been achieved with current experimental data; however, most studies were carried out with idealist spherical geometries of the hip prostheses rather than the realistic worn surfaces, either for simplification reason or lacking of worn surface profile. In this study, the worn surfaces of the samples from various stages of hip simulator testing (0 to 5 million cycles) were reconstructed as solid models and were applied in the contact mechanics study. The simulator testing results suggested that the center of the head has various departure value from that of the cup and the value of the departure varies with progressively increased wear. This finding was adopted into the finite element study for better evaluation accuracy. Results indicated that the realistic model provided different evaluation from that of the ideal spherical model. Moreover, with the progressively increased wear, large increase of the contact pressure (from 12 to 31 MPa) was predicted on the articulating surface, and the predicted maximum von Mises stress was increased from 7.47 to 13.26 MPa, indicating the marked effect of the worn surface profiles on the contact mechanics of the joint. This study seeks to emphasize the importance of realistic worn surface profile of the acetabular cup especially following large wear volume. Copyright © 2015 Elsevier Ltd. All rights reserved.

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.

Effect of gap distance on tensile strength of preceramic base metal solder joints.

PubMed

Fattahi, Farnaz; Motamedi, Milad

2011-01-01

In order to fabricate prostheses with high accuracy and durability, soldering techniques have been introduced to clinical dentistry. However, these prostheses always fail at their solder joints. The purpose of this study was to evaluate the effect of gap distance on the tensile strength of base metal solder joints. Based on ADA/ISO 9693 specifications for tensile test, 40 specimens were fabricated from a Ni-Cr alloy and cut at the midpoint of 3-mm diameter bar and placed at desired positions by a specially designed device. The specimens were divided into four groups of 10 samples according to the desired solder gap distance: Group1: 0.1mm; Group2: 0.25mm; Group3: 0.5mm; and Group4: 0.75mm. After soldering, specimens were tested for tensile strength by a universal testing machine at a cross-head speed of 0.5mm/min with a preload of 10N. The mean tensile strength values of the groups were 162, 307.8, 206.1 and 336.7 MPa, respectively. The group with 0.75-mm gap had the highest and the group with 0.1-mm gap had the lowest tensile strength. Bonferroni test showed that Group1 and Group4 had statistically different values (P=0.023), but the differences between other groups were not sig-nificant at a significance level of 0.05. There was no direct relationship between increasing soldering gap distance and tensile strength of the solder joints.

Retrospective cohort study of the performance of the Pinnacle metal on metal (MoM) total hip replacement: a single-centre investigation in combination with the findings of a national retrieval centre

PubMed Central

Langton, David John; Sidaginamale, Raghavendra Prasad; Avery, Peter; Waller, Sue; Tank, Ghanshyabhai; Lord, James; Joyce, Thomas; Cooke, Nick; Logishetty, Raj; Nargol, Antoni Viraf Francis

2016-01-01

Objectives To determine risk factors for revision in patients implanted with a commonly used metal on metal (MoM) hip replacement. Design Retrospective cohort study in combination with a prospective national retrieval study (Northern Retrieval Registry (NRR)). Setting Combined orthopaedic unit in combination with the NRR. Participants All patients implanted with a DePuy Pinnacle MoM hip prostheses by the 2 senior authors were invited to attend for a review which included clinical examination, blood metal ion measurements, radiographs and targeted imaging. Explanted components underwent wear analysis using validated methodology and these results were compared with those obtained from the NRR. Results 489 MoM Pinnacle hips were implanted into 434 patients (243 females and 191 males). Of these, 352 patients attended the MoM recall clinics. 64 patients had died during the study period. For the purposes of survival analysis, non-attendees were assumed to have well-functioning prostheses. The mean follow-up of the cohort as a whole was 89 months. 71 hips were revised. Prosthetic survival for the whole cohort was 83.6% (79.9–87.3) at 9 years. The majority of explanted devices exhibited signs of taper junction failure. Risk factors for revision were bilateral MoM prostheses, smaller Pinnacle liners, and implantation in 2006 and later years. A significant number of devices were found to be manufactured out of their specifications. This was confirmed with analysis of the wider data set from the NRR. Conclusions This device was found to have an unacceptably high revision rate. Bilateral prostheses, those implanted into female patients and devices implanted in later years were found to be at greater risk. A significant number of explanted components were found to be manufactured with bearing diameters outside of the manufacturer's stated tolerances. Our findings highlight the clinical importance of hitherto unrecognised variations in device production. PMID:27130159

Hypersensitivity reactions to metal implants: laboratory options.

PubMed

Carossino, Anna Maria; Carulli, Christian; Ciuffi, Simone; Carossino, Roberto; Zappoli Thyrion, Giorgia Donata; Zonefrati, Roberto; Innocenti, Massimo; Brandi, Maria Luisa

2016-11-23

All implant compounds undergo an electrochemical process when in contact with biological fluids, as well as mechanical corrosion due to abrasive wear, with production of metal debris that may inhibit repair processes. None of the commonly-used methods can diagnose implant allergies when used singly, therefore a panel of tests should be performed on allergic patients as pre-operative screening, or when a postoperative metal sensitisation is suspected. We analysed patients with painful prostheses and subjects prone to allergies using the Patch Test in comparison with the Lymphocyte Transformation Test. Cytokine production was evaluated to identify prognostic markers for early diagnosis of aseptic loosening. Metal debris endocytosis and cytoskeletal rearrangement was visualised by confocal microscopy. Our results demonstrate that the Lymphocyte Transformation Test can identify patients who have a predisposition to develop allergic reactions and can confirm the diagnosis of hypersensitivity in patients with painful prostheses. The prevalence of a Th2-cytokine pattern may be used to identify predisposition to the development of allergic diseases, while the selective presence of osteoclastogenic cytokines may be used as predictor of a negative outcome in patients with painful prosthesis. The hypothesis of the prognostic value of these cytokines as early markers of aseptic loosening is attractive, but its confirmation would require extensive testing. The Lymphocyte Transformation Test is the most suitable method for testing systemic allergies. We suggest that the combined use of the Patch Test and the Lymphocyte Transformation Test, associated with cytokine detection in selected patients, could provide a useful tool for preventive evaluation of immune reactivity in patients undergoing primary joint replacement surgery, and for clinical monitoring of the possible onset of a metal sensitization in patients with implanted devices.

Effect of prosthesis endplate lordosis angles on L5-S1 kinematics after disc arthroplasty.

PubMed

Tsitsopoulos, Parmenion P; Wojewnik, Bartosz; Voronov, Leonard I; Havey, Robert M; Renner, Susan M; Zelenakova, Julia; McIntosh, Braden; Carandang, Gerard; Abjornson, Celeste; Patwardhan, Avinash G

2012-06-01

We hypothesized that L5-S1 kinematics will not be affected by the lordosis distribution between the prosthesis endplates. Twelve cadaveric lumbosacral spines (51.3 ± 9.8 years) were implanted with 6° or 11° prostheses (ProDisc-L) with four combinations of superior/inferior lordosis (6°/0°, 3°/3°, 11°/0°, 3°/8°). Specimens were tested intact and after prostheses implantation with different lordosis distributions. Center of rotation (COR) and range of motion (ROM) were quantified. Six-degree lordosis prostheses (n = 7) showed no difference in flexion-extension ROM, regardless of design (6°/0° or 3°/3°) (p > 0.05). In lateral bending (LB), both designs reduced ROM (p < 0.05). In axial rotation, only the 3°/3° design reduced ROM (p < 0.05). Eleven-degree lordosis prostheses (n = 5) showed no difference in flexion-extension ROM for either design (p > 0.05). LB ROM decreased with distributed lordosis prostheses (3°/8°) (p < 0.05). Overall, L5-S1 range of motion was not markedly influenced by lordosis distribution among the two prosthesis endplates. The ProDisc-L prosthesis design where all lordosis is concentrated in the superior endplate yielded COR locations that were anterior and caudal to intact controls. The prosthesis with lordosis distributed between the two endplates yielded a COR that tended to be closer to intact. Further clinical and biomechanical studies are needed to assess the long-term impact of lordosis angle distribution on the fate of the facet joints.

SU-E-T-504: Usefulness of CT-MR Fusion in Radiotherapy Planning for Prostate Cancer Patient with Bilateral Hip Replacements

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

He, R.; Giri, Shankar; VA Medical Center at Jackson, Mississippi

2014-06-01

Purpose: Target localization of prostate for Intensity Modulated Radiation Therapy (IMRT) in patients with bilateral hip replacements is difficult due to artifacts in Computed Tomography (CT) images generated from the prostheses high Z materials. In this study, Magnetic Resonance (MR) images fused with CT images are tested as a solution. Methods: CT images of 2.5 mm slice thickness were acquired on a GE Lightspeed scanner with a flat-topped couch for a prostate cancer patient with bilateral hip replacements. T2 weighted images of 5 mm separation were acquired on a MR Scanner. After the MR-CT registration on a radiotherapy treatment planningmore » system (Eclipse, Varian), the target volumes were defined by the radiation oncologists on MR images and then transferred to CT images for planning and dose calculation. The CT Hounsfield Units (HU) was reassigned to zero (as water) for artifacts. The Varian flat panel treatment couch was modeled for dose calculation accuracy with heterogeneity correction. A Volume Matrix Arc Therapy (VMAT) and a seven-field IMRT plans were generated, each avoiding any beam transversing the prostheses; the two plans were compared. The superior VMAT plan was used for treating the patient. In-vivo dosimetry was performed using MOSFET (Best Canada) placed in a surgical tube inserted into the patient rectum during therapy. The measured dose was compared with planned dose for MOSFET location. Results: The registration of MR-CT images and the agreement of target volumes were confirmed by three physicians. VMAT plan was deemed superior to IMRT based on dose to critical nearby structures and overall conformality of target dosing. In-vivo measured dose compared with calculated dose was -4.5% which was likely due to attenuation of the surgical tube surrounding MOSFET. Conclusion: When artifacts are present on planning CT due to bilateral hip prostheses, MR-CT image fusion is a feasible solution for target delineation.« less

Does location of rotation center in artificial disc affect cervical biomechanics?

PubMed

Mo, Zhongjun; Zhao, Yanbin; Du, Chengfei; Sun, Yu; Zhang, Ming; Fan, Yubo

2015-04-15

A 3-dimensional finite element investigation. To compare the biomechanical performances of different rotation centers (RCs) in the prevalent artificial cervical discs. Various configurations are applied in artificial discs. Design parameters may influence the biomechanics of implanted spine. The RC is a primary variation in the popular artificial discs. Implantation of 5 prostheses was simulated at C5-C6 on the basis of a validated finite element cervical model (C3-C7). The prostheses included ball-in-socket design with a fixed RC located on the inferior endplate (BS-FI) and on the superior endplate (BS-FS), with a mobile RC at the inferior endplate (BS-MI), dual articulation with a mobile RC between the endplates (DA-M), and sliding articulation with various RCs (SA-V). The spinal motions in flexion and extension served as a displacement loading at the C3 vertebrae. Total disc replacements reduced extension moment. The ball-in-socket designs required less flexion moment, whereas the flexion stiffness of the spines with DA-M and SA-V was similar to that of the healthy model. The contributions of the implanted level to the global motions increased in the total disc replacements, except in the SA-V and DA-M models (in flexion). Ball-in-socket designs produced severe stress distributions in facet cartilage, whereas DA-M and SA-V produced more severe stress distribution on the bone-implant interface. Cervical stability was extremely affected in extension and partially affected in flexion by total disc replacement. With the prostheses with mobile RC, cervical curvature was readjusted under a low follower load. The SA-V and BS-FS designs exhibited better performances in the entire segmental stiffness and in the stability of the operative level than the BS-MI and BS-FI designs in flexion. The 5 designs demonstrated varying advantages relative to the stress distribution in the facet cartilages and on the bone-implant interface. 5.

Success rate in implant-supported overdenture and implant-supported fixed denture in cleft lip and palate patients

PubMed Central

Zanolla, Jaine; Amado, Flávio Monteiro; da Silva, Willian Saranholi; Ayub, Bruno; de Almeida, Ana Lúcia Pompéia Fraga; Soares, Simone

2016-01-01

Background: The prosthetic treatment in cleft patients is challenging. Based on this, the aim of this study was to evaluate the longevity of prosthetic rehabilitation treatment with implant-supported overdenture (IOD) and implant-supported fixed denture (IFD) in cleft lip and palate patients in a period of 22 years. Materials and Methods: The medical records of 72 patients were analyzed (29 males and 43 females), and the survival rate of the implants was evaluated. Moreover, the prostheses’ time of use and the reason for the changing of these were also evaluated. Results: Four-hundred-seventeen implants were installed, and 370 implants survive today. The mean survival time of the implants was 7.6 years. Regarding the 97 prostheses made, the time of average use was 3.28 for the IFDs and 3.92 for IODs. The reasons for the replacements of the prostheses were mainly: fracture of the acrylic base (29.6%) and loss of vertical dimension of occlusion (VDO) (18.5%) in the IFDs. Moreover, in IODs, these were accounted for the loss of VDO due to teeth damage (17.2%) and implant loss (14.6%). Conclusions: The maintenance of the prostheses was challenging because the patients had difficulties returning for periodic control, but this fact did not result in the decrease of the success rate of the implants. The longevity of implants and prostheses was satisfactory; however, the prostheses showed repetitions mainly due to the wear of the teeth, with decreased vertical dimension and fracture of acrylic base. PMID:28299262

Comparison of patellofemoral outcomes after TKA using two prostheses with different patellofemoral design features.

PubMed

Bae, Dae Kyung; Baek, Jong Hun; Yoon, Kyung Tack; Son, Hyuck Sung; Song, Sang Jun

2017-12-01

The purpose of the present study was to compare the clinical and radiographic results after TKA using two prostheses with different sagittal patellofemoral design features, including outcomes related to compatibility of the patellofemoral joint. The clinical and radiographic results of 81 patients (100 knees) who underwent TKA using the specific prosthesis (group A) were compared with those in a control group who underwent TKA using the other prosthesis (group B). The presence of anterior knee joint pain, patellar crepitation, and patellar clunk syndrome was also checked. The function score and maximum flexion angle at the last follow-up were slightly better in group A than those in group B (92.0 ± 2.3 vs. 90.6 ± 4.2) (133.6° ± 8.4° vs. 129.6° ± 11.4°). Anterior knee pain was observed in 6 knees and patellar crepitation in four knees in group A. In group B, these symptoms were observed in 22 knees and 18 knees, respectively. There was no patellar clunk syndrome in either group. The alignment was corrected with satisfactory positioning of components. The patellar height remained unchanged after TKA in the two groups. The differences between preoperative and postoperative patellar tilt angle and patellar translation were small. When comparing the clinical and radiographic results after TKA using two prostheses with different sagittal patellofemoral design features, TKA using the specific prosthesis provided satisfactory results with less clinical symptoms related to the patellofemoral kinematics with TKA using the other prosthesis. III.

Disintegration of porous polyethylene prostheses.

PubMed

Kerr, A G; Riley, D N

1999-06-01

A Plastipore (porous polyethylene) Total Ossicular Replacement Prosthesis gave an excellent initial hearing result which was maintained for 14 years. Hearing then began to deteriorate and revision surgery showed disintegration of the prosthesis and a defect in the stapes footplate. Histological examination confirmed previous findings in porous polyethylene with multinucleated foreign body giant cells and breakdown of the material.

Effect of Gap Distance on Tensile Strength of Preceramic Base Metal Solder Joints

PubMed Central

Fattahi, Farnaz; Motamedi, Milad

2011-01-01

Background and aims In order to fabricate prostheses with high accuracy and durability, soldering techniques have been introduced to clinical dentistry. However, these prostheses always fail at their solder joints. The purpose of this study was to evaluate the effect of gap distance on the tensile strength of base metal solder joints. Materials and methods Based on ADA/ISO 9693 specifications for tensile test, 40 specimens were fabricated from a Ni-Cr alloy and cut at the midpoint of 3-mm diameter bar and placed at desired positions by a specially designed device. The specimens were divided into four groups of 10 samples according to the desired solder gap distance: Group1: 0.1mm; Group2: 0.25mm; Group3: 0.5mm; and Group4: 0.75mm. After soldering, specimens were tested for tensile strength by a universal testing machine at a cross-head speed of 0.5mm/min with a preload of 10N. Results The mean tensile strength values of the groups were 162, 307.8, 206.1 and 336.7 MPa, respectively. The group with 0.75-mm gap had the highest and the group with 0.1-mm gap had the lowest tensile strength. Bonferroni test showed that Group1 and Group4 had statistically different values (P=0.023), but the differences between other groups were not sig-nificant at a significance level of 0.05. Conclusion There was no direct relationship between increasing soldering gap distance and tensile strength of the solder joints. PMID:22991610

Medical Surveillance Monthly Report (MSMR). Volume 22, Number 5, May 2015

DTIC Science & Technology

2015-05-01

aTotal column equals one joint replacement per person per period. bAn individual could be counted once in each of the types of joint replacements. cRate...Percentages of joint replace- ment cases who remained in service or had left service, 2 years post-joint replacement, by gender , active component...Musculoskeletal-related disability in US Army personnel: prevalence, gender and military occupational specialties. J Occup Environ Med. 1997;39(1):68–78

Occlusion for implant-supported fixed dental prostheses in partially edentulous patients: a literature review and current concepts

PubMed Central

Sukotjo, Cortino

2013-01-01

Implant treatment has become the treatment of choice to replace missing teeth in partially edentulous areas. Dental implants present different biological and biomechanical characteristics than natural teeth. Occlusion is considered to be one of the most important factors contributing to implant success. Most literature on implant occlusal concepts is based on expert opinion, anecdotal experiences, in vitro and animal studies, and only limited clinical research. Furthermore, scientific literature regarding implant occlusion, particularly in implant-supported fixed dental prostheses remains controversial. In this study, the current status of implant occlusion was reviewed and discussed. Further randomized clinical research to investigate the correlation between implant occlusion, the implant success rate, and its risk factors is warranted to determine best clinical practices. PMID:23678387

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.

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 - ...

[Surgical silicone prostheses in the treatment of biliary tract cancers: long prostheses or short prostheses? Results apropos of 500 cases].

PubMed

Kron, B

1992-10-01

The interest of surgical prostheses in the palliative treatment of biliary tract cancer is well established, on the basis of their good tolerance, the more than 15 year follow up experience and the number of patients operated upon. After exeresis, they allow re-establishment of continuity, either by use of a prosthesis in Y when the right and let ducts can be dissected, or by using two prostheses, a multiperforated long prosthesis reimplanted in the duodenum and a short prosthesis reimplanted in the common bile duct without attaining the sphincter of Oddi. Of the 1000 cases treated, 500 were the object of a statistical analysis, 46 being operated upon by the author, in 60% of cases for biliary tract cancer, either primary or as an extension from the gallbladder. One-third of the patients had advanced lesions and a short survival of less than 3 months. Two-thirds a median survival of 9 months. In 10%, a radical exeresis was performed with survival of more than one year without recurrence of jaundice. Failure of treatment with persistence of jaundice was due to advanced disease for which surgery is unsatisfactory. Essential complications were premature bile leaks (5%) without serious consequences if sufficient drainage was maintained, since it stopped spontaneously, and angiocholitis (6%), the result of territory exclusion or reflux. Recurrence of jaundice was related to extension of the neoplasm to the secondary bile ducts, and to hepatic metastases. Obstruction of the prosthesis before two months was rare (6%) and was preceded by angiocholitis. In the absence of recurrence of the cancer the prosthesis can be replaced surgically without difficulty.

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.

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

Code of Federal Regulations, 2010 CFR

2010-04-01

... device includes prostheses that consist of a metallic stem made of alloys, such as cobalt-chromium-molybdenum, with an integrated cylindrical trunnion bearing at the upper end of the stem that fits into a... head of the device to rotate on its stem. The prosthesis is intended for use with bone cement (§ 888...

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

Code of Federal Regulations, 2014 CFR

2014-04-01

... device includes prostheses that consist of a metallic stem made of alloys, such as cobalt-chromium-molybdenum, with an integrated cylindrical trunnion bearing at the upper end of the stem that fits into a... head of the device to rotate on its stem. The prosthesis is intended for use with bone cement (§ 888...

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

Code of Federal Regulations, 2011 CFR

2011-04-01

... device includes prostheses that consist of a metallic stem made of alloys, such as cobalt-chromium-molybdenum, with an integrated cylindrical trunnion bearing at the upper end of the stem that fits into a... head of the device to rotate on its stem. The prosthesis is intended for use with bone cement (§ 888...

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

Code of Federal Regulations, 2012 CFR

2012-04-01

... device includes prostheses that consist of a metallic stem made of alloys, such as cobalt-chromium-molybdenum, with an integrated cylindrical trunnion bearing at the upper end of the stem that fits into a... head of the device to rotate on its stem. The prosthesis is intended for use with bone cement (§ 888...

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

Code of Federal Regulations, 2013 CFR

2013-04-01

... device includes prostheses that consist of a metallic stem made of alloys, such as cobalt-chromium-molybdenum, with an integrated cylindrical trunnion bearing at the upper end of the stem that fits into a... head of the device to rotate on its stem. The prosthesis is intended for use with bone cement (§ 888...

Development of a prosthesis shoulder mechanism for upper limb amputees: application of an original design methodology to optimize functionality and wearability.

PubMed

Troncossi, Marco; Borghi, Corrado; Chiossi, Marco; Davalli, Angelo; Parenti-Castelli, Vincenzo

2009-05-01

The application of a design methodology for the determination of the optimal prosthesis architecture for a given upper limb amputee is presented in this paper along with the discussion of its results. In particular, a novel procedure was used to provide the main guidelines for the design of an actuated shoulder articulation for externally powered prostheses. The topology and the geometry of the new articulation were determined as the optimal compromise between wearability (for the ease of use and the patient's comfort) and functionality of the device (in terms of mobility, velocity, payload, etc.). This choice was based on kinematic and kinetostatic analyses of different upper limb prosthesis models and on purpose-built indices that were set up to evaluate the models from different viewpoints. Only 12 of the 31 simulated prostheses proved a sufficient level of functionality: among these, the optimal solution was an articulation having two actuated revolute joints with orthogonal axes for the elevation of the upper arm in any vertical plane and a frictional joint for the passive adjustment of the humeral intra-extra rotation. A prototype of the mechanism is at the clinical test stage.

Rapid Molecular Microbiologic Diagnosis of Prosthetic Joint Infection

PubMed Central

Cazanave, Charles; Greenwood-Quaintance, Kerryl E.; Hanssen, Arlen D.; Karau, Melissa J.; Schmidt, Suzannah M.; Gomez Urena, Eric O.; Mandrekar, Jayawant N.; Osmon, Douglas R.; Lough, Lindsay E.; Pritt, Bobbi S.; Steckelberg, James M.

2013-01-01

We previously showed that culture of samples obtained by prosthesis vortexing and sonication was more sensitive than tissue culture for prosthetic joint infection (PJI) diagnosis. Despite improved sensitivity, culture-negative cases remained; furthermore, culture has a long turnaround time. We designed a genus-/group-specific rapid PCR assay panel targeting PJI bacteria and applied it to samples obtained by vortexing and sonicating explanted hip and knee prostheses, and we compared the results to those with sonicate fluid and periprosthetic tissue culture obtained at revision or resection arthroplasty. We studied 434 subjects with knee (n = 272) or hip (n = 162) prostheses; using a standardized definition, 144 had PJI. Sensitivities of tissue culture, of sonicate fluid culture, and of PCR were 70.1, 72.9, and 77.1%, respectively. Specificities were 97.9, 98.3, and 97.9%, respectively. Sonicate fluid PCR was more sensitive than tissue culture (P = 0.04). PCR of prosthesis sonication samples is more sensitive than tissue culture for the microbiologic diagnosis of prosthetic hip and knee infection and provides same-day PJI diagnosis with definition of microbiology. The high assay specificity suggests that typical PJI bacteria may not cause aseptic implant failure. PMID:23658273

Dose-dependent cytotoxicity evaluation of graphite nanoparticles for diamond-like carbon film application on artificial joints.

PubMed

Liao, T T; Deng, Q Y; Wu, B J; Li, S S; Li, X; Wu, J; Leng, Y X; Guo, Y B; Huang, N

2017-01-24

While a diamond-like carbon (DLC)-coated joint prosthesis represents the implant of choice for total hip replacement in patients, it also leads to concern due to the cytotoxicity of wear debris in the form of graphite nanoparticles (GNs), ultimately limiting its clinical use. In this study, the cytotoxicity of various GN doses was evaluated. Mouse macrophages and osteoblasts were incubated with GNs (<30 nm diameter), followed by evaluation of cytotoxicity by means of assessing inflammatory cytokines, results of alkaline phosphatase assays, and related signaling protein expression. Cytotoxicity evaluation showed that cell viability decreased in a dose-dependent manner (10-100 μg ml -1 ), and steeply declined at GNs concentrations greater than 30 μg ml -1 . Noticeable cytotoxicity was observed as the GN dose exceeded this threshold due to upregulated receptor of activator of nuclear factor kB-ligand expression and downregulated osteoprotegerin expression. Meanwhile, activated macrophage morphology was observed as a result of the intense inflammatory response caused by the high doses of GNs (>30 μg ml -1 ), as observed by the increased release of TNF-α and IL-6. The results suggest that GNs had a significant dose-dependent cytotoxicity in vitro, with a lethal dose of 30 μg ml -1 leading to dramatic increases in cytotoxicity. Our GN cytotoxicity evaluation indicates a safe level for wear debris-related arthropathy and could propel the clinical application of DLC-coated total hip prostheses.

A 3D finite element model to investigate prosthetic interface stresses of different posterior tibial slope.

PubMed

Shen, Yi; Li, Xiaomiao; Fu, Xiaodong; Wang, Weili

2015-11-01

Posterior tibial slope that is created during proximal tibial resection in total knee arthroplasty has emerged as an important factor in the mechanics of the knee joint and the surgical outcome. But the ideal degree of posterior tibial slope for recovery of the knee joint function and preventions of complications remains controversial and should vary in different racial groups. The objective of this paper is to investigate the effects of posterior tibial slope on contact stresses in the tibial polyethylene component of total knee prostheses. Three-dimensional finite element analysis was used to calculate contact stresses in tibial polyethylene component of total knee prostheses subjected to a compressive load. The 3D finite element model of total knee prosthesis was constructed from the images produced by 3D scanning technology. Stresses in tibial polyethylene component were calculated with four different posterior tibial slopes (0°, 3°, 6° and 9°). The 3D finite element model of total knee prosthesis we presented was well validated. We found that the stress distribution in the polythene as evaluated by the distributions of the von Mises stress, the maximum principle stress, the minimum principle stress and the Cpress were more uniform with 3° and 6° posterior tibial slopes than with 0° and 9° posterior tibial slopes. Moreover, the peaks of the above stresses and trends of changes with increasing degree of knee flexion were more ideal with 3° and 6° posterior slopes. The results suggested that the tibial component inclination might be favourable to 7°-10° so far as the stress distribution is concerned. The range of the tibial component inclination also can decrease the wear of polyethylene. Chinese posterior tibial slope is bigger than in the West, and the current domestic use of prostheses is imported from the West, so their demands to tilt back bone cutting can lead to shorten the service life of prostheses; this experiment result is of important clinical significance, guiding orthopaedic surgeon after the best angle to cut bone.

The accuracy and precision of radiostereometric analysis in upper limb arthroplasty.

PubMed

Ten Brinke, Bart; Beumer, Annechien; Koenraadt, Koen L M; Eygendaal, Denise; Kraan, Gerald A; Mathijssen, Nina M C

2017-06-01

Background and purpose - Radiostereometric analysis (RSA) is an accurate method for measurement of early migration of implants. Since a relation has been shown between early migration and future loosening of total knee and hip prostheses, RSA plays an important role in the development and evaluation of prostheses. However, there have been few RSA studies of the upper limb, and the value of RSA of the upper limb is not yet clear. We therefore performed a systematic review to investigate the accuracy and precision of RSA of the upper limb. Patients and methods - PRISMA guidelines were followed and the protocol for this review was published online at PROSPERO under registration number CRD42016042014. A systematic search of the literature was performed in the databases Embase, Medline, Cochrane, Web of Science, Scopus, Cinahl, and Google Scholar on April 25, 2015 based on the keywords radiostereometric analysis, shoulder prosthesis, elbow prosthesis, wrist prosthesis, trapeziometacarpal joint prosthesis, humerus, ulna, radius, carpus. Articles concerning RSA for the analysis of early migration of prostheses of the upper limb were included. Quality assessment was performed using the MINORS score, Downs and Black checklist, and the ISO RSA Results - 23 studies were included. Precision values were in the 0.06-0.88 mm and 0.05-10.7° range for the shoulder, the 0.05-0.34 mm and 0.16-0.76° range for the elbow, and the 0.16-1.83 mm and 11-124° range for the TMC joint. Accuracy data from marker- and model-based RSA were not reported in the studies included. Interpretation - RSA is a highly precise method for measurement of early migration of orthopedic implants in the upper limb. However, the precision of rotation measurement is poor in some components. Challenges with RSA in the upper limb include the symmetrical shape of prostheses and the limited size of surrounding bone, leading to over-projection of the markers by the prosthesis. We recommend higher adherence to RSA guidelines and encourage investigators to publish long-term follow-up RSA studies.

The operation of the century: total hip replacement.

PubMed

Learmonth, Ian D; Young, Claire; Rorabeck, Cecil

2007-10-27

In the 1960s, total hip replacement revolutionised management of elderly patients crippled with arthritis, with very good long-term results. Today, young patients present for hip-replacement surgery hoping to restore their quality of life, which typically includes physically demanding activities. Advances in bioengineering technology have driven development of hip prostheses. Both cemented and uncemented hips can provide durable fixation. Better materials and design have allowed use of large-bore bearings, which provide an increased range of motion with enhanced stability and very low wear. Minimally invasive surgery limits soft-tissue damage and facilitates accelerated discharge and rehabilitation. Short-term objectives must not compromise long-term performance. Computer-assisted surgery will contribute to reproducible and accurate placement of implants. Universal economic constraints in healthcare services dictate that further developments in total hip replacement will be governed by their cost-effectiveness.

[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.

Seeding arterial prostheses with vascular endothelium. The nature of the lining.

PubMed Central

Herring, M B; Dilley, R; Jersild, R A; Boxer, L; Gardner, A; Glover, J

1979-01-01

Arterial prostheses seeded with autogenous vascular endothelium demonstrate a well-organized, cellular, inner lining. To determine the nature of the lining cells, six animals underwent replacement of the infrarenal aorta with Dacron prostheses. During the preparation of three such grafts, endothelium was scraped from the saphenous vein with a steel wool pledget, suspended in chilled Sack's solution, and mixed with blood used to preclot the graft. This suspension was omitted from the three control grafts. After six weeks, the grafts were removed, rinsed and examined. Fluorescent Factor VIII related antigen (F VIII-RA) strongly stained the lining cells. Silver nitrate Haütchen and electron microscopy preparations revealed a lining pattern characteristic of vascular endothelium. Endothelial cell-specific Weibel-Palade bodies were identified in the lining cell cytoplasm. Masson's trichrome staining revealed a relatively collagen-poor connective tissue within the seeded fabric. Transmission electron microscopy disclosed vascular smooth muscle cells between the seeded graft fabric and the lining cells. Vasa vasorum, arising from the outer capsule, penetrated the fabric to supply the inner capsules of the seeded grafts. It is concluded that the cells lining seeded canine arterial prostheses are true vascular endothelium supported by vascular smooth muscle cells, that the lining contains minimal connective tissue, and that vasa vasorum develop. Unseeded control grafts lacked these features. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. Fig. 7. Fig. 8. Fig. 9. Fig. 10. PMID:464684

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...

A Meta-Analysis Examining Differences in Short-Term Outcomes Between Sutureless and Conventional Aortic Valve Prostheses.

PubMed

Hurley, Eoghan T; O'Sullivan, Katie E; Segurado, Ricardo; Hurley, John P

2015-01-01

Sutureless aortic valve prostheses are anchored by radial force in a mechanism similar to that of transcatheter aortic valve implantation. Transcatheter aortic valve implantation is associated with an increased permanent pacemaker (PPM) requirement in a significant proportion of patients. We undertook a meta-analysis to examine the incidence of PPM insertion associated with sutureless compared with conventional surgical aortic valve replacement. A systematic review was conducted in accordance with the Prisma guidelines. All searches were performed on August 10, 2014. Studies between 2007 and 2014 were included in the search. A total of 832 patients were included in the sutureless group and 3,740 in the conventional group. Aortic cross-clamp (39.8 vs 62.4 minutes; P < 0.001) and cardiopulmonary bypass (64.9 vs 86.7 minutes; P = 0.002) times were shorter in the sutureless group. Permanent pacemaker implantation rate was higher in the sutureless cohort (9.1% vs 2.4%; P = 0.025). Sutureless aortic valve prostheses are associated with significantly shorter cardiopulmonary bypass and aortic cross-clamp times and a higher incidence of PPM insertion than conventional. Further investigation of the prognostic significance is required.

The Development of an Accelerometer System for Measuring Pelvic Motion During Walking.

DTIC Science & Technology

1979-01-01

9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT, PROJECT, T ASK AFIT STUDENT AT: University of Oxford CONTROLLING OFFICE NAME AND...bones, joints or muscles and physiotherapy to improve the functioning of impaired lower limbs. When irreparable damage occurs, the normal locomotor system...restoring near normal functioning of the locomotor system. Any improvement in surgical procedures, physiotherapy techniques, orthoses or prostheses

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

Novel double-layer Silastic testicular prosthesis with controlled release of testosterone in vitro, and its effects on castrated rats

PubMed Central

Chen, Hui-Xing; Yang, Shi; Ning, Ye; Shao, Hai-Hao; Ma, Meng; Tian, Ru-Hui; Liu, Yu-Fei; Gao, Wei-Qiang; Li, Zheng; Xia, Wei-Liang

2017-01-01

Testicular prostheses have been used to deal with anorchia for nearly 80 years. Here, we evaluated a novel testicular prosthesis that can controllably release hormones to maintain physiological levels of testosterone in vivo for a long time. Silastic testicular prostheses with controlled release of testosterone (STPT) with different dosages of testosterone undecanoate (TU) were prepared and implanted into castrated Sprague-Dawley rats. TU oil was applied by oral administration to a separate group of castrated rats. Castrated untreated and sham-operated groups were used as controls. Serum samples from every group were collected to measure the levels of testosterone (T), follicle-stimulating hormone and luteinizing hormone (LH). Maximum intracavernous penile pressure (ICPmax) was recorded. The prostates and seminal vesicles were weighed and subjected to histology, and a terminal dexynucleotidyl transferase-mediated UTP nick end labeling (TUNEL) assay was used to evaluate apoptosis. Our results revealed that the weights of these tissues and the levels of T and LH showed significant statistical differences in the oral administration and TU replacement groups compared with the castrated group (P < 0.05). Compared with the sham-operated group, the ICPmax, histology and TUNEL staining for apoptosis, showed no significant differences in the hormone replacement groups implanted with medium and high doses of STPT. Our results suggested that this new STPT could release TU stably through its double semi-permeable membranes with excellent biocompatibility. The study provides a new approach for testosterone replacement therapy. PMID:27174160

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: ...

Neuronal ensemble control of prosthetic devices by a human with tetraplegia

NASA Astrophysics Data System (ADS)

Hochberg, Leigh R.; Serruya, Mijail D.; Friehs, Gerhard M.; Mukand, Jon A.; Saleh, Maryam; Caplan, Abraham H.; Branner, Almut; Chen, David; Penn, Richard D.; Donoghue, John P.

2006-07-01

Neuromotor prostheses (NMPs) aim to replace or restore lost motor functions in paralysed humans by routeing movement-related signals from the brain, around damaged parts of the nervous system, to external effectors. To translate preclinical results from intact animals to a clinically useful NMP, movement signals must persist in cortex after spinal cord injury and be engaged by movement intent when sensory inputs and limb movement are long absent. Furthermore, NMPs would require that intention-driven neuronal activity be converted into a control signal that enables useful tasks. Here we show initial results for a tetraplegic human (MN) using a pilot NMP. Neuronal ensemble activity recorded through a 96-microelectrode array implanted in primary motor cortex demonstrated that intended hand motion modulates cortical spiking patterns three years after spinal cord injury. Decoders were created, providing a `neural cursor' with which MN opened simulated e-mail and operated devices such as a television, even while conversing. Furthermore, MN used neural control to open and close a prosthetic hand, and perform rudimentary actions with a multi-jointed robotic arm. These early results suggest that NMPs based upon intracortical neuronal ensemble spiking activity could provide a valuable new neurotechnology to restore independence for humans with paralysis.

Protocol for concomitant temporomandibular joint custom-fitted total joint reconstruction and orthognathic surgery utilizing computer-assisted surgical simulation.

PubMed

Movahed, Reza; Teschke, Marcus; Wolford, Larry M

2013-12-01

Clinicians who address temporomandibular joint (TMJ) pathology and dentofacial deformities surgically can perform the surgery in 1 stage or 2 separate stages. The 2-stage approach requires the patient to undergo 2 separate operations and anesthesia, significantly prolonging the overall treatment. However, performing concomitant TMJ and orthognathic surgery (CTOS) in these cases requires careful treatment planning and surgical proficiency in the 2 surgical areas. This article presents a new treatment protocol for the application of computer-assisted surgical simulation in CTOS cases requiring reconstruction with patient-fitted total joint prostheses. The traditional and new CTOS protocols are described and compared. The new CTOS protocol helps decrease the preoperative workup time and increase the accuracy of model surgery. Copyright © 2013 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

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

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 ...

Gait asymmetry of transfemoral amputees using mechanical and microprocessor-controlled prosthetic knees.

PubMed

Kaufman, Kenton R; Frittoli, Serena; Frigo, Carlo A

2012-06-01

Amputees walk with an asymmetrical gait, which may lead to future musculoskeletal degenerative changes. The purpose of this study was to compare the gait asymmetry of active transfemoral amputees while using a passive mechanical knee joint or a microprocessor-controlled knee joint. Objective 3D gait measurements were obtained in 15 subjects (12 men and 3 women; age 42, range 26-57). Research participants were longtime users of a mechanical prosthesis (mean 20 years, range 3-36 years). Joint symmetry was calculated using a novel method that includes the entire waveform throughout the gait cycle. There was no significant difference in hip, knee and ankle kinematics symmetry when using the different knee prostheses. In contrast, the results demonstrated a significant improvement in lower extremity joint kinetics symmetry when using the microprocessor-controlled knee. Use of the microprocessor-controlled knee joint resulted in improved gait symmetry. These improvements may lead to a reduction in the degenerative musculoskeletal changes often experienced by amputees. Copyright © 2011 Elsevier Ltd. All rights reserved.

Five-year results after valve replacement with the Björk-Shiley 70 degrees convexo-concave prosthesis.

PubMed

Koldsland, S; Svennevig, J L; Abdelnoor, M; Aas, H; Semb, G

1992-01-01

In the 18 months up to July 1983, 120 Björk-Shiley convexo-concave prostheses with 70 degrees opening angle were implanted in 47 women and 61 men aged 19-78 (mean 58.6) years. The prosthetic valves were aortic in 65 cases, mitral in 23 and both aortic and mitral in 20 cases. Emergency operation was required in ten cases, and concomitant surgery was performed in 43 (39.8%). The early mortality was 5.5%. A follow-up study, comprising 498 patient years, revealed 73.1% 5-year survival. There were three mechanical failures of prosthesis, in one of which re-replacement was successful. Elective prosthesis replacement was performed in four other cases judged to be at high risk of strut fracture.

Practical considerations for volumetric wear analysis of explanted hip arthroplasties.

PubMed

Langton, D J; Sidaginamale, R P; Holland, J P; Deehan, D; Joyce, T J; Nargol, A V F; Meek, R D; Lord, J K

2014-01-01

Wear debris released from bearing surfaces has been shown to provoke negative immune responses in the recipient. Excessive wear has been linked to early failure of prostheses. Analysis using coordinate measuring machines (CMMs) can provide estimates of total volumetric material loss of explanted prostheses and can help to understand device failure. The accuracy of volumetric testing has been debated, with some investigators stating that only protocols involving hundreds of thousands of measurement points are sufficient. We looked to examine this assumption and to apply the findings to the clinical arena. We examined the effects on the calculated material loss from a ceramic femoral head when different CMM scanning parameters were used. Calculated wear volumes were compared with gold standard gravimetric tests in a blinded study. Various scanning parameters including point pitch, maximum point to point distance, the number of scanning contours or the total number of points had no clinically relevant effect on volumetric wear calculations. Gravimetric testing showed that material loss can be calculated to provide clinically relevant degrees of accuracy. Prosthetic surfaces can be analysed accurately and rapidly with currently available technologies. Given these results, we believe that routine analysis of explanted hip components would be a feasible and logical extension to National Joint Registries. Cite this article: Bone Joint Res 2014;3:60-8.

Rapid Prototyping for In Vitro Knee Rig Investigations of Prosthetized Knee Biomechanics: Comparison with Cobalt-Chromium Alloy Implant Material

PubMed Central

Schröder, Christian; Steinbrück, Arnd; Müller, Tatjana; Woiczinski, Matthias; Chevalier, Yan; Müller, Peter E.; Jansson, Volkmar

2015-01-01

Retropatellar complications after total knee arthroplasty (TKA) such as anterior knee pain and subluxations might be related to altered patellofemoral biomechanics, in particular to trochlear design and femorotibial joint positioning. A method was developed to test femorotibial and patellofemoral joint modifications separately with 3D-rapid prototyped components for in vitro tests, but material differences may further influence results. This pilot study aims at validating the use of prostheses made of photopolymerized rapid prototype material (RPM) by measuring the sliding friction with a ring-on-disc setup as well as knee kinematics and retropatellar pressure on a knee rig. Cobalt-chromium alloy (standard prosthesis material, SPM) prostheses served as validation standard. Friction coefficients between these materials and polytetrafluoroethylene (PTFE) were additionally tested as this latter material is commonly used to protect pressure sensors in experiments. No statistical differences were found between friction coefficients of both materials to PTFE. UHMWPE shows higher friction coefficient at low axial loads for RPM, a difference that disappears at higher load. No measurable statistical differences were found in knee kinematics and retropatellar pressure distribution. This suggests that using polymer prototypes may be a valid alternative to original components for in vitro TKA studies and future investigations on knee biomechanics. PMID:25879019

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.

Experiences in the provision, fitting and supply of external breast prostheses: findings from a national survey.

PubMed

Gallagher, P; Buckmaster, A; O'Carroll, S; Kiernan, G; Geraghty, J

2009-11-01

A good-quality external breast prosthesis and prosthesis-fitting service is integral to recovery post-mastectomy. However, this area of care has minimal information or research available. The aim of this study was to investigate women's experience of the provision, fitting, supply and use of breast prostheses in Ireland. Three national surveys were undertaken with women (n = 527), breast care nurses (BCNs) (n = 32) and retail prosthesis fitters (n = 12). The findings identified the importance of the prosthesis for shape, appearance to self, appearance to others, sense of well-being, self-confidence and femininity. Dissatisfaction with weight, comfort and movement of the prosthesis was identified. Cost and travel distance were found to influence the replacement of the prosthesis. Dissatisfaction emerged with the display and choice of products, and brochure availability at the prosthesis fitting. Women preferred to be fitted for the first silicone prosthesis by a BCN in a hospital setting whereas for the replacement prosthesis they preferred a trained fitter at a specialized prosthesis supplier. BCNs and retail fitters identified the need for service guidelines and increased availability of professional development opportunities in prosthesis-fitting. These findings contributed to the development of standards of care for breast prosthesis-fitting services to benefit women and to provide guidelines for those providing the service.

Whole-body angular momentum during stair walking using passive and powered lower-limb prostheses.

PubMed

Pickle, Nathaniel T; Wilken, Jason M; Aldridge, Jennifer M; Neptune, Richard R; Silverman, Anne K

2014-10-17

Individuals with a unilateral transtibial amputation have a greater risk of falling compared to able-bodied individuals, and falling on stairs can lead to serious injuries. Individuals with transtibial amputations have lost ankle plantarflexor muscle function, which is critical for regulating whole-body angular momentum to maintain dynamic balance. Recently, powered prostheses have been designed to provide active ankle power generation with the goal of restoring biological ankle function. However, the effects of using a powered prosthesis on the regulation of whole-body angular momentum are unknown. The purpose of this study was to use angular momentum to evaluate dynamic balance in individuals with a transtibial amputation using powered and passive prostheses relative to able-bodied individuals during stair ascent and descent. Ground reaction forces, external moment arms, and joint powers were also investigated to interpret the angular momentum results. A key result was that individuals with an amputation had a larger range of sagittal-plane angular momentum during prosthetic limb stance compared to able-bodied individuals during stair ascent. There were no significant differences in the frontal, transverse, or sagittal-plane ranges of angular momentum or maximum magnitude of the angular momentum vector between the passive and powered prostheses during stair ascent or descent. These results indicate that individuals with an amputation have altered angular momentum trajectories during stair walking compared to able-bodied individuals, which may contribute to an increased fall risk. The results also suggest that a powered prosthesis provides no distinct advantage over a passive prosthesis in maintaining dynamic balance during stair walking. Copyright © 2014 Elsevier Ltd. All rights reserved.

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.

Development of speech prostheses: current status and recent advances

PubMed Central

Brumberg, Jonathan S; Guenther, Frank H

2010-01-01

Brain–computer interfaces (BCIs) have been developed over the past decade to restore communication to persons with severe paralysis. In the most severe cases of paralysis, known as locked-in syndrome, patients retain cognition and sensation, but are capable of only slight voluntary eye movements. For these patients, no standard communication method is available, although some can use BCIs to communicate by selecting letters or words on a computer. Recent research has sought to improve on existing techniques by using BCIs to create a direct prediction of speech utterances rather than to simply control a spelling device. Such methods are the first steps towards speech prostheses as they are intended to entirely replace the vocal apparatus of paralyzed users. This article outlines many well known methods for restoration of communication by BCI and illustrates the difference between spelling devices and direct speech prediction or speech prosthesis. PMID:20822389

[Computer-aided method and rapid prototyping for the personalized fabrication of a silicone bandage digital prosthesis].

PubMed

Ventura Ferreira, Nuno; Leal, Nuno; Correia Sá, Inês; Reis, Ana; Marques, Marisa

2014-01-01

The fabrication of digital prostheses has acquired growing importance not only for the possibility for the patient to overcome psychosocial trauma but also to promote grip functionality. An application method of three dimensional-computer-aided design technologies for the production of passive prostheses is presented by means of a fifth finger amputee clinical case following bilateral hand replantation.Three-dimensional-computerized tomography was used for the collection of anthropometric images of the hands. Computer-aided design techniques were used to develop the digital file-based prosthesis from the reconstruction images by inversion and superimposing the contra-lateral finger images. The rapid prototyping manufacturing method was used for the production of a silicone bandage prosthesis prototype. This approach replaces the traditional manual method by a virtual method that is basis for the optimization of a high speed, accurate and innovative process.

Fifteen-year survival of anterior all-ceramic cantilever resin-bonded fixed dental prostheses.

PubMed

Kern, Matthias

2017-01-01

The aim of this follow-up study was to report the long-term outcome of all-ceramic cantilever resin-bonded fixed dental prostheses (RBFDPs). In 16 patients (mean age of 33.3±17.5years) 22 RBFDPs made from a glass-infiltrated alumina ceramic (In-Ceram) were inserted with a phosphate monomer containing luting agent after air-abrasion of the retainer wings. The abutment preparation included a shallow groove on the cingulum and a small proximal box. The restorations replacing 16 maxillary and 6 mandibular incisors were followed over a mean observation time of 188.7 months. No restoration debonded. Two RBFDPs fractured and were lost 48 and 214 months after insertion, respectively. The 10-year and 15-year survival rates were both 95.4% and dropped to 81.8% after 18 years. Anterior all-ceramic cantilever RBFDPs exhibited an excellent clinical longevity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Fixed and mobile-bearing total ankle prostheses: Effect on tibial bone strain.

PubMed

Terrier, Alexandre; Fernandes, Caroline Sieger; Guillemin, Maïka; Crevoisier, Xavier

2017-10-01

Total ankle replacement is associated to a high revision rate. To improve implant survival, the potential advantage of prostheses with fixed bearing compared to mobile bearing is unclear. The objective of this study was to test the hypothesis that fixed and mobile bearing prostheses are associated with different biomechanical quantities typically associated to implant failure. With a validated finite element model, we compared three cases: a prosthesis with a fixed bearing, a prosthesis with a mobile bearing in a centered position, and a prosthesis with mobile bearing in an eccentric position. Both prostheses were obtained from the same manufacturer. They were tested on seven tibias with maximum axial compression force during walking. We tested the hypothesis that there was a difference of bone strain, bone-implant interfacial stress, and bone support between the three cases. We also evaluated, for the three cases, the correlations between bone support, bone strain and bone-implant interfacial stress. There were no statistically significant differences between the three cases. Overall, bone support was mainly trabecular, and less effective in the posterior side. Bone strain and bone-implant interfacial stress were strongly correlated to bone support. Even if slight differences are observed between fixed and mobile bearing, it is not enough to put forward the superiority of one of these implants regarding their reaction to axial compression. When associated to the published clinical results, our study provides no argument to warn surgeons against the use of two-components fixed bearing implants. Copyright © 2017 Elsevier Ltd. All rights reserved.

A comparison of laser-welded titanium and conventional cast frameworks supported by implants in the partially edentulous jaw: a 3-year prospective multicenter study.

PubMed

Jemt, T; Henry, P; Lindén, B; Naert, I; Weber, H; Bergström, C

2000-01-01

The purpose of this prospective multicenter study was to evaluate and compare the clinical performance of laser-welded titanium fixed partial implant-supported prostheses with conventional cast frameworks. Forty-two partially edentulous patients were provided with Brånemark system implants and arranged into 2 groups. Group A was provided with a conventional cast framework with porcelain veneers in one side of the jaw and a laser-welded titanium framework with low-fusing porcelain on the other side. The patients in group B had an old implant prosthesis replaced by a titanium framework prosthesis. The patients were followed for 3 years after prosthesis placement. Clinical and radiographic data were collected and analyzed. Only one implant was lost, and all prostheses were still in function after 3 years. The 2 framework designs showed similar clinical performance with few clinical complications. Only one abutment screw (1%) and 9 porcelain tooth units (5%) fractured. Four prostheses experienced loose gold screws (6%). In group A, marginal bone loss was similar for both designs of prostheses, with a mean of 1.0 mm and 0.3 mm in the maxilla and mandible, respectively. No bone loss was observed on average in group B. No significant relationship (P > 0.05) was observed between marginal bone loss and placement of prosthesis margin or prosthesis design. The use of laser-welded titanium frameworks seems to present similar clinical performance to conventional cast frameworks in partial implant situations after 3 years.

Efficacy of total ankle replacement with meniscal-bearing devices: a systematic review and meta-analysis.

PubMed

Stengel, Dirk; Bauwens, Kai; Ekkernkamp, Axel; Cramer, Jörg

2005-03-01

The reputation of total ankle arthroplasty for treating end-stage ankle arthritis of different origin is dubious. Newer generation meniscal-bearing prostheses may have overcome the known problems with earlier implants. There is, however, no systematic approach to the available scientific evidence allowing for a critical appraisal of their benefits and risks. We conducted a systematic review meta-analysis of studies exploring the efficacy of three-component total ankle prostheses. We demanded a minimum sample size of 20 subjects, at least 1 year of follow-up, and a clinically relevant study endpoint (for example, results of ankle scoring, ranges of motion [ROM], complications, and survival rates). We identified citations by electronic medical databases and a manual search. We made no restrictions for language. We used an eight-point quality scale to appraise methodological standards, and modeled outcomes by random-effects meta-regression analysis. Eighteen of 1830 citations including 1086 patients fulfilled our eligibility criteria. Studies met a median of four quality items (interquartile range 2-5). Outcome estimates did not depend on methodological quality. There was no evidence of strong heterogeneity or publication bias. With standardized 100-point ankle and hindfoot scores, formal data pooling was possible for 10 trials (n =497), showing a mean improvement of 45.2 points (95% confidence interval [CI] 39.3-51.1). Overall ROM improved slightly (6.3 degrees, 95%CI 2.2-10.5 degrees ). Weighted complication rates ranged from 1.6% (deep infections) to 14.7% (impingement). Secondary surgery had to be performed in 12.5%, whereas secondary arthrodesis was necessary in 6.3%. The weighted 5-year prosthesis survival rate averaged 90.6%. Ankle arthroplasty improves pain and joint mobility in end-stage ankle arthritis. Its performance in comparison to the current reference standard (that is, ankle fusion) remains to be defined in a properly designed randomized trial.

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

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.

Compatibility of the totally replaced hip. Reduction of wear by amorphous diamond coating.

PubMed

Santavirta, Seppo

2003-12-01

Particulate wear debris in totally replaced hips causes adverse local host reactions. The extreme form of such a reaction, aggressive granulomatosis, was found to be a distinct condition and different from simple aseptic loosening. Reactive and adaptive tissues around the totally replaced hip were made of proliferation of local fibroblast like cells and activated macrophages. Methylmethacrylate and high-molecular-weight polyethylene were shown to be essentially immunologically inert implant materials, but in small particulate form functioned as cellular irritants initiating local biological reactions leading to loosening of the implants. Chromium-cobalt-molybdenum is the most popular metallic implant material; it is hard and tough, and the bearings of this metal are partially self-polishing. In total hip implants, prerequisites for longevity of the replaced hip are good biocompatibility of the materials and sufficient tribological properties of the bearings. The third key issue is that the bearing must minimize frictional shear at the prosthetic bone-implant interface to be compatible with long-term survival. Some of the approaches to meet these demands are alumina-on-alumina and metal-on-metal designs, as well as the use of highly crosslinked polyethylene for the acetabular component. In order to avoid the wear-based deleterious properties of the conventional total hip prosthesis materials or coatings, the present work included biological and tribological testing of amorphous diamond. Previous experiments had demonstrated that a high adhesion of tetrahedral amorphous carbon coatings to a substrate can be achieved by using mixing layers or interlayers. Amorphous diamond was found to be biologically inert, and simulator testing indicated excellent wear properties for conventional total hip prostheses, in which either the ball or both bearing surfaces were coated with hydrogen-free tetrahedral amorphous diamond films. Simulator testing with such total hip prostheses showed no measurable wear or detectable delamination after 15,000,000 test cycles corresponding to 15 years of clinical use. The present work clearly shows that wear is one of the basic problems with totally replaced hips. Diamond coating of the bearing surfaces appears to be an attractive solution to improve longevity of the totally replaced hip.

Adaptive sports ankle prosthetics. Interview by Sarah A. Curran.

PubMed

Lyle, David K

2012-09-01

Participating in sport at all levels is gaining a dedicated following and this is also apparent in individuals with an amputation. Currently, there is a wide variety of ankle prostheses available which attempt to provide function, control, and comfort, as well as good aesthetic appeal. Participation in sport, however, increases the demands placed upon ankle prostheses. This can compromise function and performance, and constrain the opportunities of participation in various outdoor and water sports. In acknowledging this limitation and the need to develop more versatile ankle prostheses, this article introduces the evolution of a prototype ankle prosthesis referred to as "Adaptive Sports Ankle." The ankle prosthesis, which is compatible with any foot pyramid adapter, offers the same range of motion as the normal human ankle joint and is made up of components that are chemical and corrosion resistant. These design features that are specifically created to accommodate below-the-knee amputees provide an ideal prosthesis for those wishing to lead an active lifestyle and participate in aquatic (i.e. swimming, surfing, and scuba diving), snowboarding, and equestrian activities. Although it is acknowledged that there is a need to establish research on the Adaptive Sports Ankle, its introduction to the market will enhance and expand opportunities of those individuals with a lower limb amputation to lead an active and healthy lifestyle.

[Late complications following Björk-Shiley and St. Jude Medical heart valve replacement].

PubMed

Horstkotte, D; Körfer, R; Budde, T; Haerten, K; Schulte, H D; Bircks, W; Loogen, F

1983-05-01

Valve-related complications after Björk-Shiley mitral (n = 475), aortic (n = 424), or mitral-aortic implantation (n = 119) were compared to complications after St. Jude mitral (n = 173), aortic (n = 152), and St. Jude mitral and aortic (n = 63) replacements. The 1,018 consecutive patients with Björk-Shiley valves had been operated upon between 1974 and 1982, those with St. Jude valves between 1978 and 1982. All patients were placed on anticoagulant therapy with phenprocoumon early after operation and no significant intergroup differences in the effectiveness of the anticoagulant therapy were found. At a comparable follow-up time of approximately 23 months, 24 major thromboembolic episodes were observed after Björk-Shiley mitral (BSM) and 3 after St. Jude mitral valve implantation (SJM), corresponding to a thromboembolic rate of 2.82/100 patient years with BSM and 0.93/100 patient years with SJM. After aortic valve replacements, 1.93 events in 100 patient years occurred after Björk-Shiley aortic (BSA) and 0.73 after St. Jude aortic implantation (SJA). In patients with double valve replacements, these rates were 3.2 (BSM + BSA) and 0.88 (SJM + SJA), respectively. The cerebral vessels were involved in 52% and the arteries of the extremities in 22% of these major events. Six Björk-Shiley prostheses had to be replaced because of valve thrombosis. The overall incidence of severe hemorrhagic complications was 2.94/100 patient years in BSM and 1.79 in SJM. After aortic valve replacement, we found rates of 1.80/100 patient years (BSA) and 2.57/100 patient years (SJA), respectively. Intravascular hemolysis no longer seems to be a significant clinical problem. However, indications of red cell damage after heart valve replacement were significantly greater in patients with perivalvular leakage, valve thrombosis, or dysfunction than in those with normally functioning prostheses. Reoperations were necessary because of valve thrombosis (0.46%), perivalvular leakage (2.2%), or prosthetic valve endocarditis with concomitant perivalvular regurgitation (0.46%). One valve had to be replaced because of fracture of the outlet strut of a BSM prosthesis. Hemorrhage due to the anticoagulant treatment was thus the most frequent complication, without significant intergroup differences, while thromboembolic complications were significantly more frequent after Björk-Shiley mitral, aortic, and double valve replacements than after St. Jude implantation. This may lead to the consideration of a change in the prophylaxis of thrombus formations with the St. Jude valve, especially in aortic valve replacements with sinus rhythm.

ELECTROMYOGRAPHIC EVALUATION OF MASTICATION AND SWALLOWING IN ELDERLY INDIVIDUALS WITH MANDIBULAR FIXED IMPLANTSUPPORTED PROSTHESES

PubMed Central

Berretin-Felix, Giédre; Nary, Hugo; Padovani, Carlos Roberto; Trindade, Alceu Sergio; Machado, Wellington Monteiro

2008-01-01

This study evaluated the effect of implant-supported oral rehabilitation in the mandible on the electromyographic activity during mastication and swallowing in edentulous elderly individuals. Fifteen patients aged more than 60 years were evaluated, being 10 females and 5 males. All patients were edentulous, wore removable complete dentures on both dental arches, and had the mandibular dentures replaced by implant-supported prostheses. All patients were submitted to electromyographic evaluation of the masseter, superior orbicularis oris muscles, and the submental muscles, before surgery and 3, 6 and 18 months postoperatively, using foods of different textures. The results obtained at the different periods were analyzed statistically by Kruskal-Wallis non-parametric test. Statistical analysis showed that only the masseter muscle had a significant loss in electromyographic activity (p<0.001), with a tendency of similar response for the submental muscles. Moreover, there was an increase in the activity of the orbicularis oris muscle during rubber chewing after treatment, yet without statistically significant difference. Mandibular fixed implant-supported prostheses in elderly individuals revealed a decrease in electromyographic amplitude for the masseter muscles during swallowing, which may indicate adaptation to new conditions of stability provided by fixation of the complete denture in the mandibular arch. PMID:19089202

External breast prostheses in post-mastectomy care: women's qualitative accounts.

PubMed

Gallagher, P; Buckmaster, A; O'Carroll, S; Kiernan, G; Geraghty, J

2010-01-01

A good-quality external breast prosthesis and prosthesis-fitting service is an integral part of the recovery process post-mastectomy. However, this is an area of care that has minimal information or research available. The aim of this research was to investigate women's experience of the provision, fitting, supply and use of breast prostheses in Ireland. To ascertain women's own personal and subjective experiences, five focus groups with 47 women recruited through national cancer advocacy/support organizations and four Follow-up Breast Clinics throughout Ireland were conducted. As a result, five main themes emerged: (1) The fitting experience--Fitting? (2) Post-mastectomy products--Having? (3) Cost--Affording? (4) Information--Knowing? and (5) Adaptation--Accepting? The emerging themes pinpointed the impact of the fitting experience, fitting environment and the qualities of a prosthesis fitter on a woman's experience in obtaining a first or replacement breast prosthesis; the importance of the physical characteristics of the prosthesis and mastectomy bras; cost, affordability and entitlements; a lack of and perceived difficulty in getting information; and the myriad of personal and social impacts of a breast prosthesis for the woman. These findings are integral for the development of standards of practice in the fitting and supply of external breast prostheses in post-mastectomy care.

Survival of anterior cantilevered all-ceramic resin-bonded fixed dental prostheses made from zirconia ceramic.

PubMed

Sasse, Martin; Kern, Matthias

2014-06-01

This study evaluated the clinical outcome of all-ceramic resin-bonded fixed dental prostheses (RBFDPs) with a cantilevered single-retainer design made from zirconia ceramic. Forty-two anterior RBFDPs with a cantilevered single-retainer design were made from yttrium oxide-stabilized zirconium oxide ceramic. RBFDPs were inserted using Panavia 21 TC as luting agent after air-abrasion of the ceramic bonding surface. During a mean observation time of 61.8 months two debondings occurred. Both RBFDPs were rebonded using Panavia 21 TC and are still in function. A caries lesion was detected at one abutment tooth during recall and was treated with a composite filling. Therefore, the overall six-year failure-free rate according to Kaplan-Meier was 91.1%. If only debonding was defined as failure the survival rate increased to 95.2%. Since all RBFDPs are still in function the overall survival rate was 100% after six years. Cantilevered zirconia ceramic RBFDPs showed promising results within the observation period. Single-retainer resin-bonded fixed dental prostheses made from zirconia ceramic show very good mid-term clinical survival rates. They should therefore be considered as a viable treatment alternative for the replacement of single missing anterior teeth especially as compared to an implant therapy. Copyright © 2014 Elsevier Ltd. All rights reserved.

Hip and knee joints are more stabilized than driven during the stance phase of gait: an analysis of the 3D angle between joint moment and joint angular velocity.

PubMed

Dumas, R; Cheze, L

2008-08-01

Joint power is commonly used in orthopaedics, ergonomics or sports analysis but its clinical interpretation remains controversial. Some basic principles on muscle actions and energy transfer have been proposed in 2D. The decomposition of power on 3 axes, although questionable, allows the same analysis in 3D. However, these basic principles have been widely criticized, mainly because bi-articular muscles must be considered. This requires a more complex computation in order to determine how the individual muscle force contributes to drive the joint. Conversely, with simple 3D inverse dynamics, the analysis of both joint moment and angular velocity directions is essential to clarify when the joint moment can contribute or not to drive the joint. The present study evaluates the 3D angle between the joint moment and the joint angular velocity and investigates when the hip, knee and ankle joints are predominantly driven (angle close to 0 degrees and 180 degrees ) or stabilized (angle close to 90 degrees ) during gait. The 3D angle curves show that the three joints are never fully but only partially driven and that the hip and knee joints are mainly stabilized during the stance phase. The notion of stabilization should be further investigated, especially for subjects with motion disorders or prostheses.

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.

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

Jacobs, G.B.; Kiraly, R.J.; Nose, Y.

The objective of the study is to define the human thorax in a quantitative statistical manner such that the information will be useful to the designers of cardiac prostheses, both total replacement and assist devices. This report pertains specifically to anatomical parameters relevant to the total cardiac prosthesis. This information will also be clinically useful in that the proposed recipient of a cardiac prosthesis can by simple radiography be assured of an adequate fit with the prosthesis prior to the implantation.

Sealing maxillary titanium obturators with removable flexible caps.

PubMed

Reitemeier, Bernd; Schaal, Wolfgang; Wolf, Annette; Walter, Michael

2016-03-01

Maxillary obturator prostheses with hollow metal obturators can be made of titanium to reduce weight. To prevent perforation of the hollow obturator during modifications, the obturator is slightly undersized and covered with a replaceable cap. This cap is made of a soft copolymer to facilitate uncomplicated modifications in the resection area and to improve function. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Corrosion on the acetabular liner taper from retrieved modular metal-on-metal total hip replacements.

PubMed

Gascoyne, Trevor C; Dyrkacz, Richard M; Turgeon, Thomas R; Burnell, Colin D; Wyss, Urs P; Brandt, Jan-M

2014-10-01

Eight retrieved metal-on-metal total hip replacements displayed corrosion damage along the cobalt-chromium alloy liner taper junction with the Ti alloy acetabular shell. Scanning electron microscopy indicated the primary mechanism of corrosion to be grain boundary and associated crevice corrosion, which was likely accelerated through mechanical micromotion and galvanic corrosion resulting from dissimilar alloys. Coordinate measurements revealed up to 4.3mm(3) of the cobalt-chromium alloy taper surface was removed due to corrosion, which is comparable to previous reports of corrosion damage on head-neck tapers. The acetabular liner-shell taper appears to be an additional source of metal corrosion products in modular total hip replacements. Patients with these prostheses should be closely monitored for signs of adverse reaction towards corrosion by-products. Copyright © 2014 Elsevier Inc. All rights reserved.

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

EAO consensus conference: economic evaluation of implant-supported prostheses.

PubMed

Beikler, Thomas; Flemmig, Thomas F

2015-09-01

There are various alternatives for the management of oral conditions that may lead to or already have lead to partial or full edentulism. Economic evaluations measure the efficiency of alternative healthcare interventions and provide useful information for decision-making and the allocation of scarce resources. The current English literature dealing with "cost-effectiveness" of dental implant therapy versus different alternative treatment modalities, that is, complete and fixed partial dentures, root canal, and periodontal treatment, has been included in this narrative review. Due to the high heterogeneity within the literature, a meta-analysis could not be conducted. The available evidence from economic evaluations indicated that for the treatment of central incisors with irreversible pulpitis and coronal lesions, root canal treatments were most cost-effective initial treatment options. When initial root canal treatments failed, orthograde retreatments were most cost-effective. When root canal retreatments failed, extractions and replacement with single implant-supported crowns were more cost-effective compared to fixed or removable partial dentures. In the treatment of periodontitis in molars with Class I furcation invasion, non-surgical periodontal therapy was more effective and costed less than implant-supported single crowns. For the replacement of single missing teeth, two evaluations indicated that implant-supported single crowns provided better outcomes in terms of greater quality-adjusted tooth years or survival rates at lower costs compared to fixed partial prostheses. Another economic evaluation found that implant-supported crowns costed more, but provided greater survival rates compared to fixed partial dentures. For the restoration of edentulous mandibles, two evaluations indicated that overdentures retained by two or four implants improved oral health-related quality of life outcomes, but costed more than complete dentures. To better assess the efficiency of implant-supported prostheses in various clinical conditions, more economic evaluations are needed that follow well-established methodologies in health economics. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The role of synovial fluid analysis in the detection of periprosthetic hip and knee infections: a systematic review and meta-analysis.

PubMed

De Fine, Marcello; Giavaresi, Gianluca; Fini, Milena; Illuminati, Andrea; Terrando, Silvio; Pignatti, Giovanni

2018-05-01

This study tried to ascertain (1) the accuracy of synovial fluid white blood cell count and polymorphonucleate percentage in the diagnosis of periprosthetic hip and knee infections, (2) which test yielded superior test performance, and (3) the influence on diagnostic accuracy of study characteristics such as patient number, study design, study level, anatomic site, and threshold value. A systematic search was conducted including papers assessing more effective cutoffs for synovial fluid tests, having comparative design, evaluating an exclusive cohort of hip or knee prostheses, including a clear definition of infected cases, and reporting sufficient data for the calculation of true-positive, false-positive, false-negative, and true-negative. A total of 375 articles were collected and, given the inclusion criteria, ten manuscripts were included. These studies assessed 1155 hip prostheses (276 infected cases) and 1235 knee prostheses (401 infected cases). The specificity of synovial fluid white blood cell count was significantly increased by using the threshold value ≥ 3000 cell/μL (p = 0.006); the sensitivity of polymorphonucleate percentage was significantly higher in detecting knee infections (p = 0.034). Both tests had a high specificity and sensitivity in detecting periprosthetic joint infections, and no clear superiority of one over the other existed. Furthermore, cutoff and anatomic site significantly influenced synovial fluid white blood cell count and polymorphonucleate percentage, respectively. Synovial fluid analysis is adequate in differentiating patients with periprosthetic hip and knee infections. Our data confirms international guidelines suggesting the use of 3000 cell/μL as cutoff threshold for synovial fluid white blood cell count. Since an anatomic site effect has been demonstrated, the goal of future studies will be to identify different cutoffs for hip and knee prostheses.

Antibiotic cements in articular prostheses: current orthopaedic concepts.

PubMed

Langlais, F; Belot, N; Ropars, M; Thomazeau, H; Lambotte, J C; Cathelineau, G

2006-08-01

The possibilities and limits of antibiotic cements (ACs) have been assessed by many researchers. ACs are now approved by many drug agencies, including the US Food and Drug Administration (approval in 2003), with widespread use in prophylaxis and curative treatments. Laboratory experiments have achieved satisfactory antibiotic delivery without impairing the mechanical properties of ACs. Implantation in large animals (e.g. sheep) showed an antibiotic concentration in the bone cortex four times the minimal inhibitory concentration (MIC) 6 months after implantation. Human pharmacokinetics during total hip replacement (THR) show antibiotic concentrations 20 times the MIC in drainage fluids. No toxic concentrations have been detected in blood or urine, and no allergies, toxic effects, mechanical failures or selection of resistant microorganisms have been observed. Antibioprophylaxis has been assessed in prospective studies in over 1600 cases. In data from the Scandinavian arthroplasty registers, with an exhaustive follow-up of more than 240000 THRs, infection rate was reduced by ca. 50% (0.9% compared with 1.9%). In prostheses with severe infection, use of AC increases the infection control rate from 86% to 93% when using two-stage prosthetic exchanges. In moderate infection, a similar infection control rate (86%) was achieved either by two-stage exchange without local antibiotic or by one-stage exchange with AC; however, one-stage exchange achieved better functional results at lower cost and with reduced pain and hospital stay. Therefore, AC prophylaxis is widely used in countries with prostheses registers (Northern Europe), and use of ACs as treatment for infected prostheses is often considered as the gold standard in the EU and North America. However, AC is only an adjuvant treatment, and excision of infected and devascularized tissues as well as systemic antibiotic treatment managed by a multidisciplinary team remain the main factors of infection control.

Integration of the Residual Limb with Prostheses via Direct Skin-Bone-Peripheral Nerve Interface

DTIC Science & Technology

2017-10-01

discussion of stated goals not met. Description shall include pertinent data and graphs in sufficient detail to explain any significant results achieved...A succinct description of the methodology used shall be provided. As the project progresses to completion, the emphasis in reporting in this section...correlation for eq. 1 was r = 0.836. The detailed description of how the joint moments and EMG activities were obtained and processed has been

Practical considerations for volumetric wear analysis of explanted hip arthroplasties

PubMed Central

Langton, D. J.; Sidaginamale, R. P.; Holland, J. P.; Deehan, D.; Joyce, T. J.; Nargol, A. V. F.; Meek, R. D.; Lord, J. K.

2014-01-01

Objectives Wear debris released from bearing surfaces has been shown to provoke negative immune responses in the recipient. Excessive wear has been linked to early failure of prostheses. Analysis using coordinate measuring machines (CMMs) can provide estimates of total volumetric material loss of explanted prostheses and can help to understand device failure. The accuracy of volumetric testing has been debated, with some investigators stating that only protocols involving hundreds of thousands of measurement points are sufficient. We looked to examine this assumption and to apply the findings to the clinical arena. Methods We examined the effects on the calculated material loss from a ceramic femoral head when different CMM scanning parameters were used. Calculated wear volumes were compared with gold standard gravimetric tests in a blinded study. Results Various scanning parameters including point pitch, maximum point to point distance, the number of scanning contours or the total number of points had no clinically relevant effect on volumetric wear calculations. Gravimetric testing showed that material loss can be calculated to provide clinically relevant degrees of accuracy. Conclusions Prosthetic surfaces can be analysed accurately and rapidly with currently available technologies. Given these results, we believe that routine analysis of explanted hip components would be a feasible and logical extension to National Joint Registries. Cite this article: Bone Joint Res 2014;3:60–8. PMID:24627327

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

Equally good fixation of cemented and uncemented cups in total trapeziometacarpal joint prostheses. A randomized clinical RSA study with 2-year follow-up.

PubMed

Hansen, Torben Baek; Stilling, Maiken

2013-02-01

Cup failure is a recognized problem in total trapeziometacarpal (TM) joint prostheses; it may be related to poor fixation, which can be revealed by radiostereometric analysis (RSA). We compared the early implant migration of cemented trapezium cups to that of uncemented screw cups. In a prospective, parallel-group, randomized patient-blinded clinical trial, we included 32 hands in 28 patients (5 males) with a mean age of 58 (40-77) years and with Eaton stage-2 or -3 osteoarthritis of the trapeziometacarpal joint. Patients were randomized to surgery with a cemented DLC all-polyethylene cup (C) (n = 16) or an uncemented hydroxyapatite-coated chrome-cobalt Elektra screw cup (UC) (n = 16). Uncemented cups were inserted without threading of the bone. Stereoradiographs for evaluation of cup migration (primary effect size) and DASH and pain scores were obtained during 2 years of follow-up. The 2-year total translation (TT) was similar (p = 0.2): 0.24 mm (SD 0.10) for the C (n = 11) and 0.19 mm (SD 0.16) for the UC (n = 11). Variances were similar (p = 0.4). Judged by RSA, 2 UC cups and 1 C cup became loose (TT > 1 mm). Both UC cups were found to be loose at revision. Grip strength, pain, and DASH scores were similar between groups at all measurement points. Early implant fixation and clinical outcome were equally good with both cup designs. This is the first clinical RSA study on trapezium cups, and the method appears to be clinically useful for detection of loose implants.

Performance of automated multiplex PCR using sonication fluid for diagnosis of periprosthetic joint infection: a prospective cohort.

PubMed

Renz, Nora; Feihl, Susanne; Cabric, Sabrina; Trampuz, Andrej

2017-12-01

Sonication of explanted prostheses improved the microbiological diagnosis of periprosthetic joint infections (PJI). We evaluated the performance of automated multiplex polymerase chain reaction (PCR) using sonication fluid for the microbiological diagnosis of PJI. In a prospective cohort using uniform definition criteria for PJI, explanted joint prostheses were investigated by sonication and the resulting sonication fluid was analyzed by culture and multiplex PCR. McNemar's Chi-squared test was used to compare the performance of diagnostic tests. Among 111 patients, PJI was diagnosed in 78 (70%) and aseptic failure in 33 (30%). For the diagnosis of PJI, the sensitivity and specificity of periprosthetic tissue culture was 51 and 100%, of sonication fluid culture 58 and 100%, and of sonication fluid PCR 51 and 94%, respectively. Among 70 microorganisms, periprosthetic tissue culture grew 52 (74%), sonication fluid culture grew 50 (71%) and sonication fluid PCR detected 37 pathogens (53%). If only organisms are considered, for which primers are included in the test panel, PCR detected 37 of 58 pathogens (64%). The sonication fluid PCR missed 19 pathogens (predominantly oral streptococci and anaerobes), whereas 7 additional microorganisms were detected only by PCR (including Cutibacterium spp. and coagulase-negative staphylococci). The performance of multiplex PCR using sonication fluid is comparable to culture of periprosthetic tissue or sonication fluid. The advantages of PCR are short processing time (< 5 h) and fully automated procedure. However, culture technique is still needed due to the low sensitivity and the need of comprehensive susceptibility testing. Modification of primers or inclusion of additional ones may improve the performance of PCR, especially of low-virulent organisms.

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.

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 ...

Simultaneous mobile- and fixed-bearing total knee replacement in the same patients. A prospective comparison of mid-term outcomes using a similar design of prosthesis.

PubMed

Kim, Y-H; Kim, D-Y; Kim, J-S

2007-07-01

We conducted a randomised prospective study to evaluate the clinical and radiological results of a mobile- and fixed-bearing total knee replacement of similar design in 174 patients who had bilateral simultaneous knee replacement. The mean follow-up was for 5.6 years (5.2 to 6.1). The total knee score, pain score, functional score and range of movement were not statistically different (p > 0.05) between the two groups. Osteolysis was not seen in any knee in either group. Two knees (1%) in the mobile-bearing group required revision because of infection; none in the fixed-bearing group needed revision. Excellent results can be achieved with both mobile- and fixed-bearing prostheses of similar design at mid-term follow-up. We could demonstrate no significant clinical advantage for a mobile bearing.

Rapidly growing non-tuberculous mycobacteria infection of prosthetic knee joints: A report of two cases.

PubMed

Kim, Manyoung; Ha, Chul-Won; Jang, Jae Won; Park, Yong-Beom

2017-08-01

Non-tuberculous mycobacteria (NTM) cause prosthetic knee joint infections in rare cases. Infections with rapidly growing non-tuberculous mycobacteria (RGNTM) are difficult to treat due to their aggressive clinical behavior and resistance to antibiotics. Infections of a prosthetic knee joint by RGNTM have rarely been reported. A standard of treatment has not yet been established because of the rarity of the condition. In previous reports, diagnoses of RGNTM infections in prosthetic knee joints took a long time to reach because the condition was not suspected, due to its rarity. In addition, it is difficult to identify RGNTM in the lab because special identification tests are needed. In previous reports, after treatment for RGNTM prosthetic infections, knee prostheses could not be re-implanted in all cases but one, resulting in arthrodesis or resection arthroplasty; this was most likely due to the aggressiveness of these organisms. In the present report, two cases of prosthetic knee joint infection caused by RGNTM (Mycobacterium abscessus) are described that were successfully treated, and in which prosthetic joints were finally reimplanted in two-stage revision surgery. Copyright © 2017 Elsevier B.V. All rights reserved.

Context-Dependent Upper Limb Prosthesis Control for Natural and Robust Use.

PubMed

Amsuess, Sebastian; Vujaklija, Ivan; Goebel, Peter; Roche, Aidan D; Graimann, Bernhard; Aszmann, Oskar C; Farina, Dario

2016-07-01

Pattern recognition and regression methods applied to the surface EMG have been used for estimating the user intended motor tasks across multiple degrees of freedom (DOF), for prosthetic control. While these methods are effective in several conditions, they are still characterized by some shortcomings. In this study we propose a methodology that combines these two approaches for mutually alleviating their limitations. This resulted in a control method capable of context-dependent movement estimation that switched automatically between sequential (one DOF at a time) or simultaneous (multiple DOF) prosthesis control, based on an online estimation of signal dimensionality. The proposed method was evaluated in scenarios close to real-life situations, with the control of a physical prosthesis in applied tasks of varying difficulties. Test prostheses were individually manufactured for both able-bodied and transradial amputee subjects. With these prostheses, two amputees performed the Southampton Hand Assessment Procedure test with scores of 58 and 71 points. The five able-bodied individuals performed standardized tests, such as the box&block and clothes pin test, reducing the completion times by up to 30%, with respect to using a state-of-the-art pure sequential control algorithm. Apart from facilitating fast simultaneous movements, the proposed control scheme was also more intuitive to use, since human movements are predominated by simultaneous activations across joints. The proposed method thus represents a significant step towards intelligent, intuitive and natural control of upper limb prostheses.

Rehabilitation for bilateral amputation of fingers

USGS Publications Warehouse

Stapanian, Martin A.; Stapanian, Adrienne M.P.; Staley, Keith E.

2010-01-01

We describe reconstructive surgeries, therapy, prostheses, and adaptations for a patient who experienced bilateral amputation of all five fingers of both hands through the proximal phalanges in January 1992. The patient made considerable progress in the use of his hands in the 10 mo after amputation, including nearly a 120% increase in the active range of flexion of metacarpophalangeal joints. In late 1992 and early 1993, the patient had "on-top plasty" surgeries, in which the index finger remnants were transferred onto the thumb stumps, performed on both hands. The increased web space and functional pinch resulting from these procedures made many tasks much easier. The patient and occupational therapists set challenging goals at all times. Moreover, the patient was actively involved in the design and fabrication of all prostheses and adaptations or he developed them himself. Although he was discharged from occupational therapy in 1997, the patient continues to actively find new solutions for prehension and grip strength 18 yr after amputation.

Quadriceps muscle injury in trans-femoral amputees.

PubMed

Alsindi, Z; Datta, D

1998-12-01

Two male trans-femoral amputees using modular trans-femoral prostheses lost control and fell to the ground when their prosthetic knees gave way. The semi-automatic knee lock malfunctioned in the first case while the free knee stabilising mechanics gave way in the second case. This resulted in a high tensile force acting on the contralateral quadriceps muscle causing it to rupture. As there are a significant number of patients with both kinds of prostheses it is important to be aware of this possibility so that necessary actions can be taken to minimise its occurrence. Even with the currently available weight activated stance phase control, the prosthetic knee will give way if the knee is flexed more than 20 degrees on weight bearing. Good power and control of hip extensors on the amputation side is needed to control the prosthetic knee joint, especially in the early stage of the walking cycle, i.e., from heel strike to mid-stance. Quadriceps muscle injury in amputees, as far as the authors are aware, has not been reported previously.

Quantifying the Incoming Jet Past Heart Valve Prostheses Using Vortex Formation Dynamics

NASA Astrophysics Data System (ADS)

Pierrakos, Olga

2005-11-01

Heart valve (HV) replacement prostheses are associated with hemodynamic compromises compared to their native counterparts. Traditionally, HV performance and hemodynamics have been quantified using effective orifice size and pressure gradients. However, quality and direction of flow are also important aspects of HV function and relate to HV design, implantation technique, and orientation. The flow past any HV is governed by the generation of shear layers followed by the formation and shedding of organized flow structures in the form of vortex rings (VR). For the first time, vortex formation (VF) in the LV is quantified. Vortex energy measurements allow for calculation of the critical formation number (FN), which is the time at which the VR reaches its maximum strength. Inefficiencies in HV function result in critical FN decrease. This study uses the concept of FN to compare mitral HV prostheses in an in-vitro model (a silicone LV model housed in a piston-driven heart simulator) using Time-resolved Digital Particle Image Velocimetry. Two HVs were studied: a porcine HV and bileaflet MHV, which was tested in an anatomic and non-anatomic orientation. The results suggest that HV orientation and design affect the critical FN. We propose that the critical FN, which is contingent on the HV design, orientation, and physical flow characteristics, serve as a parameter to quantify the incoming jet and the efficiency of the HV.

R&D on dental implants breakage

NASA Astrophysics Data System (ADS)

Croitoru, Sorin Mihai; Popovici, Ion Alexandru

2017-09-01

Most used dental implants for human dental prostheses are of two steps type: first step means implantation and, after several months healing and osseointegration, second step is prosthesis fixture. For sure, dental implants and prostheses are meant to last for a lifetime. Still, there are unfortunate cases when dental implants break. This paper studies two steps dental implants breakage and proposes a set of instruments for replacement and restoration of the broken implant. First part of the paper sets the input data of the study: structure of the studied two steps dental implants based on two Romanian patents and values of the loading forces found in practice and specialty papers. In the second part of the paper, using DEFORM 2D™ FEM simulation software, worst case scenarios of loading dental implants are studied in order to determine which zones and components of the dental implant set are affected (broken). Last part of the paper is dedicated to design and presentation of a set for extracting and cutting tools used to restore the broken implant set.

Clinical and radiological mid-term results of the thrust plate prosthesis

PubMed Central

v.d. Daele, R.; Simon, U.; Goetze, C.

2009-01-01

The purpose of this study was to perform an objective clinical and radiological assessment of the thrust plate prosthesis (TPP). Fifty-three prostheses were evaluated clinically using the Harris hip score (HHS), visual analog scale (VAS), and radiographically before surgery, at the time of discharge, and postoperatively after on average of 8.09 (range 4.61–9.93) years. The average HHS significantly (p ≤ 0.05) improved from 48 (range 18–77) points to 95 (range 46–100) points. The VAS revealed significant (p ≤ 0.05) reduction of pain at rest and under load. Radiographic analysis showed a considerable potential for osteolysis under the thrust plate. Sixteen prostheses revealed signs of radiolucent zones. In general, there was a good clinical outcome with no major limitations in function. Radiographic changes under the thrust plate indicate an adaptation processes resulting from changed biomechanics. This study suggests that the TPP could be a good alternative in total hip replacement in younger patients. PMID:19184010

[Aftercare for durability and profitability of single-unit and multi-unit fixed dental prostheses].

PubMed

de Baat, C; van Loveren, C; van der Maarel-Wierink, C D; Witter, D J; Creugers, N H J

2013-01-01

An important aim ofa treatment with single-unit and multi-unit fixed dental prostheses is a durable and profitable treatment outcome. That requires aftercare, too. First, the frequency of routine oral examinations should be assessed, using an individual risk profile. The objectives of the routine oral examinations are the prevention and, when necessary, the treatment of pathological conditions and complications. With regard to prevention, attention should be paid to information and instruction, oral biofilm and calculus, non-functional activities, hard tooth tissues, periodontal and peri-implant tissues, and saliva. Subsequently, it can be determined whether the intended durability and profitability have been achieved or can still be achieved, whether or not through indicated adjustments. Special attention should be paid to endodontically treated teeth. Restorative, repair or replacement treatments may be indicated in case ofcomplications, such as loose single- or multi-unitfixed dental prosthesis, fracture of a fixed dental prosthesis unit, lost tooth pulp vitality, tooth root fracture, and implant or implant abutment problems.

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.

Model-oriented review and multi-body simulation of the ossicular chain of the human middle ear.

PubMed

Volandri, G; Di Puccio, F; Forte, P; Manetti, S

2012-11-01

The ossicular chain of the human middle ear has a key role in sound conduction since it transfers vibrations from the tympanic membrane to the cochlea, connecting the outer and the inner part of the hearing organ. This study reports firstly a description of the main anatomical features of the middle ear to introduce a detailed survey of its biomechanics, focused on model development, with a collection of geometric, inertial and mechanical/material parameters. The joint issues are particularly discussed from the perspective of developing a model of the middle ear both explanatory and predictive. Such a survey underlines the remarkable dispersion of data, due also to the lack of a standardization of the experimental techniques and conditions. Subsequently, a 3D multi-body model of the ossicular chain and other structures of the middle ear is described. Such an approach is justified as the ossicles were proven to behave as rigid bodies in the human hearing range and was preferred to the more widely used finite element one as it simplifies the model development and improves joint modeling. The displacement of the umbo (a reference point of the tympanic membrane) in the 0.3-6kHz frequency range was defined as input of the model, while the stapes footplate displacement as output. A parameter identification procedure was used to find parameter values for reproducing experimental and numerical reference curves taken from the literature. This simple model might represent a valid alternative to more complex models and might provide a useful tool to simulate pathological/post-surgical/post-traumatic conditions and evaluate ossicular replacement prostheses. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

Current antibiotic management of prosthetic joint infections in Italy: the 'Udine strategy'.

PubMed

Bassetti, Matteo; Cadeo, Barbara; Villa, Giovanni; Sartor, Assunta; Cainero, Vanni; Causero, Araldo

2014-09-01

The rate of prosthetic joint infections followed and cured at our institution is constantly increasing, in line with epidemiological data from the recent literature. This is probably related to the greater number of knee and hip prostheses implanted every year. For intermediate and late infections, only the two-stage approach is applied, as this demonstrates the best outcome in our experience. Particular attention is paid to microbiological isolation of the pathogen: multiple samples of tissue are collected during the interventions, and kept in culture for a longer period of time than usual. Sonication of prosthetic devices is used to enhance the sensitivity and specificity of the microbiological cultures. Histological examination influences surgical choices either towards implantation of a new prosthesis or replacement of the spacer. An empirical antibiotic backbone of a glycopeptide/lipopeptide and rifampicin is chosen, due to the leading role of Gram-positive bacteria in this setting and the high incidence of methicillin resistance in our centre (>30%), followed by an antibiotic regimen containing linezolid. If specific risk factors are present, an anti-Gram-negative drug is added to the regimen. Duration of therapy depends upon the approach that is chosen, usually being 6 weeks when the prosthesis is removed. Despite at the moment being limited by its small sample size, data from our experience confirms that our empirical approach may represent a valid choice during the early phase of treatment, by keeping linezolid for a step-down therapy of shorter duration (4 weeks). © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

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.

Artificial organs versus regenerative medicine: is it true?

PubMed

Nosé, Yukihiko; Okubo, Hisashi

2003-09-01

Individuals engaged in the fields of artificial kidney and artificial heart have often mistakenly stated that "the era of artificial organs is over; regenerative medicine is the future." Contrarily, we do not believe artificial organs and regenerative medicine are different medical technologies. As a matter of fact, artificial organs developed during the last 50 years have been used as a bridge to regeneration. The only difference between regenerative medicine and artificial organs is that artificial organs for the bridge to regeneration promote tissue regeneration in situ, instead of outside the body (for example, vascular prostheses, neuroprostheses, bladder substitutes, skin prostheses, bone prostheses, cartilage prostheses, ligament prostheses, etc.). All of these artificial organs are successful because tissue regeneration over a man-made prosthesis is established inside the patient's body (artificial organs to support regeneration). Another usage of the group of artificial organs for the bridge to regeneration is to sustain the functions of the patient's diseased organs during the regeneration process of the body's healthy tissues and/or organs. This particular group includes artificial kidney, hepatic assist, respiratory assist, and circulatory assist. Proof of regeneration of these healthy tissues and/or organs is demonstrated in the short-term recovery of end-stage organ failure patients (artificial organs for bridge to regeneration). A third group of artificial organs for the bridge to regeneration accelerates the regenerating process of the patient's healthy tissues and organs. This group includes neurostimulators, artificial blood (red cells) blood oxygenators, and plasmapheresis devices, including hemodiafiltrators. So-called "therapeutic artificial organs" fall into this category (artificial organs to accelerate regeneration). Thus, almost all of today's artificial organs are useful in the bridge to regeneration of healthy natural tissues and organs. It does not matter whether these tissues are cultivated inside or outside the patient's body. Thus, we strongly believe in the need for joint development programs between artificial organ technologies and regenerative medicine technologies. In particular, the importance of using both man-made substitute organ technologies and natural tissue-derived substitute organ technologies is stressed for improved medical care in the future.

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.

Bony integration of titanium implants with a novel bioactive calcium titanate (Ca4Ti3O10) surface treatment in a rabbit model.

PubMed

Haenle, Maximilian; Lindner, Tobias; Ellenrieder, Martin; Willfahrt, Manfred; Schell, Hanna; Mittelmeier, Wolfram; Bader, Rainer

2012-10-01

Nowadays total joint replacement is an indispensable component of modern medicine. The surfaces characteristics of cementless prostheses may be altered to achieve an accelerated and enduring bony integration. Classic surface coatings bear the risk of loosening or flaking from the implant body. This risk is excluded by the chemical conversion of the naturally existing TiO(2) surface layer into calcium titanate. The aim of this experimental animal study was to investigate the bony integration of implants with a new calcium titanate surface (Ca(4)Ti(3)O(10)) compared with a conventional standard Ti6Al4V surface. Cylindrical implants, made of titanium alloy (Ti6Al4V) were implanted in both lateral femoral condyles of New Zealand white rabbits. In each animal, an implant with and without surface treatment was inserted in a blinded manner. Animals were sacrificed after 4, 12, and 36 weeks, respectively. The axial pull-off forces were determined for 25 animals using a universal testing machine (Zwick Z010, Ulm, Germany). Furthermore, a histological analysis of the bony integration of the implants was performed in 12 specimens. In general, the pull-off forces for untreated and treated implants increased with longer survival times of the rabbits. No significant difference could be shown after 4 weeks between treated and untreated implants. After 12 weeks, the treated implants revealed a statistical significant higher pull-off force. After 36 weeks, the pull-off forces for treated and untreated implants aligned again. Titanium implants treated with calcium titanate, may offer an interesting and promising implant surface modification for endoprosthetic implants. They might lead to an accelerated osseointegration of total hip and knee replacements. Copyright © 2012 Wiley Periodicals, Inc.

Knowledge, attitude, and practice of dental professionals regarding the effect and management of food impaction associated with fixed partial denture prostheses: A survey.

PubMed

Nagarsekar, Aradhana; Gaunkar, Ridhima; Aras, Meena

2016-01-01

This survey was undertaken to assess dentist's opinion regarding the occurrence and pattern of food impaction in relation to fixed partial denture (FPD) prostheses, its commonly observed consequences, factors contributing to it, and its management. A descriptive survey was conducted on a sample size of 150 dental practitioners. The pro forma consisted of informed consent, demographic information, and questionnaire. The results were tallied and quantitative analysis was performed to obtain the descriptive statistics for the data using SPSS version 20. All the study respondents had come across patients who complained of food impaction in relation to FPD. The most common consequences of food impaction were proximal caries of the adjacent teeth and interdental bone loss. Majority of the dentists considered faulty FPD design with improper contact relation, improper crown contour, poor margin adaptation, and faulty pontic design as the most likely reason for food impaction. Repeating the FPD with emphasis on prescribing and reinforcing the use of proper interdental aids was considered as the ideal treatment option. It was also observed that about half of the dentists always communicated inadequate information of the FPD prostheses that needed replacement to the dental laboratory technician for the successive bridge. Most of the times, prosthodontists were consulted to rectify the problem of food impaction resulting from faulty FPD prostheses. However, it is obvious that it is easier and more prudent to prevent rather than treat food impaction. This study gives an overview of some of the common errors in designing the FPD prostheses which often lead to food impaction and measures to be taken to overcome them. It may be concluded as all the dentists participating in the survey agreed that food impaction is one of the common complaint among FPD Patients. Proximal caries and interdental bone loss were the prevalent outcomes of food impaction. Faulty FPD design was allegedly attributed as the reason for food impaction. Prosthodontists were routinely consulted to resolve the dilemma of food impaction. However, it is rational to prevent food impaction rather than to tackle the sequel later.

Intravalvular Implantation of Mitral Valve Prostheses

PubMed Central

Cooley, Denton A.; Ingram, Michael T.

1987-01-01

We describe a technique of intravalvular implantation of a low-profile prosthesis that has been used in nine patients with mitral valve lesions. This technique preserves the anterior and posterior chordae and papillary mechanisms, which may decrease the incidence of postoperative left ventricular dysfunction that has been noted following standard mitral valve replacement. The technique may also be useful in some patients with aortic and tricuspid regurgitation when the annulus and leaflets are relatively normal pathologically. (Texas Heart Institute Journal 1987;14:188-193) PMID:15229740

Improvement in the assessment of wear of total knee replacements using coordinate-measuring machine techniques.

PubMed

Blunt, L A; Bills, P J; Jiang, X-Q; Chakrabarty, G

2008-04-01

Total joint replacement is one of the most common elective surgical procedures performed worldwide, with an estimate of 1.5x 10(6) operations performed annually. Currently joint replacements are expected to function for 10-15 years; however, with an increase in life expectancy, and a greater call for knee replacement due to increased activity levels, there is a requirement to improve their function to offer longer-term improved quality of life for patients. Wear analysis of total joint replacements has long been an important means in determining failure mechanisms and improving longevity of these devices. The effectiveness of the coordinate-measuring machine (CMM) technique for assessing volumetric material loss during simulated life testing of a replacement knee joint has been proved previously by the present authors. The purpose of the current work is to present an improvement to this method for situations where no pre-wear data are available. To validate the method, simulator tests were run and gravimetric measurements taken throughout the test, such that the components measured had a known wear value. The implications of the results are then discussed in terms of assessment of joint functionality and development of standardized CMM-based product standards. The method was then expanded to allow assessment of clinically retrieved bearings so as to ascertain a measure of true clinical wear.

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

Tricuspid valve replacement: postoperative and long-term results.

PubMed

Van Nooten, G J; Caes, F; Taeymans, Y; Van Belleghem, Y; François, K; De Bacquer, D; Deuvaert, F E; Wellens, F; Primo, G

1995-09-01

A series of 146 consecutive patients who underwent tricuspid valve replacement at the University Brugmann Hospital between 1967 and 1987 was reviewed. Mean age at operation was 51.4 years (+/- 12.1 years). Different types of prostheses were implanted including porcine and bovine pericardial bioprostheses and older and bileaflet mechanical valves. Most patients were severely disabled by their cardiac disease before operation, with 30.1% in New York Heart Association functional class III and 69.9% in class IV. Operative mortality and hospital mortality rates (30 days) were high (16.4%). Incremental risk factors for hospital death included icterus (p < 0.005), preoperative hepatomegaly (p = 0.012), and New York Heart Association functional class IV (p = 0.013). Multivariate analysis only selected preoperative icterus (p < 0.01) as being independently significantly related to hospital mortality. The hospital survivors were followed up for a median of 94 months. A complete follow-up was available for all patients except two for 30 months or more. At 30 months the only two significant parameters were the type of myocardial protection (p = 0.024) and the year of operation (before 1977 or after [precardioplegia era or after], p = 0.011). There were 70 late deaths during the entire follow-up period. The univariate (log-rank statistics) incremental risk factor for late death was the type of tricuspid prosthesis (Smeloff-Cutter and Kay-Shiley versus St. Jude Medical versus bioprosthesis) (p = 0.04). A trend was observed for the type of operative myocardial protection (normothermia and coronary perfusion) (p = 0.06) and preoperative New York Heart Association functional class IV (p = 0.055). Actuarial survival was 74% at 60 months and 23.4% at 180 months. Cumulative follow-up added up to 1015 patient-years. In a more detailed analysis of the effect on survival of the type of tricuspid prosthesis, a significant difference was observed between the bioprostheses and some older mechanical prostheses (Smeloff-Cutter and Kay-Shiley) (p = 0.04) but not between the bioprostheses and the bileaflet valves (p = 0.15). When the follow-up period was stratified according to less than 7 years and more than 7 years of follow-up, no difference was observed for the first period, but for the late follow-up the new mechanical prostheses did better than the bioprostheses (p = 0.05), suggesting a degradation of the bioprostheses after 7 years and favoring mechanical prostheses for those patients with a good long-term prognosis.

Long-term stress distribution patterns of the ankle joint in varus knee alignment assessed by computed tomography osteoabsorptiometry.

PubMed

Onodera, Tomohiro; Majima, Tokifumi; Iwasaki, Norimasa; Kamishima, Tamotsu; Kasahara, Yasuhiko; Minami, Akio

2012-09-01

The stress distribution of an ankle under various physiological conditions is important for long-term survival of total ankle arthroplasty. The aim of this study was to measure subchondral bone density across the distal tibial joint surface in patients with malalignment/instability of the lower limb. We evaluated subchondral bone density across the distal tibial joint in patients with malalignment/instability of the knee by computed tomography (CT) osteoabsorptiometry from ten ankles as controls and from 27 ankles with varus deformity/instability of the knee. The quantitative analysis focused on the location of the high-density area at the articular surface, to determine the resultant long-term stress on the ankle joint. The area of maximum density of subchondral bone was located in the medial part in all subjects. The pattern of maximum density in the anterolateral area showed stepwise increases with the development of varus deformity/instability of the knee. Our results should prove helpful for designing new prostheses and determining clinical indications for total ankle arthroplasty.

Initial findings using the V8 hourglass-shaped valvuloplasty balloon for postdilatation in treating paravalvular leaks associated with transcatheter self-expanding aortic valve prosthesis.

PubMed

Latib, Azeem; Pedersen, Wesley; Maisano, Francesco; Lesser, John; Ruparelia, Neil; Figini, Filippo; Colombo, Antonio; Poulose, Anil; Kolbeck, James; Mooney, Michael; Schwartz, Robert; Youssef, Alicia; Ungs, David; Goldenberg, Irv; Sorajja, Paul

2016-06-01

The aim of this study was to assess the effect of a novel hourglass-shaped balloon on reduction of paravalvular leak (PVL) in patients undergoing transcatheter aortic valve replacement (TAVR) with self-expanding prostheses. An important limitation of TAVR compared with surgical aortic valve replacement remains the higher incidence of PVL. A commonly used strategy to treat PVL is balloon postdilatation (BPD); however, the optimal technique for treating PVL after TAVR is unknown. We examined consecutive patients with severe, symptomatic aortic stenosis who underwent TAVR with the Medtronic CoreValve followed by BPD with an InterValve V8 balloon for PVL grade ≥2+. Data from echocardiographic, multidetector computed tomographic, and angiographic images were reviewed. The primary endpoint was successful reduction in PVL to grade 1+ or less as assessed by intraprocedural echocardiography. Eleven patients were studied (median age, 82 years; 64% female). Ten patients (91%) demonstrated successful reduction in PVL after V8 BPD. In three patients, PVL was reduced to zero or trace. PVL remained unchanged in one patient (2+). Two patients had complete heart block associated with valve deployment and received permanent pacemakers. There were no occurrences of annular injury or major adverse clinical events. BPD with the V8 hourglass-shaped balloon was feasible in reducing PVL from self-expanding TAVR prostheses. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Basic Science Considerations in Primary Total Hip Replacement Arthroplasty

PubMed Central

Mirza, Saqeb B; Dunlop, Douglas G; Panesar, Sukhmeet S; Naqvi, Syed G; Gangoo, Shafat; Salih, Saif

2010-01-01

Total Hip Replacement is one of the most common operations performed in the developed world today. An increasingly ageing population means that the numbers of people undergoing this operation is set to rise. There are a numerous number of prosthesis on the market and it is often difficult to choose between them. It is therefore necessary to have a good understanding of the basic scientific principles in Total Hip Replacement and the evidence base underpinning them. This paper reviews the relevant anatomical and biomechanical principles in THA. It goes on to elaborate on the structural properties of materials used in modern implants and looks at the evidence base for different types of fixation including cemented and uncemented components. Modern bearing surfaces are discussed in addition to the scientific basis of various surface engineering modifications in THA prostheses. The basic science considerations in component alignment and abductor tension are also discussed. A brief discussion on modular and custom designs of THR is also included. This article reviews basic science concepts and the rationale underpinning the use of the femoral and acetabular component in total hip replacement. PMID:20582240

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

PubMed Central

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

2009-01-01

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

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 ...

Twenty-first century challenges for biomaterials

PubMed Central

Hench, Larry L.; Thompson, Ian

2010-01-01

During the 1960s and 1970s, a first generation of materials was specially developed for use inside the human body. These developments became the basis for the field of biomaterials. The devices made from biomaterials are called prostheses. Professor Bill Bonfield was one of the first to recognize the importance of understanding the mechanical properties of tissues, especially bone, in order to achieve reliable skeletal prostheses. His research was one of the pioneering efforts to understand the interaction of biomaterials with living tissues. The goal of all early biomaterials was to ‘achieve a suitable combination of physical properties to match those of the replaced tissue with a minimal toxic response in the host’. By 1980, there were more than 50 implanted prostheses in clinical use made from 40 different materials. At that time, more than three million prosthetic parts were being implanted in patients worldwide each year. A common feature of most of the 40 materials was biological ‘inertness’. Almost all materials used in the body were single-phase materials. Most implant materials were adaptations of already existing commercial materials with higher levels of purity to eliminate release of toxic by-products and minimize corrosion. This article is a tribute to Bill Bonfield's pioneering efforts in the field of bone biomechanics, biomaterials and interdisciplinary research. It is also a brief summary of the evolution of bioactive materials and the opportunities for tailoring the composition, texture and surface chemistry of them to meet five important challenges for the twenty-first century. PMID:20484227

Advanced technologies for cardiac valvular replacement, transcatheter innovations and reconstructive surgery.

PubMed

Jamieson, W R Eric

2006-01-01

Since the 2002 Surgical Technology International monograph on valvular prostheses, there have been significant developmental and investigative advances. Aortic bioprostheses and mechanical prostheses have undergone design changes to optimize hemodynamics and prevent patient-prosthesis mismatch to have a potential satisfactory influence on survival. There has been continual technological improvements striving to bring forward advances that improve the durability of bioprostheses and reduce the thrombogenicity of mechanical prostheses. There also has been a continuance to preserve biological tissue with glutaraldehyde, rather than clinically evaluate other cross-linking technologies, by controlling or retarding calcification with therapies to control phospholipids and residual aldehydes. The techniques of mitral valve reconstruction have now been well established and new annuloplasty rings have been designed for the potential of maintaining the anatomical and physiological characteristics of the mitral annulus. Several objectives exist for annuloplasty, namely remodeling of the length and shape of the dilated annulus, prevention of dilatation of the annulus, and support for the potentially fragile area after partial-leaflet resection. Currently, there exists an emergence of catheter-based therapies for management of aortic stenosis and mitral regurgitation. For management of selected populations with critical aortic stenosis, techniques for aortic valve substitution have been developed for both antegrade and retrograde catheter techniques, as well as apical transventricular implantation. Mitral regurgitation has been addressed by experimental transcoronary sinus, stent-like devices and transventricular, edge-to-edge leaflet devices. The devices, descriptions and pictorial images comprise this monograph.

Development of a software for the design of custom-made hip prostheses using an open-source rapid application development environment.

PubMed

Viceconti, M; Testi, D; Gori, R; Zannoni, C

2000-01-01

The present work describes a technology transfer project called HIPCOM devoted to the re-engineering of the process used by a medical devices manufacturer to design custom-made hip prostheses. Although it started with insufficient support from the end-user management, a very tight scheduling and a moderate budget, the project developed into what is considered by all partners a success story. In particular, the development of the design software, called HIPCOM Interactive Design Environment (HIDE) was completed in a time shorter than any optimistic expectation. The software was quite stable since its first beta version, and once introduced at the user site it fully replaced the original procedure in less than two months. One year after the early adoption, more than 80 custom-made prostheses had been designed with HIDE and the user had reported only two bugs, both cosmetics. The scope of the present work was to report the development experience and to investigate the reasons for these positive results, with particular reference to the development procedure and the software architecture. The choice of TCL/TK as development language and the adoption of well-defined software architecture were found to be the success key factors. Other important determinants were found to be the adoption of an incremental software engineering strategy, well suited for small to medium projects and the presence in the development staff of a technology transfer expert.

Malleus-to-footplate prosthetic interposition: experience with 265 patients.

PubMed

Colletti, V; Fiorino, F G

1999-03-01

Absence of the long process of the incus with or without absence of the stapes head accounts for more than 80% of ossicular discontinuities. Total or partial replacement prostheses, made of various materials, are interposed to restore the transfer function of the middle ear. To simplify ossicular reconstruction, reduce operative times and costs, improve functional outcomes, and avoid the risk of infections, we have adopted, during the past 10 years, a technique that makes use of a personally designed alloplastic prosthetic device. The prosthesis connects the malleus to the footplate, even in the presence of the stapes superstructure. This malleus-to-footplate prosthesis consists in a plastipore-coated steel piston and hydroxyapatite head, complete with a groove. The groove is placed beneath the malleus neck after dissection of the tensor tympani tendon and the shaft of the piston on the footplate. Two hundred ninety primary ossiculoplasties with the malleus-to-footplate prostheses were performed in 265 patients from 1986 to 1995 in the ENT Department of the University of Verona. The average postoperative air-bone gap at 0.5 to 3 kHz was 11 dB at 1 year and 14 dB at 5 years. These outcomes are significantly better than those personally obtained previously with ossicular or alloplastic prostheses. No extrusions occurred. The structural characteristics of the malleus-to-foot-plate prosthesis endow the prosthesis with a high degree of biocompatibility and stability and optimal sound-transfer function. The rationale for this particular ossiculoplasty procedure is discussed.

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

Immediate and early function of Brånemark System implants placed in the esthetic zone: a 1-year prospective clinical multicenter study.

PubMed

Maló, Paulo; Friberg, Bertil; Polizzi, Giovanni; Gualini, Federico; Vighagen, Torbjörn; Rangert, Bo

2003-01-01

Immediate/early implant function means great benefits for patients and therapists because treatment time and cost can be substantially reduced. This concept has become an accepted alternative for complete arch fixed restorations in the mandible, and clinical documentation is emerging for other indications. The purpose of this prospective clinical multicenter study was to evaluate the outcome of implants placed in incisor, canine, and premolar regions in maxillas or mandibles. Implants were loaded with provisional crowns and bridges on the same day or within a few days and were followed up for 1 year during function. Four centers treated 76 patients each in need of an implant-retained prosthesis in the anterior and premolar regions in the maxilla or mandible. A total of 116 titanium implants with machined surfaces (Brånemark System , Nobel Biocare AB, Gothenburg, Sweden) were placed: 74 in maxillas and 42 in mandibles. Eighty-seven prostheses were made, of which 63 were single crowns and 24 were bridges (supported by 53 splinted implants). Twenty-two implants in 14 patients were placed in fresh extraction sites. The goal with the preparation and insertion technique was to achieve good primary implant stability and a minimum implant insertion torque of 30 Ncm before the implant was completely seated. The occlusion was adjusted to eliminate direct contact with the provisional prostheses. After 6 months, the patients received their permanent prostheses. Sixty-seven patients were followed for 1 year. Five implants were lost in five patients, three in the maxilla and two in the mandible. Four of the lost implants were single-tooth replacements and one was splinted. The cumulative survival rate (CSR) was 95.7% for all implants after 1 year and 93.7% and 98.1% for single-tooth and splinted implants, respectively. There were no implant losses in the extraction sites. The CSR of 96% at 1 year indicates that immediate function of Brånemark System implants placed in incisor to premolar regions in both jaws is a viable concept. More failures occurred with single-tooth replacements (6.3%) than with splinted implants (1.9%).

In vitro biomechanical comparison after fixed- and mobile-core artificial cervical disc replacement versus fusion

PubMed Central

Lou, Jigang; Li, Yuanchao; Wang, Beiyu; Meng, Yang; Wu, Tingkui; Liu, Hao

2017-01-01

Abstract In vitro biomechanical analysis after cervical disc replacement (CDR) with a novel artificial disc prosthesis (mobile core) was conducted and compared with the intact model, simulated fusion, and CDR with a fixed-core prosthesis. The purpose of this experimental study was to analyze the biomechanical changes after CDR with a novel prosthesis and the differences between fixed- and mobile-core prostheses. Six human cadaveric C2–C7 specimens were biomechanically tested sequentially in 4 different spinal models: intact specimens, simulated fusion, CDR with a fixed-core prosthesis (Discover, DePuy), and CDR with a mobile-core prosthesis (Pretic-I, Trauson). Moments up to 2 Nm with a 75 N follower load were applied in flexion–extension, left and right lateral bending, and left and right axial rotation. The total range of motion (ROM), segmental ROM, and adjacent intradiscal pressure (IDP) were calculated and analyzed in 4 different spinal models, as well as the differences between 2 disc prostheses. Compared with the intact specimens, the total ROM, segmental ROM, and IDP at the adjacent segments showed no significant difference after arthroplasty. Moreover, CDR with a mobile-core prosthesis presented a little higher values of target segment (C5/6) and total ROM than CDR with a fixed-core prosthesis (P > .05). Besides, the difference in IDP at C4/5 after CDR with 2 prostheses was without statistical significance in all the directions of motion. However, the IDP at C6/7 after CDR with a mobile-core prosthesis was lower than CDR with a fixed-core prosthesis in flexion, extension, and lateral bending, with significant difference (P < .05), but not under axial rotation. CDR with a novel prosthesis was effective to maintain the ROM at the target segment and did not affect the ROM and IDP at the adjacent segments. Moreover, CDR with a mobile-core prosthesis presented a little higher values of target segment and total ROM, but lower IDP at the inferior adjacent segment than CDR with a fixed-core prosthesis. PMID:29019902

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

An Investigation into a Gear-Based Knee Joint Designed for Lower Limb Prosthesis.

PubMed

Bhuiyan, M S H; Choudhury, I A; Dahari, M; Nukman, Y; Dawal, S Z

2017-01-01

A gear-based knee joint is designed to improve the performance of mechanical-type above-knee prostheses. The gear set with the help of some bracing, and bracket arrangement, is used to enable the prosthesis to follow the residual limb movement. The motion analysis and finite-element analysis (FEA) of knee joint components are carried out to assess the feasibility of the design. The maximum stress of 29.74 MPa and maximum strain of 2.393e-004 are obtained in the gear, whereas the maximum displacement of 7.975 mm occurred in the stopper of the knee arrangement. The factor of safety of 3.5 obtained from the FE analysis indicated no possibility of design failure. The results obtained from the FE analysis are then compared with the real data obtained from the literature for a similar subject. The pattern of motion analysis results has shown a great resemblance with the gait cycle of a healthy biological limb.

Identification of inducible nitric oxide synthase in human macrophages surrounding loosened hip prostheses.

PubMed Central

Watkins, S. C.; Macaulay, W.; Turner, D.; Kang, R.; Rubash, H. E.; Evans, C. H.

1997-01-01

Exposure of rodent macrophages to certain cytokines and endotoxin results in the synthesis of inducible nitric oxide synthase (iNOS or NOS-II) leading to the production of large amounts of nitric oxide (NO). Cultures of human macrophages, in contrast, do not produce iNOS after cytokine stimulation, and their ability to act as a physiological source of NO remains questionable. Here we have used immunohistochemistry and in situ hybridization to demonstrate the presence of iNOS within human macrophages present in the interfacial membrane and pseudocapsule that surround failed prosthetic hip joints. Synovial tissue recovered from normal human joints did not express iNOS. Many of the iNOS-positive macrophages within the interfacial membrane had phagocytosed large amounts of polyethylene wear debris, suggesting a role for phagocytic stimuli in inducing iNOS in human macrophages. These findings additionally support a role for NO in modulating the localized bone resorption that accompanies the aseptic loosening of prosthetic joints. Images Figure 1 Figure 2 Figure 3 PMID:9094976

An Investigation into a Gear-Based Knee Joint Designed for Lower Limb Prosthesis

PubMed Central

2017-01-01

A gear-based knee joint is designed to improve the performance of mechanical-type above-knee prostheses. The gear set with the help of some bracing, and bracket arrangement, is used to enable the prosthesis to follow the residual limb movement. The motion analysis and finite-element analysis (FEA) of knee joint components are carried out to assess the feasibility of the design. The maximum stress of 29.74 MPa and maximum strain of 2.393e−004 are obtained in the gear, whereas the maximum displacement of 7.975 mm occurred in the stopper of the knee arrangement. The factor of safety of 3.5 obtained from the FE analysis indicated no possibility of design failure. The results obtained from the FE analysis are then compared with the real data obtained from the literature for a similar subject. The pattern of motion analysis results has shown a great resemblance with the gait cycle of a healthy biological limb. PMID:28584518

The Effects of Fluid Absorption on the Mechanical Properties of Joint Prostheses Components

NASA Astrophysics Data System (ADS)

Yarbrough, David; Viano, Ann

2010-02-01

Ultra-high-molecular-weight polyethylene (UHMWPE) is the material playing the role of cartilage in human prosthetic joints. Wear debris from UHMWPE is a common reason for joint arthroplasty failure, and the exact mechanism responsible for wear remains an area of investigation. In this study, the microstructure of UHMWPE was examined as a function of fluid absorption. Samples with varying exposure to e-beam radiation (as part of the manufacturing process) were soaked for forty days in saline or artificial synovial fluid, under zero or 100 lbs load. Samples were then tensile-tested according to ASTM D-3895. The post-stressed material was then examined by transmission electron microscopy to evaluate the molecular response to stress, which correlates with macroscopic mechanical properties. Three parameters of the crystalline lamellae were measured: thickness, stacking ratio, and alignment to stress direction. Results indicate that fluid absorption does affect the mechanical properties of UHMWPE at both the microscopic and microscopic levels. )

Probabilistic analysis of the influence of the bonding degree of the stem-cement interface in the performance of cemented hip prostheses.

PubMed

Pérez, M A; Grasa, J; García-Aznar, J M; Bea, J A; Doblaré, M

2006-01-01

The long-term behavior of the stem-cement interface is one of the most frequent topics of discussion in the design of cemented total hip replacements, especially with regards to the process of damage accumulation in the cement layer. This effect is analyzed here comparing two different situations of the interface: completely bonded and debonded with friction. This comparative analysis is performed using a probabilistic computational approach that considers the variability and uncertainty of determinant factors that directly compromise the damage accumulation in the cement mantle. This stochastic technique is based on the combination of probabilistic finite elements (PFEM) and a cumulative damage approach known as B-model. Three random variables were considered: muscle and joint contact forces at the hip (both for walking and stair climbing), cement damage and fatigue properties of the cement. The results predicted that the regions with higher failure probability in the bulk cement are completely different depending on the stem-cement interface characteristics. In a bonded interface, critical sites appeared at the distal and medial parts of the cement, while for debonded interfaces, the critical regions were found distally and proximally. In bonded interfaces, the failure probability was higher than in debonded ones. The same conclusion may be established for stair climbing in comparison with walking activity.

Early implant placement for a patient with ectodermal dysplasia: Thirteen years of clinical care.

PubMed

Knobloch, Lisa A; Larsen, Peter E; Saponaro, Paola C; L'Homme-Langlois, Emilie

2017-11-29

Patients with ectodermal dysplasia have abnormalities of 2 or more structures that originate from the ectoderm. The oral manifestations often include the congenital absence of teeth and malformed teeth. This clinical report describes the interdisciplinary care from childhood through the definitive dental rehabilitation completed at skeletal maturation to replace the missing teeth in a patient with ectodermal dysplasia. Treatment began at 9 years of age with an implant-assisted mandibular overdenture to improve function and replace the missing mandibular teeth. Orthodontic treatment for the consolidation of space, composite resin restorations, and interim removable dental prostheses were provided to improve esthetics and replace the missing maxillary teeth. Skeletal growth was monitored, and orthognathic surgery was performed at the cessation of growth. The definitive rehabilitation consisted of a mandibular fixed dental prosthesis supported by dental implants and a maxillary removable dental prosthesis to restore the patient to esthetics and function. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Artificial atlanto-odontoid joint replacement through a transoral approach.

PubMed

Lu, Bin; He, Xi Jing; Zhao, Chen Guang; Li, Hao Peng; Wang, Dong

2009-01-01

Resection of the odontoid process and anterior arch of the atlas results in atlantoaxial instability, which if left uncorrected may lead to severe neurological complications. Currently, such atlantoaxial instability is corrected by anterior and/or posterior C1-C2 fusion. However, this results in considerable loss of rotation function of the atlantoaxial complex. From the viewpoint of retaining the rotation function and providing stability, we designed an artificial atlanto-odontoid joint based on anatomical measurements of 50 pairs of dry atlantoaxial specimens by digital calipers and 10 fresh cadaveric specimens by microsurgical techniques. The metal-on-metal titanium alloy joint has an arc-shaped atlas component, and a hollow cylindrical bushing into which fits a rotation axle of an inverted v-shaped axis component and is implanted through a transoral approach. After the joint was implanted onto specimens with anterior decompression, biomechanical tests were performed to compare the stability parameters in the intact state, after decompression, after artificial joint replacement, and after fatigue test. Compared to the intact state, artificial joint replacement resulted in a significant decrease in the range of motion (ROM) and neutral zone (NZ) during flexion, extension, and lateral bending (P < 0.001); however, with regard to axial rotation, there was no significant difference in ROM (P = 0.405), a significant increase in NZ (P = 0.008), and a significant decrease in stiffness (P = 0.003). Compared to the decompressed state, artificial joint replacement resulted in a significantly decreased ROM (P B 0.021) and NZ (P B 0.002) and a significantly increased stiffness (P \\ 0.001) in all directions. Following artificial joint replacement, there was no significant difference in ROM (P C 0.719), NZ (P C 0.580), and stiffness (P C 0.602) in all directions before and after the fatigue test. The artificial joint showed no signs of wear and tear after the fatigue test. This artificial atlanto-odontoid joint may be useful in cases of odontoid resection due to malunion or nonunion of odontoid fracture, atraumatic odontoid fracture, irreducible atlas dislocation, posterior atlantoaxial subluxation, or congenital skull base abnormalities.

Artificial atlanto-odontoid joint replacement through a transoral approach

PubMed Central

Lu, Bin; Zhao, Chen Guang; Li, Hao Peng; Wang, Dong

2008-01-01

Resection of the odontoid process and anterior arch of the atlas results in atlantoaxial instability, which if left uncorrected may lead to severe neurological complications. Currently, such atlantoaxial instability is corrected by anterior and/or posterior C1–C2 fusion. However, this results in considerable loss of rotation function of the atlantoaxial complex. From the viewpoint of retaining the rotation function and providing stability, we designed an artificial atlanto-odontoid joint based on anatomical measurements of 50 pairs of dry atlantoaxial specimens by digital calipers and 10 fresh cadaveric specimens by microsurgical techniques. The metal-on-metal titanium alloy joint has an arc-shaped atlas component, and a hollow cylindrical bushing into which fits a rotation axle of an inverted v-shaped axis component and is implanted through a transoral approach. After the joint was implanted onto specimens with anterior decompression, biomechanical tests were performed to compare the stability parameters in the intact state, after decompression, after artificial joint replacement, and after fatigue test. Compared to the intact state, artificial joint replacement resulted in a significant decrease in the range of motion (ROM) and neutral zone (NZ) during flexion, extension, and lateral bending (P < 0.001); however, with regard to axial rotation, there was no significant difference in ROM (P = 0.405), a significant increase in NZ (P = 0.008), and a significant decrease in stiffness (P = 0.003). Compared to the decompressed state, artificial joint replacement resulted in a significantly decreased ROM (P ≤ 0.021) and NZ (P ≤ 0.002) and a significantly increased stiffness (P < 0.001) in all directions. Following artificial joint replacement, there was no significant difference in ROM (P ≥ 0.719), NZ (P ≥ 0.580), and stiffness (P ≥ 0.602) in all directions before and after the fatigue test. The artificial joint showed no signs of wear and tear after the fatigue test. This artificial atlanto-odontoid joint may be useful in cases of odontoid resection due to malunion or nonunion of odontoid fracture, atraumatic odontoid fracture, irreducible atlas dislocation, posterior atlantoaxial subluxation, or congenital skull base abnormalities. PMID:19043745

An assessment of filamentous carbon fibre for the treatment of tendon injury in the horse.

PubMed

Goodship, A E; Brown, P N; Yeats, J J; Jenkins, D H; Silver, I A

1980-03-08

The results of an assessment of carbon fibre for biological use are given, with particular reference to the clinical use of the material in the treatment of equine tendon injury. Biocompatability of the fibres is assessed using fibroblast cell cultures and replacement of normal tendon with carbon fibre prostheses in experimental animals. The rationale and technique for using this material in clinical cases of tendon injury in the racehorse are described. Results are given from 62 implant operations in a limited series of 40 horses.

A comparison of clinical- and patient-reported outcomes of the cemented ATTUNE and PFC sigma fixed bearing cruciate sacrificing knee systems in patients who underwent total knee replacement with both prostheses in opposite knees.

PubMed

Carey, Brian W; Harty, James

2018-03-15

The ATTUNE Knee by DePuy Synthes was introduced in 2013. It is designed to provide better range of motion and address patient-reported instability. The PFC Sigma Knee, an earlier prosthesis by DePuy Synthes, is a common knee replacement with a strong clinical track record. Our aim is to compare the outcomes after primary total knee replacement for end-stage knee osteoarthritis of the PFC and ATTUNE knee systems in 21 patients who each have prosthesis in opposite knees using WOMAC, Oxford Knee and SF-12 scores and evaluation of range of motion. A review was carried out on 21 patients who underwent primary total knee replacement with both the ATTUNE and PFC knee systems. These were staged operations performed in the same institution and by the same surgeon. All cases were followed up for a minimum of 6 months. WOMAC, Oxford Knee and SF-12 scores, as well as knee range of motion were recorded preoperatively and at 6 months postoperatively. There was a significant difference in pre- to 6-month post-operative outcomes in PFC and ATTUNE groups with regard to improvement in range of motion (10° ± 8 and 13° ± 11, respectively). There was also a significant improvement in WOMAC scores (PFC group) and Oxford Knee Scores (ATTUNE group) (8.9 ± 7.7 and 12.1 ± 8.4, respectively). There was a significant improvement in SF-12 Score in both groups (10.1 ± 9.3 for PFC and 15.8 ± 13.3 for ATTUNE). The minimum clinically important difference (MCID) in scoring systems at 6 months was reached by 6 patients in the PFC group and 12 in the ATTUNE group. A significant difference was demonstrated in clinical outcome at 6 months postoperatively between PFC and ATTUNE knee systems in patients who underwent total knee arthroplasty with both prostheses. Superior results were recorded for the ATTUNE knee system.

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.

Patients' Perceptions of Joint Replacement Care in a Changing Healthcare System: A Qualitative Study

PubMed Central

Webster, Fiona; Bremner, Samantha; Katz, Joel; Watt-Watson, Judy; Kennedy, Deborah; Sawhney, Mona; McCartney, Colin

2014-01-01

Background: Ontario has introduced strategies over the past decade to reduce wait times and length of stay and improve access to physiotherapy for orthopaedic and other patients. The aim of this study is to explore patients' experiences of joint replacement care during a significant system change in their care setting. Methods: A secondary analysis was done on semi-structured qualitative interviews that were conducted in 2009 with 12 individuals who had undergone at least two hip or knee replacements five years apart at a specialized orthopaedic centre in Ontario, Canada. Interview transcripts were coded and then organized into themes. Results: Although the original study aimed to capture participants' experiences with changes in anaesthetic technique between their first and second joint replacements, the participants described several unrelated differences in the care they received during this period. For example, participants had difficulty obtaining a referral to an orthopaedic surgeon from their family physician. They also noted that the hospital stay and in-hospital physiotherapy they received were shorter after the second joint replacement surgery. They identified guidance from physiotherapists as an important component of their recovery, but sometimes had difficulty arranging physiotherapy after hospital discharge following their most recent surgery. Conclusions: The changes described between the first and second joint replacements provide the participants' perspective on the impact of policy changes on wait times, reduced lengths of hospital stay and physiotherapy access. The impact of these policy changes, often made in an attempt to improve access to care, had an unintended and detrimental effect on participants' perceptions and experiences of the quality of care provided. PMID:24726074

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.

[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.

Four-unit fixed dental prostheses replacing the maxillary incisors supported by two narrow-diameter implants - a five-year case series.

PubMed

Moráguez, Osvaldo; Vailati, Francesca; Grütter, Linda; Sailer, Irena; Belser, Urs C

2017-07-01

(1) To determine the survival rate of 10 four-unit fixed dental prostheses (FDPs) replacing the four maxillary incisors, supported by 20 narrow-diameter implants (NDIs), (2) to assess the incidence of mechanical and biological complications, and (3) to evaluate bone level changes longitudinally after final FDP insertion. Ten patients (six women, four men), mean age 49.4 ± 12.6 years, were treated with a four-unit anterior maxillary FDP (six screw-retained; four cemented). Biological parameters, eventual technical complications, radiographic measurements, and study casts were assessed at 1 (baseline), 3, and 5 years after implant placement. A multilevel logistic regression test was performed on clinical parameters and bone level changes (significance level P < 0.05). The 5-year implant and FDP survival rate was 100%. Mean modified plaque index (mPI) values were 0.03 and 0.02 at 3 and 5 years, significantly lower when compared to mPI (0.11 ± 0.31) at 1 year. Mean modified sulcus bleeding index (mSBI) was 0.08, 0.08, and 0.15 over time. Probing depth (PD) values were 1.57, 1.64, and 2.03 mm. Statistically significant differences were found between 1 vs. 5 year (P = 0.0003) and 3 vs. 5 year (P = 0.001). Keratinized mucosa (3.65 mm) remained stable during observation period. DIB mean values were 2.01 ± 0.34, 2.13 ± 0.13, and 2.17 ± 0.38 mm. Patient satisfaction based on visual analog scale revealed favorable fulfillment of overall treatment and esthetic expectations. Two NDIs supporting a four-unit FDP to replace the four missing maxillary incisors may be considered a predictable treatment modality. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Assessing the Relative Contributions of Active Ankle and Knee Assistance to the Walking Mechanics of Transfemoral Amputees Using a Powered Prosthesis

PubMed Central

Simon, Ann M.; Hargrove, Levi J.

2016-01-01

Powered knee-ankle prostheses are capable of providing net-positive mechanical energy to amputees. Yet, there are limitless ways to deliver this energy throughout the gait cycle. It remains largely unknown how different combinations of active knee and ankle assistance affect the walking mechanics of transfemoral amputees. This study assessed the relative contributions of stance phase knee swing initiation, increasing ankle stiffness and powered plantarflexion as three unilateral transfemoral amputees walked overground at their self-selected walking speed. Five combinations of knee and ankle conditions were evaluated regarding the kinematics and kinetics of the amputated and intact legs using repeated measures analyses of variance. We found eliminating active knee swing initiation or powered plantarflexion was linked to increased compensations of the ipsilateral hip joint during the subsequent swing phase. The elimination of knee swing initiation or powered plantarflexion also led to reduced braking ground reaction forces of the amputated and intact legs, and influenced both sagittal and frontal plane loading of the intact knee joint. Gradually increasing prosthetic ankle stiffness influenced the shape of the prosthetic ankle plantarflexion moment, more closely mirroring the intact ankle moment. Increasing ankle stiffness also corresponded to increased prosthetic ankle power generation (despite a similar maximum stiffness value across conditions) and increased braking ground reaction forces of the amputated leg. These findings further our understanding of how to deliver assistance with powered knee-ankle prostheses and the compensations that occur when specific aspects of assistance are added/removed. PMID:26807889

Estimation of distal arm joint angles from EMG and shoulder orientation for transhumeral prostheses.

PubMed

Akhtar, Aadeel; Aghasadeghi, Navid; Hargrove, Levi; Bretl, Timothy

2017-08-01

In this paper, we quantify the extent to which shoulder orientation, upper-arm electromyography (EMG), and forearm EMG are predictors of distal arm joint angles during reaching in eight subjects without disability as well as three subjects with a unilateral transhumeral amputation and targeted reinnervation. Prior studies have shown that shoulder orientation and upper-arm EMG, taken separately, are predictors of both elbow flexion/extension and forearm pronation/supination. We show that, for eight subjects without disability, shoulder orientation and upper-arm EMG together are a significantly better predictor of both elbow flexion/extension during unilateral (R 2 =0.72) and mirrored bilateral (R 2 =0.72) reaches and of forearm pronation/supination during unilateral (R 2 =0.77) and mirrored bilateral (R 2 =0.70) reaches. We also show that adding forearm EMG further improves the prediction of forearm pronation/supination during unilateral (R 2 =0.82) and mirrored bilateral (R 2 =0.75) reaches. In principle, these results provide the basis for choosing inputs for control of transhumeral prostheses, both by subjects with targeted motor reinnervation (when forearm EMG is available) and by subjects without target motor reinnervation (when forearm EMG is not available). In particular, we confirm that shoulder orientation and upper-arm EMG together best predict elbow flexion/extension (R 2 =0.72) for three subjects with unilateral transhumeral amputations and targeted motor reinnervation. However, shoulder orientation alone best predicts forearm pronation/supination (R 2 =0.88) for these subjects, a contradictory result that merits further study. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biotribological behavior of Ag-ZrCxN1-x coatings against UHMWPE for joint prostheses devices.

PubMed

Calderon V, S; Sánchez-López, J C; Cavaleiro, A; Carvalho, S

2015-01-01

This study aims to evaluate the structural, mechanical and tribological properties of zirconium carbonitrides (ZrCxN1-x) coatings with embedded silver nanoparticles, produced with the intention of achieving a material with enhanced multi-functional properties, including mechanical strength, corrosion resistance, tribological performance and antibacterial behavior suitable for their use in joint prostheses. The coatings were deposited by direct current (DC) reactive magnetron sputtering onto 316 L stainless steel, changing the silver content from 0 to 20 at% by modifying the current density applied to the targets. Different nitrogen and acetylene gas fluxes were used as reactive gases. The coatings revealed different mixtures of crystalline ZrCxN1-x, silver nanoparticles and amorphous carbon phases. The hardness of the films was found to be mainly controlled by the ratio between the hard (ZrCxN1-x) and soft (Ag and amorphous carbon) phases in the films, fluctuating between 7.4 and 20.4 GPa. The coefficient of friction, measured against ultra-high molecular weight polyethylene (UHMWPE) in Hank's balanced salt solution with 10 gL(-1) albumin, is governed by the surface roughness and hardness. The UHMWPE wear rates were in the same order of magnitude (between 1.4 and 2.0 × 10(-6)mm(3)N(-1)m(-1)), justified by the effect of the protective layer of albumin formed during the tests. The small differences were due to the hydrophobic/hydrophilic character of the surface, as well as to the silver content. Copyright © 2014 Elsevier Ltd. All rights reserved.

Clinical Presentation, Risk Factors, and Outcomes of Hematogenous Prosthetic Joint Infection in Patients with Staphylococcus aureus Bacteremia.

PubMed

Tande, Aaron J; Palraj, Bharath Raj; Osmon, Douglas R; Berbari, Elie F; Baddour, Larry M; Lohse, Christine M; Steckelberg, James M; Wilson, Walter R; Sohail, M Rizwan

2016-02-01

Staphylococcus aureus bacteremia is a life-threatening condition that may lead to metastatic infection, including prosthetic joint infection. To assess clinical factors associated with hematogenous prosthetic joint infection, we retrospectively reviewed all patients with a joint arthroplasty in place at the time of a first episode of S. aureus bacteremia over a 5-year period at our institution. Patients with postsurgical prosthetic joint infection without hematogenous prosthetic joint infection were excluded. There were 85 patients (143 arthroplasties) with either no prosthetic joint infection (n = 50; 58.8%) or hematogenous prosthetic joint infection in at least one arthroplasty (n = 35; 41.2%). The odds of hematogenous prosthetic joint infection was significantly increased among patients with community-acquired S. aureus bacteremia (odds ratio [OR] 18.07; 95% confidence interval [CI] 2.64-infinity; P = .001), as compared with nosocomial S. aureus bacteremia, in which there were no patients with hematogenous prosthetic joint infection. After adjusting for S. aureus bacteremia classification, the presence of ≥3 joint arthroplasties in place was associated with a nearly ninefold increased odds of hematogenous prosthetic joint infection as compared with those with 1-2 joint arthroplasties in place (OR 8.55; 95% CI 1.44-95.71; P = .012). All but one joint with prosthetic joint infection demonstrated at least one clinical feature suggestive of infection. There were 4 additional S. aureus prosthetic joint infections diagnosed during a median of 3.4 years of follow-up post hospitalization for S. aureus bacteremia. Prosthetic joint infection is frequent in patients with existing arthroplasties and concomitant S. aureus bacteremia, particularly with community-acquired S. aureus bacteremia and multiple prostheses. In contrast, occult S. aureus prosthetic joint infection without clinical features suggestive of prosthetic joint infection at the time of S. aureus bacteremia is rare. Copyright © 2016 Elsevier Inc. All rights reserved.

A quantitative comparison of transesophageal and epicardial color Doppler echocardiography in the intraoperative assessment of mitral regurgitation.

PubMed

Kleinman, J P; Czer, L S; DeRobertis, M; Chaux, A; Maurer, G

1989-11-15

Epicardial and transesophageal color Doppler echocardiography are both widely used for the intraoperative assessment of mitral regurgitation (MR); however, it has not been established whether grading of regurgitation is comparable when evaluated by these 2 techniques. MR jet size was quantitatively compared in 29 hemodynamically and temporally matched open-chest epicardial and transesophageal color Doppler echocardiography studies from 22 patients (18 with native and 4 with porcine mitral valves) scheduled to undergo mitral valve repair or replacement. Jet area, jet length and left atrial area were analyzed. Comparison of jet area measurements as assessed by epicardial and transesophageal color flow mapping revealed an excellent correlation between the techniques (r = 0.95, p less than 0.001). Epicardial and transesophageal jet length measurements were also similar (r = 0.77, p less than 0.001). Left atrial area could not be measured in 18 transesophageal studies (62%) due to foreshortening, and in 5 epicardial studies (17%) due to poor image resolution. Acoustic interference with left atrial and color flow mapping signals was noted in all patients with mitral valve prostheses when imaged by epicardial echocardiography, but this did not occur with transesophageal imaging. Thus, in patients undergoing valve repair or replacement, transesophageal and epicardial color flow mapping provide similar quantitative assessment of MR jet size. Jet area to left atrial area ratios have limited applicability in transesophageal color flow mapping, due to foreshortening of the left atrial borders in transesophageal views. Transesophageal color flow mapping may be especially useful in assessing dysfunctional mitral prostheses due to the lack of left atrial acoustic interference.

Short-term results using Kurz titanium ossicular implants.

PubMed

Vassbotn, Flemming S; Møller, Per; Silvola, Juha

2007-01-01

The efficiency of titanium middle ear prosthesis for ossicular reconstruction in chronic ear disease is investigated in a Scandinavian two-center retrospective study from a Norwegian tertiary otology referral center and a Finnish otology referral center. Retrospective chart reviews were performed for procedures involving 73 titanium prostheses between 1999 and 2004. All patients that underwent surgery including the Kurz Vario titanium prosthesis were included in the study, 38 procedures including the partial ossicular replacement prosthesis (PORP) and 35 procedures including the total ossicular replacement prosthesis (TORP). Mean follow-up was 14 months. The ossiculoplasty was performed alone (29 patients) or in combination with other chronic ear surgery procedures (34 patients). Comparisons of preoperative and postoperative pure tone averages (0.5, 1, 2, and 3 kHz) according to AAO-HNS guidelines are presented, as well as data for different PTA definitions. Otosurgery procedures, complications, revisions, and extrusion rates are reported. A postoperative air-bone gap (ABG) of

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).

Toward Balance Recovery With Leg Prostheses Using Neuromuscular Model Control

PubMed Central

Geyer, Hartmut

2016-01-01

Objective Lower limb amputees are at high risk of falling as current prosthetic legs provide only limited functionality for recovering balance after unexpected disturbances. For instance, the most established control method used on powered leg prostheses tracks local joint impedance functions without taking the global function of the leg in balance recovery into account. Here we explore an alternative control policy for powered transfemoral prostheses that considers the global leg function and is based on a neuromuscular model of human locomotion. Methods We adapt this model to describe and simulate an amputee walking with a powered prosthesis using the proposed control, and evaluate the gait robustness when confronted with rough ground and swing leg disturbances. We then implement and partially evaluate the resulting controller on a leg prosthesis prototype worn by a non-amputee user. Results In simulation, the proposed prosthesis control leads to gaits that are more robust than those obtained by the impedance control method. The initial hardware experiments with the prosthesis prototype show that the proposed control reproduces normal walking patterns qualitatively and effectively responds to disturbances in early and late swing. However, the response to mid-swing disturbances neither replicates human responses nor averts falls. Conclusions The neuromuscular model control is a promising alternative to existing prosthesis controls, although further research will need to improve on the initial implementation and determine how well these results transfer to amputee gait. Significance This work provides a potential avenue for future development of control policies that help improve amputee balance recovery. PMID:26315935

Combined registration of 3D tibia and femur implant models in 3D magnetic resonance images

NASA Astrophysics Data System (ADS)

Englmeier, Karl-Hans; Siebert, Markus; von Eisenhart-Rothe, Ruediger; Graichen, Heiko

2008-03-01

The most frequent reasons for revision of total knee arthroplasty are loosening and abnormal axial alignment leading to an unphysiological kinematic of the knee implant. To get an idea about the postoperative kinematic of the implant, it is essential to determine the position and orientation of the tibial and femoral prosthesis. Therefore we developed a registration method for fitting 3D CAD-models of knee joint prostheses into an 3D MR image. This rigid registration is the basis for a quantitative analysis of the kinematics of knee implants. Firstly the surface data of the prostheses models are converted into a voxel representation; a recursive algorithm determines all boundary voxels of the original triangular surface data. Secondly an initial preconfiguration of the implants by the user is still necessary for the following step: The user has to perform a rough preconfiguration of both remaining prostheses models, so that the fine matching process gets a reasonable starting point. After that an automated gradient-based fine matching process determines the best absolute position and orientation: This iterative process changes all 6 parameters (3 rotational- and 3 translational parameters) of a model by a minimal amount until a maximum value of the matching function is reached. To examine the spread of the final solutions of the registration, the interobserver variability was measured in a group of testers. This variability, calculated by the relative standard deviation, improved from about 50% (pure manual registration) to 0.5% (rough manual preconfiguration and subsequent fine registration with the automatic fine matching process).

A Stereophotogrammetric System For The Detection Of Prosthesis Loosening In Total Hip Arthroplasty

NASA Astrophysics Data System (ADS)

Baumrind, Sheldon; Genant, Harry K.; Hunter, John; Miller, David; Moffitt, Francis; Murray, William R.; Ross, Steven E.

1980-07-01

Loosening of the prosthetic device occurs in about 5% of cases following placement of total hip prostheses (THP). Early detection of loosening is much desired but is difficult to achieve using conventional methods. Due to errors of projection, it is quite possible to fail to detect mobility of even as much as 5 mm on single x-ray films. We are attempting to develop a simplified photogrammetric system suitable for general hospital use which could detect loosening of 0.8 mm at the 95 % level of confidence without use of complex stereoplotting equipment. Metal reference markers are placed in the shaft of the femur and in the acetabular region of the pelvis at the time of surgery. The distances between these reference markers and certain unambiguous points on the prostheses are computed analytically using an X-Y acoustical digitizer (accuracy ± 0.1 mm) and software developed previously for craniofacial measurement. Separate stereopairs of the joint region are taken under weight-bearing and nonweight-bearing conditions. Differences in the measured distances between the bo-ne markers and the prosthetic components on the two stereopairs are taken as indicators of prosthesis loosening. Measurements on a phantom using ten different x-ray stereopairs taken from as many different perspectives have established that true linear distances between reference points and prostheses can be measured at the desired reliability with the present low precision system. Preliminary in vivo measurements indicate that the main unresolved problem is the movement of the subject between the two exposures of each single stereopair. Two possible solutions to this problem are discussed.

Hemodynamic Evaluation of a Biological and Mechanical Aortic Valve Prosthesis Using Patient-Specific MRI-Based CFD.

PubMed

Hellmeier, Florian; Nordmeyer, Sarah; Yevtushenko, Pavlo; Bruening, Jan; Berger, Felix; Kuehne, Titus; Goubergrits, Leonid; Kelm, Marcus

2018-01-01

Modeling different treatment options before a procedure is performed is a promising approach for surgical decision making and patient care in heart valve disease. This study investigated the hemodynamic impact of different prostheses through patient-specific MRI-based CFD simulations. Ten time-resolved MRI data sets with and without velocity encoding were obtained to reconstruct the aorta and set hemodynamic boundary conditions for simulations. Aortic hemodynamics after virtual valve replacement with a biological and mechanical valve prosthesis were investigated. Wall shear stress (WSS), secondary flow degree (SFD), transvalvular pressure drop (TPD), turbulent kinetic energy (TKE), and normalized flow displacement (NFD) were evaluated to characterize valve-induced hemodynamics. The biological prostheses induced significantly higher WSS (medians: 9.3 vs. 8.6 Pa, P = 0.027) and SFD (means: 0.78 vs. 0.49, P = 0.002) in the ascending aorta, TPD (medians: 11.4 vs. 2.7 mm Hg, P = 0.002), TKE (means: 400 vs. 283 cm 2 /s 2 , P = 0.037), and NFD (means: 0.0994 vs. 0.0607, P = 0.020) than the mechanical prostheses. The differences between the prosthesis types showed great inter-patient variability, however. Given this variability, a patient-specific evaluation is warranted. In conclusion, MRI-based CFD offers an opportunity to assess the interactions between prosthesis and patient-specific boundary conditions, which may help in optimizing surgical decision making and providing additional guidance to clinicians. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Early Complications of Immediate Loading in Edentulous Full-Arch Restorations: A Retrospective Analysis of 88 Cases.

PubMed

Cercadillo-Ibarguren, Iñaki; Sánchez-Torres, Alba; Figueiredo, Rui; Valmaseda-Castellón, Eduard

To describe the clinical outcomes and complications related to provisional prostheses after full-arch implant-supported rehabilitation by means of an immediate loading protocol. This retrospective cohort study included patients who were consecutively treated with full-arch implant-supported restorations with a minimum of four implants (Replace Select Tapered TiUnite, Nobel Biocare AB) per arch and conical abutments (multi-unit, Nobel Biocare AB) by means of an immediate loading protocol. The surgical procedures were performed between May 2006 and June 2014 by a single oral surgeon. Demographic, surgical, and prosthetic variables were collected, and biologic and mechanical complications were registered. A total of 61 maxillae (57%) and 46 mandibles (43%) were treated in 88 patients (40 men and 48 women) with a mean age of 62.4 years. A total of 558 implants were placed, 295 in postextraction sockets. A total of 331 implants (59.3%) were placed in the maxilla and 227 (40.7%) in the mandible. Within a 9-month period, 18 prostheses (16.8%) fractured (15 maxillary and 3 mandibular); in nine of these patients the opposing dentition was a full-arch, implant-supported restoration, and in the remaining nine patients, it was natural dentition. Six (1.1%) maxillary and three (0.5%) mandibular implants failed. A high implant survival rate is expected in the short term following this immediate loading protocol. Fracture of the provisional prosthesis is a common finding, affecting 17% of patients, and is significantly more prevalent in patients with bruxism and in maxillary prostheses.

Comparison of Metal-Ceramic and All-Ceramic Three-Unit Posterior Fixed Dental Prostheses: A 3-Year Randomized Clinical Trial.

PubMed

Nicolaisen, Maj H; Bahrami, Golnosh; Schropp, Lars; Isidor, Flemming

2016-01-01

The aim of this randomized clinical study was to compare the 3-year clinical outcome of metal-ceramic fixed dental prostheses (MC-FDPs) and zirconia all-ceramic fixed dental prostheses (AC-FDPs) replacing a posterior tooth. A sample of 34 patients with a missing posterior tooth were randomly chosen to receive either a MC-FDP (n = 17) or an AC-FDP (n = 17). The FDPs were evaluated at baseline and yearly until 3 years after cementation. They were assessed using the California Dental Association assessment system. Periodontal parameters were measured at the abutment teeth, and the contralateral teeth served as control. The statistical unit was the FDP/patient. The survival rates for MC-FDPs and AC-FDPs were 100%. The success rate was 76% and 71% for MC-FDPs and AC-FDPs, respectively. Three technical complications were observed in the MC-FDP group and five in the AC-FDP group, all chipping fractures of the ceramic veneer. Furthermore, one biologic complication in the MC-FDP group (an apical lesion) was observed. No framework fractures occurred. All patients had optimal oral hygiene and showed no bleeding on periodontal probing at any of the recalls. Only minor changes in the periodontal parameters were observed during the 3 years of observation. Three-unit posterior MC-FDPs and AC-FDPs showed similar high survival rates and acceptable success rates after 3 years of function, and ceramic veneer chipping fracture was the most frequent complication for both types of restorations.

Five-year prospective clinical study of posterior three-unit zirconia-based fixed dental prostheses.

PubMed

Sorrentino, Roberto; De Simone, Giorgio; Tetè, Stefano; Russo, Simona; Zarone, Fernando

2012-06-01

This prospective clinical trial aimed at evaluating the clinical performance of three-unit posterior zirconia fixed dental prostheses (FDPs) after 5 years of clinical function. Thirty-seven patients received 48 three-unit zirconia-based FDPs. The restorations replaced either a premolar or a molar. Specific inclusion criteria were needed. Tooth preparation was standardized. Computer-aided design/computer-assisted manufacturing frameworks with a 9-mm(2) cross section of the connector and a 0.6-mm minimum thickness of the retainer were made. The restorations were luted with resin cement. The patients were recalled after 1, 6, 12, 24, 36, 48, and 60 months. The survival and success of the ceramics and zirconia were evaluated. The technical and aesthetic outcomes were examined using the United States Public Health Service criteria. The biologic outcomes were analyzed at abutment and contralateral teeth. Descriptive statistics were performed. All FDPs completed the study, resulting in 100% cumulative survival rate and 91.9% and 95.4% cumulative success rates for patients wearing one and two FDPs, respectively. No losses of retention were recorded. Forty-two restorations were rated alpha in all measured parameters. A minor chipping of the ceramics was detected in three restorations. No significant differences between the periodontal parameters of the test and control teeth were observed. Five-year clinical results proved that three-unit posterior zirconia-based FDPs were successful in the medium term for both function and aesthetic. Zirconia can be considered a promising substitute of metal frameworks for the fabrication of short-span posterior prostheses.

Neuroprostheses to treat neurogenic bladder dysfunction: current status and future perspectives.

PubMed

Rijkhoff, Nico J M

2004-02-01

Neural prostheses are a technology that uses electrical activation of the nervous system to restore function to individuals with neurological or sensory impairment. This article provides an introduction to neural prostheses and lists the most successful neural prostheses (in terms of implanted devices). The article then focuses on neurogenic bladder dysfunction and describes two clinically available implantable neural prostheses for treatment of neurogenic bladder dysfunction. Special attention is given to the usage of these neural prostheses in children. Finally, three new developments that may lead to a new generation of implantable neural prostheses for bladder control are described. They may improve the neural prostheses currently available and expand further the population of patients who can benefit from a neural prosthesis.

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.

Longitudinal research on the oral environment of elderly wearing fixed or removable prostheses.

PubMed

Tanaka, Junko; Tanaka, Masahiro; Kawazoe, Takayoshi

2009-04-01

The purpose of this study was to investigate oral environmental risk factors involved in caries incidence in the elderly. We investigated the relationship between the oral environment factors of the elderly with both fixed prostheses and removable prostheses at baseline and at follow-up and examined time-course changes of each oral environmental factor by prosthesis type. The subject group consisted 11 elderly patients with fixed prostheses and 11 who wore removable prostheses. We examined oral environmental factors by saliva tests. Five oral environmental factors were examined: the stimulated salivary flow rate, buffering capacity, and the counts of mutans streptococci (SM), lactobacilli (LB), and Candida (CA). We compared these factors for subjects with fixed prostheses and those wearing removable prostheses at baseline and at follow-up. Furthermore, 3-year changes in the factors of each oral environment were compared and evaluated. Significant differences were observed between the two groups in the salivary microbial counts of SM and LB at baseline and at follow-up. The LB counts increased in the Denture group during the 3-year period and significant differences were noted. We found that fixed prostheses are less cariogenic, and removable prostheses cause an increase in the cariogenic bacterial count. Regarding time-course changes by the type of prosthesis, the LB count tended to increase in the subjects with removable prostheses. The risk of caries due to a fixed prosthesis may be lower than that of removable prostheses.

[Increasing the safety of ceramic femoral heads for hip prostheses].

PubMed

Willmann, G; Pfaff, H G; Richter, H G

1995-12-01

Since 1974 Biolox ceramic femoral ball heads have been used successfully for artificial modular hip joints. The revision rate due to ball head fracture is lower than 0.02%. This is an extremely low value. In this article it is shown how the safety of a ceramic ball head can be improved using the procedures of HIPing, engraving by laser technique, and 100% proof testing. By applying these means the materials properties density, grain size, grain size distribution, and the strength of the ball head, i.e. the fracture load can be improved significantly.

Design and clinical outcome of a novel 3D-printed prosthetic joint replacement for the human temporomandibular joint.

PubMed

Ackland, David; Robinson, Dale; Lee, Peter Vee Sin; Dimitroulis, George

2018-05-11

Stock prosthetic temporomandibular joint replacements come in limited sizes, and do not always encompass the joint anatomy that presents clinically. The aims of this study were twofold. Firstly, to design a personalized prosthetic total joint replacement for the treatment of a patient's end-stage temporomandibular joint osteoarthritis, to implant the prosthesis into the patient, and assess clinical outcome 12-months post-operatively; and secondly, to evaluate the influence of changes in prosthetic condyle geometry on implant load response during mastication. A 48-year-old female patient with Grade-5 osteoarthritis to the left temporomandibular joint was recruited, and a prosthesis developed to match the native temporomandibular joint anatomy. The prosthesis was 3D printed, sterilized and implanted into the patient, and pain and function measured 12-months post-operatively. The prosthesis load response during a chewing-bite and maximum-force bite was evaluated using a personalized multi-body musculoskeletal model. Simulations were performed after perturbing condyle thickness, neck length and head sphericity. Increases in prosthetic condyle neck length malaligned the mandible and perturbed temporomandibular joint force. Changes in condylar component thickness greatly influenced fixation screw stress response, while a more eccentric condylar head increased prosthetic joint-contact loading. Post-operatively, the prosthetic temporomandibular joint surgery reduced patient pain from 7/10 to 1/10 on a visual analog scale, and increased intercisal opening distance from 22 mm to 38 mm. This study demonstrates effectiveness of a personalized prosthesis that may ultimately be adapted to treat a wide-range of end-stage temporomandibular joint conditions, and highlights sensitivity of prosthesis load response to changes in condylar geometry. Copyright © 2018 Elsevier Ltd. All rights reserved.

a Review of Retinal Prosthesis Approaches

NASA Astrophysics Data System (ADS)

Kien, Tran Trung; Maul, Tomas; Bargiela, Andrzej

Age-related macular degeneration and retinitis pigmentosa are two of the most common diseases that cause degeneration in the outer retina, which can lead to several visual impairments up to blindness. Vision restoration is an important goal for which several different research approaches are currently being pursued. We are concerned with restoration via retinal prosthetic devices. Prostheses can be implemented intraocularly and extraocularly, which leads to different categories of devices. Cortical Prostheses and Optic Nerve Prostheses are examples of extraocular solutions while Epiretinal Prostheses and Subretinal Prostheses are examples of intraocular solutions. Some of the prostheses that are successfully implanted and tested in animals as well as humans can restore basic visual functions but still have limitations. This paper will give an overview of the current state of art of Retinal Prostheses and compare the advantages and limitations of each type. The purpose of this review is thus to summarize the current technologies and approaches used in developing Retinal Prostheses and therefore to lay a foundation for future designs and research directions.

Leaflet embolisation from Duromedics valves: a report of two cases.

PubMed

Kumar, N; Balasundaram, S; Rickard, M; al Halees, Z; Duran, C M

1991-12-01

Embolization of parts of mechanical valves has been reported since the inception of prosthetic valve implantation. We report here two cases of embolization of one hemileaflet of a Duromedic bileaflet prosthesis in the mitral position due to a pivot fracture. Both presented with moderately severe mitral regurgitation and pulmonary edema and were successfully managed by replacement of the malfunctioning prostheses. The embolised disc was located in the left common iliac artery by abdominal ultrasound and removed by an inguinal, retroperitoneal approach with low morbidity. Both patients left hospital and are doing well to-date.

Dissociation of modular total hip arthroplasty at the neck-stem interface without dislocation.

PubMed

Kouzelis, A; Georgiou, C S; Megas, P

2012-12-01

Modular femoral and acetabular components are now widely used, but only a few complications related to the modularity itself have been reported. We describe a case of dissociation of the modular total hip arthroplasty (THA) at the femoral neck-stem interface during walking. The possible causes of this dissociation are discussed. Successful treatment was provided with surgical revision and replacement of the modular neck components. Surgeons who use modular components in hip arthroplasties should be aware of possible early complications in which the modularity of the prostheses is the major factor of failure.

Joint registries as continuous surveillance systems: the experience of the Catalan Arthroplasty Register (RACat).

PubMed

Allepuz, Alejandro; Martínez, Olga; Tebé, Cristian; Nardi, Joan; Portabella, Frederic; Espallargues, Mireia

2014-03-01

The aim was to present results on prosthesis performance in Catalonia for the period 2005-2010. All publicly funded hospitals submit in an electronic format data on hip and knee arthroplasties: patients' insurance identification number, hospital, joint (hip/knee), type of arthroplasty (primary/revision), side (right/left), date of surgery and prosthesis (manufacturer name and catalogue number). A standard survival analysis based on Kaplan-Meier estimation was carried out. Fifty-two hospitals have sent information to the RACat which has data on 36,951 knee and 26,477 hip arthroplasties. Cumulative prostheses revision risks at 3 years were 3.3% (95% CI: 3.1-3.6) for knee, 2.9% (95% CI: 2.5-3.3) for total hip and 2.5% (95% CI: 2.0-3.1) for partial hip. When compared to other registries a higher risk of revision was observed. © 2013.

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...

Silver Nanocoating Technology in the Prevention of Prosthetic Joint Infection

PubMed Central

Gallo, Jiri; Panacek, Ales; Prucek, Robert; Kriegova, Eva; Hradilova, Sarka; Hobza, Martin; Holinka, Martin

2016-01-01

Prosthetic joint infection (PJI) is a feared complication of total joint arthroplasty associated with increased morbidity and mortality. There is a growing body of evidence that bacterial colonization and biofilm formation are critical pathogenic events in PJI. Thus, the choice of biomaterials for implanted prostheses and their surface modifications may significantly influence the development of PJI. Currently, silver nanoparticle (AgNP) technology is receiving much interest in the field of orthopaedics for its antimicrobial properties and a strong anti-biofilm potential. The great advantage of AgNP surface modification is a minimal release of active substances into the surrounding tissue and a long period of effectiveness. As a result, a controlled release of AgNPs could ensure antibacterial protection throughout the life of the implant. Moreover, the antibacterial effect of AgNPs may be strengthened in combination with conventional antibiotics and other antimicrobial agents. Here, our main attention is devoted to general guidelines for the design of antibacterial biomaterials protected by AgNPs, its benefits, side effects and future perspectives in PJI prevention. PMID:28773461

Nano-material aspects of shock absorption in bone joints.

PubMed

Tributsch, H; Copf, F; Copf, P; Hindenlang, U; Niethard, F U; Schneider, R

2010-01-01

This theoretical study is based on a nano-technological evaluation of the effect of pressure on the composite bone fine structure. It turned out, that the well known macroscopic mechano-elastic performance of bones in combination with muscles and tendons is just one functional aspect which is critically supported by additional micro- and nano- shock damping technology aimed at minimising local bone material damage within the joints and supporting spongy bone material. The identified mechanisms comprise essentially three phenomena localised within the three-dimensional spongy structure with channels and so called perforated flexible tensulae membranes of different dimensions intersecting and linking them. Kinetic energy of a mechanical shock may be dissipated within the solid-liquid composite bone structure into heat via the generation of quasi-chaotic hydromechanic micro-turbulence. It may generate electro-kinetic energy in terms of electric currents and potentials. And the resulting specific structural and surface electrochemical changes may induce the compressible intra-osseal liquid to build up pressure dependent free chemical energy. Innovative bone joint prostheses will have to consider and to be adapted to the nano-material aspects of shock absorption in the operated bones.

Within-subject comparisons of implant-supported mandibular prostheses: psychometric evaluation.

PubMed

de Grandmont, P; Feine, J S; Taché, R; Boudrias, P; Donohue, W B; Tanguay, R; Lund, J P

1994-05-01

In a within-subject cross-over clinical trial, psychometric and functional measurements were taken while 15 completely edentulous subjects wore mandibular fixed prostheses and long-bar removable implant-supported prostheses. In this paper, the results of a psychometric assessment are presented. Eight subjects first received the fixed bridge and seven the removable type. After having worn a prosthesis for a minimum of two months, subjects responded to psychometric scales that measured their perceptions of various factors associated with prostheses. They also chewed test foods while masticatory activity was recorded. The prostheses were then changed and the procedures repeated. At the end of the study, patients were asked to choose the prosthesis that they wished to keep. Patients assigned significantly higher scores, on visual analogue scales, to both types of implant-supported prostheses than to their original conventional prostheses for all factors tested, including general satisfaction. However, no statistically significant differences between the two implant-supported prostheses were detected except for the difficulty of chewing carrot, apple, and sausage. For these foods, the fixed prostheses were rated higher. Subjects' responses to category scales were consistent with their responses to the visual analogue scales. These results suggest that, although patients find the fixed bridge to be significantly better for chewing harder foods, there is no difference in their general satisfaction with the two types of prostheses.

[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.

HiL simulation in biomechanics: a new approach for testing total joint replacements.

PubMed

Herrmann, Sven; Kaehler, Michael; Souffrant, Robert; Rachholz, Roman; Zierath, János; Kluess, Daniel; Mittelmeier, Wolfram; Woernle, Christoph; Bader, Rainer

2012-02-01

Instability of artificial joints is still one of the most prevalent reasons for revision surgery caused by various influencing factors. In order to investigate instability mechanisms such as dislocation under reproducible, physiologically realistic boundary conditions, a novel test approach is introduced by means of a hardware-in-the-loop (HiL) simulation involving a highly flexible mechatronic test system. In this work, the underlying concept and implementation of all required units is presented enabling comparable investigations of different total hip and knee replacements, respectively. The HiL joint simulator consists of two units: a physical setup composed of a six-axes industrial robot and a numerical multibody model running in real-time. Within the multibody model, the anatomical environment of the considered joint is represented such that the soft tissue response is accounted for during an instability event. Hence, the robot loads and moves the real implant components according to the information provided by the multibody model while transferring back the position and resisting moment recorded. Functionality of the simulator is proved by testing the underlying control principles, and verified by reproducing the dislocation process of a standard total hip replacement. HiL simulations provide a new biomechanical testing tool for analyzing different joint replacement systems with respect to their instability behavior under realistic movements and physiological load conditions. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

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.

Fungal Endocarditis Due to Aspergillus oryzae: The First Case Reported in the Literature.

PubMed

Mazza, Andrea; Luciani, Nicola; Luciani, Marco; Cammertoni, Federico; Giaquinto, Alessia; Pavone, Natalia; Bruno, Piergiorgio; Massetti, Massimo

2017-03-01

Infective endocarditis (IE) is a severe disease with high mortality and morbidity. Prosthetic valve endocarditis is a life-threatening complication which can occur in less than 10% of patients with valve prosthesis. A fungal etiology of IE is rare and accounts for only 2-4% of all case of endocarditis, but is associated with a higher mortality and morbidity. Herein is reported the first case of fungal endocarditis of aortic valve prosthesis due to Aspergillus oryzae in a 67-year-old caucasian man who nine years previously underwent mitral and aortic valve replacement with mechanical prostheses, and tricuspid annuloplasty for acute IE due to Enterococcus spp. Seven months previously, the patient also underwent a redo cardiac procedure to replace a mitral valve prosthesis with a new mechanical device due to a leakage. Aspergillus oryzae showed impressive growth with strong and unexpected virulence in both local and systemic settings.

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. ...

Ankle mechanics during sidestep cutting implicates need for 2-degrees of freedom powered ankle-foot prostheses.

PubMed

Ficanha, Evandro M; Rastgaar, Mohammad; Kaufman, Kenton R

2015-01-01

The ankle joint of currently available powered prostheses is capable of controlling one degree of freedom (DOF), focusing on improved mobility in the sagittal plane. To increase agility, the requirements of turning in prosthesis design need to be considered. Ankle kinematics and kinetics were studied during sidestep cutting and straight walking. There were no significant differences between the ankle sagittal plane mechanics when comparing sidestep cutting and straight walking; however, significant differences were observed in ankle frontal plane mechanics. During straight walking, the inversion-eversion (IE) angles were smaller than with sidestep cutting. The ankle that initiated the sidestep cutting showed progressively increasing inversion from 2 to 13 degrees while the following contralateral step showed progressively decreasing inversion from 8 to -4 degrees during normal walking speed. The changes in IE kinematics were the most significant during sidestep cutting compared with straight walking. The IE moments of the step that initiated the sidestep cutting were always in eversion, acting as a braking moment opposing the inverting motion. This suggests that an ankle-foot prosthesis with active DOFs in the sagittal and frontal planes will increase the agility of gait for patients with limb loss.

Biomechanics of the ankle-foot system during stair ambulation: implications for design of advanced ankle-foot prostheses.

PubMed

Sinitski, Emily H; Hansen, Andrew H; Wilken, Jason M

2012-02-02

Unilateral lower limb prosthesis users display temporal, kinematic, and kinetic asymmetries between limbs while ascending and descending stairs. These asymmetries are due, in part, to the inability of current prosthetic devices to effectively mimic normal ankle function. The purpose of this study was to provide a comprehensive set of biomechanical data for able-bodied and unilateral transtibial amputee (TTA) ankle-foot systems for level-ground (LG), stair ascent (SA), and stair descent (SD), and to characterize deviations from normal performance associated with prosthesis use. Ankle joint kinematics, kinetics, torque-angle curves, and effective shapes were calculated for twelve able-bodied individuals and twelve individuals with TTA. The data from this study demonstrated the prosthetic limb can more effectively mimic the range of motion and power output of a normal ankle-foot during LG compared to SA and SD. There were larger differences between the prosthetic and able-bodied limbs during SA and SD, most evident in the torque-angle curves and effective shapes. These data can be used by persons designing ankle-foot prostheses and provide comparative data for assessment of future ankle-foot prosthesis designs. Published by Elsevier Ltd.

Metal hypersensitivity after knee arthroplasty: fact or fiction?

PubMed

Innocenti, Massimo; Vieri, Berti; Melani, Tommaso; Paoli, Tommaso; Carulli, Christian

2017-06-07

Hypersensitivity to metals in the general population has an incidence of about 15%, and in rising also for the higher number of joint replacements in the last decades. Total Knee Arthroplasty (TKA) represents the most performed orthopaedic procedure during last years, and it seems to be particularly associated with sensitization after surgery. On the other hand, there is a rising amount of patients with painful but well implanted and functioning TKAs: in certain cases, after the exclusion of the most frequent causes of failure, a condition of hypersensitivity may be found, and a revision with anallergic implants is mandatory. The present study is a review of the potential problems related to hypersensitivity in TKA, its possible diagnostic procedures, and the surgical options to date available. Medical history, patch testing, and other specific laboratory assays are useful to assess a status of metals hypersensitivity before surgery in subjects undergoing a knee replacement, or even after TKA in patients complaining pain in otherwise well implanted and aligned prostheses. However, few groups worlwide deal with such condition, and all proposed diagnostic protocols may be considered still today conjectural. On the other hand, these represent the most updated knowledge of this condition, and may be useful for both the patient and the orthopaedic surgeon. Once assessed a possible or ascertained allergy to metals, several options are available for primary andr revision knee surgery, in order to avoid the risk of hypersensitivity. A review of the recent publications on this topic and an overview of the related aspects has been made to understand a condition to date considered negligible. Hypersensitivity to metals has not to be nowadays considered a "fiction", but rather a possible preoperative risk or a postoperative cause of failure of TKA. Crucial is the information of patients and the medical history, associated in suspect cases to laboratory testings. Today in the market several knee implants are available and safe for allergic patients undergoing TKA.

Early beneficial effect of preservation of papillo-annular continuity in mitral valve replacement on left ventricular function.

PubMed

Dilip, D; Chandra, A; Rajashekhar, D; Padmanabhan, M

2001-05-01

Impairment of left ventricular (LV) function after mitral valve replacement (MVR) has been the most important factor to determine morbidity and mortality. With this in mind, LV performance in the postoperative period was assessed with and without preservation of papillo-annular continuity in MVR. Between March 1994 and August 1998, a total of 383 valve prostheses (202 MVR, 65 AVR, 58 MVR+AVR) were implanted in 325 patients, 177 of whom underwent MVR with Starr Edwards ball cage prostheses (the study group). Of these 177 patients, 105 had MVR with preservation of the posterior mitral leaflet (group I), and 72 had conventional MVR (group II). Predominant lesions were mitral stenosis in 81, mitral regurgitation in 42, and mixed mitral lesion (MS/MR) in 54. Concomitant tricuspid valve annuloplasty was performed in 13, and atrial septal defect repair in five. Sixteen patients underwent MVR for mitral restenosis. In-vivo performance of the prostheses and LV function was evaluated by M-mode and Doppler echocardiography. At 3-6 months clinical improvement was seen in NYHA class, with reduction in cardiothoracic ratio among patients with preserved papillo-annular continuity, irrespective of lesion type. Significant reductions (p <0.05) were seen in left atrial dimensions (54.10 +/- 8.79 preop. versus 44.64 +/- 8.54 postop.; p <0.05), left ventricular end-diastolic dimensions (LVEDD) (50.84 +/- 10.42 preop. versus 41.21 +/- 7.16 postop.; p <0.05) and end-systolic dimensions (LVESD) (34.76 +/- 7.94 preop. versus 28.81 +/- 5.79 postop.; p <0.05) in patients who had their posterior mitral leaflet preserved with significant improvement in ejection fraction (60.31 +/- 8.22 versus 64.47 +/- 7.93; p <0.05). Further analysis of data in group I patients showed significant reductions in left atrial dimensions, LVESD and peak gradient, along with improved ejection fraction compared with conventional (group II) patients. Deterioration in LV function in patients undergoing conventional MVR indicates chordal resection as a putative mechanism. This study supports the concept that maintenance of continuity between the mitral annulus and papillary muscles has a beneficial effect on postoperative LV function, and is particularly important in patients with mitral stenosis with depressed preoperative LV systolic function.

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

Design Optimization and Development of Tubular Isogrid Composites Tubes for Lower Limb Prosthesis

NASA Astrophysics Data System (ADS)

Junqueira, Diego Morais; Gomes, Guilherme Ferreira; Silveira, Márcio Eduardo; Ancelotti, Antonio Carlos

2018-04-01

From the beginnings of humanity, natural or unnatural misfortunes such as illnesses, wars, automobile accidents cause loss of body limbs like teeth, arms, legs, etc. The solution found for the replacement of these missing limbs is in the use of prostheses. Lower limbs tubes or pylons are prosthetics components that are claimed to support loads during walking and other daily tasks activities. Commonly, prosthetic tubes are manufactured using metal materials such as stainless steel, aluminum and titanium. The mass of these tubes is generally high compared to tubes made of carbon fiber reinforced polymer matrix (CFRP) composite. Therefore, this work has the objective of design, manufacturing and analyzing the feasibility of a new tube concept, made of composite material, which makes use of lattice structure and inner layer. Until the present moment, lower limb prosthesis tubes using lattice structure and ineer layer have never been studied and/or tested to date. It can be stated that the tube of rigid ribs with inner layer and angle of 40° is more efficient than those of 26° and 30°. The proposed design allows a structural weight reduction in high performance prostheses from 120 g to 40 g.

Asymptomatic strut fracture in DeBakey-Surgitool aortic valves: incidence, management, and metallurgic aspects.

PubMed

Von Der Emde J, J; Eberlein, U; Breme J, J

1990-01-01

From August 1971 through November 1972, we implanted 62 Model 2 DeBakey-Surgitool aortic valve prostheses in 62 patients, 4 of whom later had clinically asymptomatic strut fractures. In 1 case, the patient died suddenly, and autopsy revealed detachment of the ball-cage; in each of the other 3 cases, fractures of 2 struts close to the base of the prosthesis were diagnosed fluoroscopically, and the patients underwent successful reoperation. The interval between implantation and reoperation ranged from 11 months to 16 years, 9 months. In 1 patient, retrospective study of chest radiographs revealed that the fracture had been present for 2(1/2) years. Larger valves (>/= A6) were affected significantly more often than smaller ones. We performed metallurgic analysis of 1 prosthesis: results revealed strut wear from fatigue cracking and secondary abrasion. Strut fracture was also promoted by suspension of the cage at right angles to the prosthetic ring and by use of a pyrolytic carbon ball in a titanium cage (i.e., an occluder harder than its holder). Patients with DeBakey-Surgitool aortic valve prostheses should undergo annual radiologic examinations to enable early detection of strut fractures. Prophylactic valve replacement is not indicated.

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...

Collagen-conjugated tracheal prosthesis tested in dogs without omental wrapping and silicone stenting.

PubMed

Liu, Yu; Lu, Tao; Zhang, Yongxing; Qiao, Yulei; Xi, Junjie; Wang, Qun

2016-11-01

Artificial tracheas fabricated from collagen-conjugated mesh appear to overcome fatal postoperative complications, namely anastomotic dehiscence and prosthesis dislocation. Such prostheses are incorporated by host tissue, provided they are wrapped in omentum (necessitating an additional abdominal procedure) and a silicone tube is used as a stent (to be extracted several weeks postoperatively). To mitigate related host impact (i.e. injury, pain and distress), we investigated the feasibility of implanting this type of tracheal prosthesis (∼5 cm in length) alone, without omental wrapping and use of a silicone stent. Porous-type tracheal prostheses that were reinforced with a continuous polypropylene spiral and sealed by collagen sponge from porcine skin replaced segments of cervical trachea (∼5 cm long) in 10 dogs through the method of telescopic anastomosis. Omental wrapping and silicone stent placement were omitted. Postoperatively, bronchoscopic examination was performed periodically. When dogs died or were sacrificed, tracheal prostheses were harvested for haematoxylin and eosin staining and electron microscopic scanning of luminal surface conditions. With the exception of one death from an anaesthesia-related incident during fibre-optic bronchoscopy (postsurgical week 1), nine dogs survived uneventfully (until sacrifice), without prosthesis dislocation or anastomotic dehiscence. The longest observation period was 2 years and 8 months. Bronchoscopic examination revealed that no stenosis or local infection was evident in the prostheses of five dogs. Moderate (n = 2) and slight (n = 2) stenoses were observed in the other four animals. All four animals survived for a long time, without dyspnoea or stridor. Histological examination showed that partial inner surface of the artificial trachea was covered with the pseudostratified ciliated epithelium. Regeneration of ciliated epithelium was also confirmed by scanning electron microscopy. This pilot study revealed that implantation of a collagen-conjugated tracheal prosthesis (∼5 cm in length) is feasible without the need for omental wrapping and silicone stenting as ancillary measures. This approach considerably simplified the surgical procedures to minimize host intrusion, which indicated a possible clinical application. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Primary total hip arthroplasty in Catalonia: What is the clinical evidence that supports our prosthesis?

PubMed

Chaverri-Fierro, D; Lobo-Escolar, L; Espallargues, M; Martínez-Cruz, O; Domingo, L; Pons-Cabrafiga, M

The implementation of National Prostheses Registries allows us to obtain a large amount of data and make conclusions in order to improve the use of them. Sweden was the first country to implement a National Prostheses Registry in 1979. Catalonia has been doing this since 2005. The aim of our study is to analyse the evidence that supports primary total hip replacement in Catalonia in the last 9 years, based on the Arthroplasty Registry of Catalonia (RACat). A review of the literature was carried out of the prosthesis (acetabular cups/stems) reported in the RACat between the period 2005 to 2013 in the following databases: ODEP (Orthopaedic Data Evaluation Panel), TRIP database, PubMed, and Google Scholar. Those prostheses implanted in less than 10 units (182 acetabular components corresponding to 49 models/228 stems corresponding to 63 models) were excluded. A total of 18,634 (99%) implanted acetabular cups were analysed out of a total number of 18,816, corresponding to 74 different models. In 18 models (2527 acetabular cups) no clinical evidence to support its use was found. An analysis was performed on 19,367 (98.84%) out of a total number of 19,595 implanted stems, corresponding to 75 different models. In 16 models (1845 stems) no clinical evidence was found to support their use. Variable evidence was found in the 56 models of acetabular cups (16,107) and 59 models of stems (17,522), most of it corresponding to level iv clinical evidence. There was a significant number implanted prostheses evaluated (13.56% acetabular cups/9.5% stems) for which no clinical evidence was found. The elevated number of models is highlighted (49 types for acetabular cups/63 types for stems) with less than 10 units implanted, which corresponds to only 1% of the total implants. The use of arthroplasty registers is shown to be an extremely helpful tool that allows analyses and conclusions to be made for the follow-up and post-marketing surveillance period. Copyright © 2016 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

Metal artifact reduction software used with abdominopelvic dual-energy CT of patients with metal hip prostheses: assessment of image quality and clinical feasibility.

PubMed

Han, Seung Chol; Chung, Yong Eun; Lee, Young Han; Park, Kwan Kyu; Kim, Myeong Jin; Kim, Ki Whang

2014-10-01

The objective of our study was to determine the feasibility of using Metal Artifact Reduction (MAR) software for abdominopelvic dual-energy CT in patients with metal hip prostheses. This retrospective study included 33 patients (male-female ratio, 19:14; mean age, 63.7 years) who received total hip replacements and 20 patients who did not have metal prostheses as the control group. All of the patients underwent dual-energy CT. The quality of the images reconstructed using the MAR algorithm and of those reconstructed using the standard reconstruction was evaluated in terms of the visibility of the bladder wall, pelvic sidewall, rectal shelf, and bone-prosthesis interface and the overall diagnostic image quality with a 4-point scale. The mean and SD attenuation values in Hounsfield units were measured in the bladder, pelvic sidewall, and rectal shelf. For validation of the MAR interpolation algorithm, pelvis phantoms with small bladder "lesions" and metal hip prostheses were made, and images of the phantoms both with and without MAR reconstruction were evaluated. Image quality was significantly better with MAR reconstruction than without at all sites except the rectal shelf, where the image quality either had not changed or had worsened after MAR reconstruction. The mean attenuation value was changed after MAR reconstruction to its original expected value at the pelvic sidewall (p < 0.001) and inside the bladder (p < 0.001). The SD attenuation value was significantly decreased after MAR reconstruction at the pelvic sidewall (p = 0.019) but did not show significant differences at the bladder (p = 0.173) or rectal shelf (p = 0.478). In the phantom study, all lesions obscured by metal artifacts on the standard reconstruction images were visualized after MAR reconstruction; however, new artifacts had developed in other parts of the MAR reconstruction images. The use of MAR software with dual-energy CT decreases metal artifacts and increases diagnostic confidence in the assessment of the pelvic cavity but also introduces new artifacts that can obscure pelvic structures.

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.

Biomechanical evaluation of two types of short-stemmed hip prostheses compared to the trust plate prosthesis by three-dimensional measurement of micromotions.

PubMed

Fottner, Andreas; Schmid, Markus; Birkenmaier, Christof; Mazoochian, Farhad; Plitz, Wolfgang; Volkmar, Jansson

2009-06-01

Stemless and short-stemmed hip prostheses have been developed to preserve femoral bone stock. While all these prostheses claim a more or less physiological load transfer, clinical long-term results are only available for the stemless thrust plate prosthesis. In this study, the in vitro primary stability of the thrust plate prosthesis was compared to two types of short-stemmed prostheses. In addition to the well-established Mayo prosthesis, the modular Metha prosthesis was tested using cone adapters with 130 degrees and 140 degrees neck-shaft-angles. The prostheses were implanted in composite femurs and loaded dynamically (300-1700 N). Three-dimensional micromotions at the bone-prosthesis interface were measured. In addition, the three-dimensional deformations at the surface of the composite femur were measured to gain data on the strain distribution. For all tested prostheses, the micromotions did not exceed 150 microm, the critical value for osteointegration. The thrust plate prosthesis revealed similar motions as the short-stemmed prostheses. The short-stemmed prosthesis with the 130 degrees cone tended to have the highest micromotions of all tested short-stemmed prostheses. The thrust plate prosthesis revealed the lowest alteration of bone surface deformation after implantation. The comparably low micromotions of the thrust plate prosthesis and the short-stemmed prostheses should be conducive to osseous integration. The higher alteration of load transmission after implantation reveals a higher risk of stress shielding for the short-stemmed prostheses.

First metatarsophalangeal joint replacement with modular three-component press-fit implant. Preliminary report.

PubMed

Kolodziej, L; Bohatyrewicz, A; Zietek, P

2013-01-01

The aim of this retrospective study was to assess functional and radiographic results of the first metatarsophalangeal joint replacement with use of unconstrained, modular, three components, porous titanium and hydroxyapatite coated, press-fit METIS® prosthesis. According to author's knowledge, results of that type of prosthesis have never been published before. 25 prosthesis were implanted in 24 patients between February 2009 and May 2011. American Orthopaedic Foot and Ankle Society Hallux Metatarsophalangeal Interphalangeal scoring system (AOFAS-HMI) was used to assess functional results. Patients were also asked if they would undergo procedure again or recommend it to other people. Weight bearing radiographs ware made at final follow up and analyzed for presence of osteolysis and radiolucencies. In 8 patients total joint replacement was introduced as a salvage after failure of previous surgery like Keller resection arthroplasty, failed arthrodesis, avascular necrosis and postoperative arthritis. In 11 patients the reason for prosthetic replacement were hallux rigidus, in 4 cases rheumatoid arthritis and gout in one patient. In two patients additional procedures like Akin phalangeal osteotomy and in one case fifth metatarsal osteotomy, was performed. There were 20 females and 4 males in presented group. The mean age at the operation was 56 years. The average follow up period was 18 months (from 12 to 36 months). The median postoperative value of AOFAS-HMI scores was 88 points (from 75 to 95 points). First metatarsophalangeal joint motion (dorsiflexion plus plantarflexion) was classified according to AOFAS-HMI ranges as: moderately restricted (between 30 to 70 degrees) in 19 patients 80% (20 prosthesis) and severely restricted (less then 30 degrees) in 5 patients (20%). 15 (64%) patients were completely satisfied, 5 (20%) reported moderate satisfaction and (16%) 4 were totally disappointed and would not undergo this procedure again. A limited hallux dorsiflexion was the main dissatisfaction reason. Partial radiolucent line was seen in one patient (4%). Authors noticed two serious complications. In one patient, with rheumatoid arthritis, deep infection occurred 12 months after prosthesis implantation. In second case phalangeal implant was revised due to misalignment. METIS® metatarsophalangeal joint replacement allows alleviate of pain relating to hallux rigidus and partial restoration of joint movement, even in patients after failures of primary metatarsophalangeal joint surgery. AOFAS-HMI results are better than previously reported in the literature in assessment of the first metatarsophalangeal joint replacement. Radiographic results imply satisfactory bone ingrowth into the cementless implants.

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.

Survival of the Scandinavian total ankle replacement (STAR): results of ten to nineteen years follow-up.

PubMed

Frigg, Arno; Germann, Ursula; Huber, Martin; Horisberger, Monika

2017-10-01

The purpose of this study was to evaluate survival and clinical outcome of the Scandinavian total ankle replacement (STAR) prosthesis after a minimum of ten years up to a maximum of 19 years. Fifty STAR prostheses in 46 patients with end stage ankle osteoarthritis operated between 1996 and 2006 by the same surgeon (MH) were included. Minimal follow-up was ten years (median 14.6 years, 95% confidence interval [CI] 12.9-16.4). Clinical (Kofoed score) and radiological assessments were taken before the operation and at one, ten (+2), and 16 (±3) years after implantation. The primary endpoint was defined as exchange of the whole prosthesis or conversion to arthrodesis (def. 1), exchange of at least one metallic component (def. 2), or exchange of any component including the inlay (due to breakage or wear) (def. 3). Survival was estimated according to Kaplan-Meier. Further reoperations related to STAR were also recorded. The ten year survival rate was (def. 1) 94% (CI 82-98%), (def. 2) 90% (CI, 77-96%), and (def. 3) 78% (CI 64-87%). The 19-year survival rate was (def. 1) 91% (CI 78-97%), (def. 2) 75% (CI 53-88%), and (def. 3) 55% (CI 34-71%). Considering any re-operations related to STAR, 52% (26/50) of prostheses were affected by re-operations. Mean pre-operative Kofoed score was 49, which improved to 84 after one year (n = 50), to 90 after ten years (n = 46), and to 89 after 16 years (n = 28). The survival rate for def. 1 and 2 was high. However, re-operations occurred in 52% of all STAR prosthesis. Retrospective cohort study, evidence Level 4.

Tribological assessment of a flexible carbon-fibre-reinforced poly(ether-ether-ketone) acetabular cup articulating against an alumina femoral head.

PubMed

Scholes, S C; Inman, I A; Unsworth, A; Jones, E

2008-04-01

New material combinations have been introduced as the bearing surfaces of hip prostheses in an attempt to prolong their life by overcoming the problems of failure due to wear-particle-induced osteolysis. This will hopefully reduce the need for revision surgery. The study detailed here used a hip simulator to assess the volumetric wear rates of large-diameter carbon-fibre-reinforced pitch-based poly(ether-ether-ketone) (CFR-PEEK) acetabular cups articulating against alumina femoral heads. The joints were tested for 25 x 10(6) cycles. Friction tests were also performed on these joints to determine the lubrication regime under which they operate. The average volumetric wear rate of the CFR-PEEK acetabular component of 54 mm diameter was 1.16 mm(3)/10(6) cycles, compared with 38.6 mm(3)/10(6) cycles for an ultra-high-molecular-weight polyethylene acetabular component of 28 mm diameter worn against a ceramic head. This extremely low wear rate was sustained over 25 x 10(6) cycles (the equivalent of up to approximately 25 years in vivo). The frictional studies showed that the joints worked under the mixed-boundary lubrication regime. The low wear produced by these joints showed that this novel joint couple offers low wear rates and therefore may be an alternative material choice for the reduction of osteolysis.

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.

In vitro method for assessing the biomechanics of the patellofemoral joint following total knee arthroplasty.

PubMed

Coles, L G; Gheduzzi, S; Miles, A W

2014-12-01

The patellofemoral joint is a common site of pain and failure following total knee arthroplasty. A contributory factor may be adverse patellofemoral biomechanics. Cadaveric investigations are commonly used to assess the biomechanics of the joint, but are associated with high inter-specimen variability and often cannot be carried out at physiological levels of loading. This study aimed to evaluate the suitability of a novel knee simulator for investigating patellofemoral joint biomechanics. This simulator specifically facilitated the extended assessment of patellofemoral joint biomechanics under physiological levels of loading. The simulator allowed the knee to move in 6 degrees of freedom under quadriceps actuation and included a simulation of the action of the hamstrings. Prostheses were implanted on synthetic bones and key soft tissues were modelled with a synthetic analogue. In order to evaluate the physiological relevance and repeatability of the simulator, measurements were made of the quadriceps force and the force, contact area and pressure within the patellofemoral joint using load cells, pressure-sensitive film, and a flexible pressure sensor. The results were in agreement with those previously reported in the literature, confirming that the simulator is able to provide a realistic physiological loading situation. Under physiological loading, average standard deviations of force and area measurements were substantially lower and comparable to those reported in previous cadaveric studies, respectively. The simulator replicates the physiological environment and has been demonstrated to allow the initial investigation of factors affecting patellofemoral biomechanics following total knee arthroplasty. © IMechE 2014.

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.

Vertical augmentation with interpositional blocks of anorganic bovine bone vs. 7-mm-long implants in posterior mandibles: 1-year results of a randomized clinical trial.

PubMed

Felice, Pietro; Pellegrino, Gerardo; Checchi, Luigi; Pistilli, Roberto; Esposito, Marco

2010-12-01

To evaluate whether 7-mm-long implants could be an alternative to longer implants placed in vertically augmented posterior mandibles. Sixty patients with posterior mandibular edentulism with 7-8 mm bone height above the mandibular canal were randomized to either vertical augmentation with anorganic bovine bone blocks and delayed 5-month placement of ≥10 mm implants or to receive 7-mm-long implants. Four months after implant placement, provisional prostheses were delivered, replaced after 4 months, by definitive prostheses. The outcome measures were prosthesis and implant failures, any complications and peri-implant marginal bone levels. All patients were followed to 1 year after loading. One patient dropped out from the short implant group. In two augmented mandibles, there was not sufficient bone to place 10-mm-long implants possibly because the blocks had broken apart during insertion. One prosthesis could not be placed when planned in the 7 mm group vs. three prostheses in the augmented group, because of early failure of one implant in each patient. Four complications (wound dehiscence) occurred during graft healing in the augmented group vs. none in the 7 mm group. No complications occurred after implant placement. These differences were not statistically significant. One year after loading, patients of both groups lost an average of 1 mm of peri-implant bone. There no statistically significant differences in bone loss between groups. When residual bone height over the mandibular canal is between 7 and 8 mm, 7 mm short implants might be a preferable choice than vertical augmentation, reducing the chair time, expenses and morbidity. These 1-year preliminary results need to be confirmed by follow-up of at least 5 years. © 2010 John Wiley & Sons A/S.

Cardiac arrest due to left circumflex coronary artery embolism as a complication of subtherapeutic oral anticoagulation in a patient with mitral and aortic mechanical valve prostheses

PubMed Central

Protasiewicz, Marcin; Gajek, Jacek; Mysiak, Andrzej

2013-01-01

We report a case of a 65-year-old female patient after replacement of aortic and mitral valve with mechanical prostheses and implantation of a pacemaker hospitalized in our clinic due to acute coronary syndrome complicated with cardiac arrest due to ventricular fibrillation. The electrocardiogram performed on admission showed signs of myocardial infarction with concomitant ventricular pacing. After successful resuscitation the coronary angiography was performed, which showed occlusion of the left circumflex artery (LCx) by thrombus. On the basis of intravascular ultrasound imaging the presence of vulnerable plaque, parietal thrombus and dissection of LCx were excluded. It suggested that occlusion of the LCx resulted from its embolism by left-sided heart thrombus due to subtherapeutic oral anticoagulation. In this case suboptimal anticoagulation was partially iatrogenic. Two weeks before the patient had been given vitamin K intravenously due to indeterminable international normalized ratio (INR) level, which caused transient resistance to oral anticoagulants. This case report illustrates tragic difficulties in the treatment with vitamin K antagonists, which concern as many as 2/3 of anticoagulated patients. These troubles contributed to the search for new, more efficient and safer anticoagulants. There are two classes of new oral anticoagulant drugs, which do not require monitoring of coagulation: direct thrombin inhibitors (e.g. dabigatran) and factor Xa inhibitors (e.g. rivaroxaban). In spite of their proven efficacy in the prevention of ischaemic stroke related to atrial fibrillation and prevention or treatment of deep vein thrombosis and pulmonary embolism, the use of new oral anticoagulants for the treatment of patients with mechanical valve prostheses needs further research. PMID:24570697

Cardiac arrest due to left circumflex coronary artery embolism as a complication of subtherapeutic oral anticoagulation in a patient with mitral and aortic mechanical valve prostheses.

PubMed

Protasiewicz, Marcin; Rojek, Aleksandra; Gajek, Jacek; Mysiak, Andrzej

2013-01-01

We report a case of a 65-year-old female patient after replacement of aortic and mitral valve with mechanical prostheses and implantation of a pacemaker hospitalized in our clinic due to acute coronary syndrome complicated with cardiac arrest due to ventricular fibrillation. The electrocardiogram performed on admission showed signs of myocardial infarction with concomitant ventricular pacing. After successful resuscitation the coronary angiography was performed, which showed occlusion of the left circumflex artery (LCx) by thrombus. On the basis of intravascular ultrasound imaging the presence of vulnerable plaque, parietal thrombus and dissection of LCx were excluded. It suggested that occlusion of the LCx resulted from its embolism by left-sided heart thrombus due to subtherapeutic oral anticoagulation. In this case suboptimal anticoagulation was partially iatrogenic. Two weeks before the patient had been given vitamin K intravenously due to indeterminable international normalized ratio (INR) level, which caused transient resistance to oral anticoagulants. This case report illustrates tragic difficulties in the treatment with vitamin K antagonists, which concern as many as 2/3 of anticoagulated patients. These troubles contributed to the search for new, more efficient and safer anticoagulants. There are two classes of new oral anticoagulant drugs, which do not require monitoring of coagulation: direct thrombin inhibitors (e.g. dabigatran) and factor Xa inhibitors (e.g. rivaroxaban). In spite of their proven efficacy in the prevention of ischaemic stroke related to atrial fibrillation and prevention or treatment of deep vein thrombosis and pulmonary embolism, the use of new oral anticoagulants for the treatment of patients with mechanical valve prostheses needs further research.

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...

Fisics-Incor bovine pericardial bioprostheses: 15 year results.

PubMed

Pomerantzeff, P M; Brandao, C M; Cauduro, P; Puig, L B; Grinberg, M; Tarasoutchi, F; Cardoso, L F; Lerner, A; Stolf, N A; Verginelli, G; Jatene, A D

1998-01-01

From March 1982 to December 1995, 2,607 Fisics-Incor bovine pericardial bioprostheses were implanted in 2,259 patients. Mean age was 47.2 +/- 17.5 years, and 55% were male. Rheumatic fever was present in 1,301 (45.7%) patients. One thousand and seventy-three aortic valve replacements, 1,085 mitral replacements, 27 tricuspid replacements, 195 mitral-aortic replacements, and 16 other combined valve replacements were carried out. Combined procedures were performed in 788 (32.9%) patients, the most frequent being tricuspid valve repair (9.2%) and coronary artery bypass grafting (7.7%). Hospital mortality was 8.6% (194 patients), 8.6% for the mitral group, 4.7% for the aortic group, and 12.8% for double-valve replacements. The linear rates for calcification, thromboembolism, rupture, leak and endocarditis were, respectively, 1.1%, 0.2%, 0.9%, 0.1% and 0.5% patient-year. The actuarial survival curve was 56.7 +/- 5.4% in 15 years. Survival free from endocarditis was 91.92%, survival free from thromboembolism was 95 +/- 1.7%, survival free from rupture was 43.7 +/- 9.8%, survival free from leak was 98.9 +/- 4.5%, and survival free from calcification was 48.8 +/- 7.9% in 15 years. In the late postoperative period, 1,614 (80.6%) patients were in New York Heart Association functional Class I. We conclude that the results with the Fisics-Incor bovine pericardial prostheses were satisfactory in our group of patients.

Bacterial colonization of penile prosthesis after its withdrawal due to mechanical failure.

PubMed

Etcheverry-Giadrosich, B; Torremadé-Barreda, J; Pujol-Galarza, L; Vigués-Julià, F

2017-12-01

Prosthetic surgery to treat erectile dysfunction has a risk of infection of up to 3%, but this risk can increase to 18% when the surgery involves replacement. This increased risk of infection is attributed to the bacterial colonization of the prosthesis during the initial surgery. To analyse the presence of germs in the prosthesis that is withdrawn due to mechanical failure (not infection), as well as the surgical results and its progression. A retrospective study was conducted of all replacements performed between 2013 and 2016 at a single centre. We analysed demographic data, prior type of prosthesis, surgical procedure, microbiological study and follow-up. Of the 12 replacement procedures, a microbiological study of the extracted prosthesis was performed in a total of 10 cases. Of the 10 replacements, the cultures were positive in 5 cases (50%). Staphylococcus epidermidis was the most prevalent germ. All patients underwent a flushing procedure, and an antibiotic-coated prosthesis was implanted. We recorded no infections with the new implanted device after a mean follow-up of 27.33 months (SD 4.13; 95% CI 18.22-36.43). In our study population, we observed a high rate of bacterial colonization of the prostheses that were replaced due to mechanical failure. When a flushing procedure was performed during the replacement surgery, there were no more infections than those reported in treatment-naive cases. Copyright © 2017 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

[Time course of microbial colonization of different voice prostheses].

PubMed

Schuldt, T; Dommerich, S; Pau, H-W; Kramp, B

2010-10-01

For the vocal rehabilitation of laryngectomized patients, voice prostheses are actually one of the best known methods. Caused by the surface colonisation with bacteria and fungi the life time of the prostheses is limited to 3-4 months. In a time period of 127 months we analysed the surface colonisation of 118 voice prostheses. The mean life time of the prostheses was 156 days. In reference to the prosthesis model we also recorded different times of usage (ESKA-Herrmann 141, Provox 2 184 and Provox 1 204 days (p>0.05)). In the microbiological examination the dominating bacteria were S. aureus, Klebsiella sp. and Proteus sp. It was possible to cultivate all these bacteria on every type of prosthesis used in the study. In addition C. albicans, C. glabrata, C. krusei and C. tropicalis were the main fungi on the silicone surface. Thereby a more frequent colonisation with C. krusei on ESKA-Herrmann prostheses was measured, caused by the bigger contact area with saliva on this model (p=0.034). Because of the similar position and way of function, all types of voice prostheses are colonized by almost the same species of bacteria and fungi. But in dependency of the type an affinity of individual species to special prostheses exist. The knowledge of these individual affinities is necessary for the further development of voice prostheses. Furthermore the diversity of bacteria and fungi species showed a level of saturation on the surface. This is caused by the limited space on the silicone prostheses. © Georg Thieme Verlag KG Stuttgart · New York.

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...

Mechanical characterization and comparison of energy storage and return prostheses.

PubMed

Rigney, Stacey M; Simmons, Anne; Kark, Lauren

2017-03-01

The suitability of finite element analysis (FEA) for standardizing the mechanical characterization of energy storage and return (ESAR) prostheses was investigated. A methodology consisting of both experimental and numerical analysis was proposed and trialed for the Vari-flex ® Modular TM , Flex-foot Cheetah and Cheetah Xtreme by Össur ® and a 1E90 Sprinter by Ottobock ® . Gait analysis was conducted to determine suitable orientation angles for non-destructive testing (NDT) of the ESAR prostheses followed by a quasi-static inverse FEA procedure within COMSOL Multiphysics ® , where the NDT conditions were replicated to determine the homogenized material properties of the prostheses. The prostheses' loading response under bodyweight for an 80kg person was then simulated, using both Eigenfrequency and time-dependent analysis. The apparent stiffness under bodyweight was determined to be 94.7, 48.6, 57.4 and 65.0Nmm -1 for the Vari-flex ® Modular TM , Flex-foot Cheetah, Cheetah Xtreme and 1E90 Sprinter, respectively. Both the energy stored and returned by the prostheses varied negatively with stiffness, yet the overall efficiency of the prostheses were similar, at 52.7, 52.0, 51.7 and 52.4% for the abovementioned prostheses. The proposed methodology allows the standardized assessment and comparison of ESAR prostheses without the confounding influences of subject-specific gait characteristics. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

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.

[Long-term observation of 920 porcelain fused to metal prostheses].

PubMed

Jiang, Yong-Lin; Sun, Jian; Weng, Wei-Min; Zhang, Fu-Qiang

2006-10-01

To evaluate the long-term clinical results of porcelain fused to metal prostheses. Since January 1995, 920 porcelain fused to metal prostheses were fabricated. The long-term outcome were evaluated according to the condition of the prosthese, abutment and the periodontal tissue in the respects of successful rate and causes of failure. 74 patients were found to be during the follow up period, including 36 anterior crowns (46 units), 18 posterior crowns (22 units), 12 percentage of anterior bridges and 8 posterior bridges. The overall failure rate was 8.04%, 4.84% for crown, 8.77% for bridge. The failed prostheses was 5.39%. Porcelain fused to metal prostheses is an ideal method for restoration. The standard process both for the clinician and the technician must be obeyed to improve the success rate.

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.

Combined tooth-implant-supported telescopic prostheses in a midterm follow-up of > 2 years.

PubMed

Joda, Tim

2013-01-01

The aim of this trial was to evaluate telescopic-retained prostheses on teeth and implants. Ten patients with a mean of 2.8 teeth received strategic implants to achieve triangular/quadrangular support. Survival and complication rates were estimated for telescopic abutments and prostheses. After a mean observation period of > 2 years, no abutment was lost and all prostheses were in function. Complication rates were low, and maintenance services were limited to minor interventions. Combined tooth-implant-retained telescopic prostheses improve prosthetic support and offer successful function over a midterm period in patients with a severely reduced dentition.

Aortic Root Replacement for Children With Loeys-Dietz Syndrome.

PubMed

Patel, Nishant D; Alejo, Diane; Crawford, Todd; Hibino, Narutoshi; Dietz, Harry C; Cameron, Duke E; Vricella, Luca A

2017-05-01

Loeys-Dietz syndrome (LDS) is an aggressive aortopathy with a proclivity for aortic aneurysm rupture and dissection at smaller diameters than other connective tissue disorders. We reviewed our surgical experience of children with LDS to validate our guidelines for prophylactic aortic root replacement (ARR). We reviewed all children (younger than 18 years) with a diagnosis of LDS who underwent ARR at our institution. The primary endpoint was mortality, and secondary endpoints included complications and the need for further interventions. Thirty-four children with LDS underwent ARR. Mean age at operation was 10 years, and 15 (44%) were female. Mean preoperative root diameter was 4 cm. Three children (9%) had composite ARR with a mechanical prosthesis, and 31 (91%) underwent valve-sparing ARR. Concomitant procedures included arch replacement in 2 (6%), aortic valve repair in 1 (3%), and patent foramen ovale closure in 16 (47%). There was no operative mortality. Two children (6%) required late replacement of the ascending aorta, 5 (15%) required arch replacement, 1 (3%) required mitral valve replacement, and 2 (6%) had coronary button aneurysms/pseudoaneurysms requiring repair. Three children required redo valve-sparing ARR after a Florida sleeve procedure, and 2 had progressive aortic insufficiency requiring aortic valve replacement after a valve-sparing procedure. There were 2 late deaths (6%). These data confirm the aggressive aortopathy of LDS. Valve-sparing ARR should be performed when feasible to avoid the risks of prostheses. Serial imaging of the arterial tree is critical, given the rate of subsequent intervention. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Repair or Replacement for Isolated Tricuspid Valve Pathology? Insights from a Surgical Analysis on Long-Term Survival

PubMed Central

Farag, Mina; Arif, Rawa; Sabashnikov, Anton; Zeriouh, Mohamed; Popov, Aron-Frederik; Ruhparwar, Arjang; Schmack, Bastian; Dohmen, Pascal M.; Szabó, Gábor; Karck, Matthias; Weymann, Alexander

2017-01-01

Background Long-term follow-up data concerning isolated tricuspid valve pathology after replacement or reconstruction is limited. Current American Heart Association guidelines equally recommend repair and replacement when surgical intervention is indicated. Our aim was to investigate and compare operative mortality and long-term survival in patients undergoing isolated tricuspid valve repair surgery versus replacement. Material/Methods Between 1995 and 2011, 109 consecutive patients underwent surgical correction of tricuspid valve pathology at our institution for varying structural pathologies. A total of 41 (37.6%) patients underwent tricuspid annuloplasty/repair (TAP) with or without ring implantation, while 68 (62.3%) patients received tricuspid valve replacement (TVR) of whom 36 (53%) were mechanical and 32 (47%) were biological prostheses. Results Early survival at 30 days after surgery was 97.6% in the TAP group and 91.1% in the TVR group. After 6 months, 89.1% in the TAP group and 87.8% in the TVR group were alive. In terms of long-term survival, there was no further mortality observed after one year post surgery in both groups (Log Rank p=0.919, Breslow p=0.834, Tarone-Ware p=0.880) in the Kaplan-Meier Survival analysis. The 1-, 5-, and 8-year survival rates were 85.8% for TAP and 87.8% for TVR group. Conclusions Surgical repair of the tricuspid valve does not show survival benefit when compared to replacement. Hence valve replacement should be considered generously in patients with reasonable suspicion that regurgitation after repair will reoccur. PMID:28236633

Beating heart mitral valve replacement with a bovine pericardial bioprosthesis for treatment of mitral valve dysplasia in a Bull Terrier.

PubMed

Behr, Luc; Chetboul, Valérie; Sampedrano, Carolina Carlos; Vassiliki, Gouni; Pouchelon, Jean-Louis; Laborde, François; Borenstein, Nicolas

2007-04-01

To describe an open, beating heart surgical technique and use of a bovine pericardial prosthetic valve for mitral valve replacement (MVR) in the dog. Clinical case report. Male Bull Terrier (17-month-old, 26 kg) with mitral valve dysplasia and severe regurgitation. A bovine pericardial bioprosthesis was used to replace the mitral valve using an open beating heart surgical technique and cardiopulmonary bypass. Successful MVR was achieved using a beating heart technique. Mitral regurgitation resolved and cardiac performances improved (left ventricular end-diastolic diameter decreased from 57.6 to 48.7 mm, and left atrium/aorta ratio returned to almost normal, from 1.62 to 1.19). Cardiopulmonary by-pass time and total surgical duration were decreased compared with standard cardioplegic techniques. Surgical recovery was uneventful and on echocardiography 6 months later valve function was excellent. Considering the technique advantages (no cardiac arrest, ischemic reperfusion injury, and hypothermia, or the need for aortic dissection and cannulation for administration of cardioplegic solution), short-term mortality and morbidity may be reduced compared with standard cardioplegic techniques. Based on experience in this dog, beating heart mitral valvular replacement is a seemingly safe and viable option for the dog and bovine pericardial prosthesis may provide better long-term survival than mechanical prostheses.

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.

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.

[Application of negative molds technology based on three-dimensional printing in digital maxillofacial prostheses].

PubMed

Gu, X Y; Chen, X B; Jiao, T; Zhang, F Q; Jiang, X Q

2017-06-09

Objective: To explore a digital negative molds technique based on three-dimensional (3D) printing to assist in the manufacture of maxillofacial prostheses, and to improve the deficiency of the current clinical treatment. Methods: Seventeen patients with maxillofacial defects (including nasal defects, orbital defects, cheek defects, auricle defect) were scanned by means of facial optical scanning and computer tomography (CT). The 3D models were then reconstructed and global registration was made to merge the reconstructed models into a new digital model for 3D design. The 3D design of the prostheses was implemented in software. The mechanical connection structure was designed by forward engineering technology for 3 patients with intra-oral defects in maxilla who needed to make removable partial dentures, so that the silicone prostheses and removable partial denture could be combined. The removable partial dentures were made by conventional method and connected with the prostheses. According to the 3D data of the prostheses, the digital negative molds were designed, and the 3D printing technology was used to finish the processing of the resin molds. Silicone for prostheses were filled and cured in the resin molds to fabricate the clinical restorations for the patients. The margin adaptation and retention of the prostheses was detected. Results: Twenty patients with varying degrees of maxillofacial defects were rehabilitated using the courses developed in the study. All patients reported no pain or discomfort during the treatment; and they were satisfied with the final prostheses of the shape, color, retention, stability, etc. Eighteen of the prostheses showed good marginal adaptation, and sixteen of the prostheses showed good retention effect. Conclusions: The digital negative molds technique used in this study could greatly reduce the intensity of manual operation and provided a good therapeutic effect for patients with maxillofacial defects.

Use of implantable prostheses for the treatment of urinary incontinence and impotence.

PubMed

Kaufman, J J; Raz, S

1975-08-01

Silicone-Silastic implants to restore continence and potency have been used in one hundred twenty and twenty-five patients, respectively, and in eight patients a combined anti-impotence and anti-incontinence operation has been performed. The results have been gratifying, the complication rate has been minimal with fewer than five patients in our series having infection and a draining perineal sinus after the incontinence implant, and in no patient have delayed problems with the penile implants developed. Because of the design of the penile implants, fracture is extremely unlikely to occur, and the rods can be replaced if necessary because of inadequate length or asymmetry.

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.

Comparison of bone-anchored prostheses and socket prostheses for patients with a lower extremity amputation: a systematic review.

PubMed

Leijendekkers, Ruud A; van Hinte, Gerben; Frölke, Jan Paul; van de Meent, Hendrik; Nijhuis-van der Sanden, Maria W G; Staal, J Bart

2017-06-01

This study aimed to provide an overview of a) the used measurement instruments in studies evaluating effects on quality of life (QoL), function, activity and participation level in patients with a lower extremity amputation using bone-anchored prostheses compared to socket prostheses and b) the effects themselves. A systematic literature search was conducted in MEDLINE, Cochrane, EMBASE, CINAHL and Web of Science. Included studies compared QoL, function, activity and/or participation level in patients with bone-anchored or socket prostheses. A best-evidence synthesis was performed. Out of 226 studies, five cohort and two cross-sectional studies were eligible for inclusion, all had methodological shortcomings. These studies used 10 different measurement instruments and two separate questions to assess outcome. Bone-anchored prostheses were associated with better condition-specific QoL and better outcomes on several of the physical QoL subscales, outcomes on the physical bodily pain subscale were inconclusive. Outcomes on function and activity level increased, no change was found at participation level. The level of evidence was limited. There is a need for a standard set of instruments. There was limited evidence that bone-anchored prostheses resulted in higher QoL, function and activity levels than socket prostheses, in patients with socket-related problems. Implications for Rehabilitation Use of bone-anchored prostheses in combination with intensive outpatient rehabilitation may improve QoL, function and activity level compared with socket prosthesis use in patients with a transfemoral amputation and socket-related problems. All clinicians and researchers involved with bone-anchored prostheses should use and publish data on QoL, function, activity and participation level. There needs to be an agreement on a standard set of instruments so that interventions for patients with a lower extremity amputation are assessed consistently.

[Evolution of the number and type of penile prostheses implanted in France for erectile dysfunction: Analysis of French national coding database (2006-2013)].

PubMed

Lipsker, A; Saljoghi, R; Lecuelle, D; Caillet, K; Alezra, E; Le Roux, F; Demailly, M; Saint, F

2016-09-01

Patients who are not responding to injectable and/or vacuum oral pharmacological treatments can receive a penile prosthesis. Three types of penile prostheses are used in France: rigid, semi-rigid and inflatable prostheses 3-piece or 2-piece. We have assessed the National surgical insertion practices between 2006 and 2013 (number of prostheses insertions, types, procedure locations, number of surgeons and distribution [public or private sectors]). Data analysis from the French Technical Agency of Information on Hospitals (ATIH) (2006-2013) using the common classification of medical acts (CCAM) and after code extractions related to this surgery (JHLA002, JHLA003, JHLA004). Between 2006 and 2013, the number of penile implants in France doubled (307 to 633), inflatable penile prostheses with an extracavernous component remained the most frequently used (87 %) (228 to 552) (+142 %). The use of semi-rigid prostheses declined by 26.7 %. The distribution between the private and public sector was close to 1 in 2013. More than half of French penile prostheses were implanted in three regions (Île-de-France, Languedoc-Roussillon, Rhône-Alpes). Nearly 62 % of surgeons implanted only one or two three-compartment prostheses in 2013. The number of penile prostheses in France doubled between 2006 and 2013. Three regions were particularly active as far as this surgery is concerned (Île-de-France, Languedoc-Roussillon, Rhône-Alpes). They were boosted by 5 surgeons with more than 20 prostheses surgeries a year. 4. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Periprosthetic bone loss in total hip arthroplasty. Polyethylene wear debris and the concept of the effective joint space.

PubMed

Schmalzried, T P; Jasty, M; Harris, W H

1992-07-01

Thirty-four hips in which there had been prosthetic replacement were selected for study because of the presence of linear (diffuse) or lytic (localized) areas of periprosthetic bone loss. In all hips, there was careful documentation of the anatomical location of the material that had been obtained for histological analysis, and the specific purpose of the removal of the tissue was for examination to determine the cause of the resorption of bone. Specimens from twenty-three hips were retrieved during an operation and from eleven hips, at autopsy. The area of bone loss was linear only in sixteen hips, lytic only in thirteen, and both linear and lytic in five. In all thirty-four hips, intracellular particulate debris was found in the macrophages that were present in the area of bone resorption. All thirty-four had intracellular particles of polyethylene, many of which were less than one micrometer in size. Thirty-one hips had extracellular particles of polyethylene as well. Twenty-two of the thirty-four hips had intracellular metallic debris; in ten, metallic debris was found extracellularly as well. Ten of the sixteen cemented specimens had intracellular and extracellular polymethylmethacrylate debris. In the mechanically stable prostheses--cemented and uncemented--polyethylene wear debris was identified in areas of bone resorption far from the articular surfaces. The number of macrophages in a microscopic field was directly related to the amount of particulate polyethylene debris that was visible by light microscopy. Although the gross radiographic appearances of linear bone loss and lytic bone loss were different, the histological appearance of the regions in which there was active bone resorption was similar. Regardless of the radiographic appearance and anatomical origin of the specimen, bone resorption was found to occur in association with macrophages that were laden with polyethylene debris. In general, the number of macrophages present had a direct relationship to the degree of bone resorption that was seen. We believe that these findings indicate that joint fluid penetrates far more extensively than previously thought, even in a well fixed component, along the interface between the prosthesis and bone and in the periprosthetic tissues; it is often more extensive than is shown by arthrography. We therefore suggest the concept of the effective joint space to include all periprosthetic regions that are accessible to joint fluid and thus accessible to particulate debris.(ABSTRACT TRUNCATED AT 400 WORDS)

[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.

Heart valve replacement with the Sorin tilting-disc prosthesis. A 10-year experience.

PubMed

Milano, A; Bortolotti, U; Mazzucco, A; Mossuto, E; Testolin, L; Thiene, G; Gallucci, V

1992-02-01

From 1978 to 1988, 697 patients with a mean age of 48 +/- 11 years (range 5 to 75 years) received a Sorin tilting-disc prosthesis; 358 had had aortic valve replacement, 247 mitral valve replacement, and 92 mitral and aortic valve replacement. Operative mortality rates were 7.8%, 11.3%, and 10.8%, respectively, in the three groups. Cumulative duration of follow-up is 1650 patient-years for aortic valve replacement (maximum follow-up 11.4 years), 963 patient-years for mitral valve replacement (maximum follow-up 9.9 years) and 328 patient-years for mitral and aortic valve replacement (maximum follow-up 9.4 years). Actuarial survival at 9 years is 72% +/- 4% after mitral valve replacement, 70% +/- 3% after aortic valve replacement, and 50% +/- 12% after mitral and aortic valve replacement, and actuarial freedom from valve-related deaths is 97% +/- 2% after mitral valve replacement, 92% +/- 2% after aortic valve replacement, and 62% +/- 15% after mitral and aortic valve replacement. Thromboembolic events occurred in 21 patients with aortic valve replacement (1.3% +/- 0.2%/pt-yr), in 12 with mitral valve replacement (1.2% +/- 0.3% pt-yr), and in seven with mitral and aortic valve replacement (2.1% +/- 0.8%), with one case of prosthetic thrombosis in each group; actuarial freedom from thromboembolism at 9 years is 92% +/- 3% after mitral valve replacement, 91% +/- 3% after aortic valve replacement, and 74% +/- 16% after mitral and aortic valve replacement. Anticoagulant-related hemorrhage was observed in 15 patients after aortic valve replacement (0.9% +/- 0.2%/pt-yr), in 9 after mitral valve replacement (0.9% +/- 0.3%/pt-yr), and in 6 with mitral and aortic valve replacement (0.9% +/- 0.5%/pt-yr); actuarial freedom from this complication at 9 years is 94% +/- 2% after aortic valve replacement, 91% +/- 4% after mitral valve replacement, and 68% +/- 16% after mitral and aortic valve replacement. Actuarial freedom from reoperation at 9 years is 97% +/- 2% after mitral and aortic valve replacement, 92% +/- 4% after mitral valve replacement, and 89% +/- 3% after aortic valve replacement, with no cases of mechanical fracture. The Sorin valve has shown a satisfactory long-term overall performance, comparable with other mechanical prostheses, and an excellent durability that renders it a reliable heart valve substitute for the mitral and aortic positions.

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.

Dual jaw treatment of edentulism using implant-supported monolithic zirconia fixed prostheses.

PubMed

Altarawneh, Sandra; Limmer, Bryan; Reside, Glenn J; Cooper, Lyndon

2015-01-01

This case report describes restoration of the edentulous maxilla and mandible with implant supported fixed prostheses using monolithic zirconia, where the incisal edges and occluding surfaces were made of monolithic zirconia. Edentulism is a debilitating condition that can be treated with either a removable or fixed dental prosthesis. The most common type of implant-supported fixed prosthesis is the metal acrylic (hybrid), with ceramo-metal prostheses being used less commonly in complete edentulism. However, both of these prostheses designs are associated with reported complications of screw loosening or fracture and chipping of acrylic resin and porcelain. Monolithic zirconia implant-supported fixed prostheses have the potential for reduction of such complications. In this case, the CAD/CAM concept was utilized in fabrication of maxillary and mandibular screw-retained implant-supported fixed prostheses using monolithic zirconia. Proper treatment planning and execution coupled with utilizing advanced technologies contributes to highly esthetic results. However, long-term studies are required to guarantee a satisfactory long-term outcome of this modality of treatment. This case report describes the clinical and technical procedures involved in fabrication of maxillary and mandibular implant-supported fixed prostheses using monolithic zirconia as a treatment of edentulism, and proposes the possible advantages associated with using monolithic zirconia in eliminating dissimilar interfaces in such prostheses that are accountable for the most commonly occurring technical complication for these prostheses being chipping and fracture of the veneering material. © 2015 Wiley Periodicals, Inc.

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.

[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.

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

CardiaMed mechanical valve: mid-term results of a multicenter clinical trial.

PubMed

Nazarov, Vladimir M; Zheleznev, Sergey I; Bogachev-Prokophiev, Alexandr V; Afanasyev, Alexandr V; Nemchenko, Eugene V; Jeltovskiy, Yuri V; Lavinyukov, Sergey O

2014-01-01

Prosthesis choice is a major concern in valvular surgery. A multicenter clinical trial was performed to assess the efficacy and safety of the CardiaMed prosthetic heart valve. The study enrolled 420 patients who underwent mitral (209) or aortic (211) valve replacement from 2003 to 2004 at 7 institutions in Russia, and who were followed up from 2006 to 2011. The mean age was 52.2 ± 10.2 years (range, 12-78 years), 47.4% were female, and 99.05% completed the study. The maximum observation term was 7.5 years (2188.5 patient-years); 1081.6 patient-years for aortic and 1106.9 patient-years for mitral valve replacement. The overall 7-year survival rate was 85.1%  ± 3.7%; 86.1%  ± 4.8% and 84.4%  ± 5.4% for aortic and mitral valve replacement, respectively. The 7-year freedom from valve-related death was 93.9%  ± 3.7% and 94.5%  ± 3.2% for aortic and mitral valve replacement, respectively. When early mortality (<30 days) was excluded, these rates were 94.8%  ± 3.1% and 93.8%  ± 3.82%, respectively. Linearized valve-dependent complication rates were determined for structural valve failure (0%/patient-year overall), thrombosis (0.63%/patient-year, all for mitral valve replacement), thromboembolic complications including transient neurologic deficits (0.13%/patient-year overall, 0.5%/patient-year for aortic valve replacement, 0.8%/patient-year for mitral valve replacement), hemorrhagic bleeding (0.64%/patient-year overall, 0.55%/patient-year for aortic valve replacement, 0.09%/patient-year for mitral valve replacement), prosthetic endocarditis (0.28%/patient-year overall, 0.28%/patient-year for aortic valve replacement, 0%/patient-year for mitral valve replacement), and hemolysis (0%/patient-year overall). The CardiaMed mechanical heart valve prostheses meets world standards of safety and efficacy.

Microbial biofilms on facial prostheses.

PubMed

Ariani, Nina; Vissink, Arjan; van Oort, Robert P; Kusdhany, Lindawati; Djais, Ariadna; Rahardjo, Tri Budi W; van der Mei, Henny C; Krom, Bastiaan P

2012-01-01

The composition of microbial biofilms on silicone rubber facial prostheses was investigated and compared with the microbial flora on healthy and prosthesis-covered skin. Scanning electron microscopy showed the presence of mixed bacterial and yeast biofilms on and deterioration of the surface of the prostheses. Microbial culturing confirmed the presence of yeasts and bacteria. Microbial colonization was significantly increased on prosthesis-covered skin compared to healthy skin. Candida spp. were exclusively isolated from prosthesis-covered skin and from prostheses. Biofilms from prostheses showed the least diverse band-profile in denaturing gradient gel electrophoresis (DGGE) whereas prosthesis-covered skin showed the most diverse band-profile. Bacterial diversity exceeded yeast diversity in all samples. It is concluded that occlusion of the skin by prostheses creates a favorable niche for opportunistic pathogens such as Candida spp. and Staphylococcus aureus. Biofilms on healthy skin, skin underneath the prosthesis and on the prosthesis had a comparable composition, but the numbers present differed according to the microorganism.

Position of the prosthesis components in total ankle replacement and the effect on motion at the replaced joint.

PubMed

Cenni, Francesco; Leardini, Alberto; Cheli, Andrea; Catani, Fabio; Belvedere, Claudio; Romagnoli, Matteo; Giannini, Sandro

2012-03-01

In some cases of total ankle replacement, perfect alignment of the prosthetic components is not achieved. This study analyses the extent to which component positioning is critical for the final range of motion. Fourteen patients undergoing total ankle replacement were assessed preoperatively and postoperatively at seven and 13 months follow-up. X-ray pictures of the ankle were taken in static double leg stance, i.e. at neutral joint position, and in maximum plantarflexion and dorsiflexion. Measurements were obtained by a specially devised computer program based on anatomical reference points digitised on the radiograms. These allowed calculation of the position and orientation of the components in the sagittal and coronal planes, together with the joint range of motion. The mean range of motion was about 34 degrees at the first follow-up and maintained at the second. Tibial and talar components were more anterior than the mid-tibial shaft in 11 and nine patients, respectively. Mean inclination was about four degrees posterior for the tibial component and nearly one degree anterior for the talar component. A significantly larger range of motion was found in ankles both with the talar component located and inclined more anteriorly than the tibial. Correlation, though weak, was found between motion at the replaced ankle and possible residual subluxation and inclination of the components. However, a satisfactory range of motion was also achieved in those patients where recommended locations for the components could not be reached because of the size of the original joint deformity.

Nano-Material Aspects of Shock Absorption in Bone Joints

PubMed Central

Tributsch, H; Copf, F; Copf, p; Hindenlang, U; Niethard, F.U; Schneider, R

2010-01-01

This theoretical study is based on a nano-technological evaluation of the effect of pressure on the composite bone fine structure. It turned out, that the well known macroscopic mechano-elastic performance of bones in combination with muscles and tendons is just one functional aspect which is critically supported by additional micro- and nano- shock damping technology aimed at minimising local bone material damage within the joints and supporting spongy bone material. The identified mechanisms comprise essentially three phenomena localised within the three–dimensional spongy structure with channels and so called perforated flexible tensulae membranes of different dimensions intersecting and linking them. Kinetic energy of a mechanical shock may be dissipated within the solid-liquid composite bone structure into heat via the generation of quasi-chaotic hydromechanic micro-turbulence. It may generate electro-kinetic energy in terms of electric currents and potentials. And the resulting specific structural and surface electrochemical changes may induce the compressible intra-osseal liquid to build up pressure dependent free chemical energy. Innovative bone joint prostheses will have to consider and to be adapted to the nano-material aspects of shock absorption in the operated bones. PMID:21625375

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.

The effects of progressive lateralization of the joint center of rotation of reverse total shoulder implants.

PubMed

Costantini, Oren; Choi, Daniel S; Kontaxis, Andreas; Gulotta, Lawrence V

2015-07-01

There has been a renewed interest in lateralizing the center of rotation (CoR) in implants used in reverse shoulder arthroplasty. The aim of this study was to determine the sensitivity of lateralization of the CoR on the glenohumeral joint contact forces, muscle moment arms, torque across the bone-implant interface, and the stability of the implant. A 3-dimensional virtual model was used to investigate how lateralization affects deltoid muscle moment arm and glenohumeral joint contact forces. This model was virtually implanted with 5 progressively lateralized reverse shoulder prostheses. The joint contact loads and deltoid moment arms were calculated for each lateralization over the course of 3 simulated standard humerothoracic motions. Lateralization of the CoR leads to an increase in the overall joint contact forces across the glenosphere. Most of this increased loading occurred through compression, although increases in anterior/posterior and superior/inferior shear were also observed. Moment arms of the deltoid consistently decreased with lateralization. Bending moments at the implant interface increased with lateralization. Progressive lateralization resulted in improved stability ratios. Lateralization results in increased joint loading. Most of that loading occurs through compression, although there were also increases in shear forces. Anterior/posterior shear is currently not accounted for in implant fixation studies, leaving its effect on implant fixation unknown. Future studies should incorporate shear forces into their models to more accurately assess fixation methods. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Amputation rehabilitation and prosthetic restoration. From surgery to community reintegration.

PubMed

Esquenazi, Alberto

The purpose of this review is to summarize the literature related to the advances that have taken place in the management and rehabilitation care of limb amputation. Prostheses for the lower and upper limb amputee have changed greatly over the past several years, with advances in components, socket fabrication and fitting techniques, suspension systems and sources of power and electronic controls. Higher levels of limb amputation can now be fitted with functional prostheses, which allow more patients to achieve independent life styles. This is of particular importance for the multi-limb amputee. The rehabilitation of more traditional lower limb levels of amputation have also greatly benefited from the technological advances including energy storing feet, electronic control hydraulic knees, ankle rotators and shock absorbers to mention a few. For the upper limb amputee, myoelectric and proportional controlled terminal devices and elbow joints are now used routinely in some rehabilitation facilities. Experimental prosthetic fitting techniques and devices such as the use of osseo-implantation for suspension of the prosthesis, tension control hands or electromagnetic fluids for knee movement control will also be briefly discussed in this paper. It is possible to conclude from this review that many advances have occurred that have greatly impacted the functional outcomes of patients with limb amputation.

Computer-aided dental prostheses construction using reverse engineering.

PubMed

Solaberrieta, E; Minguez, R; Barrenetxea, L; Sierra, E; Etxaniz, O

2014-01-01

The implementation of computer-aided design/computer-aided manufacturing (CAD/CAM) systems with virtual articulators, which take into account the kinematics, constitutes a breakthrough in the construction of customised dental prostheses. This paper presents a multidisciplinary protocol involving CAM techniques to produce dental prostheses. This protocol includes a step-by-step procedure using innovative reverse engineering technologies to transform completely virtual design processes into customised prostheses. A special emphasis is placed on a novel method that permits a virtual location of the models. The complete workflow includes the optical scanning of the patient, the use of reverse engineering software and, if necessary, the use of rapid prototyping to produce CAD temporary prostheses.

A structurally decoupled mechanism for measuring wrist torque in three degrees of freedom

NASA Astrophysics Data System (ADS)

Pan, Lizhi; Yang, Zhen; Zhang, Dingguo

2015-10-01

The wrist joint is a critical part of the human body for movement. Measuring the torque of the wrist with three degrees of freedom (DOFs) is important in some fields, including rehabilitation, biomechanics, ergonomics, and human-machine interfacing. However, the particular structure of the wrist joint makes it difficult to measure the torque in all three directions simultaneously. This work develops a structurally decoupled instrument for measuring and improving the measurement accuracy of 3-DOF wrist torque during isometric contraction. Three single-axis torque sensors were embedded in a customized mechanical structure. The dimensions and components of the instrument were designed based on requirement of manufacturability. A prototype of the instrument was machined, assembled, integrated, and tested. The results show that the structurally decoupled mechanism is feasible for acquiring wrist torque data in three directions either independently or simultaneously. As a case study, we use the device to measure wrist torques concurrently with electromyography signal acquisition in preparation for simultaneous and proportional myoelectric control of prostheses.

A structurally decoupled mechanism for measuring wrist torque in three degrees of freedom.

PubMed

Pan, Lizhi; Yang, Zhen; Zhang, Dingguo

2015-10-01

The wrist joint is a critical part of the human body for movement. Measuring the torque of the wrist with three degrees of freedom (DOFs) is important in some fields, including rehabilitation, biomechanics, ergonomics, and human-machine interfacing. However, the particular structure of the wrist joint makes it difficult to measure the torque in all three directions simultaneously. This work develops a structurally decoupled instrument for measuring and improving the measurement accuracy of 3-DOF wrist torque during isometric contraction. Three single-axis torque sensors were embedded in a customized mechanical structure. The dimensions and components of the instrument were designed based on requirement of manufacturability. A prototype of the instrument was machined, assembled, integrated, and tested. The results show that the structurally decoupled mechanism is feasible for acquiring wrist torque data in three directions either independently or simultaneously. As a case study, we use the device to measure wrist torques concurrently with electromyography signal acquisition in preparation for simultaneous and proportional myoelectric control of prostheses.

Linking of total elbow prosthesis during surgery; a biomechanical analysis.

PubMed

De Vos, Maarten J; Wagener, Marc L; Hendriks, Jan C M; Eygendaal, Denise; Verdonschot, Nico

2013-09-01

Presently, 2 types of elbow prostheses are used: unlinked and linked. The Latitude total elbow prosthesis allows the surgeon to decide during the implantation whether the prosthesis is placed unlinked or linked, and whether the native radial head is retained, resected, or replaced. The purpose of this study is to assess and to compare the varus and valgus laxity of the unlinked and linked version of the latitude total elbow prosthesis with: (1) the native radial head preserved, (2) the native radial head excised, and (3) the native radial head replaced by a radial head component. Biomechanical testing was performed on 14 fresh-frozen upper limb specimens. Linking the prosthesis predominantly influences the valgus laxity of the elbow. Linking the Latitude total elbow prosthesis results in increased valgus stability. In the linked version of the total elbow prosthesis, the radial head only plays a small part in both valgus and varus stability. An unlinked situation is not advised in absence of a native radial head or in case of inability to replace the radial head. Copyright © 2013 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

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.

Quantification of dental prostheses on cone‐beam CT images by the Taguchi method

PubMed Central

Kuo, Rong‐Fu; Fang, Kwang‐Ming; TY, Wong

2016-01-01

The gray values accuracy of dental cone‐beam computed tomography (CBCT) is affected by dental metal prostheses. The distortion of dental CBCT gray values could lead to inaccuracies of orthodontic and implant treatment. The aim of this study was to quantify the effect of scanning parameters and dental metal prostheses on the accuracy of dental cone‐beam computed tomography (CBCT) gray values using the Taguchi method. Eight dental model casts of an upper jaw including prostheses, and a ninth prosthesis‐free dental model cast, were scanned by two dental CBCT devices. The mean gray value of the selected circular regions of interest (ROIs) were measured using dental CBCT images of eight dental model casts and were compared with those measured from CBCT images of the prosthesis‐free dental model cast. For each image set, four consecutive slices of gingiva were selected. The seven factors (CBCTs, occlusal plane canting, implant connection, prosthesis position, coping material, coping thickness, and types of dental restoration) were used to evaluate scanning parameter and dental prostheses effects. Statistical methods of signal to noise ratio (S/N) and analysis of variance (ANOVA) with 95% confidence were applied to quantify the effects of scanning parameters and dental prostheses on dental CBCT gray values accuracy. For ROIs surrounding dental prostheses, the accuracy of CBCT gray values were affected primarily by implant connection (42%), followed by type of restoration (29%), prostheses position (19%), coping material (4%), and coping thickness (4%). For a single crown prosthesis (without support of implants) placed in dental model casts, gray value differences for ROIs 1–9 were below 12% and gray value differences for ROIs 13–18 away from prostheses were below 10%. We found the gray value differences set to be between 7% and 8% for regions next to a single implant‐supported titanium prosthesis, and between 46% and 59% for regions between double implant‐supported, nickel‐chromium alloys (Ni‐Cr) prostheses. Quantification of the effect of prostheses and scanning parameters on dental CBCT gray values was assessed. PACS numbers: 87.59.bd, 87.57Q PMID:26894354

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

Rehabilitation of a missing ear with an implant retained auricular prosthesis

PubMed Central

Guttal, Satyabodh Sheshraj; Shanbhag, Shruti; Kulkarni, Sudhindra S.; Thakur, Srinath L.

2015-01-01

Burns can leave a patient with a severely debilitating disability even after treatment. The objectives of burn rehabilitation are to minimize the adverse effects caused by the injury while rehabilitating the patient's physical and psychological well-being, maximizing social integration. Long-term success of maxillofacial prostheses mainly depends on the retention. Extra oral implant retained prostheses have proved to be a predictable treatment option for maxillofacial rehabilitation. Replacement of a severely deformed external ear with burned tissues may be satisfactorily accomplished by a cosmetic prosthesis anchored by implants integrated in the skull. The use of such implants is now a well-recognized method for creating a stable result in maxillofacial rehabilitation. This case report describes a safe, simple and economical method for the rehabilitation of a patient with missing right auricle using an implant supported silicone prosthesis. The implant was placed in the mastoid region of the temporal bone. Reconstruction of the ear was done with auricular silicone prosthesis, retained using magnets incorporated in an autopolymerizing resin shim to decrease the weight of the prosthesis on a single implant. This method eliminates the need of tedious laboratory procedures and exact casting and fitting requirements of a metal substructure while minimizing the overall weight and cost of the prosthesis while maintaining adequate support, esthetics and retention of the prosthesis. PMID:26929490

Axillary silicone lymphadenopathy presenting with a lump and altered sensation in the breast: a case report

PubMed Central

2009-01-01

Introduction Silicone lymphadenopathy is a rare but recognised complication of procedures involving the use of silicone. It has a poorly understood mechanism but is thought to occur following the transportation of silicone particles from silicone-containing prostheses to lymph nodes by macrophages. Case presentation We report of a case involving a 35-year-old woman who presented to the breast clinic with a breast lump and altered sensation below her left nipple 5 years after bilateral cosmetic breast augmentations. A small lump was detected inferior to the nipple but clinical examination and initial ultrasound investigation showed both implants to be intact. However, mammography and magnetic resonance imaging of both breasts revealed both intracapsular and extracapsular rupture of the left breast prosthesis. The patient went on to develop a flu-like illness and tender lumps in the left axilla and right mastoid regions. An excision biopsy of the left axillary lesion and replacement of the ruptured implant was performed. Subsequent histological analysis showed that the axillary lump was a lymph node containing large amounts of silicone. Conclusion The exclusion of malignancy remains the priority when dealing with lumps in the breast or axilla. Silicone lymphadenopathy should however be considered as a differential diagnosis in patients in whom silicone prostheses are present. PMID:19830102

Use of mini dental implants in ectodermal dysplasia children: follow-up of three cases.

PubMed

Sfeir, E; Nassif, N; Moukarzel, C

2014-07-01

Ectodermal dysplasia is a hereditary genodermatosis characterised by a congenital defect of ectodermal structures, causing tooth malformations and anomalies. Implantology has become accepted in these subjects. However cases are often complicated by a reduction in the size of the alveolar process, making the insertion of conventional implants difficult without bone grafting. The reduced diameter of mini-implants and their ease of insertion provide an interesting solution in supporting removable or fixed prosthesis. The purpose of this paper is to report the follow-up of three cases of children (11-12 year- old) with ectodermal dysplasia in which mini-implants were used to support the prostheses. In the first case, two mini-implants were inserted into the anterior part of the mandible for stabilising a removable denture (2 years follow-up). In the other two cases, mini- implants were inserted in the maxilla and mandible to replace missing front teeth with fixed prostheses. Patients were called for follow- up every 6 months: in the sencod case follow-up lasted 4 years in the mandible and 2 years in the maxilla; in the third case, 2 years in the maxilla and 1 year in the mandible. The use of mini-implants in children with ectodermal dysplasia can enhance aesthetics, and functional and psychosocial development.

New Design for Rapid Prototyping of Digital Master Casts for Multiple Dental Implant Restorations

PubMed Central

Romero, Luis; Jiménez, Mariano; Espinosa, María del Mar; Domínguez, Manuel

2015-01-01

Aim This study proposes the replacement of all the physical devices used in the manufacturing of conventional prostheses through the use of digital tools, such as 3D scanners, CAD design software, 3D implants files, rapid prototyping machines or reverse engineering software, in order to develop laboratory work models from which to finish coatings for dental prostheses. Different types of dental prosthetic structures are used, which were adjusted by a non-rotatory threaded fixing system. Method From a digital process, the relative positions of dental implants, soft tissue and adjacent teeth of edentulous or partially edentulous patients has been captured, and a maser working model which accurately replicates data relating to the patients oral cavity has been through treatment of three-dimensional digital data. Results Compared with the conventional master cast, the results show a significant cost savings in attachments, as well as an increase in the quality of reproduction and accuracy of the master cast, with the consequent reduction in the number of patient consultation visits. The combination of software and hardware three-dimensional tools allows the optimization of the planning of dental implant-supported rehabilitations protocol, improving the predictability of clinical treatments and the production cost savings of master casts for restorations upon implants. PMID:26696528

New Design for Rapid Prototyping of Digital Master Casts for Multiple Dental Implant Restorations.

PubMed

Romero, Luis; Jiménez, Mariano; Espinosa, María Del Mar; Domínguez, Manuel

2015-01-01

This study proposes the replacement of all the physical devices used in the manufacturing of conventional prostheses through the use of digital tools, such as 3D scanners, CAD design software, 3D implants files, rapid prototyping machines or reverse engineering software, in order to develop laboratory work models from which to finish coatings for dental prostheses. Different types of dental prosthetic structures are used, which were adjusted by a non-rotatory threaded fixing system. From a digital process, the relative positions of dental implants, soft tissue and adjacent teeth of edentulous or partially edentulous patients has been captured, and a maser working model which accurately replicates data relating to the patients oral cavity has been through treatment of three-dimensional digital data. Compared with the conventional master cast, the results show a significant cost savings in attachments, as well as an increase in the quality of reproduction and accuracy of the master cast, with the consequent reduction in the number of patient consultation visits. The combination of software and hardware three-dimensional tools allows the optimization of the planning of dental implant-supported rehabilitations protocol, improving the predictability of clinical treatments and the production cost savings of master casts for restorations upon implants.

Factors Associated with Prosthetic Looseness in Lower Limb Amputees.

PubMed

Phonghanyudh, Thong; Sutpasanon, Taweesak; Hathaiareerug, Chanasak; Devakula, M L Buddhibongsa; Kumnerddee, Wipoo

2015-12-01

To determine the factors associated with prosthetic looseness in lower limb amputees in Sisaket province. The present was a cross-sectional descriptive study. Subjects were lower limb amputees who previously obtained prostheses and required prosthetic replacements at the mobile prosthetic laboratory unit under the Prostheses Foundation of H.R.H. the Princess Mother at Khun Han Hospital, Sisaket province, in February 2013. Data including participant characteristics, prosthetic looseness data, and various variables were collected by direct semi-structured interview. Energy expenditures in physical activities were measured using the Thai version of the short format international physical activity questionnaire. Data between participants with and without prosthetic looseness were compared to determine prosthetic loosening associated factors. Among 101 participants enrolled, 33 (32.7%) had prosthetic looseness with average onset of 1.76 ± 1.67 years. Diabetes mellitus was the only significant factor associated with prosthetic looseness from both univariate and multivariate analyses (HR = 7.05, p = 0.002 and HR = 5.93, p = 0.007 respectively). Among the lower limb amputees in Sisaket province, diabetes mellitus was the only factor associated with prosthetic looseness. Therefore, diabetic screening should be supplemented in lower limb amputee assessment protocol. In addition, we recommend that amputees with diabetes mellitus should receive prosthesis check out at approximately

Design and experimental analysis of a new malleovestibulopexy prosthesis using a finite element model of the human middle ear.

PubMed

Vallejo Valdezate, Luis A; Hidalgo Otamendi, Antonio; Hernández, Alberto; Lobo, Fernando; Gil-Carcedo Sañudo, Elisa; Gil-Carcedo García, Luis M

2015-01-01

Many designs of prostheses are available for middle ear surgery. In this study we propose a design for a new prosthesis, which optimises mechanical performance in the human middle ear and improves some deficiencies in the prostheses currently available. Our objective was to design and assess the theoretical acoustic-mechanical behaviour of this new total ossicular replacement prosthesis. The design of this new prosthesis was based on an animal model (an iguana). For the modelling and mechanical analysis of the new prosthesis, we used a dynamic 3D computer model of the human middle ear, based on the finite elements method (FEM). The new malleovestibulopexy prosthesis design demonstrates an acoustical-mechanical performance similar to that of the healthy human middle ear. This new design also has additional advantages, such as ease of implantation and stability in the middle ear. This study shows that computer simulation can be used to design and optimise the vibroacoustic characteristics of middle ear implants and demonstrates the effectiveness of a new malleovestibulopexy prosthesis in reconstructing the ossicular chain. Copyright © 2014 Elsevier España, S.L.U. y Sociedad Española de Otorrinolaringología y Patología Cérvico-Facial. All rights reserved.

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

Valve replacement in children: a challenge for a whole life.

PubMed

Henaine, Roland; Roubertie, François; Vergnat, Mathieu; Ninet, Jean

2012-10-01

Valvular pathology in infants and children poses numerous challenges to the paediatric cardiac surgeon. Without question, valvular repair is the goal of intervention because restoration of valvular anatomy and physiology using native tissue allows for growth and a potentially better long-term outcome. When reconstruction fails or is not feasible, valve replacement becomes inevitable. Which valve for which position is controversial. Homograft and bioprosthetic valves achieve superior haemodynamic results initially but at the cost of accelerated degeneration. Small patient size and the risk of thromboembolism limit the usefulness of mechanical valves, and somatic outgrowth is an universal problem with all available prostheses. The goal of this article is to address valve replacement options for all four valve positions within the paediatric population. We review current literature and our practice to support our preferences. To summarize, a multitude of opinions and surgical experiences exist. Today, the valve choices that seem without controversy are bioprosthetic replacement of the tricuspid valve and Ross or Ross-Konno procedures when necessary for the aortic valve. On the other hand, bioprostheses may be implanted when annular pulmonary diameter is adequate; if not or in case of right ventricular outflow tract discontinuity, it is better to use a pulmonary homograft with the Ross procedure. Otherwise, a valved conduit. Mitral valve replacement remains the most problematic; the mechanical prosthesis must be placed in the annular position, avoiding oversizing. Future advances with tissue-engineered heart valves for all positions and new anticoagulants may change the landscape for valve replacement in the paediatric population. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Changes in the periodontal condition after replacement of swaged crowns by metal.

PubMed

Plotniece-Baranovska, Anita; Soboleva, Una; Rogovska, Irena; Apse, Peteris

2006-01-01

Evidence based clinical studies have shown exact recommended design for artificial crown reconstruction with acceptable long-term results taking into an account the biological price. Previous histological and clinical studies proved that fixed prostheses might influence the periodontal condition of crowned teeth, if not all biological criteria have been considered. The aim of the present study was to assess the periodontal condition of the crowned teeth after stainless steel swaged crowns were replaced by cast metal ceramic crowns. Participants were selected at the Institute of Stomatology, Stradin's University. Selection criteria included need to replace existing swaged crowns by metal ceramic crowns for patients with absence of any systemic disease. Following symptoms of periodontal condition were examined - presence of inflammation (clinical signs, probing) and pocket depth. Assessments were carried out at four different points of time (first appointment after replacement existing swaged crowns by temporary crowns; two weeks after cementation of permanent metal ceramic restoration; after three month; after six month). Overall bleeding score "2" and "3" at the first measurement was observed in majority of study population. Bleeding scores between the 1st and the 4th measurement was significantly lower (p<0.01). The same trend was observed also in the reduction of pocket depth. Overall mean value of pocket depth gradually decreased from the 1st till the 4th measurement. Replacement of swaged crowns by metal ceramic improves gingival health and leads to better long-term prognosis for restored teeth. It is recommended that swaged crowns be replaced with more biologically friendly crowns.

PERSPECTIVE: Electrical activity enhances neuronal survival and regeneration

NASA Astrophysics Data System (ADS)

Corredor, Raul G.; Goldberg, Jeffrey L.

2009-10-01

The failure of regeneration in the central nervous system (CNS) remains an enormous scientific and clinical challenge. After injury or in degenerative diseases, neurons in the adult mammalian CNS fail to regrow their axons and reconnect with their normal targets, and furthermore the neurons frequently die and are not normally replaced. While significant progress has been made in understanding the molecular basis for this lack of regenerative ability, a second approach has gained momentum: replacing lost neurons or lost connections with artificial electrical circuits that interface with the nervous system. In the visual system, gene therapy-based 'optogenetics' prostheses represent a competing technology. Now, the two approaches are converging, as recent data suggest that electrical activity itself, via the molecular signaling pathways such activity stimulates, is sufficient to induce neuronal survival and regeneration, particularly in retinal ganglion cells. Here, we review these data, discuss the effects of electrical activity on neurons' molecular signaling pathways and propose specific mechanisms by which exogenous electrical activity may be acting to enhance survival and regeneration.

Bone Replacement Materials and Techniques Used for Achieving Vertical Alveolar Bone Augmentation

PubMed Central

Sheikh, Zeeshan; Sima, Corneliu; Glogauer, Michael

2015-01-01

Alveolar bone augmentation in vertical dimension remains the holy grail of periodontal tissue engineering. Successful dental implant placement for restoration of edentulous sites depends on the quality and quantity of alveolar bone available in all spatial dimensions. There are several surgical techniques used alone or in combination with natural or synthetic graft materials to achieve vertical alveolar bone augmentation. While continuously improving surgical techniques combined with the use of auto- or allografts provide the most predictable clinical outcomes, their success often depends on the status of recipient tissues. The morbidity associated with donor sites for auto-grafts makes these techniques less appealing to both patients and clinicians. New developments in material sciences offer a range of synthetic replacements for natural grafts to address the shortcoming of a second surgical site and relatively high resorption rates. This narrative review focuses on existing techniques, natural tissues and synthetic biomaterials commonly used to achieve vertical bone height gain in order to successfully restore edentulous ridges with implant-supported prostheses.

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.

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 - ...

[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.

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 metal-polymeric fixed partial prosthesis using optical coherence tomography

NASA Astrophysics Data System (ADS)

Sinescu, C.; Negrutiu, M. L.; Duma, V. F.; Marcauteanu, C.; Topala, F. I.; Rominu, M.; Bradu, A.; Podoleanu, A. Gh.

2013-11-01

Metal-Polymeric fixed partial prosthesis is the usual prosthetic treatment for many dental patients. However, during the mastication the polymeric component of the prosthesis is fractured and will be lost. This fracture is caused by the material defects or by the fracture lines trapped inside the esthetic components of the prosthesis. This will finally lead to the failure of the prosthetic treatment. Nowadays, there is no method of identification and forecast for the materials defects of the polymeric materials. The aim of this paper is to demonstrate the capability of Optical Coherence Tomography (OCT) as a non-invasive clinical method that can be used for the evaluation of metal-polymeric fixed partial prostheses. Twenty metal-polymeric fixed partial prostheses were used for this study. The esthetic component of the prostheses has been Adoro (Ivoclar). Optical investigations of the metal prostheses have revealed no material defects or fracture lines. All the prostheses were temporary cemented in the oral cavities of the patients for six month. The non-invasive method used for the investigations was OCT working in Time Domain mode at 1300 nm. The evaluations of the prostheses were performed before and after their cementation in the patient mouths. All the imagistic results were performed in 2D and than in 3D, after the reconstruction. The results obtained after the OCT evaluation allowed for the identification of 4 metal-polymeric fixed partial prostheses with material defects immediately after finishing the technological procedures. After 6 month in the oral environment other 3 fixed partial prostheses revealed fracture lines. In conclusion, OCT proved to be a valuable tool for the noninvasive evaluation of the metal-polymeric fixed partial prostheses.

Implant-level prostheses in the edentulous maxilla: a comparison with conventional abutment-level prostheses after 5 years of use.

PubMed

Hjalmarsson, Lars; Smedberg, Jan-Ivan; Pettersson, Mattias; Jemt, Torsten

2011-01-01

Long-term comparisons of frameworks at the implant or abutment level are not available, and knowledge of the clinical function of cobalt-chromium (Co-Cr) alloy frameworks is limited. Primarily, the aim of this study was to compare the 5-year clinical performance of frameworks with or without abutment connections to implants. Secondly, the outcomes of prostheses made from Co-Cr alloy with porcelain veneers to those made of commercially pure titanium (CP Ti) with acrylic veneers were compared. The test groups comprised patients treated with screw-retained fixed prostheses made at the implant level according to the Cresco method in either dental porcelain-veneered Co-Cr alloy (n = 15) or acrylic-veneered CP Ti (n = 25). A control group of 40 randomly selected patients were provided with prostheses made at the standard abutment level in CP Ti with acrylic veneers. For all patients, clinical and radiologic 5-year data were retrospectively collected and evaluated. Five-year implant cumulative survival rates (CSRs) were 98.6% and 97.6% for test and control groups, respectively (P > .05). No major differences in bone level were demonstrated between the groups after 5 years (P > .05). Significantly more complications occurred in the test groups compared to the control group (P < .01), with the most common complications being mucositis and fracture of veneers. After 5 years, the clinical outcomes of implant-level prostheses made of porcelain-veneered Co-Cr or acrylic-veneered CP Ti seem comparable to acrylic-veneered titanium prostheses made at the standard abutment level regarding implant CSR and bone levels. However, more complications were registered in implant-level prostheses compared to the standard abutment-level prostheses.

Effects of Design Variants in Lower-Limb Prostheses on Gait Synergy

PubMed Central

Pitkin, Mark R.

2016-01-01

A lower-limb prosthesis is the mechanical device with which an amputee’s residual limb interacts with the walking surface. The pressure and shear forces that affect the residuum due to prosthesis use are the sources of pain, residual-limb skin problems and gait deviations. Direct approaches to reducing these problems include improving fit, alignment technique and socket design as well as increasing cushioning with socket liners. A summary of typical malalignments and their consequences is presented. The malalignments are considered sources of excessive moments applied to the residuum, which simplifies the analysis of a patient’s gait. A better design of prosthetic joints could improve prosthetic gait. This article addresses the key mechanical parameter of prosthetic joints, namely the dependence “moment of resistance/angle of deflection.” A mathematical model has been developed that links stresses on the residuum in transtibial amputees with the moment of resistance in the prosthetic ankle at the critical gait phases. Analysis of the model yields a substantial decrease in stresses on the residuum during the most demanding, load-bearing phase of stance if the moment of resistance in the ankle is similar to that seen in the biological ankle joint. Gait study shows use of the experimental rolling-joint prosthetic foot more closely simulates normal gait synergy than the SACH foot. PMID:27087763

Designer Dual Therapy Nanolayered Implant Coatings Eradicate Biofilms and Accelerate Bone Tissue Repair.

PubMed

Min, Jouha; Choi, Ki Young; Dreaden, Erik C; Padera, Robert F; Braatz, Richard D; Spector, Myron; Hammond, Paula T

2016-04-26

Infections associated with orthopedic implants cause increased morbidity and significant healthcare cost. A prolonged and expensive two-stage procedure requiring two surgical steps and a 6-8 week period of joint immobilization exists as today's gold standard for the revision arthroplasty of an infected prosthesis. Because infection is much more common in implant replacement surgeries, these issues greatly impact long-term patient care for a continually growing part of the population. Here, we demonstrate that a single-stage revision using prostheses coated with self-assembled, hydrolytically degradable multilayers that sequentially deliver the antibiotic (gentamicin) and the osteoinductive growth factor (BMP-2) in a time-staggered manner enables both eradication of established biofilms and complete and rapid bone tissue repair around the implant in rats with induced osteomyelitis. The nanolayered construct allows precise independent control of release kinetics and loading for each therapeutic agent in an infected implant environment. Antibiotics contained in top layers can be tuned to provide a rapid release at early times sufficient to eliminate infection, followed by sustained release for several weeks, and the underlying BMP-2 component enables a long-term sustained release of BMP-2, which induced more significant and mechanically competent bone formation than a short-term burst release. The successful growth factor-mediated osteointegration of the multilayered implants with the host tissue improved bone-implant interfacial strength 15-fold when compared with the uncoated one. These findings demonstrate the potential of this layered release strategy to introduce a durable next-generation implant solution, ultimately an important step forward to future large animal models toward the clinic.

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

SU-E-I-75: Evaluation of An Orthopedic Metal Artifact Reduction (O-MAR) Algorithm On Patients with Spinal Prostheses Near Spinal Tumors

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

Shen, Z; Xia, P; Djemil, T

Purpose: To evaluate the impact of a commercial orthopedic metal artifact reduction (O-MAR) algorithm on CT image quality and dose calculation for patients with spinal prostheses near spinal tumors. Methods: A CT electron density phantom was scanned twice: with tissue-simulating inserts only, and with a titanium insert replacing solid water. A patient plan was mapped to the phantom images in two ways: with the titanium inside or outside of the spinal tumor. Pinnacle and Eclipse were used to evaluate the dosimetric effects of O-MAR on 12-bit and 16-bit CT data, respectively. CT images from five patients with spinal prostheses weremore » reconstructed with and without O-MAR. Two observers assessed the image quality improvement from O-MAR. Both pencil beam and Monte Carlo dose calculation in iPlan were used for the patient study. The percentage differences between non-OMAR and O-MAR datasets were calculated for PTV-min, PTV-max, PTV-mean, PTV-V100, PTV-D90, OAR-V10Gy, OAR-max, and OAR-D0.1cc. Results: O-MAR improved image quality but did not significantly affect the dose distributions and DVHs for both 12-bit and 16- bit CT phantom data. All five patient cases demonstrated some degree of image quality improvement from O-MAR, ranging from small to large metal artifact reduction. For pencil beam, the largest discrepancy was observed for OARV-10Gy at 5.4%, while the other seven parameters were ≤0.6%. For Monte Carlo, the differences between non-O-MAR and O-MAR datasets were ≤3.0%. Conclusion: Both phantom and patient studies indicated that O-MAR can substantially reduce metal artifacts on CT images, allowing better visualization of the anatomical structures and metal objects. The dosimetric impact of O-MAR was insignificant regardless of the metal location, image bit-depth, and dose calculation algorithm. O-MAR corrected images are recommended for radiation treatment planning on patients with spinal prostheses because of the improved image quality and no need to modify current dose constraints. This work was supported by a research grant from Philips Healthcare. Paul Klahr is an employee of Philips Healthcare.« less

Prostheses and orthoses for the foot and ankle.

PubMed

Rubin, G; Cohen, E

1988-07-01

The general nature and function of the AFO has been presented. These devices encompass the foot and leg crossing the ankle joint. They may insert into the shoe or attach to the shoe. The more recent AFOs are made of polypropylene and were formerly composed of steel. The indications for an AFO are for a basically ambulatory patient with problems walking, including various pathologic gaits especially drop-foot and spastic equinus. Other primary indications include ankle arthritis, Charcot foot, fractures, and post-surgery. Given the basic employment of AFOs to treat problems directly related to the foot, it is hoped that this introduction has stimulated practitioners to begin using this essential tool as an integral component of their practice.

Ageing, musculoskeletal health and work

PubMed Central

Palmer, Keith; Goodson, Nicola

2016-01-01

Changing demographics mean that many patients with soft tissue rheumatism, osteoarthritis, inflammatory arthritis, large joint prostheses, and age-related co-morbidities are seeking to work beyond the traditional retirement age. In this chapter we review the evidence on musculoskeletal health and work at older ages. We conclude that musculoskeletal problems are common in older workers and have a substantial impact on their work capacity. Factors that influence their job retention are described, together with approaches that may extend working life. Many gaps in evidence were found, notably on the health risks and benefits of continued work in affected patients and on which interventions work best. The roles of physicians and managers are also considered. PMID:26612237

Fabrication of low cost soft tissue prostheses with the desktop 3D printer

NASA Astrophysics Data System (ADS)

He, Yong; Xue, Guang-Huai; Fu, Jian-Zhong

2014-11-01

Soft tissue prostheses such as artificial ear, eye and nose are widely used in the maxillofacial rehabilitation. In this report we demonstrate how to fabricate soft prostheses mold with a low cost desktop 3D printer. The fabrication method used is referred to as Scanning Printing Polishing Casting (SPPC). Firstly the anatomy is scanned with a 3D scanner, then a tissue casting mold is designed on computer and printed with a desktop 3D printer. Subsequently, a chemical polishing method is used to polish the casting mold by removing the staircase effect and acquiring a smooth surface. Finally, the last step is to cast medical grade silicone into the mold. After the silicone is cured, the fine soft prostheses can be removed from the mold. Utilizing the SPPC method, soft prostheses with smooth surface and complicated structure can be fabricated at a low cost. Accordingly, the total cost of fabricating ear prosthesis is about $30, which is much lower than the current soft prostheses fabrication methods.

Fabrication of low cost soft tissue prostheses with the desktop 3D printer

PubMed Central

He, Yong; Xue, Guang-huai; Fu, Jian-zhong

2014-01-01

Soft tissue prostheses such as artificial ear, eye and nose are widely used in the maxillofacial rehabilitation. In this report we demonstrate how to fabricate soft prostheses mold with a low cost desktop 3D printer. The fabrication method used is referred to as Scanning Printing Polishing Casting (SPPC). Firstly the anatomy is scanned with a 3D scanner, then a tissue casting mold is designed on computer and printed with a desktop 3D printer. Subsequently, a chemical polishing method is used to polish the casting mold by removing the staircase effect and acquiring a smooth surface. Finally, the last step is to cast medical grade silicone into the mold. After the silicone is cured, the fine soft prostheses can be removed from the mold. Utilizing the SPPC method, soft prostheses with smooth surface and complicated structure can be fabricated at a low cost. Accordingly, the total cost of fabricating ear prosthesis is about $30, which is much lower than the current soft prostheses fabrication methods. PMID:25427880

Assessment of the mechanical performance of titanium cranial prostheses manufactured by super plastic forming and single point incremental forming

NASA Astrophysics Data System (ADS)

Sgambitterra, Emanuele; Piccininni, Antonio; Guglielmi, Pasquale; Ambrogio, Giuseppina; Fragomeni, Gionata; Villa, Tomaso; Palumbo, Gianfranco

2018-05-01

Cranial implants are custom prostheses characterized by quite high geometrical complexity and small thickness; at the same time aesthetic and mechanical requirements have to be met. Titanium alloys are largely adopted for such prostheses, as they can be processed via different manufacturing technologies. In the present work cranial prostheses have been manufactured by Super Plastic Forming (SPF) and Single Point Incremental Forming (SPIF). In order to assess the mechanical performance of the cranial prostheses, drop tests under different load conditions were conducted on flat samples to investigate the effect of the blank thickness. Numerical simulations were also run for comparison purposes. The mechanical performance of the cranial implants manufactured by SPF and SPIF could be predicted using drop test data and information about the thickness evolution of the formed parts: the SPIFed prosthesis revealed to have a lower maximum deflection and a higher maximum force, while the SPFed prostheses showed a lower absorbed energy.

Fabrication of low cost soft tissue prostheses with the desktop 3D printer.

PubMed

He, Yong; Xue, Guang-huai; Fu, Jian-zhong

2014-11-27

Soft tissue prostheses such as artificial ear, eye and nose are widely used in the maxillofacial rehabilitation. In this report we demonstrate how to fabricate soft prostheses mold with a low cost desktop 3D printer. The fabrication method used is referred to as Scanning Printing Polishing Casting (SPPC). Firstly the anatomy is scanned with a 3D scanner, then a tissue casting mold is designed on computer and printed with a desktop 3D printer. Subsequently, a chemical polishing method is used to polish the casting mold by removing the staircase effect and acquiring a smooth surface. Finally, the last step is to cast medical grade silicone into the mold. After the silicone is cured, the fine soft prostheses can be removed from the mold. Utilizing the SPPC method, soft prostheses with smooth surface and complicated structure can be fabricated at a low cost. Accordingly, the total cost of fabricating ear prosthesis is about $30, which is much lower than the current soft prostheses fabrication methods.

Hip prostheses in young adults. Surface prostheses and short-stem prostheses.

PubMed

Gallart, X; Riba, J; Fernández-Valencia, J A; Bori, G; Muñoz-Mahamud, E; Combalia, A

The poor results obtained in young patients when using a conventional prosthesis led to the resurgence of hip resurfacing to find less invasive implants for the bone. Young patients present a demand for additional activity, which makes them a serious challenge for the survival of implants. In addition, new information technologies contribute decisively to the preference for non-cemented prostheses. Maintaining quality of life, preserving the bone and soft tissues, as well as achieving a very stable implant, are the goals of every hip orthopaedic surgeon for these patients. The results in research point to the use of smaller prostheses, which use the metaphyseal zone more and less the diaphyseal zone, and hence the large number of the abovementioned short stem prostheses. Both models are principally indicated in the young adult. Their revision should be a more simple operation, but this is only true for hip resurfacing, not for short stems. Copyright © 2017 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

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.

[Eleven-Year Experience with Total Ankle Arthroplasty].

PubMed

Popelka, S; Sosna, A; Vavřík, P; Jahoda, D; Barták, V; Landor, I

2016-01-01

PURPOSE OF THE STUDY Total joint replacement is one of the options in surgical treatment of advanced ankle arthritis. It allows the ankle to remain mobile but, unfortunately, it does not provide the same longevity as total knee or hip replacements. Therefore, decisions concerning the kind of treatment are very individual and depend on the clinical status and opinion of each patient. MATERIAL AND METHODS A total of 132 total ankle replacements were carried out in the period from 2004 to 2015. The prostheses used included the Ankle Evolutive System (AES) in 52 patients, Mobility Total Ankle System (DePuy) in 24 patients and, recently, Rebalance Total Ankle Replacement implant in 53 patients. Three patients allergic to metal received the Taric prosthesis. Revision arthroplasty using the Hintegra prosthesis was carried out in four patients. The outcome of arthroplasty was evaluated on the American Orthopaedic Foot and Ankle Society (AOFAS) scoring scale. Indications for total ankle arthroplasty included post-traumatic arthritis in 83 patients, rheumatoid arthritis in 37 and primary arthritis in 12 patients. There were 78 women and 54 men, with an average age of 55.6 years at the time of surgery. RESULTS The average follow-up was 6.1 years (1-11 years). The average AOFAS score of the whole group increased from 33.2 before surgery to 82.5 after it. The primary indication had an important role. Arthroplasty outcomes were poorer in patients with post-traumatic arthritis than in those with rheumatoid arthritis or primary arthritis. In patients with post-traumatic arthritis, the average AOFAS score rose to 78.6 due to restricted motion of the ankle, and some patients continued to have pain when walking. The average AOFAS score in a total of 49 patients who had rheumatoid arthritis or primary arthritis reached a value of 86.4. Post-operative complications were recorded in ten patients (7.6%) in whom part of the wound was healing by second intention. Ossification was also a frequent complication and had to be removed in six patients (4.5%). No early infection was recorded and late infection was treated in three patients. The prosthesis had to be removed and ankle arthrodesis performed in seven patients (5.3%). All had necrosis of the talus with ankle instability. In five, the retrograde nail Medin was used and extensive defects remaining after talar necrosis were filled with massive bone grafts obtained from a bone bank. One patient required tibio-calcaneal arthrodesis with external fixator; surgery in one case involved the use of a Zimmer Trabecular Metal Ankle Fusion Spacer with retrograde nail fixation. The development of cystic radiolucencies adjacent to tibial or talar components presents another post-operative complication. It was recorded mostly in the patients after AES implantation, in whom eight of 52 (15.3%) had these findings. DISCUSSION Total ankle arthroplasty is a complicated surgical procedure potentially associated with various technical problems. The occurrence of complications is indirectly related to the experience of the orthopaedist performing surgery; literature data show that the number of complication decreases with an increased frequency of ankle replacements done. CONCLUSIONS Total ankle arthroplasty, as every orthopaedic surgery, has its advantages and disadvantages. The positive aspects are pain relief and improved mobility of the ankle allowing for physiological gait. However, it shows a lower survivorship rate that the other large joint replacements. A successful outcome depends on the correct indication. The ankle should be stable, the talus without signs of necrosis and valgus or varus deviations of the ankle should not exceed 10 to 15 degrees. total ankle arthroplasty, re-implantation, aseptic loosening, retrograde nail, Trabecular Metal spacer, revision arthroplasty.

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

Prosthetic joint infection caused by Pasteurella multocida: a case series and review of literature.

PubMed

Honnorat, Estelle; Seng, Piseth; Savini, Hélène; Pinelli, Pierre-Olivier; Simon, Fabrice; Stein, Andreas

2016-08-20

Pasteurella multocida is a well-recognized zoonotic agent following dog or cat bites or scratches. Nevertheless, prosthetic joint infection caused by P. multocida are rarely reported. We report here a series of six cases of prosthetic joint infection caused by P. multocida managed at a referral centre for the treatment of bone and joint infection in southern France. We also reviewed the 26 cases reported in literature. The mean age of our cases was 74 years [±8.2, range 63-85]. In majority of our cases (5 cases) were associated with knee prostheses and one case with a hip prosthesis. Most of cases occurred after cat or dog scratches or licks or contact. Diagnoses of prosthetic joint infection caused by P. multocida were made by positive cultures of surgical biopsies or needle aspiration. Mean time delay between prosthetic joint implantation and infection onset was 7.6 years (±5.12 years, range 2-17). Local inflammation, which occurred in all six cases, was the most frequent clinical symptom, followed by pain in five cases, fever and swollen joints in four cases, and a fistula with purulent discharge inside the wound in two cases. The mean time of antibiotic therapy was 8 months. Surgical treatment with prosthesis removal was performed in three cases. Six of our cases were in remission without apparent relapse at 3 years after end of treatment. Prosthetic joint infections caused by P. multocida usually occur after animal scratches or bites, but can occasionally occur after a short animal lick. These infections are usually resulting from a contiguous infection and localized in the knee. An early antibiotic therapy after surgical debridement could avoid prosthetic withdrawal, notably in elderly patients. Patients with prosthetic joints should be warned that animals are potential sources of serious infection and urgent medical advice should be sought if they are bitten or scratched.

Insidious strut fractures in a DeBakey-Surgitool aortic valve prosthesis.

PubMed

Scott, S M; Sethi, G K; Paulson, D M; Takaro, T

1978-04-01

Recent reports of cage wear occurring in DeBakey-Surgitool aortic valve prostheses prompted us to examine with image intensification all our patients who have had this type of prosthesis implanted. One patient, who was asymptomatic, was discovered to have a prosthesis with two fractured struts. This patient's prosthetic valve was replaced successfully with a stented porcine heterograft prosthesis. Including the valve removed from this patient, 8 DeBakey-Surgitool aortic valves with structural defects have been reported to the manufacturer. In the absence of a catastrophic event, patients with valves having fractured or worn struts may be totally asymptomatic, and routine periodic roentgenographic examination may be the only way of detecting strut wear or fracture.

[The Six Million Dollar Man: from fiction to reality].

PubMed

Langeveld, C H Kees

2013-01-01

The term 'bionic' has been in existence since 1958, but only gained general recognition from the television series 'The Six Million Dollar Man'. Following a crash, the central figure in this series - test pilot Steve Austin - has an eye, an arm and both legs replaced by prostheses which make him stronger and faster than a normal person. This story is based on the science fiction book 'Cyborg' by Martin Caidin. In the world of comic books and films there are a number of examples of people who are given superhuman powers by having technological gadgets built in. Although the latter is not yet possible, the bionic human has now become reality.

Treatment of Orally Handicapped Edentulous Older Adults Using Dental Implants.

PubMed

Zahedi, Charles

2016-07-01

The oral handicap of complete edentulism is the terminal outcome of a multifactorial process involving biological factors and patient-related factors. Fully edentulous orally handicapped older adults have been neglected because removable acrylic dentures have been the classic therapy for complete edentulism but are only rehabilitative, not therapeutic. Not replacing missing teeth with stable dentures could prevent adequate food intake. Osseointegrated endosseous implants used as a therapeutic adjunct can reduce the problem of long-term bone resorption to less than 0.1 mm per year. Implant-borne prostheses substantially increase the overall health and quality of life of orally handicapped fully edentulous older adults. Copyright © 2016 Elsevier Inc. All rights reserved.

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.

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

Composite Materials for Maxillofacial Prostheses.

DTIC Science & Technology

1981-08-01

necessary and Identify byv block number) MAXILLOFACIAL PROSTHESES; PROSTHETIC MATERIALS: MICROCAPSULES : SOFT FILLERS; ELASTOMER COMPOSITES 2,. ABSTRACT...used as fillers in the fabrication of maxillofacial prostheses. The projected systems are elastomeric-shelled, liquid-filled microcapsules . Improvements...elastomeric-shelled, liquid-filled microcapsules . Experiments continued on the interfacial polymerization process, with spherical, sealed, capsules

Morphological characterization of dental prostheses interfaces using optical coherence tomography

NASA Astrophysics Data System (ADS)

Sinescu, Cosmin; Negrutiu, Meda L.; Ionita, Ciprian; Marsavina, Liviu; Negru, Radu; Caplescu, Cristiana; Bradu, Adrian; Topala, Florin; Rominu, Roxana O.; Petrescu, Emanuela; Leretter, Marius; Rominu, Mihai; Podoleanu, Adrian G.

2010-03-01

Fixed partial prostheses as integral ceramic, polymers, metal-ceramic or metal-polymers bridges are mainly used in the frontal part of the dental arch (especially the integral bridges). They have to satisfy high stress as well as esthetic requirements. The masticatory stress may induce fractures of the bridges. These may be triggered by initial materials defects or by alterations of the technological process. The fractures of these bridges lead to functional, esthetic and phonetic disturbances which finally render the prosthetic treatment inefficient. Dental interfaces represent one of the most significant aspects in the strength of the dental prostheses under the masticatory load. The purpose of this study is to evaluate the capability of optical coherence tomography (OCT) to characterize the dental prostheses interfaces. The materials used were several fixed partial prostheses integral ceramic, polymers, metal-ceramic and metal-polymers bridges. It is important to produce both C-scans and B-scans of the defects in order to differentiate morphological aspects of the bridge infrastructures. The material defects observed with OCT were investigated with micro-CT in order to prove their existence and positions. In conclusion, it is important to have a non invasive method to investigate dental prostheses interfaces before the insertion of prostheses in the oral cavity.

[Clinical evaluation of "All-on-Four" provisional prostheses reinforced with carbon fibers].

PubMed

Li, Bei-bei; Lin, Ye; Cui, Hong-yan; Hao, Qiang; Xu, Jia-bin; Di, Ping

2016-02-18

To assess the clinical effects of carbon fiber reinforcement on the "All-on-Four" provisional prostheses. Provisional prostheses were divided into control group and carbon fiber reinforcing group according to whether carbon fiber reinforcement was used in the provisional prostheses base resin. In our study, a total of 60 patients (32 males and 28 females) with 71 provisional prostheses(28 maxilla and 43 mandible)were enrolled between April 2008 and December 2012 for control group; a total of 23 patients (13 males and 10 females) with 28 provisional prostheses (9 maxillas and 19 mandibles) were enrolled between January 2013 and March 2014 for carbon fiber reinforcing group. The information of provisional prostheses in the patients was recorded according to preoperative examination. We used the date of definitive prosthesis restoration as the cut-off point, observing whether fracture occurred on the provisional prostheses in the two groups. Additionally we observed whether fiber exposure occurred on the tissue surface of the provisional prostheses and caused mucosal irritation. The interface between the denture base resin and the fibers was examined using scanning electron microscopy (SEM). The age [(57.3 ± 10.1) years vs.(55.1 ± 11.4) years], gender (32 males and 28 females vs. 13 males and 10 females), maxilla and mandible distributions (28 maxillas and 43 mandibles vs. 9 maxillas and 19 mandibles), the number of extraction jaws (46 vs. 23), the average using time [(7.8 ± 1.3) months vs. (7.5 ± 1.1) months], and the opposing dentition distributions of provisional prostheses of the patients showed no significant differences between the control and reinforcing groups. There were 21(29.6%) fractures that occurred on the 71 provisional prostheses in the control group; there was no fracture that occurred on the 28 provisional prosthesesin the carbon fiber reinforcing group. The fracture rate of the carbon fiber reinforcing group was significantly lower than that of the control group (P=0.001). No carbon fiber exposure and mucosal irritation were observed from clinical examination.SEM revealed relatively continuous contact between the fiber and acrylic resin, and the resin particles adhered on the surface of the carbon fibers. The addition of carbon fibers between abutments placed on "All-on-Four" provisional fixed denture base resin may be clinically effective in preventing "All-on-Four" denture fracture and can provide several advantages for clinical use.

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 ...

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.

Characterizing the Mechanical Properties of Running-Specific Prostheses

PubMed Central

Beck, Owen N.; Taboga, Paolo; Grabowski, Alena M.

2016-01-01

The mechanical stiffness of running-specific prostheses likely affects the functional abilities of athletes with leg amputations. However, each prosthetic manufacturer recommends prostheses based on subjective stiffness categories rather than performance based metrics. The actual mechanical stiffness values of running-specific prostheses (i.e. kN/m) are unknown. Consequently, we sought to characterize and disseminate the stiffness values of running-specific prostheses so that researchers, clinicians, and athletes can objectively evaluate prosthetic function. We characterized the stiffness values of 55 running-specific prostheses across various models, stiffness categories, and heights using forces and angles representative of those measured from athletes with transtibial amputations during running. Characterizing prosthetic force-displacement profiles with a 2nd degree polynomial explained 4.4% more of the variance than a linear function (p<0.001). The prosthetic stiffness values of manufacturer recommended stiffness categories varied between prosthetic models (p<0.001). Also, prosthetic stiffness was 10% to 39% less at angles typical of running 3 m/s and 6 m/s (10°-25°) compared to neutral (0°) (p<0.001). Furthermore, prosthetic stiffness was inversely related to height in J-shaped (p<0.001), but not C-shaped, prostheses. Running-specific prostheses should be tested under the demands of the respective activity in order to derive relevant characterizations of stiffness and function. In all, our results indicate that when athletes with leg amputations alter prosthetic model, height, and/or sagittal plane alignment, their prosthetic stiffness profiles also change; therefore variations in comfort, performance, etc. may be indirectly due to altered stiffness. PMID:27973573

Outcome of Acute Prosthetic Joint Infections Due to Gram-Negative Bacilli Treated with Open Debridement and Retention of the Prosthesis▿

PubMed Central

Martínez-Pastor, Juan C.; Muñoz-Mahamud, Ernesto; Vilchez, Félix; García-Ramiro, Sebastián; Bori, Guillem; Sierra, Josep; Martínez, José A.; Font, Lluis; Mensa, Josep; Soriano, Alex

2009-01-01

The aim of our study was to evaluate the outcome of acute prosthetic joint infections (PJIs) due to gram-negative bacilli (GNB) treated without implant removal. Patients with an acute PJI due to GNB diagnosed from 2000 to 2007 were prospectively registered. Demographics, comorbidity, type of implant, microbiology data, surgical treatment, antimicrobial therapy, and outcome were recorded. Classification and regression tree analysis, the Kaplan-Meier survival method, and the Cox regression model were applied. Forty-seven patients were included. The mean age was 70.7 years, and there were 15 hip prostheses and 32 knee prostheses. The median number of days from the time of arthroplasty was 20. The most frequent pathogens were members of the Enterobacteriaceae family in 41 cases and Pseudomonas spp. in 20 cases. Among the Enterobacteriaceae, 14 were resistant to ciprofloxacin, while all Pseudomonas aeruginosa isolates were susceptible to ciprofloxacin. The median durations of intravenous and oral antibiotic treatment were 14 and 64 days, respectively. A total of 35 (74.5%) patients were in remission after a median follow-up of 463 days (interquartile range, 344 to 704) days. By use of the Kaplan-Meier survival curve, a C-reactive protein (CRP) concentration of ≤15 mg/dl (P = 0.03) and receipt of a fluoroquinolone, when all GNB isolated were susceptible (P = 0.0009), were associated with a better outcome. By use of a Cox regression model, a CRP concentration of ≤15 mg/dl (odds ratio [OR], 3.57; 95% confidence interval [CI], 1.05 to 12.5; P = 0.043) and receipt of a fluoroquinolone (OR, 9.09; 95% CI, 1.96 to 50; P = 0.005) were independently associated with better outcomes. Open debridement without removal of the implant had a success rate of 74.5%, and the factors associated with good prognosis were a CRP concentration at the time of diagnosis ≤15 mg/dl and treatment with a fluoroquinolone. PMID:19687237

Detection of Prosthetic Hip Infection at Revision Arthroplasty by Immunofluorescence Microscopy and PCR Amplification of the Bacterial 16S rRNA Gene

PubMed Central

Tunney, Michael M.; Patrick, Sheila; Curran, Martin D.; Ramage, Gordon; Hanna, Donna; Nixon, James R.; Gorman, Sean P.; Davis, Richard I.; Anderson, Neil

1999-01-01

In this study the detection rates of bacterial infection of hip prostheses by culture and nonculture methods were compared for 120 patients with total hip revision surgery. By use of strict anaerobic bacteriological practice during the processing of samples and without enrichment, the incidence of infection by culture of material dislodged from retrieved prostheses after ultrasonication (sonicate) was 22%. Bacteria were observed by immunofluorescence microscopy in 63% of sonicate samples with a monoclonal antibody specific for Propionibacterium acnes and polyclonal antiserum specific for Staphylococcus spp. The bacteria were present either as single cells or in aggregates of up to 300 bacterial cells. These aggregates were not observed without sonication to dislodge the biofilm. Bacteria were observed in all of the culture-positive samples, and in some cases in which only one type of bacterium was identified by culture, both coccoid and coryneform bacteria were observed by immunofluorescence microscopy. Bacteria from skin-flake contamination were readily distinguishable from infecting bacteria by immunofluorescence microscopy. Examination of skin scrapings did not reveal large aggregates of bacteria but did reveal skin cells. These were not observed in the sonicates. Bacterial DNA was detected in 72% of sonicate samples by PCR amplification of a region of the bacterial 16S rRNA gene with universal primers. All of the culture-positive samples were also positive for bacterial DNA. Evidence of high-level infiltration either of neutrophils or of lymphocytes or macrophages into associated tissue was observed in 73% of patients. Our results indicate that the incidence of prosthetic joint infection is grossly underestimated by current culture detection methods. It is therefore imperative that current clinical practice with regard to the detection and subsequent treatment of prosthetic joint infection be reassessed in the light of these results. PMID:10488193

Outcome of acute prosthetic joint infections due to gram-negative bacilli treated with open debridement and retention of the prosthesis.

PubMed

Martínez-Pastor, Juan C; Muñoz-Mahamud, Ernesto; Vilchez, Félix; García-Ramiro, Sebastián; Bori, Guillem; Sierra, Josep; Martínez, José A; Font, Lluis; Mensa, Josep; Soriano, Alex

2009-11-01

The aim of our study was to evaluate the outcome of acute prosthetic joint infections (PJIs) due to gram-negative bacilli (GNB) treated without implant removal. Patients with an acute PJI due to GNB diagnosed from 2000 to 2007 were prospectively registered. Demographics, comorbidity, type of implant, microbiology data, surgical treatment, antimicrobial therapy, and outcome were recorded. Classification and regression tree analysis, the Kaplan-Meier survival method, and the Cox regression model were applied. Forty-seven patients were included. The mean age was 70.7 years, and there were 15 hip prostheses and 32 knee prostheses. The median number of days from the time of arthroplasty was 20. The most frequent pathogens were members of the Enterobacteriaceae family in 41 cases and Pseudomonas spp. in 20 cases. Among the Enterobacteriaceae, 14 were resistant to ciprofloxacin, while all Pseudomonas aeruginosa isolates were susceptible to ciprofloxacin. The median durations of intravenous and oral antibiotic treatment were 14 and 64 days, respectively. A total of 35 (74.5%) patients were in remission after a median follow-up of 463 days (interquartile range, 344 to 704) days. By use of the Kaplan-Meier survival curve, a C-reactive protein (CRP) concentration of < or = 15 mg/dl (P = 0.03) and receipt of a fluoroquinolone, when all GNB isolated were susceptible (P = 0.0009), were associated with a better outcome. By use of a Cox regression model, a CRP concentration of < or = 15 mg/dl (odds ratio [OR], 3.57; 95% confidence interval [CI], 1.05 to 12.5; P = 0.043) and receipt of a fluoroquinolone (OR, 9.09; 95% CI, 1.96 to 50; P = 0.005) were independently associated with better outcomes. Open debridement without removal of the implant had a success rate of 74.5%, and the factors associated with good prognosis were a CRP concentration at the time of diagnosis < or = 15 mg/dl and treatment with a fluoroquinolone.

Rapid prototyping--when virtual meets reality.

PubMed

Beguma, Zubeda; Chhedat, Pratik

2014-01-01

Rapid prototyping (RP) describes the customized production of solid models using 3D computer data. Over the past decade, advances in RP have continued to evolve, resulting in the development of new techniques that have been applied to the fabrication of various prostheses. RP fabrication technologies include stereolithography (SLA), fused deposition modeling (FDM), computer numerical controlled (CNC) milling, and, more recently, selective laser sintering (SLS). The applications of RP techniques for dentistry include wax pattern fabrication for dental prostheses, dental (facial) prostheses mold (shell) fabrication, and removable dental prostheses framework fabrication. In the past, a physical plastic shape of the removable partial denture (RPD) framework was produced using an RP machine, and then used as a sacrificial pattern. Yet with the advent of the selective laser melting (SLM) technique, RPD metal frameworks can be directly fabricated, thereby omitting the casting stage. This new approach can also generate the wax pattern for facial prostheses directly, thereby reducing labor-intensive laboratory procedures. Many people stand to benefit from these new RP techniques for producing various forms of dental prostheses, which in the near future could transform traditional prosthodontic practices.

[Effect of CO2 laser on prostheses used in middle ear surgery].

PubMed

Szymański, Marcin

2005-01-01

The use of CO2 laser is advocated in primary and revision stapes surgery. The aim of the study was to assess the effect of CO2 laser on stapes prostheses. CO2 laser was applied on several types of stapes prostheses and PORPs, with power settings suggested by the manufacturer (continuous wave, 2 W and 6 W; 0,05 s). Application of the laser on stainless steel or titanium prosthesis did not exert any effect on the structure of the prosthesis. The use of the laser on the Teflon piston caused superficial burning with power 2 W, and melting and holes in the piston with power settings at 6W. Similar plastipore prostheses were melting. Hydroxyapatite PORP shattered after application of the laser energy. Teflon and hydroxyapatite prostheses are easily damaged by the laser energy, therefore applying a laser on them should be avoided. CO2 laser can be used on stainless steel and titanium prostheses without risk of damaging them. However the possibility of transmission of heat to the vestibule has to be taken into consideration.

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.

Plausibility and parameter sensitivity of micro-finite element-based joint load prediction at the proximal femur.

PubMed

Synek, Alexander; Pahr, Dieter H

2018-06-01

A micro-finite element-based method to estimate the bone loading history based on bone architecture was recently presented in the literature. However, a thorough investigation of the parameter sensitivity and plausibility of this method to predict joint loads is still missing. The goals of this study were (1) to analyse the parameter sensitivity of the joint load predictions at one proximal femur and (2) to assess the plausibility of the results by comparing load predictions of ten proximal femora to in vivo hip joint forces measured with instrumented prostheses (available from www.orthoload.com ). Joint loads were predicted by optimally scaling the magnitude of four unit loads (inclined [Formula: see text] to [Formula: see text] with respect to the vertical axis) applied to micro-finite element models created from high-resolution computed tomography scans ([Formula: see text]m voxel size). Parameter sensitivity analysis was performed by varying a total of nine parameters and showed that predictions of the peak load directions (range 10[Formula: see text]-[Formula: see text]) are more robust than the predicted peak load magnitudes (range 2344.8-4689.5 N). Comparing the results of all ten femora with the in vivo loading data of ten subjects showed that peak loads are plausible both in terms of the load direction (in vivo: [Formula: see text], predicted: [Formula: see text]) and magnitude (in vivo: [Formula: see text], predicted: [Formula: see text]). Overall, this study suggests that micro-finite element-based joint load predictions are both plausible and robust in terms of the predicted peak load direction, but predicted load magnitudes should be interpreted with caution.

Effect of static foot posture on the dynamic stiffness of foot joints during walking.

PubMed

Sanchis-Sales, E; Sancho-Bru, J L; Roda-Sales, A; Pascual-Huerta, J

2018-05-01

The static foot posture has been related to the development of lower limb injuries. This study aimed to investigate the dynamic stiffness of foot joints during gait in the sagittal plane to understand the role of the static foot posture in the development of injuries. Seventy healthy adult male subjects with different static postures, assessed by the Foot Posture Index (FPI) (30 normal, 20 highly pronated and 20 highly supinated), were recruited. Kinematic and kinetic data were recorded using an optical motion capture system and a pressure platform, and dynamic stiffness at the different stages of the stance was calculated from the slopes of the linear regression on the flexion moment-angle curves. The effect of foot type on dynamic stiffness and on ranges of motion and moments was analysed using ANOVAs and post-hoc tests, and linear correlation between dynamic stiffness and FPI was also tested. Highly pronated feet showed a significantly smaller range of motion at the ankle and metatarsophalangeal joints and also a larger range of moments at the metatarsophalangeal joint than highly supinated feet. Dynamic stiffness during propulsion was significantly greater at all foot joints for highly pronated feet, with positive significant correlations with the squared FPI. Highly supinated feet showed greater dynamic stiffness than normal feet, although to a lesser extent. Highly pronated feet during normal gait experienced the greatest decrease in the dorsiflexor moments during propulsion, normal feet being the most balanced regarding work generated and absorbed. Extreme static foot postures show greater dynamic stiffness during propulsion and greater absorbed work, which increases the risk of developing injuries. The data presented may be used when designing orthotics or prostheses, and also when planning surgery that modifies joint stiffness. Copyright © 2018 Elsevier B.V. All rights reserved.

Survival rates and bone loss after immediate loading of implants in fresh extraction sockets (single gaps). A clinical prospective study with 4 year follow-up

PubMed Central

Wojtovicz, Eduardo; España-Lopez, Antonio; Jimenez-Guerra, Alvaro; Monsalve-Guil, Loreto; Ortiz-Garcia, Ivan; Serrera-Figallo, Maria-Angeles

2018-01-01

Background The aim of this prospective study was to report the outcome of treatment with implants inserted after tooth extraction and immediately loaded. Material and Methods Fifty-six patients with single tooth loss were treated with 116 IPX Galimplant® implants with internal connections and a sandblasted, acid-etched surface. All implants were placed after tooth extraction using a flapless approach without bone regeneration, and they were then immediately loaded with cemented acrylic prostheses. After a period of three months, definitive cemented ceramic prostheses were placed. Patients were examined throughout a total of 4 years of follow-up. Marginal bone loss and survival rates were evaluated using digital periapical radiographs, taking into account clinical variables such as age, gender, smoking, history of periodontitis, etiology of extraction, placement site, diameter, and implant length. The Mann-Whitney U and Kruskal-Wallis non-parametric tests were used to compare differences between subgroups created based on the different clinical variables identified. Results Clinical results indicate an implant survival and success rate of 97.4%. Three implants were lost. Of the 116 immediate acrylic single crowns initially placed, 113 were replaced with definitive ceramic crowns after 3 months. A total of 77.8% of implants were inserted in the maxilla, while 22.2% were inserted in the mandible. No further complications were reported after the follow-up period (4 years). The mean marginal bone loss was 0.67 mm ± 0.40 mm. No differences were found among the subgroups of study patients. Conclusions This study indicates that dental implants that are inserted after tooth extraction and immediately loaded may constitute a successful and predictable alternative implant treatment. Key words:Dental implants, post-extraction implants, fresh sockets, immediate loading, immediate prostheses, implant dentistry. PMID:29476669

Performance of zirconia ceramic cantilever fixed dental prostheses: 3-year results from a prospective, randomized, controlled pilot study.

PubMed

Zenthöfer, Andreas; Ohlmann, Brigitte; Rammelsberg, Peter; Bömicke, Wolfgang

2015-07-01

Little is known about the clinical performance of ceramic cantilever fixed dental prostheses on natural teeth. The purpose of this randomized controlled pilot study was to evaluate the clinical performance of ceramic and metal ceramic cantilever fixed dental prostheses (CFDPs) after 3 years of service. Twenty-one participants were randomly allocated to 2 treatment groups. Participants in the ceramic (ZC) group (n=11) each received 1 CFDP made of yttria-stabilized, tetragonal zirconia polycrystal; the others (n=10) were fitted with a metal ceramic (MC) CFDP. All CFDPs were retained by 2 complete crown abutments and replaced 1 tooth. The clinical target variables were survival, incidence of complications, probing pocket depth (PPD), probing attachment level (PAL), plaque index (PI), gingival index (GI), and esthetic performance as rated by the participants. The United States Public Health Service (USPHS) criteria were used to evaluate chipping, retention, color, marginal integrity, and secondary caries. Descriptive statistics and nonparametric analyses were applied to the target variables in the 2 groups. The esthetic performance of the CFDPs was also visualized by using a pyramid comparison. The overall survival of the CFDPs was 100% in both groups. During the 3-year study, 6 clinically relevant complications requiring aftercare were observed among 5 participants (4 in the ZC group and 2 in the MC group). Changes in the PI, GI, PPD, and PAL of the abutment teeth were similar for both groups (P>.05). The participants regarded the esthetic performance of ZC-CFDPs and MC-CFDPs as satisfactory. Within the 3-year observation period, the clinical performance of MC-FDPs and ZC-FDPs was acceptable. More extensive research with larger sample sizes is encouraged, however, to confirm the evaluation of the survival of Y-TZP hand-veneered cantilever FPDs. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Long-term follow-up of stentless prosthesis.

PubMed

Sansone, Fabrizio; Dato, Guglielmo Mario Actis; Zingarelli, Edoardo; Ferrero, Emanuele; Prot, Sara; Ceresa, Fabrizio; Patanè, Francesco; Casabona, Riccardo

2014-05-01

Stentless prostheses have an interesting hemodynamic performance when compared to stented prostheses and are recommended in cases of small aortic annulus. From January 1996 to January 2004, 138 patients suffering from aortic disease, underwent aortic valve replacement. • Group A: 93 patients underwent stentless aortic valve implantation [stentless Biocor (Biocor Industria e Pesguisa Ltda, Belo Horizonte, Brazil) and stentless Sorin (Sorin Group, Saluggia, Italy)]. • Group B: 45 patients underwent stented aortic valve implantation (stented Biocor). Patients were assessed by clinical evaluation and echocardiography after a mean follow up of 124.5 ± 58.2 months. There was a significant difference in terms of time of extracorporeal circulation and aortic cross clamp. The actuarial survival at 4, 8, 12, and 15 years is 77%, 50%, 21%, and 18%, respectively. Freedom from reoperation at 4, 8, 12, and 14 years was 92%, 83%, 73%, and 63%, respectively. Freedom from all events, death, and reoperation at 4, 8, 12, and 14 years was 70%, 39%, 13%, and 8%, respectively. There is no statistical difference among the two groups in terms of actuarial survival, freedom from reoperation, and freedom from re-hospitalization for prosthesis-related causes. There was a significantly higher incidence of pacemaker implantation in Group A and the causes are not known. The rate of freedom from reoperation is high in both groups for the patients who remained alive. There was no statistical difference about prosthesis dysfunction between the two groups. The higher incidence of death in Group A cannot be explained by causes related to the prosthesis because there is no difference in terms of causes of death. Rates of reoperation did not differ between the two groups. The results obtained with stentless prostheses are encouraging even in long-term follow-up. Copyright © 2013 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

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...

Success and complications of implant-retained prostheses provided by the Post-Doctoral Prosthodontics Program, University of Puerto Rico: a cross-sectional study.

PubMed

Loza-Herrero, María A; Rivas-Tumanyan, Sona; Morou-Bermudez, Evangelia

2015-11-01

The success rate of implant-retained prostheses in a postdoctoral prosthodontics program was unknown and could not be related to any set of potential clinical issues or patient characteristics. The purpose of this study was to determine the success rate of implant-retained prostheses placed by prosthodontic residents between 1997 and 2012 and to evaluate the associations between patient classifications and specific restoration characteristics as related to prosthesis success or failure. A total of 272 prostheses in 119 patients were clinically evaluated. Success was defined as the absence of prosthetic complications or any implant-related complication that affected prosthesis survival. Logistic regression was used to evaluate associations between prosthesis success/failure and a wide array of study variables, adjusting for patient age, sex, and prosthesis longevity. The overall success rate was 71%, with a mean prosthesis age of 4.5 years (range: 4 months to 16.8 years). Implant single crowns were the most successful prosthesis type (81% success). The most common complications observed were porcelain fractures in fixed dental prostheses (15%) and lack of stability (31%) and retention (29%) in removable dental prostheses. Having a removable prosthesis (versus natural dentition) in the opposing occlusion significantly decreased the odds of success (OR=0.26, 95% CI: 0.11-0.64). Definitively cemented fixed prostheses were more successful than those cemented with an interim cement (OR=4.56, 95% CI: 1.37-15.22). The overall success rate of the implant-retained prostheses placed in the program was low compared with previously published studies. This study revealed the need for an efficient, comprehensive recall system for patients receiving implant-retained prostheses, either fixed or removable. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Handling the procurement of prostheses for total hip replacement: description of an original value based approach and application to a real-life dataset reported in the UK

PubMed Central

Messori, Andrea; Trippoli, Sabrina; Marinai, Claudio

2017-01-01

Objectives In most European countries, innovative medical devices are not managed according to cost–utility methods, the reason being that national agencies do not generally evaluate these products. The objective of our study was to investigate the cost-utility profile of prostheses for hip replacement and to calculate a value-based score to be used in the process of procurement and tendering for these devices. Methods The first phase of our study was aimed at retrieving the studies reporting the values of QALYs, direct cost, and net monetary benefit (NMB) from patients undergoing total hip arthroplasty (THA) with different brands of hip prosthesis. The second phase was aimed at calculating, on the basis of the results of cost–utility analysis, a tender score for each device (defined according to standard tendering equations and adapted to a 0–100 scale). This allowed us to determine the ranking of each device in the simulated tender. Results We identified a single study as the source of information for our analysis. Nine device brands (cemented, cementless, or hybrid) were evaluated. The cemented prosthesis Exeter V40/Elite Plus Ogee, the cementless device Taperloc/Exceed, and the hybrid device Exeter V40/Trident had the highest NMB (£152 877, £156 356, and £156 210, respectively) and the best value-based tender score. Conclusions The incorporation of value-based criteria in the procurement process can contribute to optimising the value for money for THA devices. According to the approach described herein, the acquisition of these devices does not necessarily converge on the product with the lowest cost; in fact, more costly devices should be preferred when their increased cost is offset by the monetary value of the increased clinical benefit. PMID:29259062

Antibiotic prophylaxis is not indicated prior to dental procedures for prevention of periprosthetic joint infections.

PubMed

Rademacher, Willem M H; Walenkamp, Geert H I M; Moojen, Dirk Jan F; Hendriks, Johannes G E; Goedendorp, Theo A; Rozema, Frederik R

2017-10-01

Background and purpose - To minimize the risk of hematogenous periprosthetic joint infection (HPJI), international and Dutch guidelines recommended antibiotic prophylaxis prior to dental procedures. Unclear definitions and contradictory recommendations in these guidelines have led to unnecessary antibiotic prescriptions. To formulate new guidelines, a joint committee of the Dutch Orthopaedic and Dental Societies conducted a systematic literature review to answer the following question: can antibiotic prophylaxis be recommended for patients (with joint prostheses) undergoing dental procedures in order to prevent dental HPJI? Methods - The Medline, Embase, and Cochrane databases were searched for randomized controlled trials (RCTs), reviews, and observational studies up to July 2015. Studies were included if they involved patients with joint implants undergoing dental procedures, and either considered HPJI as an outcome measure or described a correlation between HPJI and prophylactic antibiotics. A guideline was formulated using the GRADE method and AGREE II guidelines. Results - 9 studies were included in this systematic review. All were rated "very low quality of evidence". Additional literature was therefore consulted to address clinical questions that provide further insight into pathophysiology and risk factors. The 9 studies did not provide evidence that use of antibiotic prophylaxis reduces the incidence of dental HPJI, and the additional literature supported the conclusion that antibiotic prophylaxis should be discouraged in dental procedures. Interpretation - Prophylactic antibiotics in order to prevent dental HPJI should not be prescribed to patients with a normal or an impaired immune system function. Patients are recommended to maintain good oral hygiene and visit the dentist regularly.

Survival after Aortic Valve Replacement with Bovine or Porcine Valve Prostheses: A Systematic Review and Meta-Analysis.

PubMed

Glaser, Natalie; Jackson, Veronica; Franco-Cereceda, Anders; Sartipy, Ulrik

2018-05-17

 Bovine and porcine bioprostheses are commonly used for surgical aortic valve replacement. It is unknown if the long-term survival differs between the two valve types.We performed a systematic review and meta-analysis to compare survival in patients who underwent aortic valve replacement and received a bovine or a porcine prosthesis.  We performed a systematic search of Medline, Embase, Web of Science, and the Cochrane Library. Cohort studies that compared survival between patients who underwent aortic valve replacement and received either a bovine or a porcine bioprosthesis and that reported overall long-term survival with hazard ratio (HR) and 95% confidence interval (CI) were included. Two authors independently reviewed articles considered for inclusion, extracted the information from each study, and performed the quality assessment. We performed a meta-analysis using a random effects model to calculate the pooled HR (95% CI) for all-cause mortality. We did sensitivity analyses to assess the robustness of our findings.  Seven studies published between 2010 and 2015 were included, and the combined study population was 49,190 patients. Of these, 32,235 (66%) received a bovine, and 16,955 (34%) received a porcine bioprosthesis. There was no significant difference in all-cause mortality between patients who received a bovine compared with a porcine bioprosthesis (pooled HR 1.00, 95% CI: 0.92-1.09). Heterogeneity between studies was moderate (55.8%, p  = 0.04).  This systematic review and meta-analysis suggest no difference in survival between patients who received a bovine versus a porcine bioprosthesis after aortic valve replacement. Our study provides valuable evidence for the continuing use of both bovine and porcine bioprosthetic valves for surgical aortic valve replacement. Georg Thieme Verlag KG Stuttgart · New York.

Use of an absorbable membrane to position biologically inductive materials in the periprosthetic space of cemented joints.

PubMed

DiResta, Gene R; Brown, Holly; Aiken, Sean; Doty, Steven; Schneider, Robert; Wright, Timothy; Healey, John H

2006-01-01

A device is presented that positions ultrahigh molecular weight polyethylene (UHMWPE) debris against periprosthetic bone surfaces. This can facilitate the study of aseptic loosening associated with cemented joint prostheses by speeding the appearance of this debris within the periprosthetic space. The device, composed of a 100 microm thick bioabsorbable membrane impregnated with 1.4 x 10(9) sub-micron particles of UHMWPE debris, is positioned on the endosteum of the bone prior to the insertion of the cemented orthopedic implant. An in vitro pullout study and an in vivo canine pilot study were performed to investigate its potential to accelerate "time to aseptic loosening" of cemented prosthetic joints. Pullout studies characterized the influence of the membrane on initial implant fixation. The tensile stresses (mean+/-std.dev.) required to withdraw a prosthesis cemented into canine femurs with and without the membrane were 1.15+/-0.3 and 1.54+/-0.01 MPa, respectively; these findings were not significantly different (p > 0.4). The in vivo pilot study, involving five dogs, was performed to evaluate the efficacy of the debris to accelerate loosening in a canine cemented hip arthroplasty. Aseptic loosening and lameness occurred within 12 months, quicker than the 30 months reported in a retrospective clinical review of canine hip arthroplasty.

A New Powered Lower Limb Prosthesis Control Framework Based on Adaptive Dynamic Programming.

PubMed

Wen, Yue; Si, Jennie; Gao, Xiang; Huang, Stephanie; Huang, He Helen

2017-09-01

This brief presents a novel application of adaptive dynamic programming (ADP) for optimal adaptive control of powered lower limb prostheses, a type of wearable robots to assist the motor function of the limb amputees. Current control of these robotic devices typically relies on finite state impedance control (FS-IC), which lacks adaptability to the user's physical condition. As a result, joint impedance settings are often customized manually and heuristically in clinics, which greatly hinder the wide use of these advanced medical devices. This simulation study aimed at demonstrating the feasibility of ADP for automatic tuning of the twelve knee joint impedance parameters during a complete gait cycle to achieve balanced walking. Given that the accurate models of human walking dynamics are difficult to obtain, the model-free ADP control algorithms were considered. First, direct heuristic dynamic programming (dHDP) was applied to the control problem, and its performance was evaluated on OpenSim, an often-used dynamic walking simulator. For the comparison purposes, we selected another established ADP algorithm, the neural fitted Q with continuous action (NFQCA). In both cases, the ADP controllers learned to control the right knee joint and achieved balanced walking, but dHDP outperformed NFQCA in this application during a 200 gait cycle-based testing.

Composite Materials for Maxillofacial Prostheses.

DTIC Science & Technology

1979-08-01

block number) MAXILLOFACIAL PROSTHESES; PROSTHETIC MATERIALS; MICROCAPSULES ; SOFT FILLERS; ELASTuMER COMPOSITES 20,_ ABSTRACT ’Continue on reverse side...approaches were pursued toward making such microcapsules . One approach involves coaxial extrusion of a catalyzed elastomer precursor and core liquid into a...fabrication of maxillofacial prostheses. The projected composite systems are elastomeric-shelled, liquid-filled microcapsules . Two experimental approaches were

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