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PubMedDate not supplied

[Complications after implantation of a modular total hip prostheses compared with fixed head prostheses].

164 total hip prostheses of different manufacturers were implanted over an 8-year period. Clinical records were evaluated with a complication rate of 29.0% (42 of 145 joints) or 31.7% (39 of 123 dogs). The complications encountered in dogs that received the modular hip prosthesis (Biomécanique, Bretigny-sur-orge, France) amounted to 16.3% (15 of 92), dogs that received a fixed head prosthesis (5 different manufactures) had 39% complications (28 of 72). Although the complication rate was influenced by different surgeons (n = 5) with different system predelictions and a different learning curve it was obvious that luxations (n = 6 of 10) and stem fractures (n = 5) more often occurred with the fixed head prosthesis systems. These stem fractures might be due to implant material failure or due to improper cementation followed by fatigue material failure. Femur fracture or infection were encountered with both prosthesis systems.

Animals↗
PubMed2003

Performance evaluation of a modular gamma camera using a detectability index.

UNLABELLED: The performance of a modular gamma camera for the task of detecting signals in random noisy backgrounds was evaluated experimentally. The results were compared with a theoretical computer simulation. METHODS: The camera uses a 10 x 10 cm thallium-doped sodium iodide crystal, a 2 x 2 array of 53 x 53 mm photomultiplier tubes, and a parallel-hole collimator (1.5-mm bore width, 23.6-mm bore length). The camera was positioned to look down into a 10-cm-deep water bath that filled its field of view (FOV). The top surface of the water was 5 cm from the front face of the camera. The camera has 3-mm intrinsic spatial resolution (SR) in the center of its FOV and 9-mm system SR for objects 5 cm below the top surface of the water. Uniform and nonuniform random background data were collected by imaging the bath containing 740 MBq (20 mCi) (99m)Tc. Nonuniformities were created by placing water-filled objects in the bath. Each signal dataset was collected by imaging a water-filled plastic sphere, injected with (99m)Tc and set at a specific depth (Z) in the bath. Data were collected for many signal diameters (D) (4, 7, 10, 13, 16, 28 mm) at 1 depth (5 cm) and for 1 signal diameter (10 mm) at several depths (1, 3, 5, 7, 9 cm). Sets of signal-present/signal-absent image pairs (380 pairs, 10(5) events per image) for known contrasts (C) were generated for use in ideal-observer studies in which the detectability (d') was calculated. Contrast-detail (log C vs. log D) plots were created. The theoretical simulation, developed for uniform backgrounds, provided data for comparison. RESULTS: The detectability increased linearly with C and decreased nonlinearly with decreasing D or increasing Z. The C required to achieve a specific d' increased sharply for D < SR. For C = 5, D = 10 mm, and d' = 1.2, the camera consistently detected signals for Z < 6 cm. Similar results were found for nonuniform backgrounds. The theoretical simulation verified the results for uniform backgrounds. CONCLUSION: The methodology presented here provides a way of evaluating gamma cameras on the basis of signal-detection performance for specified lesions, with particular application to scintimammography.

Algorithms↗
PubMed1999

[The application of modularity design in the pulse oximeter].

This paper presents a thought of modularity design and application in our pulse oximeter and its hardware and software composition of the function board, the application can improve the reliability of the instrument greatly and make it easy to expand its function.

Equipment Design↗
PubMed2002

[Hip metallosis caused by wear of a TT-1 stem on a ceramic modular head hip prosthesis --case report].

The author presents a case of metal stem cone wear caused by a ceramic head. During revision hip arthroplasty procedure a new modular ceramic head was implanted in combination with a stable cemented TT-1 stem. 13 months after surgery the hip became symptomatic and 20 months after the procedure total loosening of the cup was observed. Wear of the stem cone was visible. During the next revision procedure all hip prosthesis elements were removed, soft tissue debridement was performed and a new cemented prosthesis was implanted. One year post-op the hip is pain free.

Ceramics↗
PubMed2003

Workflow and cost analysis on MODULAR ANALYTICS.

Four stand-alone analyzers in a centralized laboratory were replaced by two modular analytical systems processing 45 methods of the general chemistry and specific protein segment. This consolidation led to a reduction of the daily workflow and operational costs. The cost saving with 1.3 million reported results per year was 53,000 Euro, which can be assessed as an important contribution to cost reduction in the health care system.

Clinical Laboratory Techniques↗
PubMedDate not supplied

A modular laparoscopic training program for pediatric surgeons.

OBJECTIVES: A structured endoscopic training program for pediatric surgeons has not yet been established. This study was conducted to develop a modular training program (MTP) for pediatric surgeons and to evaluate its effectiveness for surgeons with and without previous experience in laparoscopic surgery. METHODS: Nine pediatric surgeons participated in the study. They were divided into 2 groups: group A (n=4), surgeons who had experienced more than 10 cases of laparoscopic surgery prior to MTP; group B (n=5), those who had experienced fewer than 10 cases. They participated in a standardized MTP workshop, which consisted of 2 "see-through" and 3 "laparoscopic" tasks. Each participant's psychomotor skills were evaluated objectively before and after MTP with a computer-generated virtual simulator and were evaluated for precision, efficiency, and speed. RESULTS: In participants, speed was significantly enhanced after MTP. In group A, no differences were observed after MTP, whereas significant improvements were noted in efficiency and speed after MTP in group B. Before MTP, efficiency was significantly higher in group A than in group B; however, no difference remained between the 2 groups after MTP. CONCLUSIONS: MTP is effective for nonlaparoscopic pediatric surgeons to become familiar with basic endoscopic skills.

Adult↗
PubMed2003

Modular organization of adaptive colouration in flounder and cuttlefish revealed by independent component analysis.

Flounders and cuttlefish have an impressive ability to change colouration, for camouflage and, in the case of cuttlefish, for communication. We pursue the hypothesis that these diverse patterns are created by combining a small number of distinct pattern modules. Independent component analysis (ICA) is a powerful tool for identifying independent sources of variation in linear mixtures of signals. Two versions of ICA are used, one assuming that sources have independence over time, and the other over space. These reveal the modularity of the skin colouration system, and suggest how the pattern modules are combined in specific behavioural contexts. ICA may therefore be a useful tool for studying animal camouflage and communication.

Adaptation, Physiological↗
PubMed1992

[Therapy of bone metastases of the lower extremity with the KMFTR modular tumor endoprosthesis system].

During the years 1975 through 1989, 189 patients have been operated because of metastases within bones of the lower extremity. Thereof, 34 patients received an endoprosthesis of the KMFTR (Kotz Modular Femur-Tibia reconstruction system) type. In detail, the following reconstruction elements had been used: proximal femur (n = 20), distal femur (n = 7), complete femur (n = 2), proximal tibia (n = 5). At the time of follow-up examination 30 patients had died. Mean survival time after resection of metastases was 18.6 months (range 8-44 months). According to histologic judgement, in 23 cases wide or marginal resections had been performed whereas 11 patients had been operated intralesionally. In no case local recurrence as relevant to therapy was observed. At the same time-point, survival periods after detection of secondary manifestations of the malignant diseases within the remaining 4 patients were 29, 61, 73 and 125 months, respectively. The following complications were observed: luxation of the prosthesis (n = 6), transient paresis of the peroneus (n = 3), deep vein thrombosis (n = 2), pulmonary infarction (n = 1), wound healing disturbances (n = 2) and hematoma (n = 3).

Acetabulum↗
PubMed2003

Amelogenin protein exhibits a modular design: implications for form and function.

The most abundant protein of forming enamel is amelogenin, a protein capable of self-assembly to form nanospheres. Naturally occurring mutations in the human amelogenin gene are responsible for at least some of the disease entities known collectively as amelogenesis imperfecta (AI), although it is clear that the AI phenotype may be caused by alteration to other genes responsible for the biogenesis of the enamel extracellular matrix. Mutations that create changes in the functional domains of the amelogenin protein do adversely affect enamel biomineralization. Protein engineering of amelogenin that phenocopies several of the known AI mutations exhibits defects in self-assembly. Amino acid alterations that occur within a domain of amelogenin appear to cause "mineral defects," that is to say hypocalcification of the enamel, whereas mutations that occur elsewhere in another domain of the amelogenin molecule result in "hypoplastic defects," a decrease in thickness of the enamel. However, not all patients with AI phenotypes segregate precisely into these arbitrary designations. Nonetheless, correlating the domain of the amelogenin protein that contains a specific mutation with the type of enamel structural alteration suggests a modular design for amelogenin that is corroborated by protein engineering using recombinant DNA techniques and transgenic animal studies.

Amelogenin↗
PubMedDate not supplied

Cemented hip prostheses: modular screw system.

The long-term results of 21 patients treated with modular screw cementless hip prostheses are reported. An examination of periprosthetic osteogenesis and function evaluated by gait analysis revealed good incorporation of the prosthesis and good clinical results in all of the cases studied.

Bone Cements↗
PubMed1976

A hybrid modular set for on-line preprocessing of data in electrophysiology.

An introductory review of hardware aspects of on-line experimental data processing reveals that the combination of a specialized (hard-wired) preprocessing unit coupled with a programmable laboratory computer is an optimal set up for an electrophysiological laboratory. The paper deals with a proposed modular system, which makes the assembly of a large number of different preprocessing units possible. Some practical applications of the preprocessing units coupled with a LINC (D.E.C.) computer are presented in conclusion.

Amplifiers, Electronic↗
PubMed1992

LD hip arthroplasty. Design concepts and first clinical trials of a new modular system.

The new LD modular hip arthroplasty is made of Ti6A14V. The acetabular component has a hemispheric expansive metallic ring and a polyethylene nucleus in the shape of a cone segment. Since June 1988, when the clinical trials began, 352 arthroplasties have been performed with 112 total hip arthroplasties among them. Only 60 noncemented total hip arthroplasties, with the longest follow-up evaluation reaching 24 months, were analyzed. Patients with revision operations were excluded. The results have been evaluated using the Merle D'Aubigne scoring scale. Good results were found in 86% of cases. Pain improved markedly at three months in the postoperative period. At six months, the Trendelenburg sign was negative in 76% and positive in 12%. The Duchenne sign was positive in 11%. Major complications included three dislocations, two acetabular component revisions caused by initial malposition, one external popliteal nerve palsy, one deep infection, and two periprosthetic fractures. No acetabular migrations have been found. There are six femoral sinkings of less than 1 cm. Heterotopic ossifications Grade II-III appear in 24% of cases. The results to date are evaluated clinically and radiologically. The acetabular design has proved efficient, and the femoral components show a low incidence of stress shielding.

Acetabulum↗
PubMed2003

Criteria for success with threaded cups (design, material and modularity).

PURPOSE OF THE STUDY: Over a period of three generations, threaded cups were developed and have become viable contemporary cementless hip implants. A few implants already have a high success rate over the mid and long term. Aim of this study was to evaluate contemporary threaded cups. MATERIAL AND METHODS: 30 of the second and third generation cups were systematically analyzed and measured using by a no-touch light section technique. Construction of inner form was determined with half sections. RESULTS: Approximately 50% have a conical shape, although there is a trend towards a more anatomical shape. 83% of the cups have a height up to 23% smaller than the radius. Only conical threaded cups have a relatively thin and constant wall thickness (1 mm-1.8 mm). Corundum blasted pure titanium, titanium alloys or HA coated implants are considered the standard materials. The insert is pre-assembled in two implants, otherwise the cups have modular inserts. Total ceramic inserts are found in four cups. Ceramic inserts with a sandwich construction are found in six cups. One cup has a full-metal insert. All other cups with metal-metal inserts have a sandwich construction. DISCUSSION: The studies by Kody (6) and our own studies (10) show that the V-cut threads have high values for turning moment and tilting stability. CONCLUSION: The screw-in behavior of threaded cups is largely determined by the design of the threads. Material and surface of threaded cups influence osseointegration and therefore long-term results. Contemporary threaded cups have a narrow V-cut and saw threads or flat threads with depths up to 3 mm, on average 4 turns, and pith values of approximately 4.5 mm. Three generations of threaded cups development were necessary to procure the current form with highly satisfactory mid- and long-term results.

Arthroplasty, Replacement, Hip↗
PubMed2004

Geometric element analysis of fretting in a model of a modular femoral component of a hip implant.

The study utilized the geometric element analysis method to investigate the effect of three variables (head diameter, d; head material; and neck material) on the y-direction displacement, due to fretting (delta), in a model of the head-neck connection in a modular version of the femoral component of a hip implant, subjected to a resultant hip joint force only. It was found that while d and neck material exerted a strong effect on delta, the head material had practically no such effect. The implications of this finding for design and materials selection issues for this connection are discussed.

Computer Simulation↗
PubMed1992

A review of the 2- to 8-year results with a proximally fixed noncemented threaded modular total hip.

A review of 50 cases of a proximally modular noncemented stem has been carried out. The primary method of fixation was a proximal threaded sleeve which was screwed into bone. Mean follow-up was 5.2 years. Six cases were revised, two for stem loosening. The remaining cases rate 69% excellent, 14.3% good, 11.9% fair and 4.8% poor. Two cases showed distal lucency due to polyethylene debris which leaked through the taper lock because of two vertical grooves. The results were felt to be adequate, but the threaded sleeve is too difficult to insert which lead to an alternative method of sleeve fixation. The longitudinal grooves, which were obviously a fault in design, have been removed.

Adult↗
PubMedDate not supplied

The modular analytical procedure and validation approach and the units of measurement for genetically modified materials in foods and feeds.

Food and feed analysts are confronted with a number of common problems, irrespective of the analytical target. The analytical procedure can be described as a series of successive steps: sampling, sample processing, analyte extraction, and ending, finally, in interpretation of an analytical result produced with, e.g., real-time polymerase chain reaction. The final analytical result is dependent on proper method selection and execution and is only valid if valid methods (modules) are used throughout the analytical procedure. The final step is easy to validate-the measurement uncertainty added from this step is relatively limited and can be estimated with a high degree of precision. In contrast, the front-end sampling and processing steps have not evolved much, and the corresponding methods are rarely or never experimentally validated according to internationally harmonized protocols. In this paper, we outlined a strategy for modular validation of the entire analytical procedure, using an upstream validation approach, illustrated with methods for genetically modified materials that may partially apply also to other areas of food and feed analyses. We have also discussed some implications and consequences of this approach in relation to reference materials, measurement units, and thresholds for labelling and enforcement, and for application of the validated methods (modules) in routine food and feed analysis.

Animal Feed↗
PubMed2004

The AneuRx modular endograft device for the treatment of abdominal aortic aneurysms. Overview of 7 years of clinical use.

Open surgical repair of abdominal aortic aneurysms (AAAs) has been performed for over 40 years now with good results. However, the procedure continues to be high-risk with numerous potential complications. The AneuRx modular bifurcated endograft was one of the first to be tested to exclude AAAs via an endovascular approach. Data from multiple clinical trials show that treatment of AAAs with the AneuRx device is comparable to open repair with regards to mortality and may have improved short-term and long-term morbidities rates. The following review discusses clinical use of the AneuRx stent graft system from the initial clinical trial in 1996 to its current commercial use.

Aorta, Abdominal↗