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PubMedDate not supplied

The canine cemented modular total hip prosthesis.

Total hip replacement (THR) is well established as a treatment modality for dogs with noninfectious, nonneoplastic, disabling conditions of the coxofemoral joint. Since the mid 1970s, a fixed-head prosthesis has been used in this procedure. A modular prosthesis, which is based on many of the technical advances found in human prostheses, now is available for use in veterinary medicine. The prosthesis, surgical instrumentation, surgical technique, and clinical results have been evaluated in a prospective study conducted at The Ohio State University's College of Veterinary Medicine. The modular prosthesis provides results equal to or better than the fixed-head prosthesis.

Animals↗

PubMed1992

Modular hemiarthroplasty for fractures of the proximal part of the humerus.

A new biomodular prosthesis was used for the treatment of a displaced fracture of the proximal part of the humerus in twenty-two shoulders in twenty-two patients. The fractures were classified according to the Neer system; there were thirteen four-part, five three-part, and four head-splitting fractures. There were fifteen women and seven men, and the mean age was seventy years (range, forty-nine to eighty-seven years). The hemiarthroplasty was performed an average of eleven days (range, one to forty-five days) after the injury. The deltopectoral interval was used in all patients, and the prosthesis was implanted with cement in twenty of the shoulders. All of the patients participated in a supervised program of rehabilitation. The patients were followed for an average of thirty-six months (range, twenty-six to forty-nine months). Twenty of the twenty-two patients had a good or excellent result. The active forward elevation averaged 119 degrees; external rotation, 40 degrees; and internal rotation, to the twelfth thoracic vertebra. All of the patients except for the two who had a poor result had satisfactory relief of pain. The two patients who had a poor result had a successful revision with a modular prosthesis of the same design. The modular head could be removed, enabling the surgeon to gain access to the glenoid and to adjust the soft tissues. The over-all scores correlated inversely with the age of the patients and the interval from the injury to the operation.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1991

Resection of malignant bone tumors about the shoulder. A preliminary report of reconstruction with a new modular spacer.

Reconstruction after resection of malignant bone tumors about the shoulder is difficult. Twelve patients had reconstruction using a new titanium modular spacer. This modular system allows the surgeon to reconstruct variable lengths of the proximal humerus. Although the patient has no active shoulder motion, excellent hand and elbow function is preserved. The spacer serves as a temporary device in the young active patient. A more definitive reconstructive procedure can be performed after the completion of chemotherapy and a sufficient disease-free interval.

Adolescent↗

PubMedDate not supplied

[Preparation of and stability studies on enteral modular diets at the Pharmacy Service].

It is generally admitted fact in daily medical practice in some patients who require to be fed artificially, the treatment must always be directed, whenever possible, through "enteral route". There are patients whose nutritional needs cannot adapt to the standardized diets available in the market. In these cases it is necessary to draw up individualized diets for them, planned derived from the modules. It is equally known that there is always a problem to obtain, at the available means in the pharmaceutical services, established modular diets. It is described in this report a method of planning a modular enteral diets, physic-chemically stable and contaminating bacteria free. It is also detailed the election of adequate emulsion and stabilizer and the final concentration of each of these in the diets of different composition quali and quantitatively.

Enteral Nutrition↗

PubMed1989

Intrastriatal grafts derived from fetal striatal primordia. I. Phenotypy and modular organization.

Fetal striatal grafts display a striking modularity of composition. With acetylcholinesterase (AChE) histochemistry, the tissue of such grafts can be divided into regions with strong AChE staining of the neuropil and regions in which AChE staining of the neuropil is weak. In the experiments reported here, we reexamined the nature of this modularity. Striatal grafts were made by injecting dissociated cells of E15 ganglionic eminence into the striatum of adult rats, which 7 days before had recived intrastriatal deposits of ibotenic acid. Some donors had been exposed to 3H-thymidine at E11-E15. After 9-17 month survivals, the anatomical organization of the grafts was studied by histochemistry, immunohistochemistry, and autoradiography. In every graft, the AChE-rich regions formed patches (P regions) in a larger AChE-poor surround (NP regions). Neurons labeled with 3H-thymidine appeared in both P and NP regions, suggesting that donor cells were distributed in each type of region and that neither type of tissue, P or NP, was composed exclusively of host tissue. In the AChE-rich P regions, markers characteristic of normal perinatal and mature rat striatum were expressed by medium-sized cells: calcium-binding protein (calbindin D28k) immunostaining, metenkephalin (mENK) immunostaining, and, more rarely, somatostatin (SOM) immunostaining. In the NP regions, however, medium-sized cells expressing calbindin and mENK immunostaining were very rare, and there was an abundance of neuronal types not found in normal mature striatal tissue. These included (1) large, multipolar, calbindin-positive neurons with well-ramified, densely stained dendrites, (2) large, SOM-positive neurons with prominent dendritic trees, and (3) mENK-positive cells smaller than typical striatal, medium-sized, mENK-immunoreactive neurons. In Nissl stains, the AChE-rich P regions resembled the normal striatum of mature animals, whereas the AChE-poor NP regions did not. These findings suggest that the P regions of fetal striatal grafts achieve a phenotypy similar to that of normal striatum at maturity and during much of postnatal development. The dominant expression of perikaryal calbindin-like immunoreactivity in the P regions further suggests that these zones have a high proportion of tissue resembling striatal matrix. By contrast, expression of marker antigens in the NP zones of the grafts suggests that these zones are predominantly composed of nonstriatal tissue or that they have the phenotypy of immature striatum intermixed with some nonstriatal cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Acetylcholinesterase↗

PubMedDate not supplied

[Modular diet and parenteral support in persistent diarrhea].

Eleven infants with protracted diarrhea were treated with modular diet and short-term parenteral nutrition. Mean age at admission was 3.7 months with males predominating. Enteropathogenic E. coli, classic serotypes, were isolated from 7 patients and rotavirus from one. A child with combined, severe immunodeficiency died. Milk protein intolerance was diagnosed in another patient. Balance studies and peroral biopsies were performed. Malnutrition was more frequent and hospital stay was longer in those infants who developed nosocomial infections. Even though this treatment shortened the duration of the hospitalization, the negative nutritional impact persisted: Weight/Age (NCHS) decreased from 84% to 61%, with rapid recovery after discharge. Fecal lactic acid excretion was increased on admission to 1,296 mg x day and disaccharidase activity was decreased. The modular diet decreased both fecal volume and lactic acid excretion.

Diarrhea, Infantile↗

PubMed1989

Tibial tray augmentation with modular metal wedges for tibial bone stock deficiency.

Peripheral defects in the proximal tibia can be difficult to treat during total knee arthroplasty. Attempts can be made to solve the problem with cement, cement with screws, bone grafts, metal wedges, and custom components. In vitro testing has shown that a custom-augmented prosthesis with a built-up metal wedge is mechanically superior in resisting deflections when loaded. Using modular metal wedges, the tibial tray can be customized at the time of surgery. In vitro testing has also shown the wedge to be superior to the use of cement alone or cement reinforced by screws. The authors report on modular metal wedges to augment tibial bone stock deficiency. Twenty-two knees (20 patients) were followed for a minimum of two years with an average follow-up time of 37 months. The average age of the patients at the time of surgery was 70 years. There have been no failures of this technique and no loosening of tibial components. The incidence of nonprogressive radiolucent lines was 27%. All but one patient was pain-free, and this patient's discomfort was not related to the tibial component fixation. No patient has had subsequent revision surgery. This technique should be considered in the treatment of severe peripheral tibial deficiencies in the elderly, low-demand patient.

Aged↗

PubMed1979

[Modular way of sampling for determination of the degree of occupational exposure at industrial plants with periodically changing dust concentration].

A work station with dustiness changing periodically during a workshift is one of the most common types of work stations, as regards exposure dynamics. Cyclic significant concentrations of dust occurring from time to time result from a specific technological treatment used. The measuring module will be the time of measurement, starting with the beginning of the cycle of working out a given detail or--the technological process through the whole treating and technological process as well as breaks--due to various reasons--until starting another, analogous operation. What was found is that average dust concentrations obtained from modular measurements correspond to average concentration to which an employee is exposed during the whole workshift. Modular measurements allow to reconstruct work conditions inducing silicosis, and may be helpful in settling the maximum allowable concentration.

Air Pollutants↗

PubMed1983

[A new modular system for respiratory therapy].

Diversification of respiratory therapy into humidification and secretolysis, oxygen therapy, augmentation of FRC, substitution of the work of breathing and changing inspiratory gas distribution is the basis of a modular device system. The basic unit of the modular system consists of an oxygen-air-mixer, a flow module and an emergency O2-supply for resuscitation bags. The system is preferably attached to the wall rail system and the modules locked into each other. The main advantages are: Reduction in the number of devices around the patient's bed, comprehensive setup; reduction of required storage capacity; cost reduction; easy integration at low cost of new therapeutical procedures; quick and easy change of therapy whilst maintaining basic parameters constant.

Respiratory Therapy↗

PubMedDate not supplied

[Rheumatism documentation--a uniform, modular documentation system for therapeutic studies in rheumatic diseases].

Being progressive and also involving variations in the severity of symptoms, chronic rheumatic diseases present difficulties with respect to documentation. Since dramatic changes in the course of disease are rare, early detection of very slight changes is essential to successful antirheumatic therapy. Practical means of documentation are necessary if an overview of the various clinical findings and subjectively reported symptoms is to be maintained over a period of many years. This is especially true in the case of therapeutic studies. The documentation form should enable the recording of suitably grouped data on the various rheumatic diseases and modes of therapy. With governmental support (BMFT project MT 0289), a uniform documentation form, "Dokumentation Rheuma", was set up and tested at 14 hospitals for rheumatic diseases. The modular form chosen and the definition of items were well received by the clinicians. After several modifications, a modularly structured documentation system is now available, elements of which can be expanded according to the needs of the individual therapeutic study. The form can both constitute a part of the patient history and act as a link between different but parallel-running studies, thus making it unnecessary to record the same information twice for different purposes. At the same time, the data base can be used to answer scientific and epidemiological questions independent of the study in progress.

Computers↗

PubMed1983

The development and integration of fine motor sequences in 12- to 18-month-old children: a test of the modular theory of motor skill acquisition.

According to the modular model, skill development proceeds through the development of stable units of action called subroutines. The development of these programmed units frees the child to attend to those parts of the action not yet mastered. Once consolidated they can be applied to many different contexts. Thus, complex skill sequences can be produced. The theory generates several predictions, most fundamental being an association between increasing proficiency and increasing consistency. Experiment 1 was a longitudinal study in which six 12-month-old children were observed over a period of eight months. Various manipulative tasks were used, notably the placement of rods in corresponding holes. Experiment 2 was a cross-sectional study of performance consistency in rod placement (N = 30). Results showed that consistency decreases as proficiency increases. It is concluded therefore that the programmed components of complex actions are not characterized by the invariance predicted by modular theory.

Child Development↗

PubMed1995

Local and distant products from modularity.

In this study, the local and distant distribution of solid and soluble products of corrosion from the head and neck junction of modular femoral total hip prosthetic components were characterized. Particulate corrosion products from retrieved implants and surrounding tissues were analyzed. Serum transport and urinary excretion of metal was measured in correlation with the degree of corrosion at the head and neck junction. Particles of metal oxides, metal chlorides, and chromium phosphate corrosion products were identified on implants of 10 designs from 6 manufacturers. The most abundant solid corrosion product on the implant and within the periprosthetic tissues (size range, < 1-200 micrometers) was an amorphous chromium orthophosphate hydrate-rich material. Serum cobalt and urine chromium concentrations were elevated significantly in patients with implants that had moderate to severe corrosion in comparison with those with no to mild corrosion. Solid corrosion products from modular femoral stems may accelerate articular wear via a 3-body mechanism. Phagocytosable particles of these corrosion products may stimulate macrophage-mediated periprosthetic bone loss. Systemic dissemination of metallic corrosion products raises the issue of systemic toxicity; however, no overt evidence of metal toxicity was observed in this study.

Adult↗

PubMed1995

Polyethylene wear debris in modular acetabular prostheses.

The longevity of total hip arthroplasty has brought forth the recognition of aseptic loosening of prosthetic components as the leading cause of implant failure. Modularity of implants, although a significant improvement in versatility, may increase debris formation, a recognized cause of implant failure. This study was designed to measure the relative motion, and to assess the polyethylene wear debris production at the interface between the metal acetabular shell and the back side of the polyethylene liner, in modular hip prostheses. Five models from 4 manufacturers with different locking mechanisms and acetabular shell surface treatments were tested under long-term simultaneous sinusoidal and static loading (10(7) cycles at 3 Hz with +/- 2.5 Nmeter and 220 N static load). Results showed that there were marked differences in the security of the acetabular shell and polyethylene liner locking mechanism, wear pattern, damage sites, and amount of polyethylene debris on the acetabular shell and polyethylene liner surfaces. The range of polyethylene liner motion observed among the 5 models during 1 cycle of testing varied from an average of 0.96 degrees to movement too small to be detected by the test machines. Image and scanning electron microscopy analysis showed different wear patterns and a wide range in the average polyethylene liner surface wear area (0.26 cm2-4.61 cm2). In general, a stable locking mechanism and a smooth acetabular shell surface are essential in minimizing polyethylene liner wear and polyethylene debris production.

Biomechanical Phenomena↗

PubMed1994

Polyethylene and metal debris generated by non-articulating surfaces of modular acetabular components.

We report a prospective study of the liner-metal interfaces of modular uncemented acetabular components as sources of debris. We collected the pseudomembrane from the screw-cup junction and the empty screw holes of the metal backing of 19 acetabula after an average implantation of 22 months. Associated osteolytic lesions were separately collected in two cases. The back surfaces of the liners and the screws were examined for damage, and some liners were scanned by electron microscopy. The tissues were studied histologically and by atomic absorption spectrophotometry to measure titanium content. The pseudomembrane from the screw-cup junction contained polyethylene debris in seven specimens and metal debris in ten. The material from empty screw holes was necrotic tissue or dense fibroconnective tissue with a proliferative histiocytic infiltrate and foreign-body giant-cell reaction. It contained polyethylene debris in 14 cases and metal in five. The two acetabular osteolytic lesions also showed a foreign-body giant-cell reaction to particulate debris. The average titanium levels in pseudomembranes from the screw-cup junction and the empty screw holes were 959 micrograms/g (48 to 11,900) and 74 micrograms/g (0.72 to 331) respectively. The tissue from the two lytic lesions showed average titanium levels of 139 and 147 micrograms/g respectively. The back surfaces of the PE liners showed surface deformation, burnishing, and embedded metal debris. All 30 retrieved screws demonstrated fretting at the base of the head and on the proximal shaft. Non-articular modular junctions create new interfaces for the generation of particulate debris, which may cause granulomatous reaction.

Acetabulum↗

PubMed1994

Redefining care delivery: a modular system.

Personnel from all departments involved in patient care--nursing and ancillary--redefined a care delivery system. This pilot study defines committee and modular formation, physical changes, communication and goals of the modular system.

Communication↗

PubMed1994

Fixation of the modular total hip femoral component in cementless total hip arthroplasty.

Cementless femoral component fixation with a modular design that achieved tight fit in the proximal and distal femur was evaluated. The base of the femoral neck made the most important contribution, but diaphyseal bony interlock also contributed significantly to immediate torsional fixation. Fluted surface and slotted distal design produced fixation that was superior to fully porous-coated and cemented cylindrical stems. Early cyclical loading improved fixation, and under moderate torsional loads (up to 20 N-m), no measurable interface slippage occurred with the modular implant.

Biomechanical Phenomena↗

PubMed1994

The two- to six-year results with a proximally modular noncemented total hip replacement used in hip revisions.

A review of the two- to six-year results of revision cases using a proximally modular noncemented total hip replacement has been carried out. There were 91 cases. A primary stem was used in 29 and a long curved revision calcar replacement stem in 62. The results of the primary cases were 80% excellent, 6% good, 9% fair, and 5% poor. In the revision stem cases, 69.4% were excellent, 11.5% good, 7.6% fair, and 11.5% poor. One primary stem case was revised for acetabular migration. Ten of the revision stem cases were rerevised, four for femoral perforation, three for sepsis reactivation, one for acetabular migration, one acetabular component for dislocation, and one stem for trochanteric nonunion. There have been no stems or sleeve fractures, no implant dissociations and no osteolysis. In those reexplored, no metallosis has been found. Only three cases required structural allografting on the femoral side. These early results are promising and no untoward reactions have occurred as the result of the use of a modular stem.

Adult↗

PubMed1994

Corrosion and wear at the modular interface of uncemented femoral stems.

We examined 108 uncemented femoral stems with modular femoral heads which had been retrieved for reasons other than loosening. There were detectable amounts of wear and corrosion in 10 of 29 (34.5%) mixed-alloy components and 7 of 79 (9%) single-alloy components after a mean implantation time of 25 months. We found no correlation between the presence or extent of corrosion or surface damage and any of time in situ, initial diagnosis, reason for removal, age, or weight. Stems with wear and corrosion were less likely to show histological bony ingrowth. The interface between the head and stem of modular total hip components is a possible source of ion release and wear debris, but wear and corrosion were totally absent in most specimens. This suggests that this problem could be avoided, and that further research is required to develop manufacturing methods which would minimise such changes.

Cementation↗