¿Influye el deterioro cognitivo preoperatorio en los resultados de la artroplastia total de rodilla? / Does pre-surgical cognitive impairment affect knee replacement results?

Objetivo. Determinar la influencia del deterioro cognitivo preoperatorio en los resultados de la artroplastia total de rodilla, no solo desde la perspectiva del médico sino también del paciente. Material y método. Estudio prospectivo de pacientes procedentes de la lista de espera quirúrgica, sometidos a artroplastia total de rodilla primaria. De los 265 pacientes de la muestra inicial, 50 fueron excluidos. El deterioro cognitivo fue valorado preoperatoriamente mediante el Mini Examen Cognoscitivo (MEC-35). Tanto preoperatoriamente como al año postoperatorio se utilizó la Escala Analógica Visual (EVA), la Knee Society Score (KSS), el Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), y el Hospital Anxiety and Depression Scale (HADS). Resultados. Se analizaron 215 pacientes (57 varones y 158 mujeres). El deterioro cognitivo no influyó en los resultados de la artroplastia total de rodilla, no alcanzando significación estadística en ninguna de las escalas analizadas. Los pacientes con deterioro cognitivo presentaron niveles más elevados de ansiedad y depresión, preoperatoriamente, y al año de intervención, siendo estas diferencias estadísticamente significativas. Discusión. Todos los pacientes experimentaron una mejoría de los resultados tanto específicos como de calidad de vida tras un procedimiento como la artroplastia total de rodilla independientemente de la presencia de deterioro cognitivo preoperatorio (AU)

Objective. To determine the influence of the pre-operative cognitive impairment on results of the total knee arthroplasty according to a doctor and patient perspective. Material and method. A prospective study was conducted on patient from the surgical waiting list who had undergone a primary total knee arthroplasty. The sample initially included 265 patients, but 50 were subsequently excluded. Cognitive impairment was assessed pre-operatively by the Mini Cognitive Examination (MEC-35). The Visual Analog Scale (VAS), the Knee Society Score (KSS), the Western Ontario and McMaster Osteoarthritis Index (WOMAC), and the Hospital Anxiety and Depression Scale (HADS), were used pre-operatively and one year later post-operatively. Results. A total of 215 patients were assessed (57 men and 158 women). Cognitive impairment had no influence on the results of total knee arthroplasty. In fact, there was no statistical significance in any of the scales analyzed. Preoperatively, and one year later, the patients with cognitive impairment showed higher levels of anxiety and depression, with these differences being statistically significant. Discussion. All of the patients experienced an improvement in the specific outcomes and quality of life after the total knee arthroplasty procedure, regardless of the presence of preoperative cognitive impairment (AU)

[Does pre-surgical cognitive impairment affect knee replacement results?]. / ¿Influye el deterioro cognitivo preoperatorio en los resultados de la artroplastia total de rodilla?

OBJECTIVE: To determine the influence of the pre-operative cognitive impairment on results of the total knee arthroplasty according to a doctor and patient perspective. MATERIAL AND METHOD: A prospective study was conducted on patient from the surgical waiting list who had undergone a primary total knee arthroplasty. The sample initially included 265 patients, but 50 were subsequently excluded. Cognitive impairment was assessed pre-operatively by the Mini Cognitive Examination (MEC-35). The Visual Analog Scale (VAS), the Knee Society Score (KSS), the Western Ontario and McMaster Osteoarthritis Index (WOMAC), and the Hospital Anxiety and Depression Scale (HADS), were used pre-operatively and one year later post-operatively. RESULTS: A total of 215 patients were assessed (57 men and 158 women). Cognitive impairment had no influence on the results of total knee arthroplasty. In fact, there was no statistical significance in any of the scales analyzed. Preoperatively, and one year later, the patients with cognitive impairment showed higher levels of anxiety and depression, with these differences being statistically significant. DISCUSSION: All of the patients experienced an improvement in the specific outcomes and quality of life after the total knee arthroplasty procedure, regardless of the presence of preoperative cognitive impairment.

Influencia de un hidrogel en la cicatrización del tendón. Estudio experimental con P(HEMA) / Influence of a hydrogel on tendon healing. Experimental study with P(HEMA)

Objetivo: Un hidrogel preparado por la polimerización del monómero metacrilato de 2-hidroxietilo P(HEMA) fue administrado localmente al tendón de Aquiles del conejo parcialmente seccionado con el objeto de evaluar su influencia y compatibilidad en el proceso de cicatrización.Diseño experimental: Se estudiaron un total de 40 tendones distribuidos de forma uniforme en dos grupos, control y experimental, a los cuales se aplicó el hidrogel. Los animales fueron sacrificados a los 3, 7, 14 y 28 días para llevar a cabo una evaluación histológica.Después de 28 días de la lesión los especímenes fueron también estudiados con microscopio electrónico y se realizó un análisis biomecánico con objeto de determinar la fuerza necesaria para el fracaso de la cicatriz. Resultados: Se ha constatado una ausencia de reacción tisular adversa al hidrogel, una limitada presencia de adherencias peritendinosas, así como una uniforme proliferación fibroblástica en los tendones tratados con el hidrogel. A nivel ultraestructural se observó la presencia de colágeno intracelular, fenómeno asociado con una síntesis acelerada de fibra colágena. El análisis biomecánico no logró establecer diferencias estadísticas con el grupo control.Conclusiones: El hidrogel aplicado a un tendón puede prevenir la formación de adherencias peritendinosas y constituir un vehículo apropiado para la administración local de agentes farmacológicos que faciliten la reparación del tendón sin interferir con su cicatrización (AU)

[Alpha-1-antitrypsin in early infections after hip prosthesis surgery]. / L'alpha-1-antitrypsine dans les infections précoces après prothèse de hanche.

PURPOSE OF THE STUDY: The aim of this work was to determine whether erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and alpha-1-antitrypsin (A1AT) levels are correlated significantly with early postoperative infectious complications after hip prosthetic surgery. MATERIALS AND METHODS: This prospective study was conducted on 100 total hip replacements performed between 1994 and 1995. ESR, CRP and A1AT were obtained before surgery then at 1, 2 and 6 weeks after surgery. RESULTS: Seven bacteriologically proven cases of infection were reported. Infection was considered to be superficial if it did not extend deeper than the muscles fascia. There was a strong statistical correlation between A1AT level and infection for all postoperative times (p<0.0001). A1AT was highly sensitive (87.5 p. 100) and specific (85.8 p. 100) for infection compared with ESR (sensibility 70 p. 100 and specificity 65.9 p. 100) and CRP (sensitivity 63.6 p. 100 and specificity 80.1 p. 100). DISCUSSION AND CONCLUSION: In our hands, A1AT can be a most useful diagnostic tool for infection after prosthesis hip surgery. Although not totally specific, it is highly sensitive for infection compared with other tools such as ESR and CRP more frequently used. These findings suggest an avenue of research on the role of A1AT in infectious complications after prosthetic joint surgery.

Intracellular biogenesis of collagen fibrils in 'activated fibroblasts' of tendo Achillis. An ultrastructural study in the New Zealand rabbit.

We have studied the formation of collagen fibrils in 'activated fibroblasts' of tendo Achillis of rabbits. The tendon was in the process of regeneration after experimental partial tenotomy. Samples were taken from the peri-incisional region and analysed by transmission electron microscopy. Ultrastructural examination showed the presence of a 'fine dense granular substance' inside the rough endoplasmic reticulum and procollagen filaments. These come together to form collagen fibrils in the dilated vacuoles of the rough endoplasmic reticulum. The possible intra- and extracellular origin of collagen fibrils is suggested. Within the cell biosynthesis of collagen fibrils take place with the formation of collagen substance which gives rise to procollagen filaments. These make contact in parallel apposition to produce striated 'spindle-shaped bodies' which elongate by the longitudinal attachment of more procollagen filaments and form intracellular nascent collagen fibrils.

Resorbable polyacrylic hydrogels derived from vitamin E and their application in the healing of tendons.

A hydrogel containing vitamin E (alpha-tocopherol) was prepared by free radical polymerization of 2-hydroxyethyl methacrylate (HEMA) and alpha-tocopheryl methacrylate (VEMA), the latter being synthesized previously to its use. The hydrogel containing 20 wt % of VEMA showed equilibrium water content in the range of those of hydrogel networks, at any pH. The swelling of the hydrogel followed Fick's law, indicating that sorption of water molecules is controlled by diffusion, although the values of diffusion coefficients for the VEMA-containing hydrogel were lower than those of poly-HEMA in any medium. Surface characterization of the VEMA-containing hydrogel revealed a decrease in the surface energy of solid owing to a decrease of the polar component mainly. The application of finely powdered xerogel of HEMA-VEMA copolymer bearing 20 wt % of the vitamin E derivative gave a very fast and positive response showing an activated regeneration capacity, probably due to the stimulation of the cellular proliferation or the more plausible effect, the cellular protection associated to the antioxidant properties of the vitamin E residue.

Long-term results of the treatment of severe osteoarthritis and rheumatoid arthritis with 193 total knee replacements.

We undertook a clinical and surgical study with evaluation of the long-term results (average 5 years, range 1-9 years) of 193 stabilized posterior cemented total knee replacements (TKRs) type Insall-Burstein in patients with severe osteoarthritis (OA) and rheumatoid arthritis (RA), carried out consecutively by the same surgeon from January 1986 to January 1995, at our COT Unit at the Central Military Hospital "Gomez Ulla" in Madrid, in collaboration with the Departments of Traumatology and Morphological Sciences of the University of Alcala de Henares (Madrid). The principal purpose was to examine the success rate of this type of prothesis implanted during primary surgery, according to severity of the case. Six methodology protocols were produced in this study (exploratory, surgical technique in primary surgery, revision surgery, rehabilitation, evaluation and clinical revisions), and satisfactory statistical results (SPSS/PC+) were obtained with the three scales of evaluation: Harris Galante, The Hospital for Special Surgery and Knee Society. These were: 90.5% +/- 0.8% excellent and good results for the OA series, and 83.9% +/- 5% for the RA series. The analysis of survival after long-term monitoring was also statistically significant, with a 96.95% survival rate. Complications arose in 3.10% of cases (6 revisions: 4 aseptic loosenings and 2 loosenings due to infection), which were treated with a constrained prosthesis, and in cases of infection with an arthrodesis. After undertaking a comparative study with other series, we conclude that the Insall-Burnstein stabilized posterior total knee prosthesis, is an excellent Primary replacement associated with long-term survival in patients with a severe degree of articular destruction and functional incapacity, and we give some specific recommendations to reduce complications.

Accuracy of teleradiology in skeletal disorders: solitary bone lesions and fractures.

To evaluate the diagnostic accuracy of digitized film radiography and digital teleradiology for detecting bone fractures and for studying solitary bone lesions, we examined 633 single radiographs from 373 patients (159 with solitary bone lesions, 123 with fractures and 91 without pathology). Radiographs were digitized using a commercial teleradiology workstation and transmitted to a local hospital over a standard telephone line. Images were reviewed by two groups of three experienced radiologists. Receiver operating characteristic (ROC) curves were analysed for conventional films, digitized images and transmitted teleradiology images. No significant differences were found among readers for the evaluation of bone fractures and solitary bone lesions. Teleradiology systems permit remote expert consultation, and telediagnosis therefore is a powerful tool in telemedicine.

[Skin graft protection by treatment of recipients with ultraviolet irradiated fragments of the donor spleen]. / Protección de injertos de piel por tratamiento de los receptores con fragmentos de bazo del donante irradiados con ultravioleta.

We have tested de possible protective effects of UVA radiated spleen fragments upon simultaneous skin allografts in 84 rats. Under these circumstances skin graft rejection was less evident with a 20 day graft disappearance rate of 46.87% rate in the treated series, that compares favourably with a 80% in the control series. This study shows a parallel increase in the mean survival time of skin grafts in treated specimens. The figures being 19.8 days in the treated series against 12.9 days in untreated controls. Spleen implants are finally shown to produce a healing stimulus in the skin graft zone. These differences are statistically significant.

Pericytes as a supplementary source of osteoblasts in periosteal osteogenesis.

In the adult rat femur, lifting a periosteum strip with microscopic bone flakes on its deep surface, if performed without damaging the surrounding microcirculation, rapidly leads to new bone formation and angiogenesis. Using vascular labeling, the pericytes and endothelial cells (ECs) were labeled with monastral blue (MB) in the preformed, preexisting postcapillary venules of the periosteal microcirculation. MB was detectable by light and electron microscopy and it persisted in some of the daughter cells. Between one and 21 hours, the MB labeling was restricted to the pericytes and ECs of postcapillary venules. Immediately afterward, both pericytes and ECs of these vessels were activated and continued to show MB. The phenomenon of pericyte activation includes enlargement, disruption of their basal lamina, separation from the walls of the preformed vessels, and the presence of mitotic figures. At this stage, activated pericytes with MB in their cytoplasm, fibroblast-like cells, and transitional cell forms between them were seen in interstitial areas. After 27 hours, vascular buds appeared and MB was detected in some ECs and pericytes. Between three and six days, when bone-tissue development was observed, some osteoblasts were MB labeled. Previous findings support the hypothesis that when the periosteum is activated, the process of bone formation from cells already present in the periosteum is augmented by proliferation and differentiation of pericytes, which contribute a supplementary population of osteoprogenitor cells.

Total and regional bone mineral content in normal premenopausal women.

In the present, cross-section study, a total of 185 normal premenopausal females--aged 15 through 19 years (n = 40), 20 to 29 years (n = 60), 30 through 39 years (n = 40) and 40 to 49 years (n = 45)--were assessed in order to observe and evaluate the total body bone mineral content and the regional body mineral content of different anatomical regions (head, trunk, arms and legs), when the bone mass peak is established in women and its course during premenopause. All subjects underwent bone densitometry with dual energy X-ray absorptiometry with a Norland XR-26 bone densitometer. No differences between groups were found in total body bone mineral and regional bone mineral content values. Total body bone mineral values (mean +/- SD) were 2546 +/- 461 g and 2691 +/- 499 g in the 15-19 year-old group and 40-49 year-old group respectively. The regional bone mineral content values for the same age group were 495 +/- 75 g and 499 +/- 89 g for the head, 1007 +/- 254 g and 1043 +/- 212 g for the trunk, 327 +/- 74 g and 336 +/- 81 for the arms, and 860 +/- 167 g and 811 +/- 146 g for the legs. The results of this study indicate that the peak bone mass is reached at the age of 20 years and that it remains stable in the premenopausal eugonadal females.

[Effect of alloxan-induced diabetes on hepatic regeneration]. / Influencia de la diabetes inducida por aloxana sobre la regeneración hepática.

Hepatic regeneration in alloxan-induced diabetic rats that underwent a 70% hepatectomy was compared to that of a series of non-treated rats. In diabetic rats, hepatic regeneration is lower and the liver reaches only 70% of the original weight ten days after hepatectomy. Analytical studies in these rats show a diminution of insulin and glucagon. Hepatic microcirculation as shown by measurements of CLV-CLV and CLV area undergoes changes which evolve at a different rate in the central and peripheral zones of the liver. These findings as well as the diminished hepatic regeneration may be attributed to the diminution of the insulin and glucagon values. Insulin and glucagon may be responsible for hepatic regeneration.

Age- and weight-related changes in total body bone mineral in men.

Since the incidence of osteoporotic fractures in men increase with age, bone mass, as total body bone mineral content (TBBM) measured by dual energy X-ray absorptiometry (DEXA), and other variables were determined in men in order to observe whether changes in these parameters justify the increased incidence of bone fractures in men with age. Measurements were conducted in 190 men aged 20-85 years. By correlation tests, no changes were observed in body weight and age. There was a significant correlation (r = 0.67981, r2 = 0.46214, p less than 0.001) between TBBM and body weight, and an inverse significant correlation between TBBM with age (r = 0.34729, r2 = 0.12061, p less than 0.001); this decrease is linear with age and represents a 0.3% annual bone loss. These results suggest that lower weight and/or worse psychomotor response and its effects minimizing trauma, may be responsible for the high fracture rate observed in older males.

[The EUROPAN project: conclusions of the first seminar on nursing methods]. / Proyecto EUROPAN: conclusiones del primer seminario sobre metodología de enfermería.

The First Meeting of the Spanish European Project on Nursing was held in León from May 24th to 26th 1990. This seminar was attended by nursing professionals from 11 Spanish hospitals participating in the Project. During the meeting, an important discussion was held on the protocols used with regard to practical aspects, in order to unify criteria and homologate the results obtained by the different centres. By means of this seminar, Spanish professionals made an important contribution to the design of this Spanish project, not only as collaborators but also as active participants in the research conducted.

[Preliminary aspects relating to the problem-solving process]. / Aspectos preliminares atinentes al proceso de resolución de problemas.

Certain theoretical and methodological aspects related to cognition and problem solving processes are reviewed in order to emphasize the inferencial procedures by which individuals overcome difficulties and limitations present in a problem situation and realize and overcome their own inferential limitations. The rôle that certain primary elements, like axioms, have in the process of making explicit and complete formal structures is also emphasized. Ability to demonstrate correctly and some limitations concerning the methalogic properties of axiomatic systems are also seen in relation to the inferential processes of cognition. Eliminatory inferential processes for adopting decisions are discussed and focused from opposite standpoints as those of associative learning theory and Gestalt theory. The inferential process is evaluated from the internal difficulty of a problem state of nature to the intellective resources available to the subject in order to validate the adopted decisions in problem solving. This comprises methods going from trial-and-error exploration to insight phenomena, through the formulation of all logical possibilities and the process of discarding them by means of experience or inference. According to the symbolic level that represents the problem state of nature formal structures are built up to the point by which they need to be gestallically closed by the inclusion of new primary terms or concepts that could be identified as axioms. This king of closure is postulated as a requirement of the aptitude for mathematics.

Aspectos preliminares atinentes al proceso de resolución de problemas. / [Preliminary aspects relating to the problem-solving process]

Certain theoretical and methodological aspects related to cognition and problem solving processes are reviewed in order to emphasize the inferencial procedures by which individuals overcome difficulties and limitations present in a problem situation and realize and overcome their own inferential limitations. The r¶le that certain primary elements, like axioms, have in the process of making explicit and complete formal structures is also emphasized. Ability to demonstrate correctly and some limitations concerning the methalogic properties of axiomatic systems are also seen in relation to the inferential processes of cognition. Eliminatory inferential processes for adopting decisions are discussed and focused from opposite standpoints as those of associative learning theory and Gestalt theory. The inferential process is evaluated from the internal difficulty of a problem state of nature to the intellective resources available to the subject in order to validate the adopted decisions in problem solving. This comprises methods going from trial-and-error exploration to insight phenomena, through the formulation of all logical possibilities and the process of discarding them by means of experience or inference. According to the symbolic level that represents the problem state of nature formal structures are built up to the point by which they need to be gestallically closed by the inclusion of new primary terms or concepts that could be identified as axioms. This king of closure is postulated as a requirement of the aptitude for mathematics.

Aspectos preliminares atinentes al proceso de resolucion de problemas. / Preliminary aspects relating to problem-solving process

Se revisan algunos antecedentes teoricos y metodologicos referidos a procesos de resolucion de problemas y de cognicion, a fin de proponer un relevamiento de los recursos inferenciales que utiliza el sujeto para superar las dificultades y limitaciones inferenciales, como los axiomas, en el proceso de formalizacion de un sistema de simbolos, la capacidad de demostrar teoremas correctamente, y las limitaciones inherentes a las propiedades metalogicas de los sistemas axiomaticos