421 research outputs found
Vástagos cementados y no cementados en artroplastias totales de cadera por coxopatías mecánicas
En la controversia sobre la cementación o no del componente femoral se
presenta el análisis clínico, radiológico y de supervivencia de los vástagos de una serie
de 121 artoplastias totales de cadera (61 cementadas y 60 sin cementar). El estudio no evidencia
diferencias significativas a los 5 años de seguimiento, aunque es destacable una
mayor incidencia de dolor en el muslo entre los vástagos no cementados (35%) (p < 0,1) y
una tasa de reabsorción ósea proximal más elevada (70%) que en los cementados (23%).
Estos fenómenos son diseño dependientes. Un mayor número de cirugías de revisión por
aflojamiento aséptico entre las prótesis cementadas nos hacen preferir la fijación sin cemento
del componente femoral.We discuss the cemented or non-cement fixation of the femoral components in total hip arthroplasty on a serie of 121 femoral stem (61 cemented stem and 60 non-cemented stem). Survival analysis, clinical and radiographic data showed no significant differences between the two groups at 5 years follow-up. However the incidence of pain thigh phenomenon was higher for the non-cemented stem (35%) (p < 0.1). Stress schielding was evidently higher between the non-cemented implants (70%) too, as compared with cemented stem (23%). These findings are design-dependent. The cemented arthroplasties had a higher rate of revision procedures because of aseptic loosening (13%). In this way we prefer the non-cement fixation of the femoral implant
Pseudoartrosis de escafoides carpiano tratadas mediante la técnica de Matti-Russe: estudio retrospectivo de 36 casos
Presentamos un estudio retrospectivo de una serie de 36 pacientes con pseudoartrosis
de escafoides operados mediante la técnica de Matti-Russe entre 1985 y 1991. Utilizamos
injerto córtico esponjoso obtenido del radio (50%), cresta ilíaca (42%) y cúbito (8%) sin diferencias
en la incorporación. La tasa de curación fue mayor en las pseudoartrosis medias y distales
(80%) que en las de localización proximal (54%). El 80% de los fracasos de curación en la localización
media y distal eran pseudoartrosis de más de 30 meses de evolución. Los cambios degenerativos
en el carpo de las pseudoartrosis no curadas fueron significativamente mayores
(p< 0,001) que en las que se obtuvo la consolidación. La localización y la antiguedad de la pseudoartrosis
parecen ser dos importantes factores pronósticos. La técnica de Matti-Russe presenta limitaciones
en la pseudoartrosis de localización proximal y en los carpos muy degenerados.We reported a retrospective study of 36 patients with a pseudoarthrosis of the
carpal scaphoid bone treated by the Matti-Russe operation from 1985 to 1991. We used radial
(50%), iliac (42%) or ulnar (8%) autogenous grafts without any difference in the rate of incorporation.
The rate of healing of the pseudoarthrosis was higher in mid and distal location
(80%) than in proximal location (54%). In 80% of cases, healing failures in the mid and distal
location occurred in old pseudoarthrosis ( >3 0 months evolution). Carpal degenerative changes
were significantly higher (p < 0,01) in patients with not healed pseudoarthrosis. The location
and the age of the pseudoarthrosis appear to be important prognostic factors. The Matti-Russe
technique has limitations when is performed either in proximal pseudoarthrosis or in the presence
of advanced radiocarpal osteoarthritis
Fracturas de húmero complicadas con lesión arterial
Presentamos una serie de 10 pacientes afectos de una fractura de húmero asociada
a una lesión arterial, tratados entre Enero de 1990 y Octubre de 1993. Dentro de la serie
distinguimos tres grupos, de acuerdo con la localización de la fractura (tercio proximal,
diáfisis, región supracondílea). El análisis de los resultados sugiere que el peor pronóstico corresponde
a las lesiones proximales y diafisarias por su etiología, daños asociados y menor posibilidad
de circulación colateral de suplencia. El manejo de estas lesiones complejas exige un
tratamiento quirúrgico interdisciplinario. Señalamos la utilidad de la fijación externa como método
de osteosíntesis y el uso de un «shunt» provisional para perfundir el miembro durante la
cirugía ósea. Se discute la indicación de arteriografía en los traumatismos agudos del miembro
superior.A serie of 10 patients with a fracture of the humerus and associated arterial injury
treated from January 1990 to October 1993 is reported. The serie was divided in 3
groups acording the proximal, mid shaft or supracondylar location of the fracture. Clinical results
indicate a poor prognosis of proximal and mid shaft fractures related to their etiology, associated
injuries and damage of the colateral vessels. The management of these complex
injuries require an interdisciplinar approach. External fixation is an usefull stabilitation method
for fractures associated with vascular damage. The utility of a temporary intraluminar vascular
shunt to perfuse the limb at the bone surgery and preoperative arteriography are discussed
Phage-resistant bacteria : curse or blessing?
New therapies such as bacteriophage therapy are needed to fight life-threatening infections as antibiotic therapy is progressively more limited due to resistance emergence. Phages and bacteria have co-evolved for ages so even though we know bacteria naturally develop resistance against phage infection, so do phages through counteradaptation mechanisms
Marginal bone loss around implants placed in maxillary native bone or grafted sinuses: a retrospective cohort study
Objectives To assess differences in marginal bone loss around implants placed in maxillary pristine bone and implants placed following maxillary sinus augmentation over a period of 3 years after functional loading. Material and methods Two cohorts of subjects (Group 1: Subjects who received sinus augmentation with simultaneous implant placement; Group 2: Subjects who underwent conventional implant placement in posterior maxillary pristine bone) were included in this retrospective study. Radiographic marginal bone loss was measured around one implant per patient on digitized panoramic radiographs that were obtained at the time of prosthesis delivery (baseline) and 12, 24, and 36 months later. The influence of age, gender, smoking habits, history of periodontal disease, and type of prosthetic connection (internal or external) on marginal bone loss was analyzed in function of the type of osseous support (previously grafted or pristine). Results A total of 105 subjects were included in this study. Cumulative radiographic marginal bone loss ranged from 0 mm to 3.9 mm after 36 months of functional loading. There were statistically significant differences in marginal bone loss between implants placed in grafted and pristine bone at the 12‐month assessment, but not in the subsequent progression rate. External prosthetic connection, smoking, and history of periodontitis negatively influenced peri‐implant bone maintenance, regardless of the type of osseous substrate. Conclusions Implants placed in sites that received maxillary sinus augmentation exhibited more marginal bone loss than implants placed in pristine bone, although marginal bone loss mainly occurred during the first 12 months after functional loading. Implants with external implant connection were strongly associated with increased marginal bone loss overtime.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102685/1/clr12122.pd
Performance of the \u3ci\u3eLeucaena leucocephala\u3c/i\u3e–\u3ci\u3eMegathyrsus maximus\u3c/i\u3e cv Mombasa System and Local Range Grazed by Pelibuey Ewe-Lambs
Mombasa grass and leucaena have shown an excellent agronomic performance grown in tropical semi-arid ranges, the objective of this study was to compare the agronomic performance of Leucaena-Mombasa grown as a silvopastoral system at two leucaena plant densities (10000 and 15000 plants ha-1) and of Pelibuey ewe-lambs grazing it against native unimproved tropical semi-arid range of the state of Morelos, México. Experimental design was a completely random with two replications. Unimproved native range was mainly deciduous shrubs and mixed herbaceous plants (Poaceae and Asteraceae). Stocking rate was the same across treatments and grazing lasted all rainy season. Of the agronomic variables determined, both Leucaena-Mombasa systems showed the same (p\u3e 0.05) forage on-offer total and expressed as herbage-allowance but 29 and 15% higher (p≤ 0.05) respectively than the unimproved native range. Leucaena-Mombasa at the highest leucaena density showed the highest harvest rate, 22 and 50% higher (p≤ 0.05) than the registered at the lower density and unimproved native range, respectively. Unimproved native range herbaceous layer showed 40% higher (p≤ 0.05) crude protein content than the layer at both Leucaena-Mombasa systems; tree fodder was only different (p\u3c 0.05) in in vitro dry matter digestibility, tree fodder from both Leucaena-Mombasa systems was 32% higher (p≤ 0.05) than that of unimproved native range. Ewe-lambs grazing any of the Leucaena-Mombasa systems showed a daily weight gain 1.5 times higher (p\u3c 0.05) than those grazing the unimproved native range. It was concluded that Leucaena-Mombasa system is an option to improve agronomic and animal performances compare to unimproved tropical native range
Ewe Daily-Weight Gain Grazing \u3ci\u3eLeucaena leucocephala-Megathyrsus maximus\u3c/i\u3e CV Mombasa Silvopastoral System and Tropical Native Unimproved Range
Silvopastoral systems are a viable option to increase livestock productivity, The silvopastoral arrangement of Leucaena leucocephala associated with Megathyrsus maximus CV Mombasa (LMS) is successfully cultivated in tropical environments.. The objective of the study was to determine ewe daily-weight gain grazing LMS and a tropical unimproved native range. Two LMS were tested: high and low leucaena densities, 4700 and 2383 plants/ha, respectively. Grazing was rotational, lasted 150 d (rainy season) at equivalent stocking rate of 59 ewes/ha/150 d. Experimental design was a completely random design with three replications, the experimental unit was a 192 m2 plot. Variables measured on plots were amount (dry matter basis), in vitro dry matter digestibility (IVDMD), and crude protein (CP) of forage on-offer, from mixed samples herbaceous and tree fodder. Weight and serum concentrations of Ca, P, K, Mg, Na, Zn, Cu, and Fe were measured in ewes, daily weight gain was calculated. On average forage on-offer and IVDMD concentration were 50 and 15% higher (p \u3c 0.05) in LMS than in native range, respectively, with no difference between LMS. CP concentration was 25% higher (p \u3c 0.05) in native range than both LMS, with no difference between them. LMS’s showed no difference (p \u3e 0.05) between them on ewe daily weight gain, on average 59.2 g, and were higher than native range where ewes showed a mean daily weight loss of 14.8 g. Serum concentrations of the 8 minerals measured were similar (p \u3e 0.05) across all ewes regardless the treatments. It was concluded that the Leucaena leucocephala-Megathyrsus maximus CV Mombasa silvopastoral system is an option to improve livestock productivity compared with unimproved native range due to higher forage on-offer
Ewe Daily-Weight Gain Grazing \u3ci\u3eLeucaena leucocephala-Megathyrsus maximus\u3c/i\u3e CV Mombasa Silvopastoral System and Tropical Native Unimproved Range
Silvopastoral systems are a viable option to increase livestock productivity, The silvopastoral arrangement of Leucaena leucocephala associated with Megathyrsus maximus CV Mombasa (LMS) is successfully cultivated in tropical environments.. The objective of the study was to determine ewe daily-weight gain grazing LMS and a tropical unimproved native range. Two LMS were tested: high and low leucaena densities, 4700 and 2383 plants/ha, respectively. Grazing was rotational, lasted 150 d (rainy season) at equivalent stocking rate of 59 ewes/ha/150 d. Experimental design was a completely random design with three replications, the experimental unit was a 192 m2 plot. Variables measured on plots were amount (dry matter basis), in vitro dry matter digestibility (IVDMD), and crude protein (CP) of forage on-offer, from mixed samples herbaceous and tree fodder. Weight and serum concentrations of Ca, P, K, Mg, Na, Zn, Cu, and Fe were measured in ewes, daily weight gain was calculated. On average forage on-offer and IVDMD concentration were 50 and 15% higher (p \u3c 0.05) in LMS than in native range, respectively, with no difference between LMS. CP concentration was 25% higher (p \u3c 0.05) in native range than both LMS, with no difference between them. LMS’s showed no difference (p \u3e 0.05) between them on ewe daily weight gain, on average 59.2 g, and were higher than native range where ewes showed a mean daily weight loss of 14.8 g. Serum concentrations of the 8 minerals measured were similar (p \u3e 0.05) across all ewes regardless the treatments. It was concluded that the Leucaena leucocephala-Megathyrsus maximus CV Mombasa silvopastoral system is an option to improve livestock productivity compared with unimproved native range due to higher forage on-offer
Fracturas estallido de columna toracolumbar: Evaluación clinicoradiológica y terapéutica de 90 casos
Presentamos un estudio retrospectivo de 90 fracturas toracolumbares tipo estallido con un seguimiento mínimo de 12 meses. Se realizó tratamiento ortopédico en 43 casos y en 47 se indicó una artrodesis instrumentada. Realizamos una evaluación clínico-radiológica en base al dolor residual y evolución del ángulo de cifosis con el objetivo de valorar el tratamiento ortopédico como opción terapéutica y la necesidad de distinguir fracturas estallido con afectación de 2 ó 3 columnas. No apreciamos diferencias estables significativas en el dolor y la lesión de las tres columnas. El aumento de cifosis angular media en las fracturas estallido estable no operadas es de 4.7º y de 5.2º en las fracturas estallido inestables tratadas ortopédicamente. Observamos una alta incidencia de complicaciones relacionadas con la fijación (21%) cuando la fractura asentaba en la charnela y se instrumentaba a un solo nivel. El tratamiento ortopédico es una opción aceptable en las fracturas estallido en pacientes neurológicamente indemnes.Ninety burst fractures of the thoracolumbar spine were retrospectively assessed with a minum follow-up of 12 months. Conservative treatment was indicated in 43 cases, and reduction and surgical stabilization in 47. The aim was to compare the two treatment modalities according to fracture stability. Clinical and radiological evaluation included chronic pain and kyphotic angle progression. No statistical differences were found between stable and unstable fractures as to chronic pain. The kyphotic angle average progression for stable burst fractures was 4.7º and 5.2º for unstable fractures conservatively treated. There was a high rate of complications related to instrumentation (21%) particularly when the fracture was at the thoracolumbar junction and a single level was fixed. The orthopaedic treatment is an acceptable alternative treatment for stable burst fractures without neurological injury
Sarcomas primarios de hueso: estudio por citometría estática mediante análisis digital de imagen
Se presenta un estudio morfométrico y densitométrico mediante análisis digital
de imagen de una serie de 50 tumores óseos malignos (32 osteosarcomas, 12 condrosarcomas
y 6 histiocitomas fibrosos malignos de hueso), con el fin de evaluar la utilidad
de la técnica para establecer el grado y el pronóstico de estas neoplasias. Las variables
morfométricas y la disposición de la cromatina guardan una estrecha relación con el grado
histológico (Spearman; p < 0,05) y muestran diferencias estadísticamente significativas
entre los tumores considerados de alto y bajo grado en base a su presentación y evolución
clínica. La ploidía estimada por densitometría óptica se comporta como un factor pronóstico
independiente en el análisis multivariante de la serie de tumores de alto grado (COX;
p < 0,001). La citometría estática, aunque más lenta e imprecisa que la citometría de flujo
en la determinación de los picos de ploidía, permite analizar el modelo de cromatina y
contribuye objetivamente al establecimiento del grado biológico de los tumores óseos.A densitometry and morphometric assessment by static image cytometry of
50 malignant bone tumors (32 osteosarcomas, 12 chondrosarcomas, and 6 malignant fibrous
histiocytomas of bone) was performed in order to assess the validity of the technic
in the pathobiological and prognostic evaluation of these neoplasms. A strong correlation
between the morphometric features, cromatine distribution and histologic grade was
found (Spearman; p < 0.05). These parameters are also statistically different for hight and
low grade tumors in clinical staging. The stimation of DNA ploidy by optic densitometry
is a significant prognostic factor in the multivariant analysis for the high grade tumors
(COX; p < 0.001). Although Flow cytometry is a better procedure to evaluate DNA ploidy
peaks, our study reveals static image cytometry as a useful technic for determine the
cromatine model and objective assessment of the biological grade of bone neoplasms
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