[Bearing surfaces in primary hip arthroplasty. Is there any difference?] / Pares articulares en prótesis primaria de cadera. ¿Existe alguna diferencia?

INTRODUCTION: In primary hip replacement, different materials are used for bearing surfaces. In our medium metal or ceramic heads with highly crossed-linked polyethylene (PA) are the most used. These combinations have good results, but it is not clear which is clinically superior. The objective of this study is to determine whether there is any clinically significant difference based on a systematic review of the literature and national registries of arthroplasty. MATERIAL AND METHODS: We conduct a systematic review of the literature and national registries of arthroplasty and we were looking for studies comparing bearing surfaces: ceramic-highly cross-linked polyethylene (CP) and metal-highly cross-linked polyethylene (MP); describing the revision rate according to the surface type with a minimum 10-year follow-up. The outcome evaluated was: review rate for any cause depending on surface type. RESULTS: Two out of fifteen national registries were included. The Australian registry shows a difference in the 15-year revision rate: CP: 6.3 (IC 5.8, 6.7) vs MP: 5.1 (IC 4.6, 5.7). The New Zealand registry shows no differences in revision rate/100 components/year: CP 0.54 (0.48-0.61) vs MP 0.61 (0.57-0.66). We do not find clinical studies with inclusion criteria that answer the research question. CONCLUSION: The results of this review show a high survival rate with the use of highly cross-linked polyethylene, the results are similar when using ceramic or metal heads.

INTRODUCCIÓN: En un reemplazo total de cadera primario (RTC), diferentes materiales son los que se usan para las superficies de apoyo. En nuestro medio, las cabezas de metal o cerámica con polietileno altamente entrecruzado (PA) son los más utilizados. Estas combinaciones tienen buenos resultados, pero no es claro cuál es superior clínicamente. Basados en una revisión sistemática de la literatura y de los registros nacionales de artroplastía, el objetivo de este estudio es determinar si existe alguna diferencia significativa desde el punto de vista clínico. MATERIAL Y MÉTODOS: Realizamos una revisión sistemática de la literatura y de los registros nacionales de artroplastía. Buscamos estudios en los que se compararan los tipos de superficie de contacto: cerámica-polietileno altamente entrecruzado (CP) y metal-polietileno altamente entrecruzado (MP), además de los registros nacionales de artroplastía que describieran, con un seguimiento mínimo de 10 años, la tasa de revisión según el tipo de superficie. El desenlace evaluado fue: tasa de revisión por cualquier causa según el tipo de superficie. RESULTADOS: Dos de quince registros nacionales fueron incluidos: el registro australiano muestra una diferencia en la tasa de revisión a 15 años, comparando CP: 6.3 (IC 5.8, 6.7) contra MP: 5.1 (IC 4.6, 5.7). El registro de Nueva Zelanda no muestra diferencias en la tasa de revisión/100 componentes/año: CP de 0.54 (0.48-0.61) en comparación con MP de 0.61 (0.57-0.66). No encontramos estudios clínicos con los criterios de inclusión que respondan la pregunta de investigación. CONCLUSIÓN: Los resultados de esta revisión muestran una alta supervivencia cuando se usa polietileno altamente entrecruzado; asimismo, los resultados son similares cuando se utilizan cabezas de cerámica o metálicas.

Pares articulares en prótesis primaria de cadera. ¿Existe alguna diferencia? / Bearing surfaces in primary hip arthroplasty. Is there any difference?

Resumen: Introducción: En un reemplazo total de cadera primario (RTC), diferentes materiales son los que se usan para las superficies de apoyo. En nuestro medio, las cabezas de metal o cerámica con polietileno altamente entrecruzado (PA) son los más utilizados. Estas combinaciones tienen buenos resultados, pero no es claro cuál es superior clínicamente. Basados en una revisión sistemática de la literatura y de los registros nacionales de artroplastía, el objetivo de este estudio es determinar si existe alguna diferencia significativa desde el punto de vista clínico. Material y métodos: Realizamos una revisión sistemática de la literatura y de los registros nacionales de artroplastía. Buscamos estudios en los que se compararan los tipos de superficie de contacto: cerámica-polietileno altamente entrecruzado (CP) y metal-polietileno altamente entrecruzado (MP), además de los registros nacionales de artroplastía que describieran, con un seguimiento mínimo de 10 años, la tasa de revisión según el tipo de superficie. El desenlace evaluado fue: tasa de revisión por cualquier causa según el tipo de superficie. Resultados: Dos de quince registros nacionales fueron incluidos: el registro australiano muestra una diferencia en la tasa de revisión a 15 años, comparando CP: 6.3 (IC 5.8, 6.7) contra MP: 5.1 (IC 4.6, 5.7). El registro de Nueva Zelanda no muestra diferencias en la tasa de revisión/100 componentes/año: CP de 0.54 (0.48-0.61) en comparación con MP de 0.61 (0.57-0.66). No encontramos estudios clínicos con los criterios de inclusión que respondan la pregunta de investigación. Conclusión: Los resultados de esta revisión muestran una alta supervivencia cuando se usa polietileno altamente entrecruzado; asimismo, los resultados son similares cuando se utilizan cabezas de cerámica o metálicas.

Abstract: Introduction: In primary hip replacement, different materials are used for bearing surfaces. In our medium metal or ceramic heads with highly crossed-linked polyethylene (PA) are the most used. These combinations have good results, but it is not clear which is clinically superior. The objective of this study is to determine whether there is any clinically significant difference based on a systematic review of the literature and national registries of arthroplasty. Material and methods: We conduct a systematic review of the literature and national registries of arthroplasty and we were looking for studies comparing bearing surfaces: ceramic-highly cross-linked polyethylene (CP) and metal-highly cross-linked polyethylene (MP); describing the revision rate according to the surface type with a minimum 10-year follow-up. The outcome evaluated was: review rate for any cause depending on surface type. Results: Two out of fifteen national registries were included. The Australian registry shows a difference in the 15-year revision rate: CP: 6.3 (IC 5.8, 6.7) vs MP: 5.1 (IC 4.6, 5.7). The New Zealand registry shows no differences in revision rate/100 components/year: CP 0.54 (0.48-0.61) vs MP 0.61 (0.57-0.66). We do not find clinical studies with inclusion criteria that answer the research question. Conclusion: The results of this review show a high survival rate with the use of highly cross-linked polyethylene, the results are similar when using ceramic or metal heads.

¿Cómo seleccionar una prótesis para un reemplazo primario de cadera? Mínima supervivencia aceptable: resultados de un consenso de expertos / How to select a prosthesis for a primary hip replacement? Minimum acceptable survival: results of a consensus of experts

Resumen: Introducción: Uno de los puntos más críticos en la planeación de las artroplastías de cadera es la selección del implante, puesto que su supervivencia impacta significativamente la salud de los pacientes. Sin embargo, hasta el momento no se ha definido cuál es la supervivencia ideal que debe demostrar un implante para ser seleccionado. El objetivo de este consenso es definir los estándares mínimos de desempeño para la selección de prótesis en reemplazo primario convencional de cadera. Material y métodos: El consenso se realizó mediante la metodología de «grupo nominal¼. Esto incluyó: 1. Revisión de la evidencia disponible y definición de los temas a evaluar, 2. Reunión para la votación y discusión y 3. Análisis estadístico cuantitativo con medianas (M) y rangos intercuartílicos (RIC) y cualitativo con proporciones de los resultados obtenidos para generar recomendaciones. Resultados: La fuente primaria de información para la selección de prótesis (M: 8; RIC: 7-9) y de elección en caso de evidencia contradictoria (M: 8; RIC: 7-9) o limitada en la literatura (M: 7; RIC: 4.75-825) son los registros nacionales. El mínimo seguimiento aceptable es 10 años (M: 9; RIC: 8-9) y el mínimo de supervivencia aceptable es 90% a 10 años (M: 8; RIC: 5-8.5). Discusión: De acuerdo con estos resultados, el consenso de expertos propone que la selección del implante en el reemplazo articular primario convencional de cadera se realice con base en la información publicada en los registros nacionales y que dicha prótesis tenga un seguimiento mínimo de 10 años y demuestre una supervivencia mínima de 90%.

Abstract: Background: One of the most critical points in the planning of hip replacement surgeries is the selection of the implant, since its survival significantly impacts the patients' health. However, the ideal survival time that an implant must prove to be selected has not been defined. The objective of this consensus is to define minimum performance standards for the selection of conventional primary hip replacement prosthesis. Material and methods: The consensus was carried out using the methodology of 'nominal group'. This included: 1. A review of the available evidence and the issues to be evaluated, 2. Meeting for the vote and discussion, 3. Quantitative statistical analysis with median (M) and interquartile range (IQR) and qualitative one with proportions of the results to generate recommendations. Results: The primary source of information for prosthesis selection (M: 8; IQR: 7-9), choice in the event of conflicting evidence (M: 8; IQR: 7-9), or limited evidence in the literature (M: 7; IQR: 4.75-825) should be national registries. The minimum acceptable follow-up is 10 years (M: 9; IQR: 8-9) and the minimum acceptable survival is 90% at 10 years (M: 8; IQR: 5-8.5). Discussion: According to these results, the consensus of experts proposed that the selection of the implant for conventional primary hip replacement must be based on the information published in the national registries and that the prosthesis must have a minimum follow-up of 10 years and show a minimum survival of 90%.

[How to select a prosthesis for a primary hip replacement? Minimum acceptable survival: results of a consensus of experts]. / ¿Cómo seleccionar una prótesis para un reemplazo primario de cadera? Mínima supervivencia aceptable: resultados de un consenso de expertos.

BACKGROUND: One of the most critical points in the planning of hip replacement surgeries is the selection of the implant, since its survival significantly impacts the patients health. However, the ideal survival time that an implant must prove to be selected has not been defined. The objective of this consensus is to define minimum performance standards for the selection of conventional primary hip replacement prosthesis. MATERIAL AND METHODS: The consensus was carried out using the methodology of nominal group. This included: 1. A review of the available evidence and the issues to be evaluated, 2. Meeting for the vote and discussion, 3. Quantitative statistical analysis with median (M) and interquartile range (IQR) and qualitative one with proportions of the results to generate recommendations. RESULTS: The primary source of information for prosthesis selection (M: 8; IQR: 7-9), choice in the event of conflicting evidence (M: 8; IQR: 7-9), or limited evidence in the literature (M: 7; IQR: 4.75-825) should be national registries. The minimum acceptable follow-up is 10 years (M: 9; IQR: 8-9) and the minimum acceptable survival is 90% at 10 years (M: 8; IQR: 5-8.5). DISCUSSION: According to these results, the consensus of experts proposed that the selection of the implant for conventional primary hip replacement must be based on the information published in the national registries and that the prosthesis must have a minimum follow-up of 10 years and show a minimum survival of 90%.

INTRODUCCIÓN: Uno de los puntos más críticos en la planeación de las artroplastías de cadera es la selección del implante, puesto que su supervivencia impacta significativamente la salud de los pacientes. Sin embargo, hasta el momento no se ha definido cuál es la supervivencia ideal que debe demostrar un implante para ser seleccionado. El objetivo de este consenso es definir los estándares mínimos de desempeño para la selección de prótesis en reemplazo primario convencional de cadera. MATERIAL Y MÉTODOS: El consenso se realizó mediante la metodología de «grupo nominal¼. Esto incluyó: 1. Revisión de la evidencia disponible y definición de los temas a evaluar, 2. Reunión para la votación y discusión y 3. Análisis estadístico cuantitativo con medianas (M) y rangos intercuartílicos (RIC) y cualitativo con proporciones de los resultados obtenidos para generar recomendaciones. RESULTADOS: La fuente primaria de información para la selección de prótesis (M: 8; RIC: 7-9) y de elección en caso de evidencia contradictoria (M: 8; RIC: 7-9) o limitada en la literatura (M: 7; RIC: 4.75-825) son los registros nacionales. El mínimo seguimiento aceptable es 10 años (M: 9; RIC: 8-9) y el mínimo de supervivencia aceptable es 90% a 10 años (M: 8; RIC: 5-8.5). DISCUSIÓN: De acuerdo con estos resultados, el consenso de expertos propone que la selección del implante en el reemplazo articular primario convencional de cadera se realice con base en la información publicada en los registros nacionales y que dicha prótesis tenga un seguimiento mínimo de 10 años y demuestre una supervivencia mínima de 90%.

Genetic variability in Blanco Orejinegro breed cattle populations in Colombia.

We analyzed population structure and genetic diversity in Blanco Orejinegro Creole cattle with 12 microsatellite markers, genotyping 138 individuals belonging to 7 commercial and 3 conservation herds. These markers showed a high level of polymorphism; 171 alleles were identified. The mean number of alleles per locus was 5.63 (3.82-6.58). The total number of alleles per marker was 14.2 and ranged from 16 (TGLA126) to 22 (TGLA227). The mean expected heterozygosity (0.73) was higher than the observed heterozygosity (0.65), with a significant excess of heterozygosity in almost all populations (FIS = 0.09; P < 0.05). This may be due to crossing between different lines of this breed, affecting the inbreeding levels. Analysis of relationships among populations, assessed by principal component analysis and Nei's genetic distances, indicated a close relationship between some herds. Furthermore, analysis of population structure demonstrated a low probability of admixture with Zebu breeds, as it shows the cluster assignment and the FST values obtained. We conclude that there is high allelic diversity in this breed, even though a low effective population size has been maintained and the level of inbreeding has not been monitored. Therefore, appropriate conservation efforts should be undertaken, such as adopting strategies aimed at minimizing inbreeding, to avoid losing genetic variability.

The benefits of exercise for patients with haemophilia and recommendations for safe and effective physical activity.

Most health care professionals involved in the management of people with haemophilia (PWH) believe that exercise is beneficial and its practice is widely encouraged. This article aims to demonstrate that appropriate exercise (adapted to the special needs of the individual PWH) may be beneficial for all PWH through improved physical, psychosocial and medical status. Based on evidence gathered from the literature, many PWH, particularly those using long-term prophylaxis or exhibiting a mild/moderate bleeding phenotype, are as active as their healthy peers. PWH experience the same benefits of exercise as the general population, being physically healthier than if sedentary and enjoying a higher quality of life (QoL) through social inclusion and higher self-esteem. PWH can also gain physically from increased muscle strength, joint health, balance and flexibility achieved through physiotherapy, physical activity, exercise and sport. Conversely, very little data exist on activity levels of PWH in countries with limited resources. However, regarding specific exercise recommendations in PWH, there is a lack of randomized clinical trials, and consequently formal, evidence-based guidelines have not been produced. Based on published evidence from this review of the literature, together with the clinical experience of the authors, a series of recommendations for the safe participation of PWH in regular physical activities, exercises and sport are now proposed. In summary, we believe that appropriately modified programmes can potentially allow all PWH to experience the physical and psychosocial benefits of being physically active which may ultimately lead to an improved QoL.

Guidelines for the management of hemophilia.

Hemophilia is a rare disorder that is complex to diagnose and to manage. These evidence-based guidelines offer practical recommendations on the diagnosis and general management of hemophilia, as well as the management of complications including musculoskeletal issues, inhibitors, and transfusion-transmitted infections. By compiling these guidelines, the World Federation of Hemophilia aims to assist healthcare providers seeking to initiate and/or maintain hemophilia care programs, encourage practice harmonization around the world and, where recommendations lack adequate evidence, stimulate appropriate studies.

The target joint.

Bleeding into the joints is the most common manifestation of severe haemophiliacs. Although it may resolve spontaneously or with treatment, some patients find that one particular joint has recurrent bleeding; this is termed a target joint. Recurrent bleeding prevents the joint from regaining its range of motion, muscle strength and normal appearance. These changes become permanent, leading eventually to osteoarthritis. A target joint requires urgent and comprehensive treatment, especially in young patients, if permanent damage is to be prevented. Treatment with factor concentrate prophylaxis and physiotherapy can help to prevent new bleeds and allow the synovitis to resolve, but for persistent synovitis, synovectomy is recommended. The target ankle joint is a special challenge as it often develops in very young children when the articular cartilage is susceptible and compliance with conservative treatment is difficult.

Characteristics of degeneration in an unstable knee with a coronal surface step-off.

To investigate the effect of instability on the remodelling of a minor articular surface offset, we created a 0.5 mm coronal step-off of the medial femoral condyle in 12 New Zealand white rabbits and transected the anterior cruciate ligament (ACL). A control group of 12 rabbits had only ACL resection and the opposite knee was used as the non-operated control. The osteoarthritic changes at 6, 12 and 24 weeks after surgery were evaluated histologically. In addition, changes in the immunological detection of 3-B-3(-) and 7-D-4 chondroitin-6-sulphate epitopes were determined because of the previous association of such changes with repair of cartilage and early osteoarthritis. In the instability/step-off group there was rapidly progressing focal degeneration of cartilage on the high side of the defect, not seen in previous step-off studies in stable knees. The rest of the femoral condyles and the tibial plateaux of the instability/step-off group had moderate osteoarthritis similar to that of the instability group. 3-B-3(-) was detectable in the early and the intermediate stages of osteoarthritis but no staining was seen in the severely damaged cartilage zones. Immunoreactivity with 7-D-4 increased as degeneration progressed.

Maternal histone deacetylase is accumulated in the nuclei of Xenopus oocytes as protein complexes with potential enzyme activity.

Reversible acetylation of core histones plays an important regulatory role in transcription and replication of chromatin. The acetylation status of chromatin is determined by the equilibrium between activities of histone acetyltransferases (HATs) and histone deacetylases (HDACs). The Xenopus protein HDACm shows sequence homology to other putative histone deacetylases, but its mRNA is expressed only during early development. Both HDACm protein and acetylated non-chromosomal histones are accumulated in developing oocytes, indicating that the key components for histone deposition into new chromatin during blastula formation are in place by the end of oogenesis. Here we show that the 57 kDa HDACm protein undergoes steady accumulation in the nucleus, where it is organized in a multiprotein complex of approx. 300 kDa. A second, major component of the nuclear complex is the retinoblastoma-associated protein p48 (RbAp48/46), which may be used as an adaptor to contact acetylated histones in newly assembled chromatin. The nuclear complex has HDAC activity that is sensitive to trichostatin A, zinc ions and phosphatase treatment. The 57 kDa protein serves as a marker for total HDAC activity throughout oogenesis and early embryogenesis. The active HDACm complex and its acetylated histone substrates appear to be kept apart until after chromatin assembly has taken place. However, recombinant HDACm, injected into the cytoplasm of oocytes, not only is translocated to the nucleus, but also is free to interact with the endogenous chromatin.

Effects of trkB and trkC neurotrophin receptor agonists on thermal nociception: a behavioral and electrophysiological study.

Nerve-growth factor (NGF), a member of the neurotrophin family, plays an important role in nociceptor function. Prompted by a previous uinexpected finding that NT-4/5, as well as NGF sensitizes single nociceptors to noxious heat, we have explored the relative potency of all neurotrophins in eliciting thermal hyperalgesia. NGF, brain-derived neurotrophic factor (BDNF), NT-4/5 and NT-3 were injected locally into the hind paw of rats, and the behavioral response to noxious heat was compared with that from the other paw that received an identical injection of vehicle. Like NGF, agonists of tyrosine kinaseB (trkB) receptors (NT-4/5 and BDN F) induced thermal hyperalgesia in the first 5 h after treatment (NT-4/5 > BDNF) but the effect had worn off by 24 h. In contrast, the trkC agonist NT-3 had no effect on the response to noxious heat. Electrophysiological recordings from single C-fibres in the in vitro skin-saphenous nerve preparation revealed sensitization to noxious heat stimuli after direct application of BDNF to the receptive field, as previously noted for NT-4/5, and in parallel with the behavioral findings. NT-3 was ineffective as in the behavioral studies. These results suggest that trkB agonists BDNF and NT-4/5 as well as the trkA agonist NGF can regulate nociceptive responses to noxious heat.

Mechanism of failure in hips with an uncemented, all polyethylene socket.

The outcome of 32 patients with 33 primary total hip replacements performed using noncemented uncoated polyethylene acetabular cups (RM cup) with cemented titanium alloy monoblock stems (STH-2 stem) was reviewed. At a mean followup of 6.3 years (range, 6 months-10 years), the failure rate was 57%, more than 14 times higher than the rate typically seen with cemented polyethylene acetabular cups used with the STH stem. Failure was characterized by rapidly progressive acetabular or femoral osteolytic lesions that resulted in extensive bone loss, often in patients who had no symptoms. In addition to the debris that typically is generated by a metal on plastic bearing couple, an abundance of polyethylene particles of submicron size were produced at the cup-bone interface. Tissues retrieved from areas of osteolysis revealed the presence of intracellular submicron polyethylene particles in macrophages. It is recommended that patients with no symptoms who have RM noncemented, uncoated acetabular cups be followed up yearly and undergo early revision surgery when faced with osteolysis to prevent extensive bone loss.

Cartilage changes caused by a coronal surface stepoff in a rabbit model.

Coronal stepoffs of 0.5 mm (equal to the cartilage height) were created on the medial femoral condyles of adult, skeletally mature rabbits as a model for articular surface incongruity. After 3, 6, 12, and 24 weeks, tissue was analyzed histologically using hematoxylin and eosin and Safranin O staining, autoradiographs were made of the femoral condyles, and immunohistologic analysis was done for 3-B-3(-) and 7-D-4 chondroitin sulfate epitopes. An overlapping flap from the high toward the low side and an increase of the cartilage height on the low side of the defect were observed as permanent features of adaptation throughout the entire followup. Significant degeneration was not seen around the lesion or in the tibial cartilage opposing a stepoff defect. Autoradiography showed a three-phase response to the lesion: an early increase in radiolabeled sulfate (35SO4) uptake, a sharp decline of 35SO4 uptake, and finally a late recovery of the autoradiographic signal indicating partial recovery of proteoglycan synthetic activity. After an early increase, immunohistologic analysis for 3-B-3(-) showed a subsiding tendency by 24 weeks, and the staining with 7-D-4 remained elevated uniformly in the vicinity of the lesion. A rabbit femoral stepoff defect with an offset of 0.5 mm may remodel and not lead to degeneration within the first 6 months after injury in a stable joint.

Effect of loading and fracture motions on diaphyseal tibial fractures.

A computerized motion sensor was used to record the three-dimensional components of interfragmentary motion during healing in three patients with closed, low-energy fractures of the tibial diaphysis treated with functional braces. At the first measurement session 2 weeks after fracture, the patients applied approximately 15 kg to the injured limb. Although this produced 1-4 mm of translation of the fragments, this was recovered when the load was removed. The maximum rotational and angulatory displacements often occurred as the patients rose from the chair with no weight applied to the limb and frequently were reduced as the 15 kg of load was applied. Under load, the maximum axial rotation was 3 degrees and the maximum angular displacement was 1 degree. As with the translations, the initial rotational and angulatory positions of the fragments were recovered when the load was removed and the patient returned to the seated position. At 8 weeks, the patient applied full body weight, producing a maximum interfragmentary translation of 0.5 mm and maximum axial rotation or angulation of 0.5 degrees. Abundant peripheral callus formed in all three fractures, and they healed by 15 weeks through typical gradual consolidation and mineralization of the callus, accompanied by a corresponding reduction in interfragmentary motions.