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Resumen: Se hace una revisión narrativa del desarrollo y evolución hasta el momento de las copas de doble movilidad enfocada en sus aciertos, fallas y enseñanzas. Se mencionan las herramientas con las cuales contamos para prevenir y en su caso, tratar la luxación protésica de cadera y los principales problemas que presentan. El principal objetivo de esta publicación es hacer reflexiones y comentarios en cuanto a lo que debemos estar atentos ante un mundo de diseños que actualmente existen en el mercado con una diversidad de diseños, materiales, aleaciones, tipos de polietileno, etc. Se analizan los problemas que enfrentan algunos modelos para obtener una fijación estable a largo plazo, el problema que posiblemente representan los diferentes modelos contemporáneos de doble movilidad y sus resultados clínicos. Se discuten y comentan los puntos anteriores y se establecen conclusiones y recomendaciones.
Abstract: A narrative review of the development and evolution to date of the double mobility cups is made, focusing on their successes, failures and teachings. The tools with which we have to prevent and treat prosthetic hip dislocation and the main problems are mentioned. The main objective of this publication is to make reflections and comments about what we should be attentive to in a world of designs that currently exist in the market with a diversity of designs, materials, alloys, types of polyethylene, etc. Some models are found to obtain a stable long-term fixation, the problem that potentially represents the different contemporary models of double mobility and their clinical results. The previous points are discussed and commented and conclusions and recommendations were reached.
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Introducción: La restauración de las fuerzas biomecánicas a través del ajuste del offset y la longitud de miembros se ha convertido en un objetivo importante cuando el cirujano busca un buen resultado funcional postoperatorio. Sin embargo, las ventajas clínicas de la restauración del offset femoral y las complicaciones del fallo en la restauración no han sido claramente establecidas. Objetivo: Evaluar el efecto del offset o voladizo femoral en los resultados clínicos y funcionales de los pacientes. Adquisición de la evidencia: Se realizó una exploración en la base de datos Pubmed, con las palabras clave: artroplastia de cadera, prótesis de cadera, resultado clínico y resultado funcional.Se buscaron artículos publicados entre 2008 y 2018, basados en humanos y escritos en inglés, español o francés. Se seleccionaron seis artículos que incluían la presencia de una medición radiológica del offset femoral claramente explicada, escalas validadas y análisis comparativo. Resultados: La literatura consultada reflejó resultados heterogéneos. En el grupo de pacientes con offset disminuido, un artículo mostró menos función. En otro estudio se observó mejor puntuación en el grupo de enfermos con offset aumentado. A su vez, en una investigación se comprobó menos dolor en el grupo de offset disminuido. Conclusiones: Debido a la inconsistencia en los resultados y en las metodologías empleadas, no ha sido posible reconocer el beneficio clínico y funcional de la restauración del offset. Algunos autores incluidos en esta revisión, después de no encontrar diferencias estadísticamente significativas, afirmaron que la restauración o el aumento del offset femoral aportó buenos resultados, sin efectos negativos(AU)
Introduction: The restoration of biomechanical forces through offset adjustment and limb length has become an important objective when the surgeon seeks a good postoperative functional result. However, the clinical advantages of femoral offset restoration and complications of restoration failure have not been clearly established. Objective: To evaluate the effect of offset or femoral cantilever on the clinical and functional results of the patients. Acquisition of evidence: An exploration was carried out in the Pubmed database, with the keywords: hip arthroplasty, hip prosthesis, clinical result and functional result. We searched for articles published from 2008 to 2018, based on humans and written in English, Spanish or French. Six articles were selected because they clearly explained the presence of a radiological measurement of the femoral offset, including validated scales and comparative analysis. Results: The literature consulted reflected heterogeneous results. In the group of patients with decreased offset, one article showed less function. In another study, a better score was observed in the group of patients with increased offset. In turn, one investigation reported less pain was found in the reduced offset group. Conclusions: Due to the inconsistency in the results and the methodologies used, it has not been possible to recognize the clinical and functional benefit of offset restoration. Some authors included in this review, after not finding statistically significant differences, stated that the restoration or increase of the femoral offset provided good results, without negative effects(AU)
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Humans , Male , Female , Evidence-Based Medicine/methods , Arthroplasty, Replacement, Hip/methods , Hip Prosthesis , Spain , Treatment OutcomeABSTRACT
Objective To investigate ISO 7206 standard used as a guidance for clinical selection of total hip prosthesis. Methods Kinematics and dynamics process of normal walking gait was simulated by establishing a numerical musculoskeletal model; the corresponding finite element model of total hip prosthesis was constructed, and gait loads were applied to calculate stress distribution on prosthesis, which were compared with that on ISO finite element model. ResultsPeaks of hip joint reaction forces were achieved at 20% gait and 54% gait during normal walking gait, which were used as gait loads for finite element simulation, and the results showed that the maximum Von Mises stress of prosthesis was reached at 20% gait. The maximum Von Mises stress of prosthesis in loosening model was higher than that in non-loosening model, and some differences existed in the distribution pattern. The maximum stresses of prosthesis both under ISO loads and gait loads by different body weights were analyzed and compared, and the maximum stress of prosthesis under ISO loads was equivalent to that under gait loads by body weight between 108 kg and 142 kg. ConclusionsThe prosthesis that passed ISO test can meet the strength requirement for normal gait loads of 100 kg body weight.
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Incidence of aseptic loosening of hip prostheses is increasing in recent years. Previous studies suggested the involvement of proteinases and cytokines in the accelerated bone lysis associated with loosening. To investigate the role of matrix metalloproteinases (MMPs) in the loosening, Gelatin/Type IV collagenases, namely, 72 KDa matrix metalloproteinase (MMP)-2 type and 92 KDa MMP-9 type were analyzed in 14 cases of the loosened endoprostheses of the hip. Zymographic and densitometric analyses revealed production of MMP-2 ancl elevated induction of MMP-9 in tissue extracts from both the interface hetween hone and implants and the capsular tissues when compared with those in synovium obtained from a patient with a t'ractured femoral neck. MMP-9 showed stronger activity than MMP-2. In the sample of a fractured femoral neck, MMP-2 was detected, but MMP-9 was not detected. In matched samples, the activity of MMP-2 and MMP-9 in the interface tissues showed stronger activity than those in the capsular tissues. There was no difference between cemented and uncemented femoral prostheses. The state of prostheses(loosening, osteolysis, and cup wear) did not influence on the activity of MMP-2 and MMP-9. Theses findings suggest a role for MMP-2 and MMP-9 type gelatinase/Type IV collagenases in the degradation of extracellular matrix of periprosthetic tissues, where they may cause weakening of the connective tissue hed and the loosening of total hip replacement endoprostheses. Consequently. we could confirm the role of MMP cascade in aseptic loosening of total hip prostheses. The further study ahout other types of MMP and the inhihitor of MMP will be needed.