A proposal for the study of cementless short-stem hip prostheses / Una propuesta para el estudio de prótesis de cadera de vástago corto

Abstract: Background: With the recent evolution of hip arthroplasty, new models of short stems have emerged. So far, we do not have a clear strategy to analyze their outcomes, since there is confusion around the definition of short stem and there is no consensus for their classification. Purposes: The purpose of this study was to review the current state of the art of cementless short stems considering the main design characteristics; it provides a definition of short stem and proposes a classification, grouping them into families by means of a nomenclature that describes them accurately. Material and methods: We conducted a search in the PubMed and Scopus databases and consulted various implant manufacturers, foundations devoted to research on joint arthroplasty, organizations of independent experts on medical device analysis, and national arthroplasty registries. The stems studied were classified according to a new nomenclature system. Conclusions: We identified 44 different models that share 84 design variables and may be grouped into three types and 16 generic families. The stems were manufactured by 20 different companies. Short stems are those occupying the neck, metaphysis and the proximal aspect of the limit between the metaphysis and diaphysis, regardless of the geometric type of endosteum present. A wide variety of models was identified, with multiple design variables. In order to classify them, it was necessary to design a whole new nomenclature capable of describing them in an unequivocal, unique and distinctive way.

Resumen: Antecedentes: Con la reciente evolución de la artroplastia de cadera han surgido nuevos modelos con componentes femorales cortos. Aún no se tiene una forma clara de analizar sus resultados pues existe confusión en las definiciones y no tenemos una clasificación universal. Objetivos: Revisar el estado del arte de los componentes femorales cortos no cementados, considerar sus características de diseño, tratar de establecer una clasificación y una nomenclatura que permita una mejor definición del implante. Material y métodos: Realizamos una búsqueda en PubMed y Scopus, consultamos a varios fabricantes, fundaciones dedicadas a la investigación en artroplastías, organizaciones dedicadas al análisis de los implantes y algunos registros nacionales de artroplastías. Los componentes femorales estudiados se agruparon en esta clasificación propuesta. Conclusiones: Identificamos 3 tipos y 16 familias genéricas de implantes, se logró establecer una clasificación que generó una nueva nomenclatura que permite la identificación específica de cada uno de los diseños.

A proposal for the study of cementless short-stem hip prostheses.

BACKGROUND: With the recent evolution of hip arthroplasty, new models of short stems have emerged. So far, we do not have a clear strategy to analyze their outcomes, since there is confusion around the definition of short stem and there is no consensus for their classification. PURPOSES: The purpose of this study was to review the current state of the art of cementless short stems considering the main design characteristics; it provides a definition of short stem and proposes a classification, grouping them into families by means of a nomenclature that describes them accurately. MATERIAL AND METHODS: We conducted a search in the PubMed and Scopus databases and consulted various implant manufacturers, foundations devoted to research on joint arthroplasty, organizations of independent experts on medical device analysis, and national arthroplasty registries. The stems studied were classified according to a new nomenclature system. CONCLUSIONS: We identified 44 different models that share 84 design variables and may be grouped into three types and 16 generic families. The stems were manufactured by 20 different companies. Short stems are those occupying the neck, metaphysis and the proximal aspect of the limit between the metaphysis and diaphysis, regardless of the geometric type of endosteum present. A wide variety of models was identified, with multiple design variables. In order to classify them, it was necessary to design a whole new nomenclature capable of describing them in an unequivocal, unique and distinctive way.

Con la reciente evolución de la artroplastia de cadera han surgido nuevos modelos con componentes femorales cortos. Aún no se tiene una forma clara de analizar sus resultados pues existe confusión en las definiciones y no tenemos una clasificación universal.

Resultados del cotilo con doble movilidad de última generación en España (135 PTC seguidas durante una media de 32 meses) / Results of the latest generation dual-mobility cup in spain (135 THAs followed-up for a mean of 32 months)

Introducción: En este estudio multicéntrico (Hospital de Cabueñes y Hospital Universitario Santa Lucía) se evalúan los resultados de una serie retrospectiva y continua de 135 PTC realizadas implantando un cotilo doble movilidad de nueva generación. Material y métodos: Se estudiaron 135 PTC intervenidas entre 2005 y 2008. El seguimiento medio fue de 32 meses. Las causas de la cirugía fueron 31.8% coxartrosis y 68.1% fracturas de cadera. La edad media era de 82.1 años. Todos los pacientes eran revisados periódicamente haciendo una valoración clínica y radiográfica. Resultados: El seguimiento pudo ser realizado durante más de 24 meses en 121 PTC (14 pacientes fallecidos). En la última revisión, mayo 2011: 119 cótilos no presentaban aflojamiento. Las complicaciones fueron: 2 luxaciones postquirúrgicas; 4 TVP; 3 infecciones PTH; 5 fracturas peri PTC; 2 aflojamientos cetilo y 1 hundimiento vástago. HHS preoperatorio medio: 45, 83 y postoperatorio medio: 80, 03. De los 135 cotilos revisados sólo dos presentaban modificaciones radiográficas sin signos clínicos. La supervivencia aislada del cótilo a los 12 meses fue 97.03% (87.3-99.2) con un intervalo de confianza del 95% y a los 5 años, un 96.7% (85.4-98.8). Discusión: En nuestro estudio el nuevo cótilo doble movilidad ha mostrado buenos resultados en las siguientes indicaciones: coxartrosis primaria y fracturas de cuello de fémur. Conclusión: Las complicaciones obtenidas en esta serie aparecen en el mismo porcentaje que en otras series de la literatura excepto para la luxación. En ésta, el porcentaje (1.48%) era mucho más pequeño que el de las series clásicas, especialmente en los pacientes con problemas neuromusculares o cognitivos (un tercio de los pacientes).

Introduction: This multi-center study (Cabueñes Hospital and Santa Lucía University Hospital) assessed the results of a retrospective and ongoing series of 135 total hip arthroplasties (THA) in which a latest generation dual-mobility cup was implanted. Material and methods: A total of 135 THAs performed between 2005 and 2008 were analyzed. Mean follow-up was 32 months. The causes of surgery were: coxarthrosis in 31.8% and hip fracture in 68.1%. Mean age was 82.1 years. All patients were seen at regular follow-up visits for clinical and radiological assessments. Results: The follow-up lasted over 24 months in 121 THAs (14 patients died). In the most recent follow-up, in May 2011, 119 cups did not show any loosening. Complications were as follows: 2 postoperative dislocations; 4 DVTs; 3 infections; 5 periprosthetic fractures; 2 loosened cups, and one subsided stem. The mean preoperative Harris Hip Score (HHS) was 45, 83; the mean postoperative HHS was 80, 03. Only two of the 135 cups analyzed had radiographic modifications without clinical signs. Isolated cup survival at 12 months was 97.03% (87.3-99.2) with a 95% confidence interval; survival at 5 years was 96.7% (85.4-98.8). Discussion: In our study, the new dual-mobility cup showed good results for the following indications: primary coxarthrosis and femur neck fractures. Conclusion: The complication rate in our series was similar to the one reported in other series in the literature, except for dislocation. The latter was considerably less frequent (1.48%) in our series compared to the rates reported by the classical series, especially in patients with neuromuscular or cognitive problems (one third of patients).

[Results of the latest generation dual-mobility cup in Spain (135 THAs followed-up for a mean of 32 months)]. / Resultados del cotilo con doble movilidad de última generación en España (135 PTC seguidas durante una media de 32 meses).

INTRODUCTION: This multi-center study (Cabuenes Hospital and Santa Lucia University Hospital) assessed the results of a retrospective and ongoing series of 135 total hip arthroplasties (THA) in which a latest generation dual-mobility cup was implanted. MATERIAL AND METHODS: A total of 135 THAs performed between 2005 and 2008 were analyzed. Mean follow-up was 32 months. The causes of surgery were: coxarthrosis in 31.8% and hip fracture in 68.1%. Mean age was 82.1 years. All patients were seen at regular follow-up visits for clinical and radiological assessments. RESULTS: The follow-up lasted over 24 months in 121 THAs (14 patients died). In the most recent follow-up, in May 2011, 119 cups did not show any loosening. Complications were as follows: 2 postoperative dislocations; 4 DVTs; 3 infections; 5 periprosthetic fractures; 2 loosened cups, and one subsided stem. The mean preoperative Harris Hip Score (HHS) was 45, 83; the mean postoperative HHS was 80.03. Only two of the 135 cups analyzed had radiographic modifications without clinical signs. Isolated cup survival at 12 months was 97.03% (87.3-99.2) with a 95% confidence interval; survival at 5 years was 96.7% (85.4-98.8). DISCUSSION: In our study, the new dual-mobility cup showed good results for the following indications: primary coxarthrosis and femur neck fractures. CONCLUSION: The complication rate in our series was similar to the one reported in other series in the literature, except for dislocation. The latter was considerably less frequent (1.48%) in our series compared to the rates reported by the classical series, especially in patients with neuromuscular or cognitive problems (one third of patients).

Cirugía de mínima invasión frente a cirugía convencional. Una aproximación desde la evidencia científica / Minimally invasive surgery versus conventional surgery. A review of the scientific evidence

En los últimos años se ha extendido en las áreas quirúrgicas, entre ellas la cirugía ortopédica, el concepto de que las incisiones pequeñas facilitan una mejor evolución en múltiples procesos. Sin embargo, no existe en algunos casos una evidencia científica (EC) suficiente para recomendar estos procedimientos. Este artículo pretende realizar una revisión actualizada de los trabajos publicados con EC suficiente sobre las ventajas de la cirugía de mínima invasión (MIS) en comparación con las vías de acceso convencionales. A través de un orden topográfico se revisan los trabajos publicados con nivel de evidencia i o ii y los meta-análisis y revisiones sistemáticas de la literatura médica. Cuando ha sido posible también se ha revisado la información disponible sobre el coste-beneficio de este tipo de cirugía (AU)

The concept that small incisions lead to a better outcome in many procedures has extended into most surgical areas, orthopaedic surgery among them. However, in some cases there is not enough scientific evidence to recommend these procedures. This article attempts to provide an updated review of the works published with sufficient scientific evidence on the advantages of minimally invasive surgery (MIS) compared to conventional access approaches. The published articles, meta-analyses and systematic literature reviews with level I or II evidence are reviewed in topographic order. Wherever possible, the information available on the costs-benefits of this type of surgery is also reviewed (AU)

[Minimally invasive surgery versus conventional surgery. A review of the scientific evidence]. / Cirugía de mínima invasión frente a cirugía convencional. Una aproximación desde la evidencia científica.

The concept that small incisions lead to a better outcome in many procedures has extended into most surgical areas, orthopaedic surgery among them. However, in some cases there is not enough scientific evidence to recommend these procedures. This article attempts to provide an updated review of the works published with sufficient scientific evidence on the advantages of minimally invasive surgery (MIS) compared to conventional access approaches. The published articles, meta-analyses and systematic literature reviews with level I or II evidence are reviewed in topographic order. Wherever possible, the information available on the costs-benefits of this type of surgery is also reviewed.

Inestabilidad de la artroplastia total de cadera. Una aproximación desde los criterios de la evidencia científica / Instability of total hip arthroplasty: An approach using the scientific evidence

La inestabilidad en las artroplastias de cadera o la luxación en su forma más dramática, es una complicación que altera la evolución de este procedimiento introduciendo una pérdida de bienestar en el paciente y una pérdida de confianza en su relación con el cirujano. Si no consideramos los fracasos por infección, la luxación supone la causa más frecuente de cirugía de revisión a corto y medio plazo y no es desdeñable el número de casos que precisan varias intervenciones para aportar estabilidad a la articulación. A pesar de la frecuencia y gravedad de esta complicación no son frecuentes estudios con alta evidencia científica en este tema. Hemos pretendido recoger la literatura publicada con su grado de evidencia acerca de la etiopatogenia, profilaxis y tratamiento de esta eventualidad. Para ello además de anotar y resumir los hallazgos de cada trabajo, hemos añadido el nivel de evidencia tras la cita bibliográfica correspondiente (AU)

The instability in hip arthroplasty, or joint dislocation in its most dramatic form, is a complication that changes the outcome of this procedure, causing a decrease in the quality of life of the patients, and a loss of confidence in their relationship with the surgeon. If we discount failures due to infection, dislocation is the most frequent cause of a short to medium term revision, and the number of cases that require several operations to provide stability to the joint is not insignificant. Despite the frequency and severity of this complication there are few studies with a high level of scientific evidence on this subject. We have attempted to review the published literature and its level of evidence on the pathogenic origin, prophylaxis and treatment of this eventuality. As well as recording and summarising the findings of each study in this review, we have added the evidence level of the corresponding literature reference (AU)

Failures of yttria-stabilised tetragonal zirconia: 52 retrieved ceramic femoral heads of total hip prostheses.

Fifty two ceramic femoral heads have been investigated after implantation. All heads had articulated against ultra high molecular weight polyethylene (UHMWPE) cups. Examination of the heads shows changes in sphericity and surface roughness due to the wear. The behaviour of these retrieved heads after clinical use confirms the problems derived from the use of yttria-stabilised tetragonal zirconia heads. In this paper, a failure mechanism for this type of ceramic is proposed. The slow yttria dissolution produces the transformation from tetragonal to monoclinic phase with a volume change. This fact provokes an important decrease in mechanical properties favouring wear. The yttria dissolution and the zirconia solid transformation were confirmed by X-ray diffraction.

Nuevos materiales en artroplastia total de cadera / New materials for total hip arthroplasty

La búsqueda de la longevidad de los implantes protésicos articulares es uno de los imperativos que más preocupan hoy día a los investigadores y a los cirujanos ortopédicos que trabajan en este campo. Efectivamente, cada día se afrontan pacientes de menor edad deseosos de seguir una actividad vital normal, incluso de participar regularmente en deportes con impactos o en tareas pesadas y de carga. En el caso de las artroplastias de cadera se ha conseguido un buen funcionamiento de las mismas, casi asegurado en los primeros 10 años tras su implantación; sin embargo, a partir de ese plazo la supervivencia decrece. El fracaso del implante suele sobrevenir por desgaste de sus componentes articulares o por pérdida de fijación al hueso huésped, estando ambas causas íntimamente relacionadas. En este artículo se revisan los materiales utilizados en superficies articulares y después se analizan los que entran a formar parte de la composición estructura del sustrato y de las superficies de fijación de la prótesis (AU)

Fractures of the fifth metatarsal in basketball players.

A prospective nonrandomized study was made of 17 basketball players with fractures of the proximal third of the shaft of the fifth metatarsal. Eight had acute fractures, which were treated with a cast without weight-bearing, and the other nine had stress fractures for which percutaneous compression screwing was initially used. In the first group, union was obtained in four cases in an average of 9 weeks, with resumption of sport by 12 weeks. Three had a good outcome and the fourth was fair. The other four cases, which had not healed after 12 weeks of immobilization, were subsequently treated using compression screws. Resumption of sport was achieved 20-24 weeks after the fracture. Two of these had a good result; in the other two the results were fair. Of the nine patients with stress fractures in which a screw was inserted, all healed between 8 and 14 weeks and returned to sport within 7-12 weeks. Seven had a good result and the other two only fair. There was one intraoperative complication, but no postoperative complications, such as nonunion or refracture, were observed. Even if the non-operative treatment is able to provide a good result, immobilization without weight-bearing does not guarantee healing. In this series, percutaneous screw fixation was able to achieve successful healing in a short period of time. Thus, this procedure seems to be preferable for primary treatment of this lesion in athletes.

Augmented repair of Achilles tendon ruptures.

We performed a series of repairs of Achilles tendon ruptures in athletes using suture augmented with a polyethylene terephthalate mesh synthetic graft. No postoperative immobilization was used. The 29 patients were aged 25 to 54 years and all practiced sports a minimum of 4 hours weekly. At the followup, ranging from 6 months to 5 years, ankle mobility was normal in all but one patient, who had lost 15 degrees of extension. All the patients were able to do a series of 10 single-limb heel raises without any impairment when compared with the uninjured side. Average ankle flexion strength was 96% that of the uninjured side (range, 87% to 110%). There were no reruptures, although in two instances problems with scarring occurred. All patients but one were able to resume their sports activities at the same level of intensity as they had before their injuries. These results testify to the advantage of not using postoperative immobilization and beginning functional rehabilitation immediately in patients with such lesions.