Vástagos modulares de anclaje diafisario con tornillos de bloqueo en la revisión de cadera con defectos femorales masivos / Modular diaphyseal anchor stems with locking screws in the hip revision with massive femoral defects

INTRODUCCIÓN: Los defectos femorales complejos con istmo insuficiente (Paprosky III y IV) y fracturas periprotésicas B3 de Vancouver condicionan la fijación de los vástagos de revisión. El objetivo es evaluar los resultados de los vástagos de revisión modular de anclaje diafisario con bloqueo distal (Sistema Revitan Zimmer Biomet GmbH, Winterthur, Suiza). Nuestra hipótesis es que ofrecen una fijación primaria estable en casos de afectación del istmo femoral. MATERIAL Y MÉTODOS: Estudio de cohortes retrospectivo de 38 pacientes, seguimiento mínimo de 12 meses (12-94) y defectos femorales severos tratados con vástagos Revitan encerrojados. Realizamos una vía endofemoral o una transfemoral. Valoramos el hundimiento según el método de Callahan y la neoformación ósea según Barnett y Nordin. Se utilizó la escala Merle d'Aubigné-Postel y se recogieron las complicaciones y reintervenciones. Se realizó un análisis estadístico con SPSS y un nivel de significación p < 0,05. RESULTADOS: Entre 2009 y 2017 se realizaron 147 revisiones con vástago Revitan, 38 encerrojados, 23 hombres y 15 mujeres, edad media de 74 años y seguimiento medio de 64 meses. Las causas de revisión fueron: 15 aflojamientos sépticos, 14 asépticos, dos fracturas y siete fijaciones fibrosas estables. Obtuvimos una correcta fijación en 27 casos; hubo cuatro aflojamientos, tres roturas de tornillos, tres infecciones, una luxación y una lesión del nervio femoral. El MDP mejoró de forma significativa de 11,26 a 14,98. CONCLUSIONES: Los vástagos modulares cónicos encerrojados son una buena alternativa en los defectos femorales con afectación ístmica si se consigue un correcto relleno del canal y una fijación bicortical de los tornillos

INTRODUCTION: Complex femoral defects with insufficient isthmus (Paprosky III and IV) and Vancouver B3 periprosthetic fractures determines the fixation of the revision stems. The objective is to evaluate the results of the modular revision stems with diaphyseal anchor and distal block (Revitan Zimmer Biomet GmbH, Winterthur, Switzerland). Our hypothesis is that this procedure offers a stable primary fixation in cases of alteration of the femoral isthmus. MATERIAL AND METHODS: Retrospective cohort study of 38 patients, minimum follow-up of 12 months (12-94) with severe femoral defects treated with Revitan stems distally blocked. An endofemoral or transfemoral approach was used. The subsidence was assessed according to Callahan's method and bone neoformation according to Nordin. Merle d'Aubigné-Postel was used and complications and reoperations were collected. A statistical analysis was performed with SPSS and a significance level p < 0.05 was considered. RESULTS: Between 2009 and 2017, 147 revisions were carried out with Revitan stem, 38 locked, 23 men and 15 women, with an average age of 74 years and an average follow-up of 64 months. The cause of the review was: 15 septic loosenings, 14 aseptic, two fractures and seven stable fibrous unions. Right fixation was obtained in 27 cases, there were four loosenings, three screw breakages, three infections, one of dislocation and one of femoral nerve injury. The MDP increased significantly from 11.26 to 14.98. CONCLUSIONS: Distally locked conical modular stems are a good alternative in femoral defects with isthmus involvement if proper canal filling and bicortical screw fixation are achieved

Modular diaphyseal anchor stems with locking screws in the hip revision with massive femoral defects. / Vástagos modulares de anclaje diafisario con tornillos de bloqueo en la revisión de cadera con defectos femorales masivos.

INTRODUCTION: Complex femoral defects with insufficient isthmus (Paprosky III and IV) and Vancouver B3 periprosthetic fractures determines the fixation of the revision stems. The objective is to evaluate the results of the modular revision stems with diaphyseal anchor and distal block (Revitan Zimmer Biomet GmbH, Winterthur, Switzerland). Our hypothesis is that this procedure offers a stable primary fixation in cases of alteration of the femoral isthmus. MATERIAL AND METHODS: Retrospective cohort study of 38 patients, minimum follow-up of 12 months (12-94) with severe femoral defects treated with Revitan stems distally blocked. An endofemoral or transfemoral approach was used. The subsidence was assessed according to Callahan's method and bone neoformation according to Nordin. Merle d'Aubigné-Postel was used and complications and reoperations were collected. A statistical analysis was performed with SPSS and a significance level p < 0.05 was considered. RESULTS: Between 2009 and 2017, 147 revisions were carried out with Revitan stem, 38 locked, 23 men and 15 women, with an average age of 74 years and an average follow-up of 64 months. The cause of the review was: 15 septic loosenings, 14 aseptic, two fractures and seven stable fibrous unions. Right fixation was obtained in 27 cases, there were four loosenings, three screw breakages, three infections, one of dislocation and one of femoral nerve injury. The MDP increased significantly from 11.26 to 14.98. CONCLUSIONS: Distally locked conical modular stems are a good alternative in femoral defects with isthmus involvement if proper canal filling and bicortical screw fixation are achieved.