Resultados clínicos de artroplastia total de cadera asistida por brazo robótico en España: estudio preliminar / Clinical results of total hip arthroplasty assisted by robotic arm in Spain: Preliminary study

Objetivos: Resultados clínicos, radiológicos y funcionales de la primera serie española de pacientes intervenidos de artroplastia total de cadera (ATC) asistida mediante brazo robótico Mako® (Stryker) del Hospital Clínico San Carlos (HCSC) de Madrid. Material y métodos: Estudio descriptivo prospectivo que analiza los primeros 25 pacientes intervenidos de ATC asistida por robot (ATCaR) en el HCSC, con un seguimiento mínimo de 4meses. Se evaluaron la demografía, los estudios de imagen (procesamiento Mako®, Rx y TAC), los parámetros clínicos, la funcionalidad (Harris modificada) y las complicaciones asociadas. Resultados: La edad media fue 67,2años (min 47, max 88), siendo el 56% varones. El 88% corresponden a coxartrosis primaria, el 4% postraumática, el 4% secundaria a NAV y el 4% secundaria a choque femoroacetabular. El tiempo medio de cirugía fue de 116,9minutos (min 92, max 150). La media de las cinco primeras intervenciones fue 122,6minutos, y la de las cinco últimas, de 108,2minutos. Como complicaciones intraoperatorias se cuantificaron 4 pérdidas de marcadores intraoperatorios. El tiempo de ingreso medio fue 4,4días (min 3, max 7), con una disminución de hemoglobina posquirúrgica media de 3,08±1,08g/dl, requiriendo transfusión en el 12% de los casos. Se registran tres complicaciones médicas durante el ingreso, destacando un síndrome confusional con caída y fractura periprotésica AG1 no desplazada. El análisis del posicionamiento de los implantes registrados con sistema Mako® fueron 40,55±1,53 grados de inclinación y 12,2±3,6 grados de anteversión acetabular. El estudio de imagen posquirúrgico realizado a los pacientes, en concordancia con Mako®, muestra valores de inclinación acetabular de 41,2±1,7 en Rx y versión acetabular de 16±4,6 en TAC. La discrepancia de longitud de cadera varía de valores preoperatorios de −3,91mm (DE: 3,9; min −12, max 3) a 1,29mm (DE: 1,96) tras la cirugía registrados con Mako...(AU)

Objectives: Clinical, radiological and functional results of the first Spanish series of patients undergoing total hip arthroplasty assisted by Mako® (Stryker) robotic arm at the Hospital Clínico San Carlos (HCSC) in Madrid. Material and methods: Prospective and descriptive study analyzing the first 25 patients who underwent robotic-assisted THA at the HCSC, with a minimum follow-up of 4months. Demographics, imaging studies (Mako® processing, Rx and CT), clinical parameters, functionality (modified Harris) and associated complications were evaluated. Results: Average age was 67.2years (min 47, max 88), being 56% male population sample. 88% involves primary coxarthrosis, 4% post-traumatic coxarthrosis, 4% secondary avascular necrosis and 4% secondary femoroacetabular impingement. Average surgery time was 116.9min (min 92, max 150). The average time of the first five surgeries was 122.6min, and, regarding the last five interventions, it was 108.2min. Found medical intraoperative complications were four intraoperative markers loss. Average admission time was 4.4days (min 3, max 7), with an average postoperative hemoglobin decrease of 3.08±1.08g/dL, requiring a transfusion in 12% of the cases. Three medical complications have been registered in the meantime of the admission, with a relevant case of a confusional syndrome and a fall, which resulted in a non-displaced AG1 periprosthetic fracture. The analysis of the positioning of registered implants with Mako® system shows 40.55±1.53 acetabular inclination degrees and 12.2±3.6 acetabular anteversion degrees. The postoperative image study carried out on patients, are consistent with Mako® s results, as it shows an acetabular inclination of 41.2±1.7 in Rx, as well as acetabular anteversion of 16±4.6 in CT. Hip length variance ranges depending on preoperative values of 3.91mm (SD: 3.9; min −12, max 3) to 1.29mm (SD: 1.96) after surgery registered with...(AU)

[Translated article] Clinical results of total hip arthroplasty assisted by robotic arm in Spain: Preliminary study / Resultados clínicos de la artroplastia total de cadera asistida por brazo robótico en España: estudio preliminar

Objetivos: Resultados clínicos, radiológicos y funcionales de la primera serie española de pacientes intervenidos de artroplastia total de cadera (ATC) asistida mediante brazo robótico Mako® (Stryker) del Hospital Clínico San Carlos (HCSC) de Madrid. Material y métodos: Estudio descriptivo prospectivo que analiza los primeros 25 pacientes intervenidos de ATC asistida por robot (ATCaR) en el HCSC, con un seguimiento mínimo de 4meses. Se evaluaron la demografía, los estudios de imagen (procesamiento Mako®, Rx y TAC), los parámetros clínicos, la funcionalidad (Harris modificada) y las complicaciones asociadas. Resultados: La edad media fue 67,2años (min 47, max 88), siendo el 56% varones. El 88% corresponden a coxartrosis primaria, el 4% postraumática, el 4% secundaria a NAV y el 4% secundaria a choque femoroacetabular. El tiempo medio de cirugía fue de 116,9minutos (min 92, max 150). La media de las cinco primeras intervenciones fue 122,6minutos, y la de las cinco últimas, de 108,2minutos. Como complicaciones intraoperatorias se cuantificaron 4 pérdidas de marcadores intraoperatorios. El tiempo de ingreso medio fue 4,4días (min 3, max 7), con una disminución de hemoglobina posquirúrgica media de 3,08±1,08g/dl, requiriendo transfusión en el 12% de los casos. Se registran tres complicaciones médicas durante el ingreso, destacando un síndrome confusional con caída y fractura periprotésica AG1 no desplazada. El análisis del posicionamiento de los implantes registrados con sistema Mako® fueron 40,55±1,53 grados de inclinación y 12,2±3,6 grados de anteversión acetabular. El estudio de imagen posquirúrgico realizado a los pacientes, en concordancia con Mako®, muestra valores de inclinación acetabular de 41,2±1,7 en Rx y versión acetabular de 16±4,6 en TAC. La discrepancia de longitud de cadera varía de valores preoperatorios de −3,91mm (DE: 3,9; min −12, max 3) a 1,29mm (DE: 1,96) tras la cirugía registrados con Mako...(AU)

Objectives: Clinical, radiological and functional results of the first Spanish series of patients undergoing total hip arthroplasty assisted by Mako® (Stryker) robotic arm at the Hospital Clínico San Carlos (HCSC) in Madrid. Material and methods: Prospective and descriptive study analyzing the first 25 patients who underwent robotic-assisted THA at the HCSC, with a minimum follow-up of 4months. Demographics, imaging studies (Mako® processing, Rx and CT), clinical parameters, functionality (modified Harris) and associated complications were evaluated. Results: Average age was 67.2years (min 47, max 88), being 56% male population sample. 88% involves primary coxarthrosis, 4% post-traumatic coxarthrosis, 4% secondary avascular necrosis and 4% secondary femoroacetabular impingement. Average surgery time was 116.9min (min 92, max 150). The average time of the first five surgeries was 122.6min, and, regarding the last five interventions, it was 108.2min. Found medical intraoperative complications were four intraoperative markers loss. Average admission time was 4.4days (min 3, max 7), with an average postoperative hemoglobin decrease of 3.08±1.08g/dL, requiring a transfusion in 12% of the cases. Three medical complications have been registered in the meantime of the admission, with a relevant case of a confusional syndrome and a fall, which resulted in a non-displaced AG1 periprosthetic fracture. The analysis of the positioning of registered implants with Mako® system shows 40.55±1.53 acetabular inclination degrees and 12.2±3.6 acetabular anteversion degrees. The postoperative image study carried out on patients, are consistent with Mako® s results, as it shows an acetabular inclination of 41.2±1.7 in Rx, as well as acetabular anteversion of 16±4.6 in CT. Hip length variance ranges depending on preoperative values of 3.91mm (SD: 3.9; min −12, max 3) to 1.29mm (SD: 1.96) after surgery registered with...(AU)

[Translated article] Validation of the Spanish version of the modified Harris score / Validación de la versión española de la escala de Harris modificada

Objetivos: Resultados clínicos, radiológicos y funcionales de la primera serie española de pacientes intervenidos de artroplastia total de cadera (ATC) asistida mediante brazo robótico Mako® (Stryker) del Hospital Clínico San Carlos (HCSC) de Madrid. Material y métodos: Estudio descriptivo prospectivo que analiza los primeros 25 pacientes intervenidos de ATC asistida por robot (ATCaR) en el HCSC, con un seguimiento mínimo de 4meses. Se evaluaron la demografía, los estudios de imagen (procesamiento Mako®, Rx y TAC), los parámetros clínicos, la funcionalidad (Harris modificada) y las complicaciones asociadas. Resultados: La edad media fue 67,2años (min 47, max 88), siendo el 56% varones. El 88% corresponden a coxartrosis primaria, el 4% postraumática, el 4% secundaria a NAV y el 4% secundaria a choque femoroacetabular. El tiempo medio de cirugía fue de 116,9minutos (min 92, max 150). La media de las cinco primeras intervenciones fue 122,6minutos, y la de las cinco últimas, de 108,2minutos. Como complicaciones intraoperatorias se cuantificaron 4 pérdidas de marcadores intraoperatorios. El tiempo de ingreso medio fue 4,4días (min 3, max 7), con una disminución de hemoglobina posquirúrgica media de 3,08±1,08g/dl, requiriendo transfusión en el 12% de los casos. Se registran tres complicaciones médicas durante el ingreso, destacando un síndrome confusional con caída y fractura periprotésica AG1 no desplazada. El análisis del posicionamiento de los implantes registrados con sistema Mako® fueron 40,55±1,53 grados de inclinación y 12,2±3,6 grados de anteversión acetabular. El estudio de imagen posquirúrgico realizado a los pacientes, en concordancia con Mako®, muestra valores de inclinación acetabular de 41,2±1,7 en Rx y versión acetabular de 16±4,6 en TAC. La discrepancia de longitud de cadera varía de valores preoperatorios de −3,91mm (DE: 3,9; min −12, max 3) a 1,29mm (DE: 1,96) tras la cirugía registrados con Mako...(AU)

Objectives: Clinical, radiological and functional results of the first Spanish series of patients undergoing total hip arthroplasty assisted by Mako® (Stryker) robotic arm at the Hospital Clínico San Carlos (HCSC) in Madrid. Material and methods: Prospective and descriptive study analyzing the first 25 patients who underwent robotic-assisted THA at the HCSC, with a minimum follow-up of 4months. Demographics, imaging studies (Mako® processing, Rx and CT), clinical parameters, functionality (modified Harris) and associated complications were evaluated. Results: Average age was 67.2years (min 47, max 88), being 56% male population sample. 88% involves primary coxarthrosis, 4% post-traumatic coxarthrosis, 4% secondary avascular necrosis and 4% secondary femoroacetabular impingement. Average surgery time was 116.9min (min 92, max 150). The average time of the first five surgeries was 122.6min, and, regarding the last five interventions, it was 108.2min. Found medical intraoperative complications were four intraoperative markers loss. Average admission time was 4.4days (min 3, max 7), with an average postoperative hemoglobin decrease of 3.08±1.08g/dL, requiring a transfusion in 12% of the cases. Three medical complications have been registered in the meantime of the admission, with a relevant case of a confusional syndrome and a fall, which resulted in a non-displaced AG1 periprosthetic fracture. The analysis of the positioning of registered implants with Mako® system shows 40.55±1.53 acetabular inclination degrees and 12.2±3.6 acetabular anteversion degrees. The postoperative image study carried out on patients, are consistent with Mako® s results, as it shows an acetabular inclination of 41.2±1.7 in Rx, as well as acetabular anteversion of 16±4.6 in CT. Hip length variance ranges depending on preoperative values of 3.91mm (SD: 3.9; min −12, max 3) to 1.29mm (SD: 1.96) after surgery registered with...(AU)

Clinical results of total hip arthroplasty assisted by robotic arm in Spain: Preliminary study. / Resultados clínicos de artroplastia total de cadera asistida por brazo robótico en España: estudio preliminar.

OBJECTIVES: Clinical, radiological and functional results of the first Spanish series of patients undergoing total hip arthroplasty assisted by Mako® (Stryker) robotic arm at the Hospital Clínico San Carlos (HCSC) in Madrid. MATERIAL AND METHODS: Prospective and descriptive study analyzing the first 25 patients who underwent robotic-assisted THA at the HCSC, with a minimum follow-up of 4months. Demographics, imaging studies (Mako® processing, Rx and CT), clinical parameters, functionality (modified Harris) and associated complications were evaluated. RESULTS: Average age was 67.2years (min 47, max 88), being 56% male population sample. 88% involves primary coxarthrosis, 4% post-traumatic coxarthrosis, 4% secondary avascular necrosis and 4% secondary femoroacetabular impingement. Average surgery time was 116.9min (min 92, max 150). The average time of the first five surgeries was 122.6min, and, regarding the last five interventions, it was 108.2min. Found medical intraoperative complications were four intraoperative markers loss. Average admission time was 4.4days (min 3, max 7), with an average postoperative hemoglobin decrease of 3.08±1.08g/dL, requiring a transfusion in 12% of the cases. Three medical complications have been registered in the meantime of the admission, with a relevant case of a confusional syndrome and a fall, which resulted in a non-displaced AG1 periprosthetic fracture. The analysis of the positioning of registered implants with Mako® system shows 40.55±1.53 acetabular inclination degrees and 12.2±3.6 acetabular anteversion degrees. The postoperative image study carried out on patients, are consistent with Mako® s results, as it shows an acetabular inclination of 41.2±1.7 in Rx, as well as acetabular anteversion of 16±4.6 in CT. Hip length variance ranges depending on preoperative values of 3.91mm (SD: 3.9; min -12, max 3) to 1.29mm (SD: 1.96) after surgery registered with Mako®, with an increase of an average hip length of 5.64mm (SD: 3.35). Rx simple study results show a postoperative difference between both hips of 0.5±3.08mm, which is consistent with Mako® results. Native femoral offset was stable after surgery with a showing difference both pre and post operative of the intervened hip of 0.1mm (SD: 3.7), registered with Mako®. Preoperatory modified Harris punctuation was 41.6±13.3, improving to postoperative values of 74.6±9.7 after four months since the surgery. No complications were registered in immediate postoperative (4month). CONCLUSIONS: Total hip arthroplasty robot-assisted achieves an adequate precision and repeatability of the implant positioning and the postoperative hip dysmetry without showing an increase of associated complications to the technique applied. Surgery time, complications and functional results in a short-time period are similar to conventional techniques applied to great series previously published.

[Translated article] Clinical results of total hip arthroplasty assisted by robotic arm in Spain: Preliminary study.

OBJECTIVES: Clinical, radiological and functional results of the first Spanish series of patients undergoing total hip arthroplasty assisted by Mako® (Stryker) robotic arm at the Hospital Clínico San Carlos (HCSC) in Madrid. MATERIAL AND METHODS: Prospective and descriptive study analyzing the first 25 patients who underwent robotic-assisted THA at the HCSC, with a minimum follow-up of 4 months. Demographics, imaging studies (Mako® processing, Rx and CT), clinical parameters, functionality (modified Harris) and associated complications were evaluated. RESULTS: Average age was 67.2 years (min 47, max 88), being 56% male population sample. 88% involves primary coxarthrosis, 4% post-traumatic coxarthrosis, 4% secondary avascular necrosis and 4% secondary femoroacetabular impingement. Average surgery time was 116.9min (min 92, max 150). The average time of the first five surgeries was 122.6min, and, regarding the last five interventions, it was 108.2min. Found medical intraoperative complications were four intraoperative markers loss. Average admission time was 4.4days (min 3, max 7), with an average postoperative haemoglobin decrease of 3.08±1.08g/dl, requiring a transfusion in 12% of the cases. Three medical complications have been registered in the meantime of the admission, with a relevant case of a confusional syndrome and a fall, which resulted in a non-displaced AG1 periprosthetic fracture. The analysis of the positioning of registered implants with Mako® system shows 40.55±1.53 acetabular inclination degrees and 12.2±3.6 acetabular anteversion degrees. The postoperative image study carried out on patients, are consistent with Mako® results, as it shows an acetabular inclination of 41.2±1.7 in Rx, as well as acetabular anteversion of 16±4.6 in CT. Hip length variance ranges depending on preoperative values of 3.91mm (SD: 3.9; min -12, max 3) to 1.29mm (SD: 1.96) after surgery registered with Mako®, with an increase of an average hip length of 5.64mm (SD: 3.35). Rx simple study results show a postoperative difference between both hips of 0.5±3.08mm, which is consistent with Mako® results. Native femoral offset was stable after surgery with a showing difference both pre and post operative of the intervened hip of 0.1mm (SD: 3.7), registered with Mako®. Preoperatory modified Harris punctuation was 41.6±13.3, improving to postoperative values of 74.6±9.7 after four months since the surgery. No complications were registered in immediate postoperative (4 months). CONCLUSIONS: Total hip arthroplasty robot-assisted achieves an adequate precision and repeatability of the implant positioning and the postoperative hip dysmetry without showing an increase of associated complications to the technique applied. Surgery time, complications and functional results in a short-time period are similar to conventional techniques applied to great series previously published.

[Results of revision after failed surgical treatment for traumatic anterior shoulder instability]. / Cirugía de revisión de la inestabilidad anterior de hombro.

INTRODUCTION AND OBJECTIVES: Persistent or recurrent glenohumeral instability after a previous operative stabilization can be a complex problem. Our aim is to establish the incidence of recurrence and its revision surgery, and to analyse the functional results of the revision instability surgery, as well as to determine surgical protocols to perform it. MATERIALS AND METHODS: A retrospective analysis was conducted on 16 patients with recurrent instability out of 164 patients operated on between 1999 and 2011. The mean follow-up was 57 months and the mean age was 29 years. To evaluate functional outcome we employed Constant, Rowe, UCLA scores and the visual analogue scale. RESULTS: Of the 12 patients who failed the initial arthroscopic surgery, 6 patients underwent an arthroscopic antero-inferior labrum repair technique, 4 using open labrum repair techniques, and 2 coracoid transfer. The two cases of open surgery with recurrences underwent surgery for coracoid transfer. Results of the Constant score were excellent or good in 64% of patients. CONCLUSIONS: Surgical revision of instability is a complex surgery essentially for two reasons: the difficulty in recognising the problem, and the technical demand (greater variety and the increasingly complex techniques).

Cirugía de revisión de la inestabilidad anterior de hombro / Results of revision after failed surgical treatment for traumatic anterior shoulder instability

Introducción y objetivos. Aunque las tasa de recidiva tras la cirugía primaria de la inestabilidad no son despreciables, son pocos los estudios que encontramos sobre su cirugía de revisión. Los objetivos de esta serie son establecer la frecuencia de recidiva de la inestabilidad en la misma y de su cirugía de revisión; analizar los resultados funcionales obtenidos, y determinar un protocolo quirúrgico de actuación ante la necesidad de realizar una cirugía de revisión. Material y métodos. Análisis retrospectivo: 16 pacientes con recidiva de inestabilidad tras cirugía previa en 164 pacientes intervenidos entre 1999-2011. Seguimiento medio de 57 meses y edad promedio 29 años. Evaluación de resultados mediante las escalas Constant, Rowe y UCLA. Resultados. De los 12 casos de cirugía artroscópica que recidivaron, en 6 se reparó el labrum mediante artroscopia, en 4 mediante reparación abierta y plicatura capsular, y en 2 mediante trasferencia de coracoides. En los 2 casos de cirugía abierta se realizó una cirugía de trasferencia de coracoides. Las puntuaciones obtenidas en la escala de Constant en el hombro intervenido fueron excelente/buena en el 64% de los pacientes. Conclusiones. Aunque las técnicas de estabilización primaria abierta y/o artroscópica se han perfeccionado mucho, el porcentaje de recurrencia no resulta nada despreciable. De ahí la importancia de establecer un protocolo quirúrgico de actuación como existe para la indicación quirúrgica de una estabilización primaria. Podemos afirmar que los resultados funcionales obtenidos tras la cirugía de revisión resultan satisfactorios para las elevadas demandas funcionales que presentan este tipo de pacientes (AU)

Introduction and objectives. Persistent or recurrent glenohumeral instability after a previous operative stabilization can be a complex problem. Our aim is to establish the incidence of recurrence and its revision surgery, and to analyse the functional results of the revision instability surgery, as well as to determine surgical protocols to perform it. Materials and methods. A retrospective analysis was conducted on 16 patients with recurrent instability out of 164 patients operated on between 1999 and 2011. The mean follow-up was 57 months and the mean age was 29 years. To evaluate functional outcome we employed Constant, Rowe, UCLA scores and the visual analogue scale. Results. Of the 12 patients who failed the initial arthroscopic surgery, 6 patients underwent an arthroscopic antero-inferior labrum repair technique, 4 using open labrum repair techniques, and 2 coracoid transfer. The two cases of open surgery with recurrences underwent surgery for coracoid transfer. Results of the Constant score were excellent or good in 64% of patients. Conclusions. Surgical revision of instability is a complex surgery essentially for two reasons: the difficulty in recognising the problem, and the technical demand (greater variety and the increasingly complex techniques) (AU)

Tratamiento de la infección recalcitrante de cadera mediante colgajo de músculo vasto lateral / Treatment of a recalcitrant hip infection with a vastus lateralis muscle flap

Introducción. La infección recalcitrante de cadera tras artroplastia es una complicación de difícil tratamiento para el cirujano ortopédico. El objetivo de este estudio es evaluar los resultados de estas infecciones de cadera recalcitrantes que hemos tenido en nuestro Servicio tratadas con el colgajo de vasto externo. Material y métodos. Estudio descriptivo retrospectivo de 5 pacientes con infecciones profundas de cadera mediante trasposición de colgajo del músculo vasto lateral. Edad media: 70,5 años. Tiempo medio de seguimiento: 30 meses (rango, 25-34 meses). Previamente todos los pacientes habían sido sometidos a distintos procedimientos quirúrgicos mayores (media de 3,7 procedimientos previos). Todos presentaban infecciones polimicrobianas previas a la cirugía. Se estudió los agentes patógenos involucrados mediante cultivo de la fístula, la evolución de la herida, así como controles analíticos, incluidos la proteína C-reactiva (PCR). Resultados. Se consiguió la curación de la herida en los 5 pacientes intervenidos, sin necesidad de realizar ningún otro procedimiento posterior ni aparición de fístula ni otros signos flogóticos de infección. La PCR se normalizó al mes de la intervención y no hubo morbi-mortalidad relacionada con la técnica quirúrgica. Conclusión. En nuestra experiencia, el colgajo de músculo vasto lateral como tratamiento para la infección profunda recalcitrante tras artroplastia de cadera ha presentado buenos resultados, siempre enmarcado dentro de un adecuado tratamiento antibiótico y desbridamiento quirúrgico, consiguiendo la curación de la herida y normalización de la PCR (AU)

Background. Recalcitrant hip infection after arthroplasty presents a reconstructive challenge to orthopedic surgeons. The aim of this study is to evaluate the results with a vastus lateralis muscle flap used to treat these recalcitrant hip infections in our Department. Material and methods. A retrospective descriptive study was conducted on five patients with deep hip infections by transposition of the vastus lateralis muscle flap. Average age: 70.5 years. Mean follow-up: 30 months (range, 25-34 months). All patients had previously undergone other major surgical procedures (mean of 3.7 previous procedures). All had multiple microbial infections before surgery. The pathogens involved using cultures of the fistula, the outcome of the wound and laboratory results, including C-reactive protein (CRP), were analysed. Results. Healing was achieved in the five patients who underwent surgery without requiring any further procedures or inflammatory signs of infection. CRP returned to normal one month after surgery, and there was no morbidity or mortality related to surgical technique. Conclusion. In our experience, the vastus lateralis muscle flap as a treatment for recalcitrant deep infection after arthroplasty has presented good results, provided there is appropriate antibiotic therapy and surgical debridement, thus achieving wound healing and a return to normal of the CRP (AU)

[Treatment of a recalcitrant hip infection with a vastus lateralis muscle flap]. / Tratamiento de la infección recalcitrante de cadera mediante colgajo de músculo vasto lateral.

BACKGROUND: Recalcitrant hip infection after arthroplasty presents a reconstructive challenge to orthopedic surgeons. The aim of this study is to evaluate the results with a vastus lateralis muscle flap used to treat these recalcitrant hip infections in our Department. MATERIAL AND METHODS: A retrospective descriptive study was conducted on five patients with deep hip infections by transposition of the vastus lateralis muscle flap. Average age: 70.5 years. Mean follow-up: 30 months (range, 25-34 months). All patients had previously undergone other major surgical procedures (mean of 3.7 previous procedures). All had multiple microbial infections before surgery. The pathogens involved using cultures of the fistula, the outcome of the wound and laboratory results, including C-reactive protein (CRP), were analysed. RESULTS: Healing was achieved in the five patients who underwent surgery without requiring any further procedures or inflammatory signs of infection. CRP returned to normal one month after surgery, and there was no morbidity or mortality related to surgical technique. CONCLUSION: In our experience, the vastus lateralis muscle flap as a treatment for recalcitrant deep infection after arthroplasty has presented good results, provided there is appropriate antibiotic therapy and surgical debridement, thus achieving wound healing and a return to normal of the CRP.

Tratamiento de las fracturas vertebrales mediante cifoplastia / Treatment of vertebral fractures by kyphoplasty

Objetivo. Análisis retrospectivo clínico y radiológico sobre los primeros casos intervenidos mediante cifoplastia en un centro de la Comunidad de Madrid. Material y método. Se revisaron 30 pacientes (43 vértebras) intervenidos entre diciembre 2002 y mayo 2005. La distribución etiológica fue: 24 pacientes con fractura osteoporótica y 6 con implantes tumorales líticos (1 caso de cáncer de pulmón, 2 de mama, un hipernefroma y 2 mielomas). El seguimiento medio fue de 13,2 meses. Se valoró la escala analógica visual (EAV), el índice de Karnosfky y la analgesia empleada antes del proceso y tras el seguimiento. También se midió el porcentaje de aplastamiento, el ángulo de Cobb local y la corrección de ambos. Resultados. El 93,2% de los pacientes mejoraron. La media de la EAV aumentó 5 puntos (p < 0,05). El índice de Karnosfky pasó de 70,63 a 90 puntos (p < 0,05). El 53% usaba opiáceos mayores antes de la cirugía, pasando el porcentaje después de la cirugía al 6,6% (p < 0,05). Veinte casos (46,5%) mejoraron radiológicamente. Excluyendo aquellas vértebras que no se corrigieron, la mejora obtenida fue de 21,7% de aplastamiento (rango 5-70%) y 13,86° de corrección ángulo de Cobb (rango 3-30°) respectivamente. Hubo 6 extravasaciones anterolaterales, todas asintomáticas. Se detectaron 2 fracturas adyacentes (ambas en los tres primeros meses tras la cirugía), una con repercusión clínica. En el subgrupo de pacientes tumorales los resultados finales fueron comparables a la serie general. Conclusiones. La mayoría de los casos mejoran sustancialmente sin complicaciones asociadas. La cifoplastia es una técnica de baja morbilidad y alta eficacia

Purpose. To conduct a retrospective clinical and radiological study of the first few cases operated by kyphoplasty at one center of Madrid. Materials and methods. Thirty patients were reviewed (43 vertebrae) who were operated between December 2002 and May 2005. The etiological distribution was as follows: 24 patients with an osteoporotic fracture and 6 with osteolytic tumors (lung cancer, 1 case; breast cancer, 2; hypernephroma, 1; and myeloma, 2). Mean follow-up was 13.2 months. Pain reduction was assessed by means of the Visual Analog Scale (VAS), the Karnosfky score and the amount of analgesia used before the procedure and during follow-up. Pre- and postoperative endplate angles were measured to assess the restoration of the sagittal alignment. Results. A 93.2% of patients improved. Mean VAS increased by 5 points (p < 0.05). Karnosfky score went from 70.63 to 90 points (p < 005). Patients using major opioids went from 53% befofre surgery to 6.6% postoperatively (p < 0.05). 20 cases (46.5%) showed radiological improvement. If we exclude uncorrected vertebrae, the improvement obtained was 21.7% as regards crushing (range: 5-70%) and 13.86° as regards Cobb's angle (range: 3-30°). There were 6 instances of anterolateral cement extravasation, all of them asymptomatic. Two adjoining fractures were detected (both in the first three months post-op), one of them with clinical repercussions. In the group of patients with tumors, final results were comparable to the general series. Conclusions. Most cases show a significant improvement with no associated complications. Kyphoplasty is a highly effective minimally invasive technique with a low degree of morbidity

Simulación en 3D de las variaciones de comportamiento en un segmento de columna al incorporar un fijador transpedicular / Three-dimensional simulation of variations in the behavior of a spinal segment with transpedicular fixation

Objetivo. Analizar las variaciones del comportamiento biomecánico mediante el análisis de elementos finitos de un segmento vertebral con un fijador transpedicular. Material y método. Se realizó un modelo matemático de elementos finitos (lineal, anisótropo y tridimensional) de un segmento vertebral lumbar (L1-L3) que fue sometido a cargas de compresión sucesivas de 1.177, 3.923 y 9.806 N. Posteriormente se incorporó al modelo un sistema de instrumentación transpedicular con las mismas cargas. Se estudió el desarrollo tensional del sistema, la redistribución de las cargas debidas al implante y las tensiones y deformaciones en el segmento instrumentado y del implante. Resultados. Los cambios en las distribuciones de las tensiones en el hueso, fueron de 502 MPa sin fijador y 460 MPa con fijador. El fijador produjo un aumento de la rigidez del 11,2%. Conclusiones. Este modelo de simulación 3D nos ha permitido estudiar el comportamiento de un segmento del raquis en diferentes situaciones y obtener datos que no son accesibles mediante los estudios experimentales, como la distribución de las concentraciones de tensiones

Aim. The aim of this study is to analyze variations in biomechanical behavior by finite-element analysis of a vertebral segment with transpedicular fixation. Materials and method. A finite-element mathematical model (linear, anisotropic, and three-dimensional) of a lumbar vertebral segment (L1-L3) that was subjected to successive compression loads of 1,177, 3,923, and 9,806 N. A transpedicular instrumentation system with the same loads was then added. The development of forces in the system, load redistribution due to the implant, and the forces and deformations in the instrumented segment and implant were studied. Results. The distribution of forces in the bone changed by 502 MPa without fixation and 460 MPa with fixation. Fixation increased resistance by 11.2%. Conclusions. This three-dimensional simulation model made it possible to study the behavior of a spinal segment in different situations and to obtain data not available from experimental studies, such as the distribution of force concentrations. Keywords: biomechanics, finite elements, spine, transpedicular fixation.En las últimas décadas se ha producido un aumento del uso instrumentaciones posteriores en las intervenciones del raquis que no se ha correlacionado con un conocimiento paralelo de las modificaciones que se producen1 . El estudio con modelos experimentales en el laboratorio es una forma directa de analizar el comportamiento del implante ante las cargas y, sin embargo, presenta una serie de limitaciones. Resulta muy difícil evaluar el desarrollo tensional y la redistribución de las cargas del sistema. Además, existe el problema de la dispersión de datos por la utilización de tejidos orgánicos. La metodología matemática de los elementos finitos nos permite superar estos problemas2 .En este estudio se analizan las variaciones del comportamiento biomecánico mediante el análisis de elementos finitos de un segmento vertebral al añadir un fijador transpedicular