[Translated article] Comparative clinical and biomechanical study of different types of osteosynthesis in the treatment of distal femur fractures.

INTRODUCTION AND OBJECTIVES: Distal femoral fractures represent a problem due to their high number of complications. The aim was to compare the results, complications and stability achieved with retrograde intramedullary nailing and the angular stable plate in the treatment of distal femoral diaphyseal fractures. MATERIAL AND METHOD: A clinical and experimental biomechanical study was carried out using finite elements. The results of the simulations allowed us to obtain the main results related to the stability of osteosynthesis. For clinical follow-up data, frequencies were used for qualitative variables, and Fisher's exact test and χ2 test were used to evaluate the significance of the different factors, with the condition of P<.05. RESULTS: In the biomechanical study, the retrograde intramedullar nails demonstrated superiority, obtaining lower values in terms of global displacement, maximum tension, torsion resistance, and bending resistance. In the clinical study, the rate of consolidation of the plates was lower than nails (77% vs. 96%, P=.02). The factor that most influenced the healing of fractures treated with plate were the central cortical thickness (P=.019). The factor that most influenced the healing of nail-treated fractures was the difference between the diameter of the medullary canal and the nail. CONCLUSIONS: Our biomechanical study shows that both osteosynthesis provide sufficient stability, but biomechanically behaves differently. Nails provide greater overall stability being preferable the use of long nails adjusted to the diameter of the canal. Plates form less rigid osteosynthesis, with little resistance to bending.

Comparative clinical and biomechanical study of different types of osteosynthesis in the treatment of distal femur fractures. / Estudio comparativo clínico y biomecánico de distintos tipos de osteosíntesis en el tratamiento de fracturas distales de fémur.

INTRODUCTION AND OBJECTIVES: Distal femoral fractures represent a problem due to their high number of complications. The aim was to compare the results, complications and stability achieved with retrograde intramedullary nailing and the angular stable plate in the treatment of distal femoral diaphyseal fractures. MATERIAL AND METHOD: A clinical and experimental biomechanical study was carried out using finite elements. The results of the simulations allowed us to obtain the main results related to the stability of osteosynthesis. For clinical follow-up data, frequencies were used for qualitative variables, and Fisher's exact test and χ2 test were used to evaluate the significance of the different factors, with the condition of P<.05. RESULTS: In the biomechanical study, the retrograde intramedullar nails demonstrated superiority, obtaining lower values in terms of global displacement, maximum tension, torsion resistance, and bending resistance. In the clinical study, the rate of consolidation of the plates was lower than nails (77% vs. 96%, P=.02). The factor that most influenced the healing of fractures treated with plate were the central cortical thickness (P=.019). The factor that most influenced the healing of nail-treated fractures was the difference between the diameter of the medullary canal and the nail. CONCLUSIONS: Our biomechanical study shows that both osteosynthesis provide sufficient stability, but biomechanically behaves differently. Nails provide greater overall stability being preferable the use of long nails adjusted to the diameter of the canal. Plates form less rigid osteosynthesis, with little resistance to bending.

Influence of plate size and screw distribution on the biomechanical behaviour of osteosynthesis by means of lateral plates in femoral fractures.

Distal femoral fractures are fractures associated with high rates of morbidity and mortality, affecting to three different groups of individuals: younger people suffering high-energy trauma, elderly people with fragile bones and people with periprosthetic fractures around previous total knee arthroplasty. They have been classically treated with conventional plates and intramedullary nails and more recently with locked plates that have increased their indications to more types of fractures. The main objective of the present work is the biomechanical study, by means of finite element simulation, of the stability achieved in the osteosynthesis of femoral fractures in zones 4 and 5 of Wiss, by using locked plates with different plate lengths and different screw configurations, and analysing the effect of screw proximity to the fracture site. A three dimensional (3D) finite element model of the femur from 55-year-old male donor was developed, and then a stability analysis was performed for the fixation provided by Osteosynthesis System LOQTEC® Lateral Distal Femur Plate in two different fracture zones corresponding to the zones 4 and 5 according to the Wiss fracture classification. The study was focused on the immediately post-operative stage, without any biological healing process. The obtained results show that more stable osteosyntheses were obtained by using shorter plates. In the cases of longer plates, it results more convenient disposing screws in a way that the upper ones are closer to fracture site. The obtained results can support surgeons to understand the biomechanics of fracture stability, and then to guide them towards the more appropriate osteosynthesis depending on the fracture type and location.

Fractura de cadera en pacientes centenarios, ¿qué podemos esperar? / Hip fracture in centenarians, what can we expect?

Introducción: La mejoría de la esperanza de vida está incrementando la incidencia de fractura de cadera en centenarios. Nuestro objetivo es comparar las características basales de una serie de centenarios con fractura de cadera frente a controles de menor edad, analizando si existen diferencias en cuanto a complicaciones, mortalidad intrahospitalaria y supervivencia a corto-medio plazo. Material y métodos: Estudio retrospectivo, tipo caso control, sobre 24 centenarios y 48 controles octogenarios con fractura de cadera. Se analizó la presencia de comorbilidades y el índice de Charlson, la demora quirúrgica, las complicaciones, la estancia hospitalaria y la mortalidad durante el ingreso. Al alta se valoró la mortalidad precoz, la supervivencia después del año y el retorno a la funcionalidad previa. Resultados: No se encontraron diferencias significativas en parámetros basales ni en comorbilidades (p>0,05), siendo el paciente tipo una mujer con fractura extracapsular. La estancia hospitalaria fue mayor en el grupo control (p=0,038) y la complicación más frecuente la anemia, que precisó transfusión sanguínea (23/24 en los centenarios, p<0,0001). La mortalidad intrahospitalaria y acumulada al año en los centenarios fue del 33 y el 67%, respectivamente, frente al 10 y 25% en octogenarios (p=0,017, OR=4,3 [1,224-15,101] y p=0,110]. Solo 2 pacientes centenarios consiguieron volver a caminar tras la intervención, frente a un 53,84% que volvió a la situación funcional previa en los controles (p=0,003). Conclusiones: Frente a un grupo control de pacientes de menor edad, la mortalidad intrahospitalaria y en el primer año tras una fractura de cadera es significativamente mayor en los centenarios y muy pocos recuperan la actividad previa a la fractura.(AU)

Introduction: Hip fractures in centenarians are rising due to the increase in life expectancy. The objective of this study is to compare the characteristics of centenarians’ hip fracture with a younger control group, and to analyze whether there are differences in terms of in-hospital mortality, complications, and short-medium-term survival between them. Material and methods: Retrospective case-control study, with a series of 24 centenarians and 48 octogenarians with a hip fracture. Comorbidities and Charlson index, surgical delay, complications and mortality during admission, and hospital stay were analyzed. At discharge, early mortality, survival after one year, and return to previous functionality were assessed. Results: No significant differences were found in baseline parameters or comorbidities (P>.05), and the type of was a woman with an extracapsular fracture. Hospital stay was longer in the control group (P=.038), and the most frequent complication was anemia requiring transfusion (23/24 in centenarians, P<.0001). In-hospital mortality and accumulated at one year in the centenarians was 33 and 67%, respectively, compared to 10 and 25% in the octogenarians (P=.017, OR=4.3 [1,224-15,101] and P=.110). Only 2 centenarian patients were able to walk again after the intervention, while in the control group 53.84% returned to the previous functional situation (P=.003). Conclusions: Compared to a control group of younger patients, in-hospital mortality and in the first year after a hip fracture is significantly higher in centenarians, and very few recover activity prior to the fracture.(AU)

Primary total hip arthroplasty for acetabular fractures in elderly patients / Artroplastia total de cadera primaria en fractura de acetábulo en el paciente anciano

Introduction: Life expectancy has risen, leading to an increase in acetabular fractures in fragile patients. Total hip arthroplasty with a reinforcement cage is a technically complex option, but allows fracture control and early mobilization. Our aim is to assess whether the use of Burch-Schneider cage in fragile patients with acetabular fractures allows immediate load stabilization without threatening the early survival of the arthroplasty. Material and methods: Descriptive study of a series of 14 patients with acetabular fractures treated by a reinforcement cage associated with autologous bonegraft plus a cemented acetabular cup, and mobilization and bearing. Judet Letournel fracture types, surgical delay, and complications during admission were analyzed. Following hospital discharge we recorded the incorporation of grafts according to Gie's classification, presence of calcifications according to Brooker, consolidation of the fracture, loosening of implants and functional aspects according to the HHS and Merlé D’Aubigné Postel score. Results: The most common fracture was both columns (6/14), with a surgical delay being of 11 days mean and 21,5 days of length of stay. One patient died after surgery. The mean follow-up was 34.4 months. All fractures healed and the bonegraft was incorporated in all cases. The mean HHS was 82 points and the Merle Score was 15/18. There were no complications related to arthroplasty. Conclusions: Total hip arthroplasty with Burch-Schneider cage on bonegraft and no added osteosynthesis is a good option of treatment of all types of displaced acetabular fractures in a fragile patient.(AU)

Introducción: El aumento de esperanza de vida está produciendo un incremento de fracturas de cotilo en el paciente anciano. La artroplastia total con anillo de refuerzo es una opción técnicamente compleja, pero permite el control de la fractura, la movilización y la deambulación precoz. Nuestro objetivo es valorar si el uso del anillo de Burch-Schneider en las fracturas de cotilo del paciente anciano permite la estabilización sin poner en riesgo la supervivencia precoz de la artroplastia. Material y métodos: Estudio descriptivo sobre una serie de 14 pacientes con fracturas de cotilo tratados mediante anillo de refuerzo asociado a autoinjerto más implante acetabular cementado e inicio precoz de movilización y deambulación. Se analizaron los tipos de fractura según la clasificación de Judet Letournel, la demora quirúrgica y las complicaciones durante el ingreso. Al alta se valoró la incorporación de injertos según la clasificación de Gie, la presencia de calcificaciones según Brooker, la consolidación de la fractura, la movilización de implantes y los aspectos funcionales según la escala de HHS y Merlé D’Aubigné Postel. Resultados: La fractura más frecuente fue la de ambas columnas (6/14), la demora quirúrgica media de 11 días y la estancia media de 21,5 días. Un paciente falleció en el postoperatorio inmediato. El seguimiento medio fue de 34,4 meses. Todas las fracturas consolidaron e incorporaron el injerto. El HHS medio fue de 82 puntos y el Merle Score de 15/18. No hubo complicaciones relativas a la artroplastia. Conclusiones: La artroplastia primaria de cadera con anillo de BS sobre injerto sin osteosíntesis añadida es una buena opción en el tratamiento de todo tipo de fracturas de cotilo desplazadas en paciente frágil.(AU)

Artroplastia total de cadera primaria en fractura de acetábulo en el paciente anciano / Primary total hip arthroplasty for acetabular fractures in elderly patients

Introducción: El aumento de esperanza de vida está produciendo un incremento de fracturas de cotilo en el paciente anciano. La artroplastia total con anillo de refuerzo es una opción técnicamente compleja, pero permite el control de la fractura, la movilización y la deambulación precoz. Nuestro objetivo es valorar si el uso del anillo de Burch-Schneider en las fracturas de cotilo del paciente anciano permite la estabilización sin poner en riesgo la supervivencia precoz de la artroplastia. Material y métodos: Estudio descriptivo sobre una serie de 14 pacientes con fracturas de cotilo tratados mediante anillo de refuerzo asociado a autoinjerto más implante acetabular cementado e inicio precoz de movilización y deambulación. Se analizaron los tipos de fractura según la clasificación de Judet Letournel, la demora quirúrgica y las complicaciones durante el ingreso. Al alta se valoró la incorporación de injertos según la clasificación de Gie, la presencia de calcificaciones según Brooker, la consolidación de la fractura, la movilización de implantes y los aspectos funcionales según la escala de HHS y Merlé D’Aubigné Postel. Resultados: La fractura más frecuente fue la de ambas columnas (6/14), la demora quirúrgica media de 11 días y la estancia media de 21,5 días. Un paciente falleció en el postoperatorio inmediato. El seguimiento medio fue de 34,4 meses. Todas las fracturas consolidaron e incorporaron el injerto. El HHS medio fue de 82 puntos y el Merle Score de 15/18. No hubo complicaciones relativas a la artroplastia. Conclusiones: La artroplastia primaria de cadera con anillo de BS sobre injerto sin osteosíntesis añadida es una buena opción en el tratamiento de todo tipo de fracturas de cotilo desplazadas en paciente frágil.(AU)

Introduction: Life expectancy has risen, leading to an increase in acetabular fractures in fragile patients. Total hip arthroplasty with a reinforcement cage is a technically complex option, but allows fracture control and early mobilization. Our aim is to assess whether the use of Burch-Schneider cage in fragile patients with acetabular fractures allows immediate load stabilization without threatening the early survival of the arthroplasty. Material and methods: Descriptive study of a series of 14 patients with acetabular fractures treated by a reinforcement cage associated with autologous bonegraft plus a cemented acetabular cup, and mobilization and bearing. Judet Letournel fracture types, surgical delay, and complications during admission were analyzed. Following hospital discharge we recorded the incorporation of grafts according to Gie's classification, presence of calcifications according to Brooker, consolidation of the fracture, loosening of implants and functional aspects according to the HHS and Merlé D’Aubigné Postel score. Results: The most common fracture was both columns (6/14), with a surgical delay being of 11 days mean and 21,5 days of length of stay. One patient died after surgery. The mean follow-up was 34.4 months. All fractures healed and the bonegraft was incorporated in all cases. The mean HHS was 82 points and the Merle Score was 15/18. There were no complications related to arthroplasty. Conclusions: Total hip arthroplasty with Burch-Schneider cage on bonegraft and no added osteosynthesis is a good option of treatment of all types of displaced acetabular fractures in a fragile patient.(AU)

Hip fracture in centenarians, what can we expect? / Fractura de cadera en pacientes centenarios, ¿qué podemos esperar?

INTRODUCTION: Hip fractures in centenarians are rising due to the increase in life expectancy. The objective of this study is to compare the characteristics of centenarians' hip fracture with a younger control group, and to analyze whether there are differences in terms of in-hospital mortality, complications, and short-medium-term survival between them. MATERIAL AND METHODS: Retrospective case-control study, with a series of 24 centenarians and 48 octogenarians with a hip fracture. Comorbidities and Charlson index, surgical delay, complications and mortality during admission, and hospital stay were analyzed. At discharge, early mortality, survival after one year, and return to previous functionality were assessed. RESULTS: No significant differences were found in baseline parameters or comorbidities (P>.05), and the type of was a woman with an extracapsular fracture. Hospital stay was longer in the control group (P=.038), and the most frequent complication was anemia requiring transfusion (23/24 in centenarians, P<.0001). In-hospital mortality and accumulated at one year in the centenarians was 33 and 67%, respectively, compared to 10 and 25% in the octogenarians (P=.017, OR=4.3 [1,224-15,101] and P=.110). Only 2 centenarian patients were able to walk again after the intervention, while in the control group 53.84% returned to the previous functional situation (P=.003). CONCLUSIONS: Compared to a control group of younger patients, in-hospital mortality and in the first year after a hip fracture is significantly higher in centenarians, and very few recover activity prior to the fracture.

Primary total hip arthroplasty for acetabular fractures in elderly patients. / Artroplastia total de cadera primaria en fractura de acetábulo en el paciente anciano.

INTRODUCTION: Life expectancy has risen, leading to an increase in acetabular fractures in fragile patients. Total hip arthroplasty with a reinforcement cage is a technically complex option, but allows fracture control and early mobilization. Our aim is to assess whether the use of Burch-Schneider cage in fragile patients with acetabular fractures allows immediate load stabilization without threatening the early survival of the arthroplasty. MATERIAL AND METHODS: Descriptive study of a series of 14 patients with acetabular fractures treated by a reinforcement cage associated with autologous bonegraft plus a cemented acetabular cup, and mobilization and bearing. Judet Letournel fracture types, surgical delay, and complications during admission were analyzed. Following hospital discharge we recorded the incorporation of grafts according to Gie's classification, presence of calcifications according to Brooker, consolidation of the fracture, loosening of implants and functional aspects according to the HHS and Merlé D'Aubigné Postel score. RESULTS: The most common fracture was both columns (6/14), with a surgical delay being of 11 days mean and 21,5 days of length of stay. One patient died after surgery. The mean follow-up was 34.4 months. All fractures healed and the bonegraft was incorporated in all cases. The mean HHS was 82 points and the Merle Score was 15/18. There were no complications related to arthroplasty. CONCLUSIONS: Total hip arthroplasty with Burch-Schneider cage on bonegraft and no added osteosynthesis is a good option of treatment of all types of displaced acetabular fractures in a fragile patient.

A new approach for initial callus growth during fracture healing in long bones.

The incidence of bone fracture has become a major clinical problem on a worldwide scale. In the past two decades there has been an increase in the use of computational tools to analyse the bone fracture problem. In several works, various study cases have been analysed to compare human and animal bone fracture healing. Unfortunately, there are not many publications about computational advances in this field and the existing approaches to the problem are usually similar. In this context, the objective of this work is the application of a diffusion problem in the model of the bone fragments resulting from fracture, working together with a mesh-growing algorithm that allows free growth of the callus depending on the established conditions, without a pre-meshed domain. The diffusion problem concerns the different biological magnitudes controlling the callus growth, among which Mesenchymal Stem Cells and chondrocytes concentrations were chosen, together with Tumour Necrosis Factor α and Bone Morphogenetic Protein as the factors influencing the velocity in the callus formation. A Finite Element approach was used to solve the corresponding diffusion problems, obtaining the concentration values along the entire domain and allowing detecting the zones in which biological magnitudes reach the necessary thresholds for callus growth. The callus growth is guided by a geometrical algorithm which performs an additional mesh generation process (self-added mesh) at each step of the iterative procedure until complete callus formation. The proposed approach was applied to different types of diaphyseal femoral fractures treated by means of intramedullary nailing. Axisymmetric models based on triangular quadratic elements were used, obtaining results in good agreement with clinical evidence of these kinds of fractures. The algorithm proposed has the advantage of a natural callus growth, without the existence of a previous mesh that may affect the conditions and direction of growth. The approach is intended for the initial phase of callus growth. Future work will address the implementation of the corresponding formulations for tissue transformation and bone remodelling in order to achieve complete fracture healing.

Outcomes of basicervical femoral neck fracture treated with percutaneous compression plate (PCCP).

INTRODUCTION: Basicervical femoral neck fracture is associated with high rates of failure due instability patterns, mainly collapse and rotational instability. The purpose of this study was to evaluate the clinical-radiological results of a group of patients with a bascervical proximal femoral fractures treated with Percutaneous Compression Plate (PCCP). MATERIAL AND METHODS: Among 5817 patients with a hip fracture who were admitted in our hospital from January 2005 to December 2017, 234 factures (4%) were diagnosed of basicervical femoral fracture. 30 of them were treated with a PCCP, 22 women and 8 men, mean age was 81.2 years (63-94). Demographic and perioperative variables were collected. The patients were followed up at 1, 3 and 6 months clinically and radiologically. RESULTS: There were no intra-operative complications and no conversions to open surgery. There was no early implant failure. No surgical wound infection was diagnosed. Crude mortality was 13% the first year and 87% were able to walk at the 6 months. The last follow-up x-rays revealed 97% fracture healing and the collapse at fracture site occurred in 4 hips. No instances of cut-out were observed. In one case, a fatigue failure of the lag screws of a PCCP plate was observed at 3 months from osteosynthesis. CONCLUSION: PCCP is an appropriated implant for basicervical femoral neck fractures.

Are the unreamed nails indicated in diaphyseal fractures of the lower extremity? A biomechanical study.

INTRODUCTION: Intramedullary nailing is generally accepted as the first choice for the treatment of diaphyseal fractures of femur and tibia, with a gradual incease in the use of unreamed nails. Different studies during last years show controversial outcomes. Some authors strongly favor unreamed nailing, but most of the authors conclude that reamed nailing have proved to be more successful. MATERIAL AND METHODS: This study simulates unreamed intramedullary nailing of four femoral and three tibial fracture types by means of Finite Element (FE) models, at early postoperative stages with a fraction of physiological loads, in order to determine whether sufficient stability is achieved, and if the extent of movements and strains at the fracture site may preclude proper consolidation. RESULTS: The behavior observed in the different fracture models is very diverse. In the new biomechanical situation, loads are only transmitted through the intramedullary nail. Mean relative displacement values of fractures in the femoral bone range from 0.30 mm to 0.82 mm, depending on the fracture type. Mean relative displacement values of the tibial fractures lie between 0.18 and 0.62 mm, depending on the type of fracture. Concerning mean strains, for femoral fractures the maximum strains ranged between 12.7% and 42.3%. For tibial fractures the maximum strains ranged between 10.9% and 40.8%. CONCLUSIONS: The results showed that unreamed nailing provides a very limited mechanical stability, taking into account that analyzed fracture patterns correspond to simple fracture without comminution. Therefore, unreamed nailing is not a correct indication in femoral fractures and should be an exceptional indication in open tibial fractures produced by high-energy mechanism.

Biomechanical behavior of retrograde intramedullary nails in distal femoral fractures.

Fractures of the distal femur affect three different groups of individuals: younger people suffering high-energy trauma, elderly people with fragile bones and people with periprosthetic fractures around previous total knee arthroplasty. Main indications of intramedullary nailing are for supracondylar fractures type A or type C of the AO classification. The main objective of the present work is to analyze, by means of FE simulation, the influence of retrograde nail length, considering different blocking configurations and fracture gaps, on the biomechanical behavior of supracondylar fractures of A type. A three dimensional (3D) finite element model of the femur from 55-year-old male donor was developed, and then a stability analysis was performed for the fixation provided by the retrograde nail at a distal fracture with different fracture gaps: 0.5 mm, 3 mm y 20 mm, respectively. Besides, for each gap, three nail lengths were studied with a general extent (320 mm, 280 mm and 240 mm), considering two transversal screws (M/L) at the distal part and different screw combinations above the fracture. The study was focused on the immediately post-operative stage, without any biological healing process. In view of the obtained results, it has been demonstrated new possibilities of blocking configuration in addition to the usual ones, which allows establishing recommendations for nail design and clinical practice, avoiding excessive stress concentrations both in screws, with the problem of rupture and loss of blocking, and in the contact of nail tip with cortical bone, with the problem of a new stress fracture.

Salvage of cephalomedullary nail cutout with the variable angle proximal femoral plate.

INTRODUCTION: Excellent results have been published in the treatment of the trochanteric fractures in the elderly with cephalomedullary nails or compression hip screws but not free of complications. The perforation of the lag screw through the superior cortex of femoral neck or head followed by rotation and varus collapse of the head-neck fragment, also known as cut-out, is one of them. Probably total hip arthroplasty is the most common solution, but there is no systematic technique for treatment. The objective of this study is to evaluate the results obtained in the treatment of this complication using a variable angle femoral plate. MATERIAL AND METHODS: This retrospective study concerns patients over 65 years with peritrochanteric fractures treated with cephalomedullary nail with cut-out failure solved by re-osteosyntesis with variable angle femoral plate between 1st January 2000 and 31 st December 2017. The series includes 29 patients, 26 women and 3 men with average age 87,3. Patients were followed up clinically and radiologically at regular intervals until fracture consolidation at least 9 months. RESULTS: No patients died at the first 9 months after surgery. Fracture mean consolidation has occurred in all patients in 14th weeks (6-20). Operative time was 93,2 minutes (62-129) including removal of nail. No intraoperative complications were observed. Five patients experienced medical complications and two had a superficial wound infection. The mean tip-apex distance (TAD) was 5mm (2-7mm). The neck-shaft angle was 127 degrees. The mean valgization achieved was 32 degrees (15-40). Only one patient needed a second revision surgery due to aseptic hip joint subluxation after 8 weeks of the surgery solved with total hip arthroplasty. CONCLUSIONS: The use of variable angle femoral plate in the cut-out treatment is an attractive option which allows the valgization of the fracture to virtually physiological limits and the placement of the cephalic screw in the most sutiable position with good outcomes and few complications.

Is the mortality higher in patients who have suffered a hip fracture? / ¿Es mayor la mortalidad en los pacientes que han sufrido una fractura de cadera?

BACKGROUND AND OBJECTIVE: The aim of this study is to value whether patients who have suffered a hip fracture have a higher mortality than expected. MATERIAL AND METHODS: A prospective, observational study was carried out where patients with hip fracture were collected as a sample over a year. The study included 284 patients and a minimum follow-up was 2 years. The mean age of these patients was 84.26 years, with 21.48% (61/284) males and 78.5% (223/284) females. Survival and previous diseases that affect mortality, as risk factors, were collected and analyzed using the Kaplan-Meier method and the Cox regression model. Actual mortality was compared with that expected according to the Charlson Comorbidity Index, adjusted for age. RESULTS: Previous pathology was the main mortality factor, with heart disease being the most significant (OR 1.817, CI95%: 1.048; 3.149). The real mortality at one year of the sample was 22.5%, while the estimated annual mortality according to the Charlson Comorbidity Index was 29.68% (CI95%:44,36-15). CONCLUSIONS: Hip fracture does not cause an increase in mortality according to the Charlson Comorbidity Index estimate.

Factores de riesgo en fractura periprotésica femoral tras artroplastia sustitutiva primaria de rodilla / Risk factors of periprosthetic femoral fracture after total knee arthroplasty

INTRODUCCIÓN Y OBJETIVOS: Las fracturas periprotésicas tras artroplastia primaria de rodilla cobran gran importancia en nuestro medio debido tanto al aumento de su incidencia, como al reto que suponen para el cirujano. Múltiples factores se han asociado a su producción. El objetivo del estudio fue identificar los factores de riesgo que podían influir en la aparición de estas fracturas, cuáles de todos ellos son modificables y generar un modelo de predicción de probabilidad de las mismas en función de dichos factores. MATERIAL Y MÉTODO: Estudio analítico, observacional, retrospectivo, no pareado, de 38 casos de fracturas periprotésicas femorales de rodilla y 80 controles con prótesis de rodilla. En total, fueron incluidos en el estudio 118 pacientes, 83 mujeres y 35 hombres con una edad media de 72,49 años. Se recogieron datos sociodemográficos, antecedentes médicos y consumo de fármacos, así como los relativos a la cirugía. Se realizó un análisis uni- y bivariante de los factores determinantes de fractura, usando un modelo de regresión logística para evitar el sesgo de confusión. RESULTADOS: De todos los factores estudiados según el modelo de regresión logística, se obtuvo que el sexo femenino (OR = 7,6), la demencia (OR = 5), la alteración motora/párkinson (OR = 19,3) y el sobrecorte femoral anterior (OR = 8,6) eran factores asociados al incremento de riesgo de este tipo de fracturas. CONCLUSIONES: Este trabajo permite concluir que hay factores de riesgo, como son el sexo femenino, la demencia y el párkinson, que aumentan la probabilidad de fractura periprotésica, que son inherentes al paciente y no son modificables. Sin embargo, existe algún otro totalmente modificable que puede evitarse siendo exigente y exhaustivo en la técnica quirúrgica, como es el sobrecorte femoral anterior

INTRODUCTION AND OBJECTIVES: Periprosthetic fractures after primary knee arthroplasty has great importance in our environment due to the increase in their incidence and to the challenge they pose to the surgeon. Multiple factors have been associated with its production. The objective of the study was to identify the risk factors that could influence the appearance of these fractures, which of them are all modifiable and generate a probability prediction model based on these factors. MATERIAL AND METHODS: Analytical, observational, retrospective, unpaired study of 38 cases of periprosthetic femoral knee fractures and 80 controls with knee prostheses. In total, 118 patients, 83 women and 35 men with a mean age of 72.49 years were included in the study. Sociodemographic data, medical history and drug consumption were collected, as well as those related to surgery. A univariate and bivariate analysis of the fracture determining factors was performed, using a logistic regression model to avoid confusion bias. RESULTS: Of all the factors studied according to the logistic regression model, it was obtained that female sex (OR = 7.6), dementia (OR = 5), motor/parkinson's alteration (OR = 19.3) and femoral overcut Previous (OR = 8.6) were factors associated with the increased risk of this type of fractures. CONCLUSIONS: This work allows us to conclude that there are risk factors such as female sex, dementia and parkinson's that increase the probability of periprosthetic fracture that are inherent to the patient and are not modifiable. However, there is any other totally modifiable that can be avoided by being demanding and thorough in the surgical technique, such as the anterior femoral overcut

Risk factors of periprosthetic femoral fracture after total knee arthroplasty. / Factores de riesgo en fractura periprotésica femoral tras artroplastia sustitutiva primaria de rodilla.

INTRODUCTION AND OBJECTIVES: Periprosthetic fractures after primary knee arthroplasty has great importance in our environment due to the increase in their incidence and to the challenge they pose to the surgeon. Multiple factors have been associated with its production. The objective of the study was to identify the risk factors that could influence the appearance of these fractures, which of them are all modifiable and generate a probability prediction model based on these factors. MATERIAL AND METHODS: Analytical, observational, retrospective, unpaired study of 38 cases of periprosthetic femoral knee fractures and 80 controls with knee prostheses. In total, 118 patients, 83 women and 35 men with a mean age of 72.49 years were included in the study. Sociodemographic data, medical history and drug consumption were collected, as well as those related to surgery. A univariate and bivariate analysis of the fracture determining factors was performed, using a logistic regression model to avoid confusion bias. RESULTS: Of all the factors studied according to the logistic regression model, it was obtained that female sex (OR = 7.6), dementia (OR = 5), motor/parkinson's alteration (OR = 19.3) and femoral overcut Previous (OR = 8.6) were factors associated with the increased risk of this type of fractures. CONCLUSIONS: This work allows us to conclude that there are risk factors such as female sex, dementia and parkinson's that increase the probability of periprosthetic fracture that are inherent to the patient and are not modifiable. However, there is any other totally modifiable that can be avoided by being demanding and thorough in the surgical technique, such as the anterior femoral overcut.

Comparative analysis of the biomechanical behavior of anterograde/retrograde nailing in supracondylar femoral fractures.

Supracondylar femoral fractures account for a noticeable percentage of the femoral shaft fractures, affecting two etiological groups: high energy trauma in young men, with good bone quality, and older women with osteoporotic femur. Surgical treatment of those kind of fractures remains controversial, with different surgical options such as plate and sliding barrel locking condylar plate, less invasive stabilization system (LISS) or intramedullary nailing, which has emerged as a new fixation choice in the treatment of that type of fractures. The present work performs a comparative study about the biomechanical behavior of anterograde and retrograde nailing in supracondylar femoral fractures type A, in order to determine the best choice of nailing and locking configuration. A three-dimensional finite element model of the femur was developed, modeling femoral supracondylar fracture and different nailing configurations, both for anterograde and retrograde nails. The study was focused on the immediately post-operative stage, verifying the appropriate stability of the osteosynthesis. The obtained results show a better biomechanical behavior for anterograde nails, providing a better stability from the point of view of global movements, lower stresses in screws, and less stress concentration in cortical bone. So, for the analyzed fractures and osteosyntheses types, anterograde nailing has demonstrated to be a better surgical option, being an excellent indication in supracondylar fractures of femur, with clear benefits compared to retrograde nailing, providing a better stabilization which enables for a more satisfactory fracture healing.

Biomechanical analysis of the stability of anterograde reamed intramedullary nails in femoral spiral fractures.

Femoral shaft fractures present high morbidity and important complications and consequences, being spiral fractures the most complicated from a biomechanical point of view, being unstable and without possibility of getting a good contact between nail and femoral endosteum. Femoral diaphyseal fractures are treated, usually, by means of intramedullary nailing. So, it is necessary to know the osteosynthesis stability and which locking screws combination is optimal. This work studies the use of reamed locked intramedullary nails in spiral femoral fractures located along zones 2 and 4 of wiss, depending on the spire length, corresponding to 32-A spiral type in AO/OTA classification, which represent a percentage of 23% within the total of diaphyseal fractures. A three-dimensional finite element model of the femur was developed, modeling a spiral fracture with different spiral lengths and gaps. A femoral nail was used, considering two transversal screws both at the proximal and the distal parts. The study was focused on the immediately post-operative stage, verifying the appropriate stability of the osteosynthesis. Reamed intramedullary blocked nails provide appropriate stability of femoral spiral fractures, considering global mobility of femoral head with respect to femoral condyles, relative displacements between fragments at fracture site, stresses at nail and locking screws, and stresses at cortical bone. The obtained results show that the use of blocked reamed nails in spiral femoral fractures can be considered as an appropriate surgical technique, providing sufficient stability in order to obtain an adequate fracture healing.

Causas de ingresos no deseados tras la realización de procedimientos quirúrgicos de cirugía ortopédica y traumatología en cirugía mayor ambulatoria / Causes of unplanned admission after orthopedic procedures in ambulatory surgery

OBJETIVO: Los procedimientos de cirugía ortopédica y traumatología realizados en unidades de cirugía mayor ambulatoria ofrecen importantes ventajas que desaparecen cuando la recuperación postoperatoria no es la esperada y los pacientes precisan ingresar. El objetivo de este estudio es analizar las causas de ingresos no deseados tras intervenciones quirúrgicas de cirugía ortopédica y traumatología en una unidad de cirugía mayor ambulatoria en relación con variables como edad, riesgo anestésico, tipo de anestesia, procedimiento o duración. MÉTODOS: Estudio de cohorte ambispectivo sobre 5.085 pacientes intervenidos desde 1995 a 2017. Se analizaron 39 variables proporcionadas por la base de datos de la unidad que se abre al ingreso en la misma y se cierra el día 30 postoperatorio. RESULTADOS: El 98,2% de los pacientes fueron dados de alta de la unidad. Precisaron ingresar 74 (1,5%). Este porcentaje demostró diferencias significativas en relación con el tipo de procedimiento, el tipo de anestesia y la duración, que condicionaron el ingreso inmediato por mal control del dolor agudo postoperatorio, náuseas o alteraciones de la herida. Diecisiete pacientes (0,3%) precisaron un ingreso diferido por complicaciones surgidas en el domicilio, siendo la más frecuente la infección de la herida. CONCLUSIONES: Los ingresos no deseados se relacionan con mayor frecuencia con el empleo de anestesia general, con operaciones de mayor duración y con procedimientos como la cirugía artroscópica, las correcciones de hallux valgus o las retiradas de material de osteosíntesis, siendo las causas de ingreso más importantes el mal control del dolor agudo postoperatorio en los inmediatos y la infección de la herida en los diferidos

OBJECTIVE: Orthopaedic procedures performed in Day Surgery Units provide important advantages which disappear when patients require admission when postoperative recovery is not as expected. The aim of this study was to analyse the reasons for unplanned hospital admissions after orthopaedic procedures in a Day Surgery Unit and their relationship between variables such as patient age, anaesthetic risk and technique, procedure or duration. METHODS: Ambispective cohort study of 5,085 patients who underwent surgical orthopaedic procedures between 1995 and 2017. Thirty-nine variables provided by the Unit's database were analysed. The database was opened on the day of admission and closed the 30th postoperative day. RESULTS: Of the patients, 98.2% were discharged from the Unit. Seventy-four (1.5%) required overnight admission. This percentage showed significant differences in relation to the type of procedure, type of anaesthesia and duration, which conditioned overnight admission due to inadequate postoperative pain management, nausea or wound complications. Seventeen patients (0.3%) required readmission after discharge due to complications that arose at home, such as wound infection, which was the most common. CONCLUSIONS: Unplanned admissions are more frequently related to general anaesthesia, lengthy surgeries and procedures such as arthroscopy, hallux valgus corrections or removal of osteosynthesis material. The major reasons for unplanned admissions were inadequate postoperative pain management for overnight admissions and wound infection for admissions after discharge