Cierre de herida en cirugía protésica de rodilla y cadera (PTR y PTC): Resultados de una encuesta sobre la práctica clínica en España / Wound closure after knee and hip replacement (TKA and THA): Survey results on the clinical practice in Spain

Introducción y objetivos: En cirugía protésica de rodilla y cadera está claro que aún no se ha desarrollado una técnica de cierre estandarizada óptima. A nivel local no existen datos que describan la práctica quirúrgica habitual en cierre de herida. El objetivo de este trabajo es analizar el cierre de herida en cirugía protésica a través de una encuesta sobre una muestra representativa a nivel nacional y así obtener información sobre el contexto del cierre en España. Material y método: Se conforma un grupo ad hoc de especialistas en cirugía protésica. El grupo de expertos, posterior al análisis de la literatura, elabora un cuestionario de 32 preguntas cerradas de opción múltiple, divididas en los siguientes bloques: hemostasia, cierre quirúrgico de la herida y apósitos. Resultados: Un total de 471 cirujanos respondieron la encuesta de forma completa y con información suficiente para efectuar el análisis descriptivo; 79% cree que el ácido tranexámico (ATX) puede influir en la disminución de tasa de infección de sitio quirúrgico; 96% cree que el tipo de cierre profundo a nivel de la artrotomía podría influir en los resultados y complicaciones tras prótesis de cadera y/o rodilla; 85% cree que el tipo de cierre superficial a nivel subcutáneo puede influir en los resultados y complicaciones tras prótesis de cadera y/o rodilla; 64% de los cirujanos utiliza la terapia de presión negativa incisional de simple uso para el tratamiento de las complicaciones de la herida quirúrgica (seromas, drenaje prolongado, dehiscencias). Conclusiones: Existe en nuestro entorno una alta variabilidad en el cierre de la herida y una baja inversión en formación sobre este tema. Los autores recomiendan a las diferentes sociedades científicas la inversión de recursos para mejorar la formación en dicho campo y reducir el porcentaje de cirujanos que se consideran inadecuadamente formados, así como adaptar las técnicas de cierre a aquellas consideradas patrón oro según la evidencia.(AU)

Background and objective: In orthopedic surgery, it is clear that an optimal standardized closure technique has not yet been developed. Locally, there are no objective data describing the standard surgical practice in wound closure. The aim of this study is to analyze the clinical practice of surgical wound closure in orthopedic surgery by means of a survey of a representative local sample and thus obtain information on the context of closure in Spain. Method: an ad hoc group of specialists in orthopedic surgery and traumatology was formed. The group of experts, after analyzing the literature, developed a questionnaire of 32 closed multiple-choice questions divided into the following blocks: hemostasis, surgical wound closure (deep, superficial, and cutaneous), and dressings. Results: A total of 471 surgeons responded to the survey completely and with sufficient information to perform the descriptive analysis. 79% believe that ATX can influence the decrease in surgical site infection rate. 96% believe that the type of deep closure at the level of the arthrotomy could influence outcomes and complications after hip and/or knee replacements. 85% believe that the type of shallow closure at the subcutaneous level may influence outcomes and complications after hip and/or knee replacement. 64% of surgeons use single-use incisional negative pressure therapy for the treatment of surgical wound complications (seroma, prolonged drainage, dehiscence). Conclusions: There is a high level of variability in wound closure in our setting and a low level of training on the subject. The authors recommend that the different scientific societies invest resources to improve training in this field and reduce the percentage of surgeons who are considered inadequately trained, as well as adapting closure techniques to those considered gold standard according to the evidence.(AU)

[Translated article] Wound closure after knee and hip replacement (TKA and THA): Survey results on the clinical practice in Spain / Cierre de herida en cirugía protésica de rodilla y cadera (PTR y PTC): resultados de una encuesta sobre la práctica clínica en España

Introducción y objetivos: En cirugía protésica de rodilla y cadera está claro que aún no se ha desarrollado una técnica de cierre estandarizada óptima. A nivel local no existen datos que describan la práctica quirúrgica habitual en cierre de herida. El objetivo de este trabajo es analizar el cierre de herida en cirugía protésica a través de una encuesta sobre una muestra representativa a nivel nacional y así obtener información sobre el contexto del cierre en España. Material y método: Se conforma un grupo ad hoc de especialistas en cirugía protésica. El grupo de expertos, posterior al análisis de la literatura, elabora un cuestionario de 32 preguntas cerradas de opción múltiple, divididas en los siguientes bloques: hemostasia, cierre quirúrgico de la herida y apósitos. Resultados: Un total de 471 cirujanos respondieron la encuesta de forma completa y con información suficiente para efectuar el análisis descriptivo; 79% cree que el ácido tranexámico (ATX) puede influir en la disminución de tasa de infección de sitio quirúrgico; 96% cree que el tipo de cierre profundo a nivel de la artrotomía podría influir en los resultados y complicaciones tras prótesis de cadera y/o rodilla; 85% cree que el tipo de cierre superficial a nivel subcutáneo puede influir en los resultados y complicaciones tras prótesis de cadera y/o rodilla; 64% de los cirujanos utiliza la terapia de presión negativa incisional de simple uso para el tratamiento de las complicaciones de la herida quirúrgica (seromas, drenaje prolongado, dehiscencias). Conclusiones: Existe en nuestro entorno una alta variabilidad en el cierre de la herida y una baja inversión en formación sobre este tema. Los autores recomiendan a las diferentes sociedades científicas la inversión de recursos para mejorar la formación en dicho campo y reducir el porcentaje de cirujanos que se consideran inadecuadamente formados, así como adaptar las técnicas de cierre a aquellas consideradas patrón oro según la evidencia.(AU)

Background and objective: In orthopedic surgery, it is clear that an optimal standardized closure technique has not yet been developed. Locally, there are no objective data describing the standard surgical practice in wound closure. The aim of this study is to analyze the clinical practice of surgical wound closure in orthopedic surgery by means of a survey of a representative local sample and thus obtain information on the context of closure in Spain. Method: an ad hoc group of specialists in orthopedic surgery and traumatology was formed. The group of experts, after analyzing the literature, developed a questionnaire of 32 closed multiple-choice questions divided into the following blocks: hemostasis, surgical wound closure (deep, superficial, and cutaneous), and dressings. Results: A total of 471 surgeons responded to the survey completely and with sufficient information to perform the descriptive analysis. 79% believe that ATX can influence the decrease in surgical site infection rate. 96% believe that the type of deep closure at the level of the arthrotomy could influence outcomes and complications after hip and/or knee replacements. 85% believe that the type of shallow closure at the subcutaneous level may influence outcomes and complications after hip and/or knee replacement. 64% of surgeons use single-use incisional negative pressure therapy for the treatment of surgical wound complications (seroma, prolonged drainage, dehiscence). Conclusions: There is a high level of variability in wound closure in our setting and a low level of training on the subject. The authors recommend that the different scientific societies invest resources to improve training in this field and reduce the percentage of surgeons who are considered inadequately trained, as well as adapting closure techniques to those considered gold standard according to the evidence.(AU)

[Translated article] Wound closure after knee and hip replacement (TKA and THA): Survey results on the clinical practice in Spain.

BACKGROUND AND OBJECTIVE: In orthopaedic surgery, it is clear that an optimal standardised closure technique has not yet been developed. Locally, there are no objective data describing the standard surgical practice in wound closure. The aim of this study is to analyse the clinical practice of surgical wound closure in orthopaedic surgery by means of a survey of a representative local sample and thus obtain information on the context of closure in Spain. MATERIAL AND METHOD: An ad hoc group of specialists in orthopaedic surgery and traumatology was formed. The group of experts, after analyzing the literature, developed a questionnaire of 32 closed multiple-choice questions divided into the following blocks: hemostasis, surgical wound closure (deep, superficial, and cutaneous), and dressings. RESULTS: A total of 471 surgeons responded to the survey completely and with sufficient information to perform the descriptive analysis. 79% believe that ATX can influence the decrease in surgical site infection rate. 96% believe that the type of deep closure at the level of the arthrotomy could influence outcomes and complications after hip and/or knee replacements. 85% believe that the type of shallow closure at the subcutaneous level may influence outcomes and complications after hip and/or knee replacement. 64% of surgeons use single-use incisional negative pressure therapy for the treatment of surgical wound complications (seroma, prolonged drainage, dehiscence). CONCLUSIONS: There is a high level of variability in wound closure in our setting and a low level of training on the subject. The authors recommend that the different scientific societies invest resources to improve training in this field and reduce the percentage of surgeons who are considered inadequately trained, as well as adapting closure techniques to those considered gold standard according to the evidence.

Wound closure after knee and hip replacement (TKA and THA): Survey results on the clinical practice in Spain. / Cierre de herida en cirugía protésica de rodilla y cadera (PTR y PTC): Resultados de una encuesta sobre la práctica clínica en España.

BACKGROUND AND OBJECTIVE: In orthopedic surgery, it is clear that an optimal standardized closure technique has not yet been developed. Locally, there are no objective data describing the standard surgical practice in wound closure. The aim of this study is to analyze the clinical practice of surgical wound closure in orthopedic surgery by means of a survey of a representative local sample and thus obtain information on the context of closure in Spain. METHOD: an ad hoc group of specialists in orthopedic surgery and traumatology was formed. The group of experts, after analyzing the literature, developed a questionnaire of 32 closed multiple-choice questions divided into the following blocks: hemostasis, surgical wound closure (deep, superficial, and cutaneous), and dressings. RESULTS: A total of 471 surgeons responded to the survey completely and with sufficient information to perform the descriptive analysis. 79% believe that ATX can influence the decrease in surgical site infection rate. 96% believe that the type of deep closure at the level of the arthrotomy could influence outcomes and complications after hip and/or knee replacements. 85% believe that the type of shallow closure at the subcutaneous level may influence outcomes and complications after hip and/or knee replacement. 64% of surgeons use single-use incisional negative pressure therapy for the treatment of surgical wound complications (seroma, prolonged drainage, dehiscence). CONCLUSIONS: There is a high level of variability in wound closure in our setting and a low level of training on the subject. The authors recommend that the different scientific societies invest resources to improve training in this field and reduce the percentage of surgeons who are considered inadequately trained, as well as adapting closure techniques to those considered gold standard according to the evidence.

Implementation of an enhanced recovery after surgery program including a patient school: Impact on quality of life results.

INTRODUCTION: Enhanced Recovery After Surgery (ERAS) protocols and educational programmes have been shown to accelerate orthopaedic surgery recovery with fewer complications, and improve patient-reported outcomes (PROs) for different types of surgery. The objective was to evaluate the impact of an ERAS programme including a patient school on health outcomes and PROs for Total Knee Replacement (TKR) surgery. MATERIAL AND METHODS: A multidisciplinary group created the programme and the patient school (preoperative consultations where the patients' surgical processes are explained and are also given instructions for an appropriate perioperative care management). An observational, prospective study was conducted on all patients operated for TKR from March 2021 to March 2022. Main health outcomes were: hospital stay length, surgical complications and surgery cancellations due to a wrong preoperative medication management. PROs evaluated were: patient satisfaction with pain management, the school, and quality of life before and after surgery (EQ-5D). RESULTS: One hundred thirty-three patients were included. Median hospital stay length was 3 days (IQR 3-5). Rate of surgical complications was 25.6%. No surgery was cancelled. Patient satisfaction rates with pain management and with the school were 8.10/10 and 9.89/10, respectively. Concerning quality of life, mean improvement in mobility and knee pain after the surgery was 0.66 (p < 0.05) and 0.84 (p < 0.05), respectively. CONCLUSIONS: The ERAS programme including a patient school was highly successful with a fast recovery, a short hospital stay length, no surgery cancellations, and improved PROs.

A novel closed technique for ultrasound-guided plantar fascia release with a needle: review of 107 cases with a minimum follow-up of 24 months.

BACKGROUND: This study aims to analyze the clinical outcome of a new ultrasound-guided surgery for partial plantar fasciotomy performed with a needle for treatment of plantar fasciitis. METHODS: We performed a retrospective review of 107 patients diagnosed with plantar fasciitis who underwent ultrasound-guided release of the plantar fascia. The series included 62 males (57.9%) and 45 females (42.1%) treated between April 2014 and February 2018, with a mean follow-up of 21.05 ± 10.96 months (7-66) and a minimum follow-up of 24 months. The mean age was 48.10 ± 10.27 years (27-72). Clinical assessments and ultrasound examination were carried out before treatment, after 1 week, and then after 1, 3, 12, and 24 months. The clinical assessment was based on a visual analog scale and the Foot and Ankle Disability Index. RESULTS: Heel pain improved in 92.5% (99) of patients, but not in 7.4% (8 patients). In the group of patients whose heel pain improved, 9 experienced overload on the lateral column and dorsum of the foot, which improved with the use of plantar orthoses and a rehabilitation program. We recorded no nerve complications (e.g., paresthesia), vascular injuries, or wound-related problems. CONCLUSION: Ultrasound-guided partial plantar fasciotomy with a needle is safe, since structures are under direct visualization of the surgeon and the risk of damage is minimal. Stitches are not necessary, and recovery is fast. Consequently, costs are low, and the patient can return to work quickly. This technique may represent a valid option for treatment of plantar fasciitis.

The knee prosthesis constraint dilemma: Biomechanical comparison between varus-valgus constrained implants and rotating hinge prosthesis. A cadaver study.

The real degree of constriction of rotating hinge knee (RHK) and condylar constrained prostheses (CCK) is a matter of discussion in revision knee arthroplasty. The objectives of this study are to compare the tibial rotation of both implants and validate the use of inertial sensors with optical tracking system as movement measurement tools. A total of 16 cadaver knees were used. Eight knees were replaced using a RHK (Endomodel LINK), and the remaining eight received a CCK prosthesis (LCCK, Zimmer). Tibial rotation range of motion was measured in full extension and at 30°, 60°, and 90° of flexion, with four continuous waveforms for each measurement. Measurements were made using two inertial sensors with specific software and compared with measurements obtained using the gold standard technique - the motion capture camera. The comparison of the accuracy of both measurement methods showed no statistically significant differences between inertial sensors and motion capture cameras, with p > .1; the mean error for tibial rotation was 0.21°. Tibial rotation in the RHK was significantly greater than in the CCK (5.25° vs. 2.28°, respectively), p < .05. We have shown that RHK permit greater tibial rotation, being closer to physiological values than CCKs. Inertial sensors have been validated as an effective and accurate method of measuring knee movement. The clinical significance: RHK appears to represent a lower constriction degree than CCK systems.

Results of ultrasound-guided release of tarsal tunnel syndrome: a review of 81 cases with a minimum follow-up of 18 months.

BACKGROUND: This study aims to analyse the clinical results of ultrasound-guided surgery for the decompression of the tibial nerve, including its distal medial and lateral branches, to treat tarsal tunnel syndrome. These structures are the complete flexor retinaculum and the deep fascia of the abductor hallucis muscle, including individualised release of the medial and lateral plantar nerve tunnels. METHOD: This is a retrospective review of 81 patients (36 men and 45 women) with an average age of 41 years old (32-62) and an average clinical course of 31 months (8-96) compatible with idiopathic tarsal tunnel syndrome, who underwent ultrasound-guided decompression of the proximal and distal tarsal tunnel between February 2015 and November 2017 (both months included), with a minimum follow-up of 18 months. RESULTS: Based on the Takakura et al. scale for the 81 patients, 76.54% obtained excellent results, 13.58% good results, and 9.87% poor results. The patients with the longest course of symptoms displayed the worst results. CONCLUSION: Although 9% of patients did not improve, ultrasound-guided tarsal tunnel release might be a viable alternative to conventional open approaches.

Espaciador femoral total biarticulado para el tratamiento de la infección periprotésica de cadera y rodilla con pérdida completa de hueso. Modificación técnica / Biarticular total femoral spacer for complete bone loss in periprosthetic joint infection. A technical modification

Antecedentes: El manejo de los defectos óseos completos secundarios a una infección periprotésica a nivel de la cadera y/o rodilla continúa siendo un auténtico reto quirúrgico. Material y métodos: Presentamos una modificación técnica para la realización de un espaciador femoral biarticulado con un enclavado femoral, sin necesidad de abordar la tibia proximal, ya sea para obtener la fijación del espaciador o la articulación del mismo. Resultados: Se han intervenido 3 pacientes mediante esta técnica, no existiendo ninguna complicación intraoperatoria, resolviéndose la infección y mejorando la función previa en todos ellos, volviendo a deambular con diferentes ayudas. Conclusiones: Esta modificación técnica es una alternativa en aquellos casos donde es preciso resecar el fémur completo pero no es necesario abordar la tibia

Background: The management of complete bone defects in hip and knee periprosthetic infection is still a real surgical challenge. Material and methods: We present a technical modification for performing a biarticular total femoral spacer with a femoral nail without the need to approach the proximal tibia. Results: Three patients were operated with this technique. There was no intraoperative complication. The infection was resolved in all patients operated at final follow-up. All patients improved their previous functional situation and could walk with different aids. Conclusions: This technical modification is an alternative for cases where it is necessary to resect the complete femur, but it is not necessary to approach the tibia

Biarticular total femoral spacer for complete bone loss in periprosthetic joint infection. A technical modification. / Espaciador femoral total biarticulado para el tratamiento de la infección periprotésica de cadera y rodilla con pérdida completa de hueso. Modificación técnica.

BACKGROUND: The management of complete bone defects in hip and knee periprosthetic infection is still a real surgical challenge. MATERIAL AND METHODS: We present a technical modification for performing a biarticular total femoral spacer with a femoral nail without the need to approach the proximal tibia. RESULTS: Three patients were operated with this technique. There was no intraoperative complication. The infection was resolved in all patients operated at final follow-up. All patients improved their previous functional situation and could walk with different aids. CONCLUSIONS: This technical modification is an alternative for cases where it is necessary to resect the complete femur, but it is not necessary to approach the tibia.

Nuevo método de liberación de antibióticos del cemento óseo (polimetilmetacrilato): redefiniendo los límites / New method for antibiotic release from bone cement (polymethylmethacrylate): redefining boundaries

Introducción. La creciente resistencia a antimicrobianos está impulsando la adición de antibióticos con elevada actividad antiestafilocócica al polimetilmetacrilato (PMMA), para su uso en los espaciadores de cemento en la infección periprotésica. El linezolid o el levofloxacino ya han sido utilizados en estudios in vitro; sin embargo, la rifampicina ha demostrado un efecto deletéreo sobre las propiedades mecánicas del PMMA, inhibiendo su polimerización. El objetivo de nuestro estudio fue aislar la rifampicina durante el proceso de polimerización mediante técnicas de microencapsulación, con el fin de obtener un PMMA apto para la fabricación de espaciadores articulares. Material y método. Se sintetizaron microcápsulas de rifampicina con alginato y PHBV, utilizando Rifaldin®. Se estudió la concentración de rifampicina mediante espectrofotometría UV-visible. Se realizaron ensayos de compresión, dureza y tiempo de fraguado con probetas de cemento CMW®1 solo, con rifampicina y microcápsulas de PHBV y alginato. Resultados. El rendimiento de producción, la eficiencia y el rendimiento de microencapsulación fueron mayores con alginato (p=0,0001). El cemento con microcápsulas mostró mayor resistencia a la compresión que el cemento con rifampicina (91,26±5,13, 91,35±6,29 y 74,04±3,57MPa en alginato, PHBV y rifampicina, respectivamente) (p=0,0001). El tiempo de fraguado disminuyó, siendo la curva de dureza del cemento con microcápsulas de alginato similar a la de control. Discusión y conclusiones. La microencapsulación con alginato es una técnica adecuada para introducir rifampicina en el PMMA preservando las propiedades de compresión y el tiempo de fraguado. Su obtención permitiría fabricar espaciadores que liberasen localmente rifampicina para el tratamiento de la infección periprotésica (AU)

Introduction. The increasing antimicrobial resistance is promoting the addition of antibiotics with high antistaphylococcal activity to polymethylmethacrylate (PMMA), for use in cement spacers in periprosthetic joint infection. Linezolid and levofloxacin have already been used in in-vitro studies, however, rifampicin has been shown to have a deleterious effect on the mechanical properties of PMMA, because it inhibits PMMA polymerization. The objective of our study was to isolate the rifampicin during the polymerization process using microencapsulation techniques, in order to obtain a PMMA suitable for manufacturing bone cement spacers. Material and method. Microcapsules of rifampicin were synthesized with alginate and PHBV, using Rifaldin®. The concentration levels of rifampicin were studied by UV-visible spectrophotometry. Compression, hardness and setting time tests were performed with CMW®1 cement samples alone, with non-encapsulated rifampicin and with alginate or PHBV microcapsules. Results. The production yield, efficiency and microencapsulation yield were greater with alginate (P = .0001). The cement with microcapsules demonstrated greater resistance to compression than the cement with rifampicin (91.26±5.13, 91.35±6.29 and 74.04±3.57 MPa in alginate, PHBV and rifampicin, respectively) (P = .0001). The setting time reduced, and the hardness curve of the cement with alginate microcapsules was similar to that of the control. Discussion and conclusions. Microencapsulation with alginate is an appropriate technique for introducing rifampicin into PMMA, preserving compression properties and setting time. This could allow intraoperative manufacturing of bone cement spacers that release rifampicin for the treatment of periprosthetic joint infection (AU)

New method for antibiotic release from bone cement (polymethylmethacrylate): Redefining boundaries. / Nuevo método de liberación de antibióticos del cemento óseo (polimetilmetacrilato): redefiniendo los límites.

INTRODUCTION: The increasing antimicrobial resistance is promoting the addition of antibiotics with high antistaphylococcal activity to polymethylmethacrylate (PMMA), for use in cement spacers in periprosthetic joint infection. Linezolid and levofloxacin have already been used in in-vitro studies, however, rifampicin has been shown to have a deleterious effect on the mechanical properties of PMMA, because it inhibits PMMA polymerization. The objective of our study was to isolate the rifampicin during the polymerization process using microencapsulation techniques, in order to obtain a PMMA suitable for manufacturing bone cement spacers. MATERIAL AND METHOD: Microcapsules of rifampicin were synthesized with alginate and PHBV, using Rifaldin®. The concentration levels of rifampicin were studied by UV-visible spectrophotometry. Compression, hardness and setting time tests were performed with CMW®1 cement samples alone, with non-encapsulated rifampicin and with alginate or PHBV microcapsules. RESULTS: The production yield, efficiency and microencapsulation yield were greater with alginate (P = .0001). The cement with microcapsules demonstrated greater resistance to compression than the cement with rifampicin (91.26±5.13, 91.35±6.29 and 74.04±3.57 MPa in alginate, PHBV and rifampicin, respectively) (P = .0001). The setting time reduced, and the hardness curve of the cement with alginate microcapsules was similar to that of the control. DISCUSSION AND CONCLUSIONS: Microencapsulation with alginate is an appropriate technique for introducing rifampicin into PMMA, preserving compression properties and setting time. This could allow intraoperative manufacturing of bone cement spacers that release rifampicin for the treatment of periprosthetic joint infection.

Moldes individualizados para alineación de la artroplastía primaria de rodilla / Individualized molds for alignment of primary knee arthroplasty

Introducción: Los sistemas de bloque de corte específicos (BCE) se han presentado como una interesante medida para obtener una correcta alineación en la artroplastía de rodilla, aunque se desconoce cuál de todos los métodos existentes para realizar la planificación es el adecuado. Material y métodos: Se ha diseñado un estudio prospectivo comparando dos sistemas de BCE con planificaciones diferentes (Signature con TAC + teleradiografia; Visionaire con RMN) con el sistema convencional de alineación. Se analizaron parámetros radiográficos, funcionales preoperatorios y postoperatorios, estancia hospitalaria, necesidad de transfusión, tiempo quirúrgico y complicaciones asociadas. Resultados: Un total de 10 pacientes fueron intervenidos por cada grupo. No se observaron diferencias estadísticamente significativas entre los dos sistemas de alineamiento específicos y el sistema convencional (p > 0.05), aunque se objetivó una mayor precisión con estos sistemas, siendo discretamente superior en el sistema Signature. También se observó un menor tiempo quirúrgico en los pacientes intervenidos con los BCE, ligeramente inferior en los intervenidos con el sistema Visionaire (p > 0.05). Conclusiones: Los nuevos sistemas BCE pueden ser útiles para mejorar la alineación en la artroplastía de rodilla así como disminuir el tiempo quirúrgico. A la espera de series mayores que corroboren estos datos, los autores recomiendan estos sistemas en aquellos casos en los que los sistemas convencionales no sean adecuados.

Introduction: Patient-specific cutting blocks (PSCB) have been proposed as an interesting option to achieve appropriate alignment in knee arthroplasty. However, there is no information as to which of the available planning methods is the right one. Material and methods: A prospective study was designed to compare two PSCB systems using different planning methods (Signature with CAT scan + teleradiography; Visionaire with MRI) with the standard alignment method. Radiographic and functional pre- and postoperative parameters were analyzed, together with hospital stay, blood transfusion needs, operative time and associated complications. Results: A total of 10 patients per group were operated on. No statistically significant differences were observed between both of the patient-specific alignment systems and the standard system (p > 0.05). However, greater precision was achieved with the former systems and the Signature system was slightly more accurate. Operative time was shorter in patients in whom PSCBs were used, and it was still slightly shorter in those in whom the Visionaire system was used (p > 0.05). Conclusions: The new PSCB systems may be useful to improve alignment in knee arthroplasty and reduce the operative time. While larger case series confirming these data become available, the authors recommend using these systems in cases in which the standard systems do not work properly.

Influencia del medio fisiológico sobre las propiedades mecánicas del cemento óseo. ¿Son los estudios actuales extrapolables? / Influence of the physiological medium on the mechanical properties of bone cement: can current studies be extrapolated?

Objetivo. El uso del cemento óseo esta muy extendido en COT, existiendo multitud de estudios experimentales que lo avalan. La mayoría de los ensayos mecánicos están realizados en seco, lo que cuestiona la extrapolación de los resultados a la clínica. El objetivo de este estudio es evaluar si las propiedades mecánicas del polimetilmetacrilato (PMMA) obtenidas en series previas en seco, se mantienen en un medio fisiológico. Material y método. Se ha diseñado un estudio experimental para evaluar este aspecto, utilizando PMMA con antibiótico (vancomicina). Cuatro grupos fueron definidos en función del medio estudiado (seco o líquido) y de la realización de un acondicionamiento previo en suero fisiológico (una semana o un mes). Se hicieron estudios de desgaste y resistencia a flexión según las normativas ISO y ASTM, valorando el desgaste, el coeficiente de fricción, la resistencia a la rotura y el modulo de Young. Las muestras fueron analizadas mediante microscopía electrónica. Resultados. Las muestras ensayadas en medio líquido presentaron menores valores de desgaste, así como menor resistencia a flexión, obteniéndose significación en el desgaste. El tipo de desgaste se modificó de un desgaste abrasivo a uno adhesivo en aquellas muestras estudiadas en medio líquido. El tiempo de acondicionamiento proporcionó menores valores de desgaste (p < 0,05). Conclusiones. Se recomienda precaución a la hora de extrapolar los resultados de los estudios sobre PMMA en seco dado el diferente comportamiento mecánico del cemento en un medio líquido mucho más cercano a la situación clínica real, como es el suero fisiológico (AU)

Purpose. The use of bone cement is widespread in orthopaedic surgery. Most of the mechanical tests are performed in dry medium, making it difficult to extrapolate the results. The objective of this study is to assess if the mechanical properties of polymethylmethacrylate (PMMA), obtained in previous reports, are still present in a liquid medium. Material and method. An experimental study was designed with antibiotic (vancomycin) loaded PMMA. Four groups were defined according to the medium (dry or liquid) and the pre-conditioning in liquid medium (one week or one month). Wear and flexural strength tests were performed according to ASTM and ISO standards. Volumetric wear, friction coefficient, tensile strength, and Young's modulus were analyzed. All samples were examined by scanning electron microscopy. Results. The samples tested in liquid medium showed lower wear and flexural strength values (P<.05). The kind of wear was modified from abrasive to adhesive in those samples studied in liquid medium. The samples with a pre-conditioning time showed lower values of wear (P<.05). Conclusions. Caution is recommended when extrapolating the results of previous PMMA results. The different mechanical strength of the cement in a liquid medium, observed in saline medium, is much closer to the clinical situation (AU)

[Individualized molds for alignment of primary knee arthroplasty]. / Moldes individualizados para alineación de la artroplastía primaria de rodilla.

INTRODUCTION: Patient-specific cutting blocks (PSCB) have been proposed as an interesting option to achieve appropriate alignment in knee arthroplasty. However, there is no information as to which of the available planning methods is the right one. MATERIAL AND METHODS: A prospective study was designed to compare two, PSCB systems using different planning methods (Signature with CAT scan + teleradiography; Visionaire with MRI) with the standard alignment method. Radiographic and functional pre- and postoperative parameters were analyzed, together with hospital stay, blood transfusion needs, operative time and associated complications. RESULTS: A total of 10 patients per group were operated on. No statistically significant differences were observed between both of the patient-specific alignment systems and the standard system (p > 0.05). However, greater precision was achieved with the former systems and the Signature system was slightly more accurate. Operative time was shorter in patients in whom PSCBs were used, and it was still slightly shorter in those in whom the Visionaire system was used (p > 0.05). CONCLUSIONS: The new PSCB systems may be useful to improve alignment in knee arthroplasty and reduce the operative time. While larger case series confirming these data become available, the authors recommend using these systems in cases in which the standard systems do not work properly.

[Influence of the physiological medium on the mechanical properties of bone cement: can current studies be extrapolated?]. / Influencia del medio fisiológico sobre las propiedades mecánicas del cemento óseo. ¿Son los estudios actuales extrapolables?

PURPOSE: The use of bone cement is widespread in orthopaedic surgery. Most of the mechanical tests are performed in dry medium, making it difficult to extrapolate the results. The objective of this study is to assess if the mechanical properties of polymethylmethacrylate (PMMA), obtained in previous reports, are still present in a liquid medium. MATERIAL AND METHOD: An experimental study was designed with antibiotic (vancomycin) loaded PMMA. Four groups were defined according to the medium (dry or liquid) and the pre-conditioning in liquid medium (one week or one month). Wear and flexural strength tests were performed according to ASTM and ISO standards. Volumetric wear, friction coefficient, tensile strength, and Young's modulus were analyzed. All samples were examined by scanning electron microscopy. RESULTS: The samples tested in liquid medium showed lower wear and flexural strength values (P<.05). The kind of wear was modified from abrasive to adhesive in those samples studied in liquid medium. The samples with a pre-conditioning time showed lower values of wear (P<.05). CONCLUSIONS: Caution is recommended when extrapolating the results of previous PMMA results. The different mechanical strength of the cement in a liquid medium, observed in saline medium, is much closer to the clinical situation.

Influencia de cefazolina y vancomicina en la resistencia al desgaste del cemento óseo / Impact of cefazolin and vancomycin on resistance to bone cement wear

Objetivo: Evaluar experimentalmente la influencia de la mezcla de dos antibióticos, vancomicina y cefazolina, sobre la resistencia al desgaste del cemento óseo (PMMA). Material y métodos: Se definieron seis grupos de estudio en función del antibiótico y su dosis, realizando tres muestras por grupo, que fueron sometidas a desgaste de su superficie utilizando un tribómetro, según el estándar ASTM G99-05. Se midieron los coeficientes de rozamiento y se cuantificó el desgaste volumétrico de cada una de ellas. Obtuvimos imágenes de microscopía electrónica de barrido de cada muestra para observar las existencia de modificaciones en la superficie de las muestras. Resultados: Todos los grupos presentaron datos de desgaste por debajo de los máximos admitidos para uso comercial. No se demostraron diferencias significativas en el coeficiente de fricción o en el desgaste volumétrico, salvo el grupo 4 (vancomicina 2,5% + cefazolina 2,5%), que presentó un mayor desgaste frente al grupo 3 (vancomicina 2,5%) (p<0,05). Vimos una tendencia de mayor desgaste y menor homogeneidad en los grupos con cefazolina en su composición. Conclusiones: Los cementos óseos actuales pueden soportar mezclas con altas dosis de antibióticos sin modificar sus propiedades mecánicas. Además de la cantidad de antibiótico, es determinante su elección, puesto que no todos los antibióticos afectan por igual a las propiedades del PMMA (AU)

Objective: To evaluate experimentally the impact of the mixture of two antibiotics, vancomycin, and cefazolin, on resistance to bone cement wear (PMMA). Material and Methods: Six study groups were defined according to antibiotic and dose, performing three samples per group, which were subjected to wearing of the surface using a tribometer according to the ASTM G99-05 standard. The friction coefficients were measured and volumetric wear of each of them was quantified. We obtained electron scanning microscope images of each sample to observe the presence of changes in the surface of the samples. Results: All groups had wear data below the maximum admitted for commercial use. No significant differences were shown in friction coefficient or volumetric wear, except in group 4 (2.5% vancomycin + 2.5% cefazolin), which showed greater wear versus group 3 (2.5% vancomycin) (p<0.05). We saw a tendency towards greater wear and lower homogeneity in groups with cefazolin in its composition. Conclusions: Current bone cements can withstand mixtures with high doses of antibiotics without altering their mechanical properties. In addition to the amount of antibiotic, the choice is decisive, as not all antibiotics equally affect the properties of PMMA (AU)

Artroplastia total tras fractura intracapsular de cadera en paciente con parálisis cerebral infantil / A case of intracapsular hip fracture in a patient with infantile cerebral palsy

Objetivo: Presentamos el caso de un paciente de 36 años con una fractura intracapsular de extremidad proximal de fémur de larga evolución que fue sometido a una artroplastia de sustitución total con un resultado funcional excelente. La tasa de aflojamiento del implante es baja a pesar de la juventud de estos pacientes, pues tienen un nivel de actividad bajo y precisan de ayuda de bastones. Hay que considerar la espasticidad, los movimientos involuntarios y la realización de tenotomías que merman la estabilidad del implante (AU)

Objective: We present the case of a 36 year-old patient with an intracapsular fracture of the proximal femur who underwent a total replacement arthroplasty with an excellent functional outcome. The loosening rate of the implant is low despite youth of these patients, as they have a low level of activity and require the aid of crutches. It should be considered that spasticity, involuntary movements and the performance of tenotomies decrease the stability of the implant (AU)

[Bilateral avascular necrosis after resurfacing hip arthroplasty. A case report]. / Necrosis avascular bilateral tras artroplastía de cadera de recubrimiento. Reporte de un caso.

Resurfacing hip arthroplasty is an alternative to conventional arthroplasty and it is indicated in young and active patients. Good results and the prevention of complications stem from a meticulous surgical technique and proper patient selection. We present herein the case of a 43 year-old patient who, after undergoing bilateral hip replacement with resurfacing prostheses, sustained a non-simultaneous fracture of both femoral necks due to avascular necrosis. He was treated by placing a metaphyseal anchoring stem. Postoperative X-rays showed proper implant placement without femoral notching, with a discrete 7 degrees valgus alignment of the femoral component. Both passive and active mobility was painful. X-rays showed cervical fracture of the right femur. The femoral head was attached to the implant, with no metallosis nor loosening of the femoral or acetabular components, but the bone had a fragmented and friable appearance that histopathologically was defined as avascular necrosis. Femoral neck fracture is the main complication after resurfacing hip arthroplasty. The effect of other factors like bone necrosis due to cement is unknown.

Estudio comparativo del tratamiento con enclavado elástico y fijador externo en las fracturas de fémur del niño: a propósito de 40 casos / Elastic nailing vs. external fixation as methods to address pediatric femoral fractures: a review of 40 cases

Objetivo: analizar los resultados de las fracturas de diáfi sis femoral del niño tratadas ennuestro centro mediante enclavado intramedular elástico y su comparación con los resultadosdel tratamiento con fi jador externo.Material y método: se estudió retrospectivamente a 40 pacientes con fracturas de fémurintervenidos en nuestro centro entre mayo de 1995 y enero de 2006. Veinte pacientes setrataron mediante enclavado elástico y 20 mediante fi jador externo. La media de tiempode seguimiento fue 20,6 (intervalo, 3-59) meses. Se analizaron los resultados radiográfi -cos iniciales y evolutivos, y su relación con el tiempo de ingreso, tiempo de consolidación,número de consultas de revisión e incidencia de complicaciones y reintervenciones.Resultados: la duración de la cirugía, la estancia media hospitalaria y las complicacionesde la herida quirúrgica son menores en el grupo de enclavado elástico. El tiempo de consolidaciónde la fractura, así como las complicaciones a largo plazo, y el número de reintervencionesfueron también menores en este grupo. Los hallazgos radiológicos demostrarontambién menores angulación, desplazamiento y discrepancia de longitud fi nal delas extremidades en los niños tratados con clavos elásticos.Conclusiones: en este trabajo se refuerza la idea de que el enclavado elástico, por lasencillez del proceso, menores agresión y necesidad de cuidados para el niño, los mejoresresultados clínico-radiológicos y la menor tasa de complicaciones y reintervenciones,es una mejor opción en el tratamiento de estas fracturas(AU)

Purpose: To analyze the outcomes of pediatric femoral shaft fractures in our hospital,comparing the results obtained with elastic intramedullary nailing with those of externalfi xation.Materials and methods: We retrospectively studied 40 patients with femoral fracturesoperated in our hospital between May 1995 and January 2006. 20 patients were treatedby means of elastic nailing and 20 with an external fi xator. Mean follow-up was 20.6months (range: 3-59). Initial and subsequent radiographic results were analyzed, as wellas their relationship with hospitalization time, time to healing, number of follow-upvisits and incidence of complications and reoperations.Results: OR time, mean hospital stay and complications related to the surgical woundwere lower in the elastic nailing group. Time to fracture union, the rate of long-termcomplications and the number of reoperations were also lower in this group. Radiologicalfi ndings also showed less angulation, displacement and fi nal leg length discrepancy inchildren treated with elastic nails.Conclusions: This study confi rms the notion that elastic nailing, given the simplicity ofthe procedure and its lower degree of invasiveness, the reduced need to protect thechild, its better clinical-radiological results and the lower rate of complications andreoperations, is a better option for treating these fractures(AU)