Anxiety is the cause of the worse outcomes of allergic patients after total knee arthroplasty.

PURPOSE: The presence of allergies has been proposed as a risk factor for worse outcomes in total knee arthroplasty surgery. The aim of this study is to evaluate if the presence of some psychiatric disorders is more frequent in patients who report allergies and if they could be the main cause for the worse outcomes. METHODS: A prospective study, including patients undergoing a primary total knee arthroplasty, was designed. In the preoperative visit, all the patients completed a questionnaire about the presence of allergies and also psychiatric tests for anxiety (State-Trait Anxiety Inventory-STAI-), depression (Remission from Depression Questionnaire-RDQ-), somatization disorder (Patient Health Questionnaire-15-PHQ-15-), pain catastrophizing syndrome (Pain Catastrophizing Scale-PCS), and personality disorder (Reduced NEO-Inventory of Five Factors-NEO-FFI-). In the preoperative and at 6 months of follow up, the functional results of the surgery were assessed by the WOMAC, the SF-12, and the KSS scores. RESULTS: A total of 209 patients was included: 136 (65%) did not have reported allergies and 73 (35%) did report some allergies. The psychiatric questionnaires showed that the presence of anxiety was more prevalent in the group of patients with reported allergies (STAI-T: no allergies 24.08 points vs. allergies 19.18 points, p = 0.039). When comparing the functional outcomes at 6 months of follow up, most of the analyzed scores improved less in the group of patients with reported allergies than in the no allergy-referred group: WOMAC-total score (34.37 vs. 40.10 points, p = 0.023), WOMAC-pain score (6.03 vs. 7.50 points, p = 0.018), WOMAC-function score (22.97 vs. 27.24 points, p = 0.023), KSS-knee score (25.37 vs. 33.79 points, p = 0.002), and SF-12 physical score (7.89 vs. 11.15 points, p = 0.046). The significance of the difference in the outcomes scores in this group was lost after adjusting for anxiety (p > 0.05). CONCLUSION: Allergies reported by patients are confirmed as a risk factor for worse results after TKA surgery. The relationship with anxiety disorder seems to explain the association between self-reported allergies and sub-optimal outcomes. LEVEL OF EVIDENCE: II.

Pressure algometry is an excellent tool to measure knee pain relief after a closing-wedge high tibial osteotomy.

PURPOSE: The aim of this study was to assess the utility of pressure algometry (PA) to measure pain relief in the medial part of the knee after a closing-wedge high tibial osteotomy (CWHTO). METHODS: Prospective study including 44 CWHTO. Pain relief was evaluated with the visual analogue scale (VAS) and PA, a radiological study was done and a functional assessment was carried out with the KSS preoperatively, at 6-months and at 1-year after the surgery. PA was applied to the medial and lateral part of the knee and to the infra-clavicular fossa as a control point. RESULTS: The mechanical femorotibial angle was changed from 172.2° (SD2.2) to 180.6° (SD2.6) (p=0.00). KSS Knee improved from 53.4 (SD11.2) to 92.8 (SD7.3) (p=0.00), KSS Function from 69.4 (SD9.3) to 93.1 (SD8) (p=0.00). The VAS went from 6.84 (SD1.5) to 2.5 (SD2.1) (p=0.00) at the 1-year follow-up. The pressure pain threshold (PPT), measured with PA in the medial part of the knee also improved from 348.8kPa (SD159.3) to 447.1kPa (SD218.8) (p=0.01). However, the PPT in the lateral part of the knee and in the sub-clavicular fossa remained the same from the preoperative period to 6-months and 1-year, postoperatively. Neither were there any differences between the 6-month and 1-year postoperative values in terms of the different functional, radiological and pain relief obtained. CONCLUSION: The pain relief obtained after a CWHTO in the medial part of the knee can be measured by using PA. Furthermore, the functional and pain improvement obtained at 1-year follow-up is no better than those obtained at 6-months postoperatively.

Pressure algometry is a useful tool to quantify pain in the medial part of the knee: an intra- and inter-reliability study in healthy subjects.

PURPOSE: Pain quantification is essential for diagnostic and pain monitoring purposes in disorders around the knee. Pressure algometry is a method described to determine pressure pain threshold (PPT) by applying controlled pressure to a given body point. The purpose of this study was to determine the reliability of this method when it was applied to the medial part of the proximal tibia metaphysis and to evaluate the PPT levels between genders. METHODS: Fifty healthy (mean age; 46.9) volunteers were recruited, 25 men and 25 women. Pressure algometry was applied to a 1 cm(2)-probe area on the medial part of the knee by 2 raters. Intra- and interclass correlation (ICC) was obtained and differences between genders were evaluated. Bland-Altman plots were performed to evaluate the variability of the measures. RESULTS: The mean values of PPT obtained by rater 1 and 2 were 497.5 Kpa and 489 Kpa respectively. The intrarater reliability values (95% IC) for rater 1 and 2 were 0.97 (0.95-0.98) and 0.84 (0.73-0.90) respectively. With regard to interrater reliability, the ICC (95% IC) for the first measurement was 0.92 (0.87-0.95) and 0.86 (0.78-0.92) for the second one. Women showed significant lower values of PPT than men. The Bland-Altmand plots showed excellent agreement. CONCLUSIONS: Pressure algometry has excellent reliability when it is applied to the medial part of the proximal metaphysis of the tibia. Women have lower values of PTT than men. The high reliability of the PA in an individual volunteer makes it a more valuable tool for longitudinal assessment of a given patient than for comparison between them. LEVEL OF EVIDENCE: Level III. Prospective study.

Topical and intravenous tranexamic acid reduce blood loss compared to routine hemostasis in total knee arthroplasty: a multicenter, randomized, controlled trial.

INTRODUCTION: Tranexamic acid (TXA) is becoming widely used in orthopedic surgery to reduce blood loss and transfusion requirements, but consensus is lacking regarding the optimal route and dose of administration. The aim of this study was to compare the efficacy and safety of topical and intravenous routes of TXA with routine hemostasis in patients undergoing primary total knee arthroplasty (TKA). MATERIALS AND METHODS: We performed a randomized, multicenter, parallel, open-label clinical trial in adult patients undergoing primary TKA. Patients were divided into three groups of 50 patients each: Group 1 received 1 g topical TXA, Group 2 received 2 g intravenous TXA, and Group 3 (control group) had routine hemostasis. The primary outcome was total blood loss. Secondary outcomes were hidden blood loss, blood collected in drains, transfusion rate, number of blood units transfused, adverse events, and mortality. RESULTS: One hundred and fifty patients were included. Total blood loss was 1021.57 (481.09) mL in Group 1, 817.54 (324.82) mL in Group 2 and 1415.72 (595.11) mL in Group 3 (control group). Differences in total blood loss between the TXA groups and the control group were clinically and statistically significant (p < 0.001). In an exploratory analysis differences between the two TXA groups were not statistically significant (p = 0.073) Seventeen patients were transfused. Transfusion requirements were significantly higher in Group 3 (p = 0.005). No significant differences were found between groups regarding adverse events. CONCLUSION: We found that 1 g of topical TXA and 2 g of intravenous TXA were both safe strategies and more effective than routine hemostasis to reduce blood loss and transfusion requirements after primary TKA. LEVEL OF EVIDENCE: I.

La geometría de la quilla condiciona el comportamiento de la bandeja tibial frente a fuerzas de torsión en prótesis totales de rodilla / The geometry of the keel determines the behaviour of the tibial tray against torsional forces in total knee replacement

El diseño de la quilla de una bandeja tibial es fundamental para la transmisión de la mayor parte de las cargas a las estructuras óseas periféricas, las cuales tienen mejores propiedades mecánicas reduciendo, de este modo, el riesgo de aflojamiento. El objetivo de este estudio es comparar el comportamiento de diferentes diseños de bandeja tibial ante cargas de torsión. Se modelizaron 4 componentes tibiales diferentes. La reconstrucción 3 D se llevó a cabo con el programa MIMICS. Los sólidos se generaron en SolidWorks. Se realizó el estudio por elementos finitos mediante Unigraphics. Se simuló una torsión de 6 Nm aplicada sobre los laterales de cada bandeja tibial. La bandeja tibial GENUTECH® con apoyo en el hueso trabecular periférico mostró un menor desplazamiento y menores tensiones transmitidos bajo fuerzas de torsión. Los resultados indican que la bandeja tibial con apoyo más periférico tienen un mejor comportamiento mecánico mejor frente a los otros diseños estudiados (AU)

The keel design of the tibial tray is essential for the transmission of the majority of the forces to the peripheral bone structures, which have better mechanical proprieties, thus reducing the risk of loosening. The aim of the present study was to compare the behaviour of different tibial tray designs submitted to torsional forces. Four different tibial components were modelled. The 3-D reconstruction was made using the Mimics software. The solid elements were generated by SolidWorks. The finite elements study was done by Unigraphics. A torsional force of 6 Nm. applied to the lateral aspects of each tibial tray was simulated. The GENUTECH® tibial tray, with peripheral trabecular bone support, showed a lower displacement and less transmitted tensions under torsional forces. The results suggest that a tibial tray with more peripheral support behaves mechanically better than the other studied designs (AU)

Técnica de microindentación ósea y algometría de presión aplicada al recambio protésico de rodilla y dolor en punta de vástago tibial. Resultados preliminares en un grupo de 20 pacientes / Bone microindentation and pressure algometry applied to revision total knee replacement and tibial end-of-stem pain. Preliminary results in a group of twenty patients

Objetivos. Valorar la relación entre la aparición de dolor en punta de vástago tibial con una disminución de la resistencia ósea preoperatoria mediante microindentación ósea. En segundo lugar, conocer la utilidad potencial de la algometría de presión en el diagnóstico y seguimiento de este grupo de pacientes. Material y método. Se realizó un estudio de correlación intra- e interobservador preliminar, para validar el método de la algometría en un grupo de 50 voluntarios sanos. Posteriormente se realizó un estudio prospectivo en un grupo de 20 pacientes con una media de edad de 74 años (57-84), sometidos a cirugía protésica de rodilla con utilización de un vástago tibial no cementado. Se realizaron mediciones de microindentación y algometría preoperatoriamente y después de un año. Para el análisis estadístico se utilizó el coeficiente de correlación intraclase y la t de Student para datos apareados. Resultados. En el trabajo preliminar, los valores de correlación intra- e interobservador obtenidos fueron excelentes; 0,91 (0,84-0,95) y 0,86 (0,74-0,92), respectivamente. En el grupo prospectivo no se observaron modificaciones significativas en los valores de microindentación (p = 0,11) ni algometría (p = 0,6) después de un año. Se observó una correlación significativa entre los valores de la algometría y las escalas de EVA (p = 0,002) y funcional (p = 0,02) en el control anual. Conclusiones. La algometría de presión fue una herramienta útil en el seguimiento de estos pacientes. La microindentación no fue adecuada para identificar pacientes en situación de riesgo de presentar dolor en punta de vástago tibial (AU)

Objectives. To study the relationship between the appearance of end-of-stem pain with a preoperative decrease in local bone strength by using the bone microindentation technique. The potential usefulness of pressure algometry in the diagnosis and monitoring of this group of patients is also determined. Material and method. A preliminary intra- and inter-rater correlation study was performed in a group of 50 healthy volunteers in order to validate the algometry technique. A prospective study was then conducted on 20 patients with a mean age of 74 years (range 57-84) undergoing knee prosthetic surgery with use of a cementless tibial stem. Bone microindentation and pressure algometry measurements were made preoperatively, and after one year of follow-up. The statistical analysis was performed using the Intraclass correlation coefficient and the Student t test for paired data. Results. The intra and inter-rater correlation values were excellent; 0.91 (0.84-0.95) and 0.86 (0.74-0.92), respectively. No significant variations were found in the microindentation (P=.11) or in the pressure algometry (P=.6) values after one year of follow-up. Nevertheless, a significant correlation was observed between the values for pressure algometry and the EVA (P=.002) and functional scale (P=.02) at the end of follow-up. Conclusions. Pressure Algometry is a useful tool to evaluate this group of patients. Bone microindentation does not seem to be useful in identifying patients with increased risk of developing tibial end-of-stem pain (AU)

[The geometry of the keel determines the behaviour of the tibial tray against torsional forces in total knee replacement]. / La geometría de la quilla condiciona el comportamiento de la bandeja tibial frente a fuerzas de torsión en prótesis totales de rodilla.

The keel design of the tibial tray is essential for the transmission of the majority of the forces to the peripheral bone structures, which have better mechanical proprieties, thus reducing the risk of loosening. The aim of the present study was to compare the behaviour of different tibial tray designs submitted to torsional forces. Four different tibial components were modelled. The 3-D reconstruction was made using the Mimics software. The solid elements were generated by SolidWorks. The finite elements study was done by Unigraphics. A torsional force of 6 Nm. applied to the lateral aspects of each tibial tray was simulated. The GENUTECH® tibial tray, with peripheral trabecular bone support, showed a lower displacement and less transmitted tensions under torsional forces. The results suggest that a tibial tray with more peripheral support behaves mechanically better than the other studied designs.

[Bone microindentation and pressure algometry applied to revision total knee replacement and tibial end-of-stem pain. Preliminary results in a group of twenty patients]. / Técnica de microindentación ósea y algometría de presión aplicada al recambio protésico de rodilla y dolor en punta de vástago tibial. Resultados preliminares en un grupo de 20 pacientes.

OBJECTIVES: To study the relationship between the appearance of end-of-stem pain with a preoperative decrease in local bone strength by using the bone microindentation technique. The potential usefulness of pressure algometry in the diagnosis and monitoring of this group of patients is also determined. MATERIAL AND METHOD: A preliminary intra- and inter-rater correlation study was performed in a group of 50 healthy volunteers in order to validate the algometry technique. A prospective study was then conducted on 20 patients with a mean age of 74 years (range 57-84) undergoing knee prosthetic surgery with use of a cementless tibial stem. Bone microindentation and pressure algometry measurements were made preoperatively, and after one year of follow-up. The statistical analysis was performed using the Intraclass correlation coefficient and the Student t test for paired data. RESULTS: The intra and inter-rater correlation values were excellent; 0.91 (0.84-0.95) and 0.86 (0.74-0.92), respectively. No significant variations were found in the microindentation (P=.11) or in the pressure algometry (P=.6) values after one year of follow-up. Nevertheless, a significant correlation was observed between the values for pressure algometry and the EVA (P=.002) and functional scale (P=.02) at the end of follow-up. CONCLUSIONS: Pressure Algometry is a useful tool to evaluate this group of patients. Bone microindentation does not seem to be useful in identifying patients with increased risk of developing tibial end-of-stem pain.

Partículas de polietileno en líquido sinovial tras artroplastia de rodilla con un polietileno convencional o uno altamente entrecruzado. Estudio preliminar / Polyethylene particles in synovial fluid after knee arthroplasty with a conventional or highly cross-linked polyethylene. Preliminary study

Objetivo. En los últimos años han aparecido polietilenos altamente entrecruzados para intentar disminuir el desgaste, tal como se ha demostrado en simuladores de rodilla. El objetivo es evaluar mediante el recuento de partículas de polietileno en líquido sinovial, si se confirma un menor desgaste en pacientes con prótesis de polietileno altamente entrecruzado. Material y método. Estudio prospectivo aleatorizado, en el que durante la implantación de una prótesis de rodilla se asignó a un grupo de pacientes la colocación de un polietileno convencional (grupo A), y a otro grupo un polietileno altamente entrecruzado (X3® de Stryker Orthopaedics) (grupo B). A los 12 meses tras la cirugía se practicó una artrocentesis de rodilla y se hizo un recuento de partículas de polietileno en el líquido sinovial mediante microscopio electrónico de barrido. Se han analizado 14 muestras en cada grupo. Resultados. Ambos grupos son comparables en todas las variables estudiadas. No hemos hallado diferencias significativas en la concentración de partículas de polietileno/ml (1,49±0,85 millones grupo A vs. 1,42±0,91 millones grupo B; p=0,60) ni en el número total de partículas aisladas entre ambos grupos. Tampoco hemos hallado diferencias en el tamaño ni la morfología de partículas entre ambos grupos. Discusión y conclusiones. Aunque diversos trabajos in vitro han hallado una reducción muy significativa del desgaste del polietileno altamente entrecruzado, no se ha hallado que en las prótesis de rodilla implantadas en pacientes este desgaste se vea reducido. La gran variabilidad del número de partículas entre individuos sugiere que el desgaste de polietileno in vivo depende de muchos factores y probablemente el tipo de polietileno no sea el más determinante (AU)

Aim of the study. In recent years cross-linked polyethylenes have been developed in an attempt to reduce the wear, as has been demonstrated in knee simulators. The aim is to assess, by counting particles of polyethylene in synovial fluid, whether the reduction in wear is confirmed in patients with a highly crosslinked polyethylene prosthesis. Material and methods. A prospective randomised study was designed. During the implantation of a knee prosthesis, one group of patients was assigned the use of a conventional polyethylene (group A), and the other group a highly crosslinked polyethylene (X3®, Stryker Orthopaedics) (group B). At 12 months after surgery a knee arthrocentesis was performed, and the number of polyethylene particles was counted in a scanning electron microscopy. Fourteen samples from each group were studied. Results. Both groups were comparable in all study variables. We found no significant differences in the concentration of polyethylene particles/ml (1.49±0.85 million in group A vs 1.42±0.91 million in group B, P=.60) or the total number of isolated particles. We found no differences either in size or morphology of particles between both groups. Discussion and conclusions. Although several in vitro studies in vitro using different types of highly crosslinked polyethylene found a significant reduction, we did not find that that wear was reduced in the knees of these patients. The great variability in the number of particles between individuals suggests that polyethylene wear in vivo depends on many factors, so perhaps the type of polyethylene is not the most significant factor (AU)

[Polyethylene particles in synovial fluid after knee arthroplasty with a conventional or highly cross-linked polyethylene. Preliminary study]. / Partículas de polietileno en líquido sinovial tras artroplastia de rodilla con un polietileno convencional o uno altamente entrecruzado. Estudio preliminar.

AIM OF THE STUDY: In recent years cross-linked polyethylenes have been developed in an attempt to reduce the wear, as has been demonstrated in knee simulators. The aim is to assess, by counting particles of polyethylene in synovial fluid, whether the reduction in wear is confirmed in patients with a highly crosslinked polyethylene prosthesis. MATERIAL AND METHODS: A prospective randomised study was designed. During the implantation of a knee prosthesis, one group of patients was assigned the use of a conventional polyethylene (group A), and the other group a highly crosslinked polyethylene (X3, Stryker Orthopaedics) (group B). At 12 months after surgery a knee arthrocentesis was performed, and the number of polyethylene particles was counted in a scanning electron microscopy. Fourteen samples from each group were studied. RESULTS: Both groups were comparable in all study variables. We found no significant differences in the concentration of polyethylene particles/ml (1.49 ± 0.85 million in group A vs 1.42 ± 0.91 million in group B, P=.60) or the total number of isolated particles. We found no differences either in size or morphology of particles between both groups. DISCUSSION AND CONCLUSIONS: Although several in vitro studies in vitro using different types of highly crosslinked polyethylene found a significant reduction, we did not find that that wear was reduced in the knees of these patients. The great variability in the number of particles between individuals suggests that polyethylene wear in vivo depends on many factors, so perhaps the type of polyethylene is not the most significant factor.

Situación actual de la reconstrucción del ligamento cruzado anterior en nuestro país. Encuesta mediante formato electrónico / Update on anterior cruciate ligament reconstruction in Spain. Survey using an electronic questionnaire

Objetivo. Conocer cuáles son las preferencias de los cirujanos de nuestro país en referencia a algunos aspectos técnicos y epidemiológicos de la reconstrucción del ligamento cruzado anterior (LCA). Material y método. Durante el mes de febrero del 2009, se realizó una encuesta mediante el envío de 910 correos electrónicos a cirujanos de nuestro país que realizan de forma habitual reconstrucciones del LCA. Constaba de 8 preguntas en relación a los años de experiencia, número de reconstrucciones realizadas, técnica de elección en 2 casos clínicos ejemplo, tipo de injerto preferido, técnica con fascículo simple o doble, fuerza y tiempo de pretensado en el caso de los isquiotibiales y técnica de realización del túnel femoral. Resultados. Se obtuvo respuesta de 102 cirujanos. Un 66% de ellos tenían una experiencia entre 5–20 años. El 60,3% de ellos realizaba entre 10–50 reconstrucciones de LCA por año. El injerto de primera elección para los 2 casos clínicos propuestos fueron los tendones isquiotibiales con un 62–64%. Asimismo, predominaron las técnicas con fascículo simple (79,1%) y transtibial (71,8%). Discusión. El tratamiento de las lesiones de LCA sigue siendo controvertido. Parece que como ha sucedido en otros países que disponen de sistemas de registro adecuados, la técnica de reconstrucción con isquiotibiales ha aumentado su popularidad. No obstante, sigue existiendo una gran falta de consenso en algunos aspectos importantes de la técnica. Conclusiones. La técnica de reconstrucción con isquiotibiales, fascículo simple y transtibial fue la predominante en esta muestra (AU)

Objective. The aim of this study was to know what were the preferences of the Spanish surgeons about different aspects of anterior cruciate ligament (ACL) reconstruction. Material and methods. In February 2009, 910 surveys regarding some technical aspects of ACL reconstruction was mailed to surgeons who perform this kind of surgery in Spain. The survey had 8 questions: number of ACL reconstructions per year, two clinical cases, what kind of graft was preferred, the use of simple or double bundle reconstruction, the time and the amount of tension to apply to the hamstrings during ACL reconstruction and finally, some aspects about the creation of the femoral tunnel. Results. A total of 102 responses were received. Most of them (66%) had between 5-20 years of experience. A 60.3% of them performed between 10–50 procedures per year. The first choice graft in both clinical cases was autologous hamstring tendons (62% and 64%). The transtibial technique (71.8%) and the single bundle technique (79.1%) were preferred. Discussion. The management of the ACL injuries remains unclear. Like in other countries with available ACL registries, autologous hamstrings have increased their use for ACL reconstruction. However, there is not consensus in some aspects of the technique. Conclusion. The preferred technique for ACL reconstruction in this group was the transtibial technique with single bundle and using autologous hamstring tendons (AU)

Cuándo aflojar el manguito neumático de isquemia: su influencia sobre las pérdidas hemáticas y posibles complicaciones en la prótesis total de rodilla. Estudio prospectivo multicéntrico / The timing of tourniquet release: its influence on blood loss and possible complications after total knee arthroplasty. A prospective multicenter study

Objetivo. Realizar un estudio prospectivo multicéntrico de selección alternante para valorar las pérdidas hemáticas postoperatorias de la prótesis total de rodilla en relación con el momento de soltar la isquemia, realizando o no hemostasia, y las posibles complicaciones locales y generales.Material y método. Se analizan 194 pacientes (194 rodillas) distribuidos en dos grupos homogéneos:1. Grupo I hemostasia (H): se libera el torniquete de isquemia después de la colocación de los implantes metálicos, realizando la hemostasia previa al cierre de la herida quirúrgica.2. Grupo II no hemostasia (NH): se coloca la prótesis, se realiza el cierre de la herida quirúrgica, se coloca vendaje compresivo y en este momento se afloja el manguito neumático.Resultados. El sangrado promedio total del grupo I (H) fue de 721cc. (30-2210) y el del grupo II (NH) fue de 625cc. (60-1540), no existiendo diferencias significativas entre ambos grupos (p = 0,3). No se encuentran tampoco diferencias significativas entre ambos grupos con respecto a las complicacioneslocales o generales.Conclusión. Las pérdidas hemáticas postoperatorias no serelacionan directamente con el momento de soltar la isquemia durante las prótesis totales de rodilla

Purpose. We conducted a prospective multicenter study with alternate selection methodology in order to evaluate postoperative blood loss further to primary knee replacement at the time of tourniquet release, with or without hemostasis, as well as possible local and systemic complications.Materials and methods. We studied 194 patients (194 knees) divided into two similar groups. Group I (Hemostasis - H) - the tourniquet was deflated intraoperatively after implantation of the metal components and hemostasis was achieved prior to wound closure. Group II (No Hemostasis - NH) - the tourniquet was released after the wound was closed and a compressive bandage applied.Results. Mean bleeding was 721ml (30-1540) for group I and 625 ml (60-1540) for group II. No statistically significant differences were found (p = 0.3). No significant differences were found between the groups as regards general or local complications.Conclusions. Postoperative blood loss is not related directly with the time of tourniquet release further to TKR. Our findings cast certain doubts on the efficacy of tourniquet release, which means that intraoperative hemostasis may not be necessary (AU)

Cirugía del ligamento cruzado anterior sin ingreso hospitalario / Surgery of the anterior cruciate ligament without hospitalization

Objetivo. Analizar de forma prospectiva la eficacia, seguridad y coste-efectividad del procedimiento de reconstrucción artroscópica del ligamento cruzado anterior en régimen de cirugía mayor ambulatoria. Material y método. Entre noviembre de 2001 y diciembre de 2002 se realizaron 96 reconstrucciones del ligamento cruzado anterior, utilizando autoinjertos hueso-tendón-hueso o isquiotibiales en 4 haces. Se realizaron gestos quirúrgicos adicionales en 39 pacientes. Los resultados se valoraron a los 5 días del postoperatorio mediante la escala de dolor visual analógica (EVA) y encuesta de control del dolor, y se reevaluaron a los 6 meses estudiando el resultado clínico según el cuestionario del International Knee Documentation Committee (IKDC), tasa de complicaciones, satisfacción de los pacientes y coste-efectividad del proceso. Resultados. A los 5 días postoperatorios el 88,5 por ciento de pacientes refirieron un buen nivel analgésico (EVA de 1,9 ñ 0,4). Ningún paciente requirió reingreso para control del dolor. A los 6 meses el IKDC era normal o casi normal en el 90,6 por ciento de pacientes y un 89,5 por ciento se mostraron satisfechos con el procedimiento ambulatorio. El ahorro económico por paciente fue del 7,9 por ciento cuando se comparó con la cirugía con ingreso. Conclusiones. Los resultados sugieren que la reconstrucción del ligamento cruzado anterior puede realizarse con seguridad de forma ambulatoria. Los analgésicos orales han resultado adecuados para el control domiciliario del dolor postoperatorio. El análisis económico demostró el costeefectividad del procedimiento (AU)

Influence of autograft removal on rabbit patellar tendon length.

Twelve adult New Zealand white rabbits were randomly divided into two groups. In group 1, 30% of the central mass of the right patellar tendon was removed. In group 2, 60% was removed. The left knees served as controls. The animals were killed 1 year later. The patella-patellar tendon-tibial tuberosity units of all knees were studied using histological and morphometric analysis. In both groups, the tendons had lengthened. Lengthening average was 2.50 mm in group 1 and 8.17 mm in group 2. In both groups, histology revealed poor alignment of the collagen fibres and high cellularity, although the findings in group 1 were nearer the normal histological pattern. The results suggest that removal of significant portions of the patellar tendon leads to lengthening of the resulting tendon. In clinical practice, it seems prudent to pay attention to the dimensions of the patellar tendon when harvesting a graft.

Osteoblasts in HIV-infected patients: HIV-1 infection and cell function.

BACKGROUND: HIV-infected patients have been shown to have a severe alteration in osteoblast function that appears to be related to the infection. OBJECTIVE: To determine whether normal human osteoblasts express CD4, whether osteoblasts from patients with HIV infection are infected by HIV-1 and whether osteoblast dysfunction observed in vivo also occurs in vitro. METHODS: Osteoblast cultures from bone marrow biopsies of HIV-infected patients (n = 14) and control patients (n = 10) were used in a cross-sectional study and a case-control prospective study. Expression of CD4 was analysed using flow cytometry and reverse transcriptase polymerase chain reaction; the presence of HIV-1 particles was determined by measuring p24 antigen in the supernatants of osteoblast cultures and viral DNA or RNA in the osteoblasts using the polymerase chain reaction. Osteoblast function was assessed by measuring cell proliferation, type I collagen and osteocalcin synthesis. RESULTS: In human osteoblasts, CD4 expression could not be determined using flow cytometry, although low levels of mRNA coding for CD4 were detected. HIV infection was not observed in osteoblast cultures from HIV-infected patients nor was there any alteration in replication and synthesis of type I collagen, although osteocalcin synthesis was increased. CONCLUSIONS: It is unlikely that HIV-1 infects human osteoblasts in vivo; therefore, the hypothesis that these cells could act as local HIV-1 reservoirs should be reconsidered.

Combined fracture of the talus: Arthroscopic treatment.

The purpose of this article is to report the treatment and short-term results of a combined fracture of the talus treated arthroscopically. A 29-year-old man sustained an anterolateral osteochondral grade III fracture of the talus dome associated with a coronal fracture of the body of the talus. This injury was reduced and fixed arthroscopically using cannulated screws. The patient returned to his daily style of living after 3 months time. One year later, the patient remains asymptomatic. Radiography showed neither signs of osteonecrosis nor osteoarthritis of the talus at the 1-year follow-up. Therefore, arthroscopic surgery could be an alternative treatment for this kind of talus fracture.

Trapezius transfer for shoulder paralysis. 6 patients with brachial plexus injuries followed for 1 year.

We transferred the trapezius with its bone insertion to the proximal humerus in 6 patients for treatment of a paralytic shoulder secondary to traumatic lesions of the brachial plexus. After 1 year, the shoulder abduction was improved from average 13 degrees (0 degrees-30 degrees) preoperatively to 76 degrees (50 degrees-100 degrees) postoperatively, and the shoulder flexion from 18 degrees (0 degrees-40 degrees) to 78 degrees (45 degrees-110 degrees) postoperatively. All the patients were satisfied with the outcome. We consider that transfer of the trapezius in a paralytic shoulder after brachial plexus injury gives a better outcome than shoulder fusion.