Prótesis unicompartimental de rodilla / Unicompartmental knee prosthesis

Resumen: En un paciente con artrosis unicompartimental de rodilla grave, donde se agotaron los tratamientos conservadores que tiene clínica dolorosa localizada en el lado afectado y con alteración del eje reductible, la prótesis unicompartimenal de rodilla (PUR) es la primera opción para nuestro grupo de trabajo. Dentro del estudio para confirmar el diagnóstico y planificar la cirugía destacan las radiografías de rodillas con carga, radiografía de Rosenberg y telerradiografías de extremidades inferiores. El objetivo de la cirugía es reemplazar la zona afectada, restituyendo la anatomía con un adecuado balance de partes blandas. Respecto al alineamiento el desafío es no sobrecargar el lado contrario ni tampoco el de la prótesis. Existen de platillo móvil y fijo y aunque los resultados clínicos y de supervivencia son semejantes, en los últimos años con la incorporación de la cirugía robótica, la balanza se ha inclinado para el uso de los platillos fijos. En pacientes con artrosis unicompartimental los resultados clínicos y funcionales son mejores con PUR y tiene menos complicaciones que cuando se usan prótesis totales (PTR). La supervivencia estudiada en registros es menor que para PTR, pero cuando se usa en centros de alto flujo en que el porcentaje de PUR es cercano a un tercio del total con una estricta selección de pacientes, la duración es tan buena como en la PTR.

Abstract: In a patient with severe unicompartmental knee osteoarthritis where conservative treatments have been exhausted, with painful symptoms located on the affected side and with a reducible axis, the unicompartmental knee prosthesis (UKP) is the first option for our work group. Within the study to confirm the diagnosis and plan the surgery, weight-bearing knee x-rays, Rosenberg x-rays, and teleradiographs of the lower extremities stand out. The objective of surgery is to replace the affected area, restoring the anatomy with an adequate balance of soft tissues. Regarding alignment, the challenge is not to overload the opposite side or that of the prosthesis. There are mobile and fixed plates and although the clinical and survival results are similar, in recent years with the incorporation of robotic surgery, the balance has tipped towards the use of fixed plates. The clinical and functional results are better and there are fewer complications than when total knee prostheses (TKP) are used in the same type of patients. The survival studied in registries is lower than for TKP, but when used in high-flow centers where the percentage of UKP is close to a third of the total with strict patient selection, the duration is as good as in PTR.

Resultados preliminares de la artroplastía de revisión de rodilla con implante modular de fijación híbrida / Preliminary results of hybrid fixation modular implant in revision knee arthroplasty

Resumen: Introducción: la artroplastía total de rodilla (ATR) de revisión es un procedimiento desafiante que requiere alineación adecuada, restauración ósea y estabilidad. Los sistemas modernos de revisión ofrecen opciones de implantes modulares con fijación híbrida. Objetivo: evaluar los resultados clínicos de un implante modular de fijación híbrida con seguimiento mínimo de dos años. Material y métodos: se incluyeron retrospectivamente cirugías de revisión de ATR realizadas entre Septiembre de 2018 y Septiembre de 2019 con el mismo implante. Se registraron datos demográficos, comorbilidades y se evaluaron los resultados clínicos utilizando puntuaciones subjetivas y la Knee Society Score (KSS). Resultados: se analizaron 23 pacientes (65% mujeres, 35% hombres; edad mediana: 71.1 años). Los defectos óseos posteriores a la extracción del implante se clasificaron como F2.T2 en 39.13% de los casos, F1.T2 en 8.69%, y F1.T1 en 52.17%. Se observaron mejoras significativas en la puntuación de la KSS (preoperatoria: 53 puntos, postoperatoria: 79 puntos; p < 0.001). Se registraron tres (13%) complicaciones totales, dos relacionadas directamente con la cirugía, y dos casos requirieron una nueva cirugía de revisión. La tasa de supervivencia a los dos años fue de 91.3%. Conclusión: el uso del implante modular con fijación híbrida en la revisión de ATR mostró una alta tasa de supervivencia a dos años, mejoras significativas en las puntuaciones clínicas y baja incidencia de complicaciones a corto plazo. Estos resultados respaldan la eficacia y seguridad de este enfoque, proporcionando resultados clínicos favorables y alta satisfacción del paciente.

Abstract: Introduction: revision total knee arthroplasty (TKA) is a challenging procedure that requires proper alignment, restoration of bone loss, and prevention of instability. Modern revision systems offer progressive implant constriction with multiple options for offset, augmentation, and fixation stems. Objective: to evaluate the clinical outcomes of a modular implant with hybrid fixation in revision TKA with a minimum follow-up of two years. Material and methods: we retrospectively included all revision TKA surgeries performed between September 2018 and September 2019, using the same implant. Patient demographics, comorbidities, and data on bone defects were recorded. Clinical outcomes were assessed using subjective roles and Maudsley scores and the Knee Society Score (KSS). Complications during follow-up were also documented. Results: a total of 23 patients were analyzed, comprising 65% females and 35% males, with a median age of 71.1 years. Bone defects following implant removal were classified as F2.T2 in 39.13% of cases, F1.T2 in 8.69%, and F1.T1 in the remaining 52.17%. There were significant improvements in the KSS score (preoperative: 53 points, postoperative: 79 points; p < 0.001). Three (13%) complications were reported, two of which were directly related to the surgery, and two patients required subsequent revision surgery. The 2-year survival rate was 91.3%. Conclusion: the use of a modular implant with hybrid fixation in revision TKA demonstrated a high 2-year survival rate, significant improvements in clinical scores, and a low incidence of short-term complications. These findings support the efficacy and safety of this approach, providing favorable clinical outcomes and high patient satisfaction.

Prevalencia de portación nasal de Staphylococcus aureus sensible y resistente a la meticilina en candidatos a artroplastia total de cadera o rodilla / Prevalence of nasal carriage of methicillin-sensitive and methicillin-resistant Staphylococcus aureus in candidates for total hip or knee arthroplasty

INTRODUCIÓN Las infecciones perioperatorias en cirugía de reemplazo articular son fuente importante de morbimortalidad, así como de altos costos económicos y sociales, tanto para el paciente como para su entorno. La colonización preoperatoria por Staphylococcus aureus ha sido reconocida como un factor de riesgo importante para desarrollar una infección de sitio quirúrgico.El objetivo de este estudio es conocer la prevalencia de portación nasal de S. aureus, tanto sensible a la meticilina (SASM) como resistente a la meticilina (SARM), en pacientes candidatos a cirugía de reemplazo articular de cadera o rodilla. MATERIALES Y MÉTODOS Se realizó un estudio observacional de una cohorte retrospectiva de pacientes con indicación de artroplastia total de cadera (ATC) y rodilla (ATR) electiva por artrosis severa en un hospital público de Chile. Los pacientes fueron sometidos a tamizaje preoperatorio de portación, cultivándose muestras obtenidas mediante hisopado de ambas fosas nasales. Los datos del laboratorio fueron recopilados y presentados como porcentaje de portación de S. aureus. RESULTADOS Se estudiaron 303 pacientes consecutivos de ATC y 343 de ATR. En total, 483 de los 646 pacientes (74,7%) tuvieron estudio preoperatorio de portación nasal. Se identificaron 123 pacientes (25,4%) portadores de S. aureus, de los cuales sólo 2 (0,41%) casos correspondieron a SARM. CONCLUSIÓN La prevalencia de portación nasal de S. aureus obtenida fue de 25%, similar a lo reportado en otras series. La prevalencia de SARM (0.41%), sin embargo, estuvo bajo lo descrito en la literatura internacional (0,6­6%). Sería de utilidad, dada la alta prevalencia de portación descrita en nuestro trabajo y de acuerdo a evidencia publicada recientemente, realizar protocolos de descolonización universales, sin necesidad de realizar tamizaje preoperatorio.

INTRODUCTION Surgical-site infections in joint replacement surgery are an important source of morbidity and mortality that entail high economic and social burden both for the patient and their environment. Preoperative colonization by Staphylococcus aureus has been recognized as an important risk factor for the development of surgical-site infection. The aim of the present study is to determine the prevalence of nasal colonization by S. aureus, both methicillin-sensitive (MSSA) and methicillin-resistant (MRSA) in patients who are candidates for total replacement of the hip or knee joints. MATERIALS AND METHODS A retrospective observational study of a cohort of 646 patients with an indication to undergo total hip arthroplasty (THA) or total knee arthroplasty (TKA) due to severe osteoarthritis was performed in a Public Hospital in Chile. The patients were submitted to a preoperative screening for S. aureus carriage, and the culture samples were obtained by swabbing both nostrils. The laboratory data was collected and presented as a percentage of carriage. RESULTS We consecutively examined 303 THA and 343 TKA patients. A total of 483 of the 646 patients (74.7%) underwent a preoperative study of nasal carriage. We identified 123 (25.4%) S. aureus carriers, and only found 2 (0.41%) cases corresponding to MRSA. CONCLUSION We found a prevalence of nasal carriage of S. aureus of 25.4%, a rate similar to that reported in other series. The prevalence of MRSA (0.41%), however, was lower than that reported in the international literature (0.6­6%). Given the high prevalence of carriage described in our work and according to recently published data, it would be worthwhile to carry out universal decolonization protocols, without the need for preoperative screening.

Resultados de la artroplastia total de rodilla no cementada en pacientes mayores de 70 años / Results of cementless total knee arthroplasty in patients over 70 years of age

Objetivo: Analizar los resultados clínicos, radiológicos, la supervivencia y las complicaciones obtenidos en pacientes de 70 años o más intervenidos mediante artroplastia total de rodilla (ATR) no cementada. Material y método: Se realizó un estudio observacional de pacientes intervenidos entre enero 2014-diciembre 2016 con el modelo Natural Knee (Zimmer®, Estados Unidos). Las variables principales fueron la puntuación de Oxford Knee Score y la de la escala visual analógica, la presencia de radiolucencias, complicaciones, supervivencia y motivo de revisión. Resultados: De 104 ATR, 86 estuvieron disponibles para su revisión. La mediana de edad fue de 76 años. El seguimiento medio fue de 5,4 años (rango 3,7-6,9). La puntuación del Oxford Knee Score presentó una mediana de 17 (rango 0-40) prequirúrgica y 37 (rango 5-48) posquirúrgica, p<0,001. El 87,2% de los pacientes obtuvo una mejoría clínicamente significativa. La mediana de la puntuación de la escala visual analógica fue 8 (rango 4-10) prequirúrgica y 2 (rango 1-9) posquirúrgica, p<0,001. El 88,3% de los pacientes obtuvo una disminución clínicamente significativa. Alrededor del platillo tibial, a los 3 meses de la cirugía, el 55,81% de las ATR presentaron radiolucencias, al final del seguimiento las radiolucencias estuvieron presentes en el 30,23% de las ATR. La supervivencia por todas las causas fue del 91,86% a los 77,2 meses y del 96,5% por aflojamiento aséptico. Conclusión: Las prótesis de rodilla no cementadas son una opción válida en pacientes de 70 o más años, presentando buenos resultados clínicos, radiológicos y de supervivencia.(AU)

Objective: To analyze the clinical and radiologic results, the survival and complications obtained in 70 year or older patients who underwent cementless total knee arthroplasty (TKA). Material and method: An observational study of patients operated between January 2014 and December 2016 was carried out according to the Natural Knee model (Zimmer®, USA). The main variables were the Oxford Knee Score, the visual analog scale, the presence of radiolucencies, complications, survival and reasons for revision. Results: Of 104 TKA, 86 were available for revision. The median age was 76 years. The mean follow-up was 5.4 years (range 3.7-6.9). The Oxford Knee Score punctuation showed a median of 17 presurgical (range 0-40) and 37 post surgical (range 5-48), P<.001. The 87.2% of the patients obtained a clinically significant improvement. The median visual analog scale punctuation was 8 for presurgical (range 4-10) and 2 for post surgical (range 1-9), P<.001. The 88.3% of the patients obtained a clinically significant decrease. Three months after the surgery, the 55.81% of the TKAs presented radiolucencies around the tibial plateau. At the end of the follow-up, radiolucencies were present in 30.23% of the TKAs. Survival from all causes was 91.86% at 77.2 months and 96.5% due to aseptic loosening. Conclusion: Cementless knee prostheses are a valid option in patients aged 70 or older, presenting good clinical, radiological and survival results.(AU)

[Translated article] Results of cementless total knee arthroplasty in patients over 70 years of age / Resultados de la artroplastia total de rodilla no cementada en pacientes mayores de 70 años

Objetivo: Analizar los resultados clínicos, radiológicos, la supervivencia y las complicaciones obtenidos en pacientes de 70 años o más intervenidos mediante artroplastia total de rodilla (ATR) no cementada. Material y método: Se realizó un estudio observacional de pacientes intervenidos entre enero 2014-diciembre 2016 con el modelo Natural Knee (Zimmer®, Estados Unidos). Las variables principales fueron la puntuación de Oxford Knee Score y la de la escala visual analógica, la presencia de radiolucencias, complicaciones, supervivencia y motivo de revisión. Resultados: De 104 ATR, 86 estuvieron disponibles para su revisión. La mediana de edad fue de 76 años. El seguimiento medio fue de 5,4 años (rango 3,7-6,9). La puntuación del Oxford Knee Score presentó una mediana de 17 (rango 0-40) prequirúrgica y 37 (rango 5-48) posquirúrgica, p<0,001. El 87,2% de los pacientes obtuvo una mejoría clínicamente significativa. La mediana de la puntuación de la escala visual analógica fue 8 (rango 4-10) prequirúrgica y 2 (rango 1-9) posquirúrgica, p<0,001. El 88,3% de los pacientes obtuvo una disminución clínicamente significativa. Alrededor del platillo tibial, a los 3 meses de la cirugía, el 55,81% de las ATR presentaron radiolucencias, al final del seguimiento las radiolucencias estuvieron presentes en el 30,23% de las ATR. La supervivencia por todas las causas fue del 91,86% a los 77,2 meses y del 96,5% por aflojamiento aséptico. Conclusión: Las prótesis de rodilla no cementadas son una opción válida en pacientes de 70 o más años, presentando buenos resultados clínicos, radiológicos y de supervivencia.(AU)

Objective: To analyze the clinical and radiologic results, the survival and complications obtained in 70 year or older patients who underwent cementless total knee arthroplasty (TKA). Material and method: An observational study of patients operated between January 2014 and December 2016 was carried out according to the Natural Knee model (Zimmer®, USA). The main variables were the Oxford Knee Score, the visual analog scale, the presence of radiolucencies, complications, survival and reasons for revision. Results: Of 104 TKA, 86 were available for revision. The median age was 76 years. The mean follow-up was 5.4 years (range 3.7-6.9). The Oxford Knee Score punctuation showed a median of 17 presurgical (range 0-40) and 37 post surgical (range 5-48), P<.001. The 87.2% of the patients obtained a clinically significant improvement. The median visual analog scale punctuation was 8 for presurgical (range 4-10) and 2 for post surgical (range 1-9), P<.001. The 88.3% of the patients obtained a clinically significant decrease. Three months after the surgery, the 55.81% of the TKAs presented radiolucencies around the tibial plateau. At the end of the follow-up, radiolucencies were present in 30.23% of the TKAs. Survival from all causes was 91.86% at 77.2 months and 96.5% due to aseptic loosening. Conclusion: Cementless knee prostheses are a valid option in patients aged 70 or older, presenting good clinical, radiological and survival results.(AU)

Ensayo clínico para determinar si el momento de administración del ácido tranexámico en la cirugía de prótesis total de rodilla con torniquete influye en el sangrado perioperatorio / Clinical trial to determine whether the timing of tranexamic acid administration influences perioperative bleeding in total knee arthroplasty

Antecedentes y objetivos: El momento óptimo para la administración de ácido tranexámico en la artroplastia de rodilla con torniquete no está claro. El objetivo principal de nuestro estudio era demostrar si su administración tras la inducción anestésica reduce el sangrado postoperatorio respecto a administrarlo antes de la liberación del torniquete. Nuestro objetivo secundario era determinar si una segunda dosis reduce significativamente el sangrado. Material y métodos: Ensayo clínico prospectivo con 212 pacientes programados para prótesis total de rodilla, aleatorizados en 4 grupos. El ácido tranexámico se administró antes de la isquemia en los «grupos preinducción» (1 y 2) y justo antes de la liberación del torniquete en los «grupos preliberación» (3 y 4). Los grupos 2 y 4 recibieron una segunda dosis 3h después. La variable principal fue el sangrado postoperatorio (visible y el calculado). Las variables secundarias fueron la variación de hemoglobina, complicaciones y transfusión. Resultados: El sangrado total calculado fue 1563ml (IC 95%: 1445-1681) en los grupos preinducción frente a 1576ml (IC 95%: 1439-1713) en los preliberación (p=0,9); los de dosis única sangraron 1579ml (IC 95%: 1452-1706) frente a 1559ml (IC 95%: 1431-1686) en los de 2 dosis (p=0,82). La hemoglobina al alta fue 10,4 (IC 95%: 10,2-10,7) con una dosis frente a 10,8g/dl (IC 95%: 10,6-11,1) con 2 dosis (p=0,06). Conclusiones: No se detectaron diferencias en sangrado ni transfusión dependiendo del momento de administración del ácido tranexámico. Una segunda dosis tampoco tuvo impacto significativo.(AU)

Background and objectives: The ideal timing of tranexamic acid administration in total knee arthroplasty with tourniquet remains unclear. Our primary objective was to prove if administering it before surgical incision, instead of before releasing the tourniquet, reduces postoperative bleeding. A second objective was to determine whether a second dose reduces post-operative bleeding. Material and methods: A prospective, double-blind clinical trial was performed on 212 patients scheduled for total knee arthroplasty. They were randomised into 4 groups. Tranexamic acid was administered before the surgical incision in “pre-induction groups” (1 and 2), and just before the tourniquet release in “pre-release groups” (3 and 4). Groups 2 and 4 received a second dose 3hours post-surgery. Main outcome was postoperative bleeding (visible blood loss and calculated total bleeding). Secondary outcomes were haemoglobin variations, complications and transfusion rate. Results: The mean calculated total bleeding was 1563ml (95%CI: 1445 to 1681) in preinduction groups versus 1576ml (95%CI: 1439 to 1713) in pre-release groups (P=.9); 1579ml (95%CI: 1452 to 1706) in single-dose groups versus 1559ml (95%CI: 1431 to 1686) in double-dose groups (P=.82). One patient was transfused. The mean haemoglobin at discharge was 10.4g/dl (95%CI: 10.2 to 10.7) in singledose groups versus 10.8 (95%CI: 10.6 to 11.1) in double-dose groups (P=.06). Conclusions: There were no differences in bleeding or transfusion regarding the time of tranexamic acid administration. The second dose had not impact on outcomes.(AU)

Clinical trial to determine whether the timing of tranexamic acid administration influences perioperative bleeding in total knee arthroplasty.

BACKGROUND AND OBJECTIVES: The ideal timing of tranexamic acid administration in total knee arthroplasty with tourniquet remains unclear. Our primary objective was to prove if administering it before surgical incision, instead of before releasing the tourniquet, reduces postoperative bleeding. A second objective was to determine whether a second dose reduces post-operative bleeding. MATERIAL AND METHODS: A prospective, double-blind clinical trial was performed on 212 patients scheduled for total knee arthroplasty. They were randomised into 4 groups. Tranexamic acid was administered before the surgical incision in "pre-induction groups" (1 and 2), and just before the tourniquet release in "pre-release groups" (3 and 4). Groups 2 and 4 received a second dose 3h post-surgery. Main outcome was postoperative bleeding (visible blood loss and calculated total bleeding). Secondary outcomes were haemoglobin variations, complications and transfusion rate. RESULTS: The mean calculated total bleeding was 1563ml (95%CI: 1445-1681) in preinduction groups versus 1576ml (95%CI: 1439-1713) in pre-release groups (P=0.9); 1579ml (95%CI: 1452-1706) in single-dose groups versus 1559ml (95%CI: 1431-1686) in double-dose groups (P=0.82). One patient was transfused. The mean haemoglobin at discharge was 10.4g/dl (95%CI: 10.2-10.7) in singledose groups versus 10.8 (95%CI: 10.6-11.1) in double-dose groups (P=0.06). CONCLUSIONS: There were no differences in bleeding or transfusion regarding the time of tranexamic acid administration. The second dose had not impact on outcomes. TRIAL REGISTRATION: EudraCT 2016-000071-24.

[Translated article] Results of cementless total knee arthroplasty in patients over 70 years of age.

OBJECTIVE: To analyse the clinical and radiologic results, the survival and complications obtained in 70 year or older patients who underwent cementless total knee arthroplasty (TKA). MATERIAL AND METHOD: An observational study of patients operated between January 2014 and December 2016 was carried out according to the Natural Knee model (Zimmer®, USA). The main variables were the Oxford Knee Score, the visual analogue scale, the presence of radiolucencies, complications, survival and reasons for revision. RESULTS: Of 104 TKA, 86 were available for revision. The median age was 76 years. The mean follow-up was 5.4 years (range 3.7-6.9). The Oxford Knee Score punctuation showed a median of 17 presurgical (range 0-40) and 37 post surgical (range 5-48), P<.001. The 87.2% of the patients obtained a clinically significant improvement. The median visual analogue scale punctuation was 8 for presurgical (range 4-10) and 2 for post surgical (range 1-9), P<.001. The 88.3% of the patients obtained a clinically significant decrease. Three months after the surgery, the 55.81% of the TKAs presented radiolucencies around the tibial plateau. At the end of the follow-up, radiolucencies were present in 30.23% of the TKAs. Survival from all causes was 91.86% at 77.2 months and 96.5% due to aseptic loosening. CONCLUSION: Cementless knee prostheses are a valid option in patients aged 70 or older, presenting good clinical, radiological and survival results.

Results of cementless total knee arthroplasty in patients over 70 years of age. / Resultados de la artroplastia total de rodilla no cementada en pacientes mayores de 70 años.

OBJECTIVE: To analyze the clinical and radiologic results, the survival and complications obtained in 70 year or older patients who underwent cementless total knee arthroplasty (TKA). MATERIAL AND METHOD: An observational study of patients operated between January 2014 and December 2016 was carried out according to the Natural Knee model (Zimmer®, USA). The main variables were the Oxford Knee Score, the visual analog scale, the presence of radiolucencies, complications, survival and reasons for revision. RESULTS: Of 104 TKA, 86 were available for revision. The median age was 76 years. The mean follow-up was 5.4 years (range 3.7-6.9). The Oxford Knee Score punctuation showed a median of 17 presurgical (range 0-40) and 37 post surgical (range 5-48), P<.001. The 87.2% of the patients obtained a clinically significant improvement. The median visual analog scale punctuation was 8 for presurgical (range 4-10) and 2 for post surgical (range 1-9), P<.001. The 88.3% of the patients obtained a clinically significant decrease. Three months after the surgery, the 55.81% of the TKAs presented radiolucencies around the tibial plateau. At the end of the follow-up, radiolucencies were present in 30.23% of the TKAs. Survival from all causes was 91.86% at 77.2 months and 96.5% due to aseptic loosening. CONCLUSION: Cementless knee prostheses are a valid option in patients aged 70 or older, presenting good clinical, radiological and survival results.

Arthrotomy debridement of arthrostic septic arthritis of the knee is more effective than arthroscopic debridement and delays the need for prosthesis despite progression. / El desbridamiento por artrotomía de la artritis séptica de rodilla artrósica es más eficaz que el artroscópico y retrasa la necesidad de prótesis a pesar de la progresión de la artrosis.

BACKGROUND AND OBJECTIVE: 40%-50% of this septic arthritis occurs in the knee, despite rapid medical surgical treatment, 24%-50% will have a poor clinical outcome. It is not clear which debridement technique, by arthrotomy or arthroscopy, is more effective in controlling infection, or whether or not previous osteoarthritis worsens the outcome. The objective of this study on septic arthritis of the osteoarthritic knee was to analyse which surgical debridement technique, arthroscopy or arthrotomy, is more effective, the clinical and radiographic outcomes of the patients, and how many go on to require a TKR after the infection has healed. MATERIAL AND METHODS: A retrospective study was performed in 27 patients with native septic arthritis of the knee. Eighteen were men and the mean age was 64.8 years (30-89years). Fifteen patients were debrided by arthrotomy and 12 by arthroscopy. The effectiveness of debridement in controlling infection, the radiographic progression of the osteoarthritis on the Ahlbäch scale, the need for subsequent replacement, and pain and functional status were analysed using the VAS and WOMAC scales at 52.8±11.2-month follow-up. RESULTS: The infection was controlled in 93% and 92% of the patients, 13% and 42% required 2 or more surgeries for infection control, 18% and 44.4% showed progression of arthritis in the arthrotomy and arthroscopy groups, respectively. One patient in each group required a knee replacement. The VAS score was superior in the arthrotomy group and there were no differences in WOMAC score. CONCLUSION: Debridement by arthrotomy in the emergency department by non-sub-specialist knee surgeons is more effective than arthroscopic debridement in controlling septic arthritis of the knee. Surgical debridement of septic arthritis in knees with previous osteoarthritis enabled control of the infection with no pain despite the progression of the osteoarthritis.

Validity of the KLIC and CRIME80 scores in predicting failure in late acute infection treated by debridement and implant retention. / Validez de las escalas KLIC y CRIME80 en la predicción del fracaso en la infección aguda tardía tratada mediante desbridamiento y retención de implantes.

It is very important to treat prosthetic infections correctly in order to ensure a higher success rate. Debridement with implant retention (DAIR) is widely used in acute and late infections, however patients who fail after this surgery are known to have a higher risk of failure in subsequent surgeries. Therefore, it is important to find a scale that enables us to predict the risk of DAIR failure. Hence the KLIC and CRIME80 scores for acute and late acute infections, respectively. This study analysed the validity of both scores in acute late periprosthetic knee infections. We observed that the KLIC score has no predictive value for this type of infection, but the CRIME80 score does.

Infecciones de prótesis total de rodilla / Total knee prosthesis infections

Objetivo: realizar una revisión bibliográfica y actualización sobre infección de prótesis total de rodilla. Materiales y métodos: : Es un Estudio bibliométrico, descriptivo transversal realizado mediante búsquedas bibliográficas en pubmed, NCBI, UP TO DATE, y revistas virtuales de Ortopedia y Traumatología del Perú e internacionales. Se seleccionó y consultó el material bibliográfico que tuviera información sobre infección de prótesis total de rodilla. Se excluyó la bibliografía sin relación con el tema y muy antigua. No hubo límites en el idioma. Los artículos seleccionados se clasificaron por relevancia, actualidad y localización. Desarrollo y discusión: La infección de prótesis de rodilla tiene una incidencia entre el 1 a 3% en prótesis primaria y 3.5 a 5% en prótesis de revisión, siendo los principales factores de riesgo principales, artritis reumatoide, cirugía previa, edad avanzada, sexo femenino, obesidad, desnutrición, diabetes e inmunodeficiencias, el diagnóstico es un reto para el médico, los cocos Gram positivos son los gérmenes más frecuentes, llegando a ser el 75% del total, el objetivo principal del tratamiento es erradicar la infección, el tratamiento quirúrgico debe ser agresivo y oportuno, es necesario recibir largos periodos de antibióticos sistémicos a fin de evitar cirugías radicales como la artrodesis y amputación. Conclusiones: la infección de prótesis de rodilla es la complicación más temida, tiene un diagnostico difícil y cuyo manejo demanda largos periodos de incapacidad, estancia hospitalaria, antibióticos de amplio espectro y cuantiosas perdida económicas la entidad prestadora de servicios de salud. (AU)

Objective: to perform a literature review and update on total knee prosthesis infection. Materials and methods: This is a bibliometric, cross-sectional descriptive study conducted through bibliographic searches in pubmed, NCBI, UP TO DATE, and virtual journals of Orthopedics and Traumatology of Peru and international. The bibliographic material that had information on total knee prosthesis infection was selected and consulted. The bibliography unrelated to the subject and very old was excluded. There were no limits in the language. The selected articles were classified by relevance, actuality and location. Development and discussion: Infection of knee prosthesis has an incidence between 1 to 3% in primary prostheses and 3.5 to 5% in revision prostheses, being the main risk factors, rheumatoid arthritis, previous surgery, advanced age, sex female, obesity, malnutrition, diabetes and immunodeficiencies, the diagnosis is a challenge for the doctor, Gram positive cocci are the most frequent germs, reaching 75% of the total, the main objective of the treatment is to eradicate the infection, the treatment surgical should be aggressive and timely, it is necessary to receive long periods of systemic antibiotics in order to avoid radical surgeries such as arthrodesis and amputation. Conclusions: knee prosthesis infection is the most feared complication, it has a difficult diagnosis and its management demands long periods of disability, hospital stay, broad spectrum antibiotics and large economic losses the health service provider entity. (AU)

Effectiveness of a patient blood management protocol on reduction of allogeneic red blood cell transfusions in orthopedic surgery. / Efectividad de un protocolo de ahorro de transfusión en la disminución de consumo de hematíes en cirugía protésica.

BACKGROUND AND OBJECTIVES: Patient blood management in orthopaedic surgery reduces transfusion risk. The best protocol is unknown. The effectiveness of a protocol based on the Seville Consensus on the reduction of transfusion risk is evaluated and a predictive transfusion equation is proposed in knee surgery. PATIENTS AND METHODS: Cohort study in patients undergoing knee and hip arthroplasty from January 2014 to December 2015 at a second level complexity hospital in Vilafranca del Penedès (Barcelona). Patients with Hb between 10 and 13g/dL were classified as anaemic with or without iron deficiency and received iron or combination of iron and erythropoietin. On the day of surgery, tranexamic acid was administered, the Hb drop was measured the next day and the requirements and the transfusion lintel were measured during the stay. RESULTS: A total of 334 patients were included in the study. The implementation of the programme decreased the transfusion risk from 41.5% to 14.8% at the end of the study. In hip surgery, transfused patients were significantly older, sicker and with lower preoperative Hb. Tranexamic acid did not decrease bleeding. In knee surgery, the administration of tranexamic acid was the variable that most decreased the transfusion risk followed by a high preoperative Hb. The equation predicts transfusion risk with a sensitivity of 55% and specificity of 95.7%. CONCLUSION: The implementation of the programme reduces transfusion risk. The effectiveness of tranexamic acid varies according to surgery site. The use of iron and recombinant human erythropoietin is necessary to improve Hb.

Arthroplasty knee registry of Catalonia: What scientific evidence supports the implantation of our prosthesis? / Registro de artroplastias de rodilla de Cataluña: ¿qué evidencia científica respalda la implantación de nuestras prótesis?

INTRODUCTION: In our environment, it is increasingly necessary to perform an activity based on scientific evidence and the field of prosthetic surgery should be governed by the same principles. The national arthroplasty registries allow us to obtain a large amount of data in order to evaluate this technique. The aim of our study is to analyse the scientific evidence that supports the primary total knee arthroplasties implanted in Catalonian public hospitals, based on the Arthoplasty Registry of Catalonia (RACat) MATERIAL AND METHODS: A review of the literature was carried out on knee prostheses (cruciate retaining, posterior stabilized, constricted and rotational) recorded in RACat between the period 2005-2013 in the following databases: Orthopedic Data Evaluation Panel, PubMed, TripDatabase and Google Scholar. The prostheses implanted in fewer than 10 units (1,358 prostheses corresponding to 62 models) were excluded. RESULTS: 41,947 prostheses (96.86%) were analysed out of 43,305 implanted, corresponding to 74 different models. In 13 models (n = 4,715) (11.24%) no clinical evidence to support their use was found. In the remaining 36 models (n = 13,609) (32.45%), level iv studies were the most predominant evidence. CONCLUSIONS: There was a significant number of implanted prostheses (11.24%) for which no clinical evidence was found. The number of models should be noted, 36 out of 110, with fewer than 10 units implanted. The use of arthroplasty registries has proved an extremely useful tool that allows us to analyse and draw conclusions in order to improve the efficiency of this surgical technique.

Evaluación con resonancia magnética de artroplastias totales de rodilla sintomáticas / MRI evaluation of symptomatic total knee arthroplasties

Introducción: Las artroplastias totales de rodilla sintomáticas con estudios normales resultan un desafío para el ortopedista. La resonancia magnética podría ser una alternativa para arribar al diagnóstico. El objetivo de este estudio fue evaluar la utilidad de la resonancia magnética con secuencias optimizadas en artroplastias totales de rodilla sintomáticas y también realizar un estudio interobservador para determinar qué estructuras anatómicas son evaluables. Materiales y Métodos: Se evaluaron retrospectivamente 15 pacientes con artroplastias totales de rodilla operados entre 2007 y 2012, con dolor periprotésico, y radiografía, centellograma y análisis de laboratorio normales, sometidos a una resonancia magnética. Se realizó un análisis interobservador utilizando los coeficientes de correlación intraclase y kappa entre cuatro profesionales, un residente de diagnóstico por imágenes y otro de Ortopedia, y dos médicos con 20 años de experiencia, uno en diagnóstico por imágenes y el otro en rodilla. Resultados: Se halló líquido articular aumentado en 14 pacientes, sinovitis en cuatro, un osículo infrarrotuliano y no se detectó osteólisis en ningún caso. En siete pacientes, fue posible evaluar correctamente los ligamentos colaterales. Los gemelos, el tejido celular subcutáneo y el aparato extensor se evaluaron sin dificultad. La resonancia magnética encontró causas de dolor en 12 casos. El coeficiente de correlación intraclase mostró concordancia para el ligamento colateral medial, el aparato extensor, los gemelos y el tejido celular subcutáneo. Conclusión: Este estudio demuestra la utilidad del método en la toma de decisiones. La concordancia interobservador fue estadísticamente significativa para el análisis del ligamento colateral medial, los gemelos y el tejido celular subcutáneo. Nivel de Evidencia: III

Introduction: Symptomatic total knee arthroplasties with normal studies are a challenge for the orthopedic surgeon. Nuclear magnetic resonance could be an alternative to reach a correct diagnosis. The objective of the study was to evaluate the usefulness of nuclear magnetic resonance using optimized sequences in symptomatic total knee arthroplasties, and to perform an interobserver study to determine which anatomical structures are evaluable. Methods: We retrospectively evaluated 15 patients operated on between 2007 and 2012 who had periprosthetic pain and normal radiographs, scintigraphy and laboratory values undergoing MRI. An interobserver analysis using intraclass correlation and kappa coefficients was performed among four professionals, a resident of diagnostic imaging and an advanced Orthopedic resident, and two physicians with 20 years of practice, one in diagnostic imaging and the other in knee surgery. Results: Joint fluid was increased in 14 patients; we detected synovitis in four cases and a case of infrapatellar ossicle, but osteolysis was not found in any of the patients. The collateral ligaments could be evaluated properly in seven cases. The gastrocnemius, the subcutaneous tissue and the extensor apparatus were evaluated without difficulty. MRI found causes of pain in 12 cases. The intraclass correlation coefficient showed concordance for the medial collateral ligament, the extensor apparatus, twins and subcutaneous tissue. Conclusion: This study demonstrates the usefulness of the method in the decision-making process. The interobserver agreement was statistically significant for the analysis of the medial collateral ligament, gastrocnemius and subcutaneous tissue. Level of Evidence: III

Vástagos cementados en recambios de prótesis total de rodilla en pacientes mayores de 75 años. Análisis clínico y radiológico / Cemented stems in revision total knee arthroplasty on patients older than 75 y/o. Clinical and radiological analysis

Resumen: Antecedentes: Analizar la evolución funcional y radiológica de los pacientes mayores de 75 años intervenidos de cirugía de revisión de rodilla con vástagos cementados. Material y métodos: Mediante análisis retrospectivo, hemos revisado a 27 individuos mayores de 75 años a quienes se les ha implantado una prótesis total de rodilla de revisión con vástagos cementados en nuestro centro entre 2008-2014. Durante el seguimiento, se realizó un análisis clínico mediante la escala Knee Society Score y de movilidad de la rodilla, un análisis radiológico de la estabilidad de los implantes por medio de la escala radiológica modificada de la Knee Society, el registro de las complicaciones y la supervivencia protésica. Resultados: Con una edad media de los participantes de 82.6 ± 4.4 años y un seguimiento medio de 43 ± 14.4 meses, no hemos observado ningún caso de aflojamiento mecánico de los componentes. La valoración funcional ha sido de 115 ± 32 puntos en la escala total KSS, de los cuales 77 ± 17.5 puntos pertenecen al KSS rodilla y 42 ± 24 puntos al KSS función. El rango medio de movilidad fue de 98o ± 17. A nivel radiológico, 18 sujetos mostraron radiolucencias periprotésicas; según los criterios de la escala radiológica de la Knee Society, solo tres requirieron seguimiento clínico-radiológico estricto. Conclusiones: La cementación de los vástagos en prótesis totales de rodilla de revisión se trata de un buen sistema de fijación en personas mayores de 75 años, con elevada supervivencia del implante, buen resultado funcional y bajo porcentaje de aflojamiento radiológico a pesar de la aparición frecuente de radiolucencias.

Abstract: Background: The purpose of this study was to analyze the clinical and radiological evolution of the total knee revision arthroplasty with cemented stems in patients over 75 years. Material and methods: A retrospective analysis was performed in all the subjects who underwent revision of total knee arthroplasty with cemented stems between 2008 and 2014 in our center. Twenty-seven individuals over 75 years met the inclusion criteria. We assessed the Knee Society Score and range of motion for clinical outcome. We evaluated the implant stability with radiographs through radiolucent lines according to the modified radiological scale of the Knee Society; we registered the complications and prosthetic survival. Results: With an average age of our participants of 82.6 ± 4.4 years and a follow-up of 43 ± 14.4 months, we did not find any mechanical failure of the components. The functional average score was 115 ± 32 in the total KSS, of which 77 ± 17.5 points were in the KSS knee and 42 ± 24 in the KSS function. The average range of motion was 98o ± 17. Radiologically, 18 patients presented radiolucent lines, but only three needed follow-up using the modified Knee Society radiographic scoring system. Conclusions: The results revealed that cemented stems are a good method for fixation in the revision of total knee arthroplasty in people over 75 years. We observed acceptable medium-term clinical results with a low risk of radiological failure, despite the high number of radiolucencies.

Rango de movilidad y resultados funcionales en tres disenos diferentes de artroplastia de rodilla primaria. estudio comparativo / Range of motion and functional results in three different designs of total knee arthroplasty. comparative study

Introducción: El objetivo de este trabajo fue analizar los resultados funcionales y el rango de movilidad entre tres grupos de pacientes con artroplastia total de rodilla: dos con prótesis de alta flexión y otro con un diseño convencional. Materiales y Métodos: Sesenta y cuatro pacientes fueron operados con una prótesis total de rodilla Zimmer® NexGen® y 34, con una Optetrack® de alta flexión. Luego de la exclusión de pacientes, 22 (grupo A) fueron tratados con un diseño Zimmer® de alta flexión; 21 (grupo B), con una prótesis Zimmer® convencional y 25 (grupo C), con una prótesis Optetrack ® PS. La evaluación funcional se realizó con el Knee Society Score, el Western Ontario and McMaster Universities Osteoarthritis index y la escala analógica visual. Resultados: En el posoperatorio, el promedio de flexión máxima subió de 99° a 113º en el grupo A, con un aumento promedio de 14º; de 106° a 118º en el grupo B, con una ganancia promedio de 12º y de 110° a 111° en el grupo C, con una ganancia de 1°. Los resultados funcionales evaluados con los dos puntajes mejoraron en los tres grupos. Conclusiones: Las evaluaciones clínicas funcionales son favorables en los tres diseños evaluados. Este estudio muestra que no hay diferencias significativas en la flexión final lograda y los resultados funcionales entre los dos primeros diseños; sin embargo, estos son significativamente superiores al diseño del tercer grupo luego de un año de seguimiento.

Introduction: The purpose of this comparative study was to analyze functional results and the range of motion of the knee among three groups of patients with total knee arthroplasty using high-flex prosthesis (in two groups) and a conventional design (one group). Methods: Sixty-four patients were surgically treated with total knee arthroplasty using a Zimmer® NexGen® prosthesis, and 34 patients received a high-flex Optetrack® design. After exclusion of patients, 22 patients (group A) were treated with a high-flex Zimmer® NexGen® design, 21 patients (group B) were treated with a conventional implant, and 25 patients (group C) received a high-flex PS Optetrack® prosthesis. Functional evaluation was performed with the Knee Society Score, the Western Ontario and McMaster Universities Osteoarthritis index, and a visual analogue scale. Results: Mean post-surgical maximum flexion increased from 99° to 113º in group A, with an average increase of 14º, from 106° to 118º in group B, with an average gain of 12º, and from 110 to 111° in group C, with an average increase of 1°. Functional results assessed with both scores showed improvements in all three groups. Conclusions: The functional and radiographic outcomes were favorable in the three designs. This study suggests that there are no significant differences in the final flexion and functional outcomes between the first two designs; however together they are significantly superior to the third group after one year of follow-up.

Influence of the ischaemic tourniquet in antibiotic prophylaxis in total knee replacement.

OBJECTIVE: There is level iv evidence that the preoperative administration of antibiotics helps in the prevention of prosthetic infection. There is controversy on whether the ischemia applied during surgery may affect the minimum inhibitory concentration of the antibiotic in the peri-prosthetic tissues. The aim of this study is to review this phenomenon through the determination of antibiotic concentration in the synovial tissue. MATERIAL AND METHOD: A prospective observational clinical study was conducted on 32 patients undergoing total knee replacement. Cefonicid 2g was administered as prophylaxis, with a tourniquet used for all patients. The antibiotic concentration was quantified by high performance liquid chromatography in samples of synovial tissue collected at the beginning and at the end of the intervention. RESULTS: The mean concentration of antibiotic was 23.16 µg/g (95% CI 19.19 to 27.13) in the samples at the beginning of the intervention and 15.45 µg/g (95% CI 13.20 to 17.69) in the final samples, being higher than the minimum inhibitory concentration of cefonicid, set at 8 µg/g. These results were statistically significant for both concentrations (P<.00001). DISCUSSION: The antibiotic concentration throughout the standard total knee prosthesis surgery performed with tourniquet gradually decreases throughout the intervention. The concentration determined at the end of the intervention was higher than the minimum inhibitory concentration required for the antibiotic studied. In conclusion, the use of a tourniquet does not increase the risk of infection.

[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.

Evaluación del componente patelar en artroplastía total de rodilla / Evaluation of patellar resurfacing in total knee arhtroplasty

Ever since the first Total Knee Arthroplasty was made to our present times, a point that still generates controversy is, if the accomplishment of patellar resurfacing will take to a higher global rate of complications. It was the final objective of our work to analyze clinically and radiologically, in addition to satisfaction degree and quality of life surveys, the patellar resurfacing in a sample of total knee arthroplasty made in our center. We can conclude that in our experience, the patellar resurfacing has a low incidence of complications, which do not affect in a significant way the quality of life of the patients carrying on a total knee arthroplasty, which justifies this procedure absolutely.

Desde que se realizan las Artroplastías Totales de Rodilla hasta la fecha, un punto que genera controversia, es, si la realización de un componente protésico patelar llevará a una mayor tasa global de complicaciones. Es por eso que el objetivo de nuestro trabajo fue analizar clínica y radiológicamente, además de encuestas del grado de satisfacción, el componente de recubrimiento patelar en una muestra de las artroplastías totales de rodilla realizadas en nuestro centro. Se concluye que en nuestra experiencia, el uso de recubrimiento patelar tiene una baja incidencia de complicaciones, las cuales no afectan de manera significativa la calidad de vida de los pacientes con artroplastía total de rodilla, lo que justifica plenamente su utilización.