Haemodynamic instability during hip prothesis removal due to metallosis: An acute chrome/cobalt intoxication? A case report.

INTRODUCTION: Metallosis is produced by friction between prothesis pieces, release of metal particles that can enter systemic circulation provoking cobalt or chromium poisoning. No studies have been found in which the mobilization of metal particles causes haemodynamic instability. CASE PRESENTATION: We present the case of an 85 years old male with metallosis, programmed for washing and prothesis extraction (Girldlestone procedure). During pseudotumor drainage and washing, patient presented sudden desaturation and hypotension refractory to volume and phenylephrine administration. Echocardiogram showed overall hypocontractility. Situation was controlled with high inspired oxygen fraction and noradrenaline perfusion. In postoperative period E. coli grew in pseudotumor samples and metal particles could be seen in soft parts as the testicles. Plasma metal concentration showed high levels of chromium, but no chelator treatment was needed. DISCUSSION: Intraoperative hypotension raises several differential diagnoses. Echocardiography was useful to rule out hypovolaemia, pulmonary embolism and cardiac ischaemia. The results of analytical tests are often delayed, especially cultures and plasma metal levels; therefore, if metal poisoning is suspected, supportive treatment should be performed. Chelation and plasmapheresis should be used once the diagnosis is certain and are therefore not useful in the acute phase. CONCLUSION: Intraoperative hemodynamic instability during hip prosthesis explant may be due to bleeding, release of inflammatory or infectious detritus, acute pulmonary thromboembolism, etc. However, the sudden increase of cobalt or chromium ions should be considered as a feasible option in patients with metallosis, despite not presenting previous clinical manifestations of intoxication.

In vitro chondral culture under compression and shear stimuli. From mesenchymal stem cells to hyaline cartilage. / Cultivo condral in vitro bajo estímulos de compresión y cizallamiento. De las células troncales mesenquimales al cartílago hialino.

INTRODUCTION: The in vitro creation of hyaline joint cartilage is a challenge since, to date, the ex vivo synthesis of a structured tissue with the same biomechanical and histological properties of the joint cartilage has not been achieved. To simulate the physiological conditions we have designed an in vitro culture system that reproduces joint movement. MATERIAL AND METHOD: We have developed a cell culture bioreactor that prints a mechanical stimulus on an elastin matrix, in which mesenchymal stem cells (MSC) are embedded. The first phase of study corresponds to the development of a bioreactor for hyaline cartilage culture and the verification of cell viability in the elastin matrix in the absence of stimulus. The second phase of the study includes the MSC culture under mechanical stimulus and the analysis of the resulting tissue. RESULTS: After culture under mechanical stimulation we did not obtain hyaline tissue due to lack of cellularity and matrix destructuring. CONCLUSION: The stimulus pattern used has not been effective in generating hyaline cartilage, so other combinations should be explored in future research.

Periprosthetic infection in elderly patients treated with hemiarthroplasty of the hip following intracapsular fracture. Should we use antibiotic-loaded bone cement? / Infección periprótesica en pacientes ancianos tratados mediante hemiartroplastia de cadera tras fractura intracapsular. ¿Debemos usar cementación con antibiótico?

INTRODUCTION: Prosthetic infections are a potentially devastating complication, especially in elderly patients. Antibiotic-loaded bone cement has been used both as a treatment and prophylaxis in prosthetic infection, and its use is not well documented in the prophylaxis of infection in patients who have suffered a hip fracture. MATERIAL: A retrospective descriptive was performed. The data were obtained from all the patients who underwent hip hemiarthroplasty due to a subcapital fracture between 2011 and 2017 (N=241). An epidemiological study of the patients studied was carried out. We analysed the incidence of periprosthetic infection in the groups treated with cement without antibiotic and antibiotic-loaded bone cement, as well as the protective effect of the antibiotic-loaded bone cement. At the same time, a pilot cost analysis study was carried out. RESULTS: In the group that received antibiotic-loaded bone cement (n=94) there were 8 infections (8%), while in the group with cement without antibiotic (n=147) there were 28 infections (19%). The odds ratio (OR) was calculated, showing a 55.3% reduction in the risk of developing late infection in the group that received cement with antibiotic (95% CI: 6.2-78.7%, P=.0025). The use of antibiotic-loaded bone cement led to significant cost savings per patient. CONCLUSIONS: The use of antibiotic-loaded bone cement is a protective factor in the development of late infection after hip hemiarthroplasty surgery in elderly patients with hip fracture.

Infección periprotésica de rodilla ¿influye la estrategia quirúrgica en el resultado funcional? / Total knee arthroplasty infection, what is the best strategy for better functional outcomes?

Resumen: Introducción: La estrategia quirúrgica al enfrentarnos a las infecciones periprotésicas de rodilla sigue siendo controvertida. Los objetivos del tratamiento son la erradicación de la infección, la mejoría del dolor y de la función articular. El manejo quirúrgico incluye el desbridamiento y retención del implante, el recambio protésico en un tiempo o el recambio en dos tiempos. Esta última estrategia quirúrgica se considera el «gold standard¼, alcanzando unas tasas de curación hasta de 80%-100%, aunque poco se ha publicado acerca de los resultados funcionales. Material y métodos: Estudio retrospectivo de 65 pacientes, con infección periprotésica de rodilla. En 20 pacientes se realizó un recambio en un tiempo y en 45 pacientes fueron recambios en dos tiempos. Evaluación pre- y postoperatoriamente con la escala modificada HSS. Todos los pacientes fueron tratados con antibioterapia intravenosa, evaluamos la respuesta analítica y clínica para confirmar la erradicación o no de la infección. Resultados: La infección se resolvió en 39 de 65 pacientes, 12 en el grupo de recambio en un tiempo y 27 para el grupo de dos tiempos. Sin diferencia significativa entre los grupos en relación con curación ni resultado funcional. Sin embargo, hay una diferencia estadísticamente significativa entre aquellos pacientes que recibieron tratamiento antibiótico vía oral antes del diagnóstico y aquéllos que no lo recibieron. Conclusión: La tasa de curación es similar en los tratados con recambio en un tiempo y recambio en dos tiempos. No pudimos demostrar superioridad en los resultados funcionales entre los dos grupos.

Abstract: Introduction: Surgical strategy in dealing with periprosthetic knee infections remains controversial. The goals of treatment are to eradicate infection, improve pain and joint function. Surgical management includes implant debridement and retention, prosthetic replacement in one-time, or two-stage replacement. This latest surgical strategy is considered the «gold standard¼, reaching healing rates up to 80%-100%, although little has been published about functional results. Material and methods: Retrospective study of 65 patients with periprosthetic knee infection. In 20 patients a replacement was made in a time and in 45 patients were in two stages. Pre- and post-operative evaluation with the modified HSS scale. All patients were treated with intravenous antibiotherapy, we evaluated the analytical and clinical response to confirm the eradication or not of the infection. Results: The infection was resolved in 39 out of 65 patients, 12 in the replacement group in a time and 27 for the two-stages group. No significant difference between the groups in relation to healing or functional result. However, there is a statistically significant difference between those patients who received oral antibiotic treatment prior to diagnosis and those who did not. Conclusions: The healing rate is similarly treated with replacement in a time and replacement in two times. We were unable to demonstrate superiority in the functional results between the two groups.

[Total knee arthroplasty infection, what is the best strategy for better functional outcomes?] / Infección periprotésica de rodilla ¿influye la estrategia quirúrgica en el resultado funcional?

INTRODUCTION: Surgical strategy in dealing with periprosthetic knee infections remains controversial. The goals of treatment are to eradicate infection, improve pain and joint function. Surgical management includes implant debridement and retention, prosthetic replacement in one-time, or two-stage replacement. This latest surgical strategy is considered the «gold standard¼, reaching healing rates up to 80%-100%, although little has been published about functional results. MATERIAL AND METHODS: Retrospective study of 65 patients with periprosthetic knee infection. In 20 patients a replacement was made in a time and in 45 patients were in two stages. Pre- and post-operative evaluation with the modified HSS scale. All patients were treated with intravenous antibiotherapy, we evaluated the analytical and clinical response to confirm the eradication or not of the infection. RESULTS: The infection was resolved in 39 out of 65 patients, 12 in the replacement group in a time and 27 for the two-stages group. No significant difference between the groups in relation to healing or functional result. However, there is a statistically significant difference between those patients who received oral antibiotic treatment prior to diagnosis and those who did not. CONCLUSIONS: The healing rate is similarly treated with replacement in a time and replacement in two times. We were unable to demonstrate superiority in the functional results between the two groups.

INTRODUCCIÓN: La estrategia quirúrgica al enfrentarnos a las infecciones periprotésicas de rodilla sigue siendo controvertida. Los objetivos del tratamiento son la erradicación de la infección, la mejoría del dolor y de la función articular. El manejo quirúrgico incluye el desbridamiento y retención del implante, el recambio protésico en un tiempo o el recambio en dos tiempos. Esta última estrategia quirúrgica se considera el «gold standard¼, alcanzando unas tasas de curación hasta de 80%-100%, aunque poco se ha publicado acerca de los resultados funcionales. MATERIAL Y MÉTODOS: Estudio retrospectivo de 65 pacientes, con infección periprotésica de rodilla. En 20 pacientes se realizó un recambio en un tiempo y en 45 pacientes fueron recambios en dos tiempos. Evaluación pre- y postoperatoriamente con la escala modificada HSS. Todos los pacientes fueron tratados con antibioterapia intravenosa, evaluamos la respuesta analítica y clínica para confirmar la erradicación o no de la infección. RESULTADOS: La infección se resolvió en 39 de 65 pacientes, 12 en el grupo de recambio en un tiempo y 27 para el grupo de dos tiempos. Sin diferencia significativa entre los grupos en relación con curación ni resultado funcional. Sin embargo, hay una diferencia estadísticamente significativa entre aquellos pacientes que recibieron tratamiento antibiótico vía oral antes del diagnóstico y aquéllos que no lo recibieron. CONCLUSIÓN: La tasa de curación es similar en los tratados con recambio en un tiempo y recambio en dos tiempos. No pudimos demostrar superioridad en los resultados funcionales entre los dos grupos.