[Translated article] In vitro elution of local anaesthetics from PMMA bone cement.

BACKGROUND AND AIM: Currently, we do not have a gold standard for pain management after total knee arthroplasty. We may use one of more drug delivery systems, none of which are ideal. An ideal depot delivery system would provide therapeutic, nontoxic, doses of drug at the surgical side, especially during 72h postoperatively. The bone cement used in arthroplasties has been used as a drug delivery system, especially antibiotics, since 1970. Based on this principle, we developed this study with the aim to characterize the elution profile of two local anaesthetics (lidocaine hydrochloride and bupivacaine hydrochloride) from PMMA (polymethilmethacrylate) bone cement. MATERIAL AND METHODS: Palacos® R+G bone cement and lidocaine hydrochloride or bupivacaine hydrochloride specimens were obtained depending on the study group. These specimens were immersed in PBS (phosphate buffered saline) and removed from the solution at different set times. Subsequently, the concentration of local anaesthetic in the liquid was analyzed by liquid chromatography. RESULTS: The percentage of lidocaine eluted from PMMA bone cement in this study was 9.74% of the total lidocaine content per specimen at 72h and 18.73% at 336h (14 days). In case of bupivacaine, the elution percentage was 2.71% of the total bupivacaine content per specimen at 72h and 2.70% at 336h (14 days). CONCLUSIONS: Local anaesthetics elute in vitro from PMMA bone cement, reaching doses at 72h close to the doses used in anaesthetic blocks.

Estudio in vitro de elución de anestésicos locales en cemento óseo de PMMA / In vitro elution of local anesthetics from PMMA bone cement

Antecedentes y objetivo:Actualmente, no disponemos de un gold standard para el manejo del dolor postoperatorio tras una artroplastia total de rodilla, dado que se pueden administrar analgésicos a través de diferentes vías y ninguna de estas está exenta de riesgos. El sistema ideal de administración de analgésicos debería proporcionar dosis terapéuticas, no tóxicas, en el sitio quirúrgico, especialmente durante las primeras 72h. El cemento óseo utilizado en las artroplastias se ha usado como un medio de liberación de fármacos, especialmente antibióticos, desde 1970. Basado en este principio, se desarrolló este estudio con el objetivo de conocer el perfil de elución de dos anestésicos locales (hidrocloruro de lidocaína e hidrocloruro de bupivacaína) desde el cemento óseo de polimetilmetacrilato (PMMA). Material y métodos: Se obtuvieron especímenes de cemento óseo Palacos® R+G e hidrocloruro de lidocaína o hidrocloruro de bupivacaína según el grupo de estudio. Estos especímenes se sumergieron en PBS (por sus siglas en inglés de phosphate buffered saline) y se retiraron de la solución en diferentes cortes temporales establecidos. Posteriormente, se analizó la concentración de anestésico local en el líquido mediante cromatografía líquida. Resultados: El porcentaje de lidocaína eludida del cemento óseo PMMA de este estudio ha sido del 9,74% del contenido total de lidocaína por espécimen a las 72h y del 18,73% a las 336h (14 días). En el caso de la bupivacaína, el porcentaje de elución ha sido del 2,71% del contenido total de bupivacaína por espécimen a las 72h y del 2,70% a las 336h (14 días). Conclusiones: Los anestésicos locales eluyen in vitro desde el cemento óseo, alcanzando a las 72h dosis cercanas a las dosis utilizadas en bloqueos anestésicos.(AU)

Background and aim: Currently, we do not have a gold standard for pain management after total knee arthroplasty. We may use one of more drug delivery systems, none of which are ideal. An ideal depot delivery system would provide therapeutic, nontoxic, doses of drug at the surgical side, especially during 72h postoperatively. The bone cement used in arthroplasties has been used as a drug delivery system, especially antibiotics, since 1970. Based on this principle, we developed this study with the aim to characterize the elution profile of two local anesthetics (lidocaine hydrochloride and bupivacaine hydrochloride) from PMMA (polymethilmethacrylate) bone cement. Material and methods: Palacos® R+G bone cement and lidocaine hydrochloride or bupivacaine hydrochloride specimens were obtained depending on the study group. These specimens were immersed in PBS (phosphate buffered saline) and removed from the solution at different set times. Subsequently, the concentration of local anesthetic in the liquid was analyzed by liquid chromatography. Results: The percentage of lidocaine eluted from PMMA bone cement in this study was 9.74% of the total lidocaine content per specimen at 72h and 18.73% at 336h (14 days). In case of bupivacaine, the elution percentage was 2.71% of the total bupivacaine content per specimen at 72h and 2.70% at 336h (14 days). Conclusions: Local anesthetics elute in vitro from PMMA bone cement, reaching doses at 72h close to the doses used in anesthetic blocks.(AU)

[Translated article] In vitro elution of local anaesthetics from PMMA bone cement / Estudio in vitro de elución de anestésicos locales en cemento óseo de PMMA

Antecedentes y objetivo:Actualmente, no disponemos de un gold standard para el manejo del dolor postoperatorio tras una artroplastia total de rodilla, dado que se pueden administrar analgésicos a través de diferentes vías y ninguna de estas está exenta de riesgos. El sistema ideal de administración de analgésicos debería proporcionar dosis terapéuticas, no tóxicas, en el sitio quirúrgico, especialmente durante las primeras 72h. El cemento óseo utilizado en las artroplastias se ha usado como un medio de liberación de fármacos, especialmente antibióticos, desde 1970. Basado en este principio, se desarrolló este estudio con el objetivo de conocer el perfil de elución de dos anestésicos locales (hidrocloruro de lidocaína e hidrocloruro de bupivacaína) desde el cemento óseo de polimetilmetacrilato (PMMA). Material y métodos: Se obtuvieron especímenes de cemento óseo Palacos® R+G e hidrocloruro de lidocaína o hidrocloruro de bupivacaína según el grupo de estudio. Estos especímenes se sumergieron en PBS (por sus siglas en inglés de phosphate buffered saline) y se retiraron de la solución en diferentes cortes temporales establecidos. Posteriormente, se analizó la concentración de anestésico local en el líquido mediante cromatografía líquida. Resultados: El porcentaje de lidocaína eludida del cemento óseo PMMA de este estudio ha sido del 9,74% del contenido total de lidocaína por espécimen a las 72h y del 18,73% a las 336h (14 días). En el caso de la bupivacaína, el porcentaje de elución ha sido del 2,71% del contenido total de bupivacaína por espécimen a las 72h y del 2,70% a las 336h (14 días). Conclusiones: Los anestésicos locales eluyen in vitro desde el cemento óseo, alcanzando a las 72h dosis cercanas a las dosis utilizadas en bloqueos anestésicos.(AU)

Background and aim: Currently, we do not have a gold standard for pain management after total knee arthroplasty. We may use one of more drug delivery systems, none of which are ideal. An ideal depot delivery system would provide therapeutic, nontoxic, doses of drug at the surgical side, especially during 72h postoperatively. The bone cement used in arthroplasties has been used as a drug delivery system, especially antibiotics, since 1970. Based on this principle, we developed this study with the aim to characterize the elution profile of two local anesthetics (lidocaine hydrochloride and bupivacaine hydrochloride) from PMMA (polymethilmethacrylate) bone cement. Material and methods: Palacos® R+G bone cement and lidocaine hydrochloride or bupivacaine hydrochloride specimens were obtained depending on the study group. These specimens were immersed in PBS (phosphate buffered saline) and removed from the solution at different set times. Subsequently, the concentration of local anesthetic in the liquid was analyzed by liquid chromatography. Results: The percentage of lidocaine eluted from PMMA bone cement in this study was 9.74% of the total lidocaine content per specimen at 72h and 18.73% at 336h (14 days). In case of bupivacaine, the elution percentage was 2.71% of the total bupivacaine content per specimen at 72h and 2.70% at 336h (14 days). Conclusions: Local anesthetics elute in vitro from PMMA bone cement, reaching doses at 72h close to the doses used in anesthetic blocks.(AU)

Situación actual de la robótica en cirugía protésica de rodilla, ¿una tecnología que ha venido para quedarse? / Current situation of robotics in knee prosthetic surgery, a technology that has come to stay?

La cirugía robótica es una técnica quirúrgica que va en aumento. El objetivo de la artroplastia total de rodilla asistida por robot (ATRar) es el de proveer al cirujano de una herramienta para ejecutar de forma precisa los cortes óseos de acuerdo con una planificación quirúrgica previa para restablecer la cinemática de una rodilla primitiva y el balance de partes blandas, pudiendo aplicar de forma precisa el tipo de alineación que escojamos. Además, la ATRar es una herramienta muy útil para la formación.Dentro de las limitaciones, encontramos la curva de aprendizaje, la necesidad de equipos específicos, los costes elevados de adquisición de los dispositivos, en algunos sistemas el aumento de radiación y que cada robot está ligado a un tipo específico de implante.Los estudios actuales muestran que con la ATRar disminuyen las variaciones de alineación del eje mecánico, mejora el dolor posoperatorio y se facilita un alta más precoz. Por otro lado, no muestran diferencias a nivel de rango de movimiento, alineación, balance de gaps, complicaciones, tiempo quirúrgico o resultados funcionales.(AU)

Robotic surgery is a surgical technique that is on the rise. The goal of robotic-assisted total knee arthroplasty (RA-TKA) is to provide the surgeon with a tool to accurately execute bone cuts according to previous surgical planning to restore knee kinematics and balance of soft tissue, being able to precisely apply the type of alignment that we choose. In addition, RA-TKA is a very useful tool for training.Within the limitations, there is the learning curve, the need for specific equipment, the high cost of the devices, the increase in radiation in some systems and that each robot is linked to a specific type of implant.Current studies show, with RA-TKA, variations in the alignment of the mechanical axis are reduced, postoperative pain is improved and earlier discharge is facilitated. On the other hand, there are no differences in terms of range of motion, alignment, gap balance, complications, surgical time or functional results.(AU)

[Translated article] Current situation of robotics in knee prosthetic surgery: A technology that has come to stay? / Situación actual de la robótica en cirugía protésica de rodilla, ¿una tecnología que ha venido para quedarse?

La cirugía robótica es una técnica quirúrgica que va en aumento. El objetivo de la artroplastia total de rodilla asistida por robot (ATRar) es el de proveer al cirujano de una herramienta para ejecutar de forma precisa los cortes óseos de acuerdo con una planificación quirúrgica previa para restablecer la cinemática de una rodilla primitiva y el balance de partes blandas, pudiendo aplicar de forma precisa el tipo de alineación que escojamos. Además, la ATRar es una herramienta muy útil para la formación.Dentro de las limitaciones, encontramos la curva de aprendizaje, la necesidad de equipos específicos, los costes elevados de adquisición de los dispositivos, en algunos sistemas el aumento de radiación y que cada robot está ligado a un tipo específico de implante.Los estudios actuales muestran que con la ATRar disminuyen las variaciones de alineación del eje mecánico, mejora el dolor posoperatorio y se facilita un alta más precoz. Por otro lado, no muestran diferencias a nivel de rango de movimiento, alineación, balance de gaps, complicaciones, tiempo quirúrgico o resultados funcionales.(AU)

Robotic surgery is a surgical technique that is on the rise. The goal of robotic-assisted total knee arthroplasty (RA-TKA) is to provide the surgeon with a tool to accurately execute bone cuts according to previous surgical planning to restore knee kinematics and balance of soft tissue, being able to precisely apply the type of alignment that we choose. In addition, RA-TKA is a very useful tool for training.Within the limitations, there is the learning curve, the need for specific equipment, the high cost of the devices, the increase in radiation in some systems and that each robot is linked to a specific type of implant.Current studies show, with RA-TKA, variations in the alignment of the mechanical axis are reduced, postoperative pain is improved and earlier discharge is facilitated. On the other hand, there are no differences in terms of range of motion, alignment, gap balance, complications, surgical time or functional results.(AU)

[Translated article] In vitro elution of local anaesthetics from PMMA bone cement.

BACKGROUND AND AIM: Currently, we do not have a gold standard for pain management after total knee arthroplasty. We may use one of more drug delivery systems, none of which are ideal. An ideal depot delivery system would provide therapeutic, nontoxic, doses of drug at the surgical side, especially during 72h postoperatively. The bone cement used in arthroplasties has been used as a drug delivery system, especially antibiotics, since 1970. Based on this principle, we developed this study with the aim to characterise the elution profile of two local anaesthetics (lidocaine hydrochloride and bupivacaine hydrochloride) from PMMA (polymethilmethacrylate) bone cement. MATERIAL AND METHODS: Palacos® R+G bone cement and lidocaine hydrochloride or bupivacaine hydrochloride specimens were obtained depending on the study group. These specimens were immersed in PBS (phosphate buffered saline) and removed from the solution at different set times. Subsequently, the concentration of local anaesthetic in the liquid was analysed by liquid chromatography. RESULTS: The percentage of lidocaine eluted from PMMA bone cement in this study was 9.74% of the total lidocaine content per specimen at 72h and 18.73% at 336h (14 days). In case of bupivacaine, the elution percentage was 2.71% of the total bupivacaine content per specimen at 72h and 2.70% at 336h (14 days). CONCLUSIONS: Local anaesthetics elute in vitro from PMMA bone cement, reaching doses at 72h close to the doses used in anaesthetic blocks.

In vitro elution of local anesthetics from PMMA bone cement. / Estudio in vitro de elución de anestésicos locales en cemento óseo de PMMA.

BACKGROUND AND AIM: Currently, we do not have a gold standard for pain management after total knee arthroplasty. We may use one of more drug delivery systems, none of which are ideal. An ideal depot delivery system would provide therapeutic, nontoxic, doses of drug at the surgical side, especially during 72h postoperatively. The bone cement used in arthroplasties has been used as a drug delivery system, especially antibiotics, since 1970. Based on this principle, we developed this study with the aim to characterize the elution profile of two local anesthetics (lidocaine hydrochloride and bupivacaine hydrochloride) from PMMA (polymethilmethacrylate) bone cement. MATERIAL AND METHODS: Palacos® R+G bone cement and lidocaine hydrochloride or bupivacaine hydrochloride specimens were obtained depending on the study group. These specimens were immersed in PBS (phosphate buffered saline) and removed from the solution at different set times. Subsequently, the concentration of local anesthetic in the liquid was analyzed by liquid chromatography. RESULTS: The percentage of lidocaine eluted from PMMA bone cement in this study was 9.74% of the total lidocaine content per specimen at 72h and 18.73% at 336h (14 days). In case of bupivacaine, the elution percentage was 2.71% of the total bupivacaine content per specimen at 72h and 2.70% at 336h (14 days). CONCLUSIONS: Local anesthetics elute in vitro from PMMA bone cement, reaching doses at 72h close to the doses used in anesthetic blocks.

[Translated article] Current situation of robotics in knee prosthetic surgery: A technology that has come to stay?

Robotic surgery is a surgical technique that is on the rise. The goal of robotic-assisted total knee arthroplasty (RA-TKA) is to provide the surgeon with a tool to accurately execute bone cuts according to previous surgical planning to restore knee kinematics and balance of soft tissue, being able to precisely apply the type of alignment that we choose. In addition, RA-TKA is a very useful tool for training. Within the limitations, there is the learning curve, the need for specific equipment, the high cost of the devices, the increase in radiation in some systems and that each robot is linked to a specific type of implant. Current studies show, with RA-TKA, variations in the alignment of the mechanical axis are reduced, postoperative pain is improved and earlier discharge is facilitated. On the other hand, there are no differences in terms of range of motion, alignment, gap balance, complications, surgical time or functional results.

Current situation of robotics in knee prosthetic surgery, a technology that has come to stay? / Situación actual de la robótica en cirugía protésica de rodilla, ¿una tecnología que ha venido para quedarse?

Robotic surgery is a surgical technique that is on the rise. The goal of robotic-assisted total knee arthroplasty (RA-TKA) is to provide the surgeon with a tool to accurately execute bone cuts according to previous surgical planning to restore knee kinematics and balance of soft tissue, being able to precisely apply the type of alignment that we choose. In addition, RA-TKA is a very useful tool for training. Within the limitations, there is the learning curve, the need for specific equipment, the high cost of the devices, the increase in radiation in some systems and that each robot is linked to a specific type of implant. Current studies show, with RA-TKA, variations in the alignment of the mechanical axis are reduced, postoperative pain is improved and earlier discharge is facilitated. On the other hand, there are no differences in terms of range of motion, alignment, gap balance, complications, surgical time or functional results.