[FG] Computational Spine BiomechanicsHead of Research Unit Prof. Dr. med.Carol-Claudius HaslerOverviewMembersPublicationsProjects & CollaborationsProjects & Collaborations OverviewMembersPublicationsProjects & Collaborations Projects & Collaborations 2 foundShow per page10 10 20 50 Patient-specific and pre-operative assessment of spine mechanical properties Research Project | 1 Project MembersBackground data: An accurate description of the biomechanical behavior of the spine is crucial for the understanding of degenerative spine disorders and spinal deformities as well as for the development of new treatment strategies. Nowadays, surgeons have limited data on the segmental spinal mobility of their patients and no information concerning their biomechanical stiffness. This is not only a major problem to select the appropriate treatment strategy, but also to standardize the procedure between surgeons and to propose guidelines and recommendations concerning the appropriate treatments. In addition, new strategies, such as artificial discs, interspinous process spacers, non-fusion techniques and target-oriented conservative approaches aim at preserving spine function. However, little is known about the complex functional behavior and stiffness of the normal and degenerated spinal segment under physiological loading conditions, because the existing studies focused solely on the spinal kinematics without considering mechanical loads. Objective: The aim of this project is to determine the mechanical properties of the spine based on pre-operative tests. The main challenge will be to develop an appropriate measurement technique able to provide the surgeons with an observer independent and reproducible three-dimensional assessment of the spine flexibility suitable for daily clinical use. Previous results: During the past years, the applicants developed a method for in-vivo measurements of the segmental spine stiffness in complex pediatric deformities. This information, acquired intra-operatively, requires significant efforts from the OR staff, additional operation time, which is not suitable for use in the clinical routine, but provides gold standard direct biomechanical data. Methods: The method will be based on standing elevation of the patient. Advanced image processing techniques will be used to extract the 3D position and orientation of the patients? vertebras from planar pre-operative images. Numerical tools will be used to model spine biomechanical behavior and identify the local stiffness characteristics. The segmental spine flexibility obtained will be compared to the intra-operative stiffness measurements obtained on the same patients with the previously developed method. Therefore, developments conducted in this project will primarily focus on the stiffness assessment for pediatric deformities and will be secondarily applied to degenerative spine pathologies. Significance: The first outcome of the project is a standardized test setup for the clinician to assess spinal flexibility in an accurate and reproducible manner. Such an approach is mandatory to compare surgical techniques across surgeons working at different institutions. Furthermore, with the increasing database of patients being measured, precise guidelines could be defined for each surgical treatment. The method will also serve stiffness-adapted implants or surgical strategies and could be used to work out non-surgical approaches, standards and ?safe zones? for daily clinical use. Additionally, this information is mandatory for the development of planning solutions that consider patient-specific biomechanical information. Such tools will become increasingly important in the future due to the ever-increasing complexity of the surgical instrumentation and procedures. Infection rate of VEPTR©-Implants in children with severe spinal and thoracic deformities Research Project | 1 Project MembersBackground: Spinal and thoracic deformities in children can be treated with vertical expandable prosthetic titanium ribs (VEPTR©, Synthes GmbH®) to stimulate thoracic and spinal growth. With these implants children s symptoms and conditions can be slowed, halted or even reversed. Because of the dynamic character of the deformity and the growth of the children, the implants have to be lengthened about every half a year. With each operation there is a small risk of infection, which might increase with number of previous surgeries. Implant associated infections are often not clinical apparent and only found in microbiological analysis. To objectify the infection rate, identify potential precursors of infections and the relevance of asymptomatic infections in children with these implants a prospective study is conducted. Hypothesis: Patients with VEPTR©-implants have asymptomatic implant-associated infections. Objective: To objectify the infection rate, we will analyze, during lengthening operation, removed implant-parts microbiological. Design: Prospective case-control study. Study population: We will prospectively include all patients who undergo lengthening operation after VEPTR©-Implantation at the University Children´s Hospital Basel (UKBB). Patients will be excluded if obvious contamination of explanted components occurred in the operation room. It is expected that 4 procedures can be included per month in the study. The study may be extended if the desired patient population (>120 procedures) is not reached within the study period. Methods: All patients and the operating surgeon fill out a questionnaire analyzing clinical signs of infection. A blood sample analyzed for CRP and white blood count is taken prior to operation during anesthesia. All anyway removed implant parts are transported to a microbiology laboratory in a sterile container and treated by sonication. The resulting sonicate fluid will be used for microbial detection by culture and molecular techniques. For potentially later histologic work up, tissue probes are taken and stored in Formalin. The infection rate will be quantified and the microbiological results will be related to clinical findings, laboratory data, operation kind and numbers. Further on the germ spectrum will be analyzed. Hypothesis: We anticipate that the total infection rate lies about 5-10% and increases with number of previous surgeries. Significance: We anticipate that: we will objectify (a) the total infection rate of patients with VEPTR©-implants, and (b) risk factors for infection, especially with low-virulent germs. The natural history (c) of the infection in asymptomatic patients will be followed to analyze its relevance, and (d) treatment regimes can be developed. The public health relevance of this work is significant since these findings: (a) may influence our management of patients with these implants, and (b) may lead to the development of improved implant designs. 1 1 OverviewMembersPublicationsProjects & Collaborations
Projects & Collaborations 2 foundShow per page10 10 20 50 Patient-specific and pre-operative assessment of spine mechanical properties Research Project | 1 Project MembersBackground data: An accurate description of the biomechanical behavior of the spine is crucial for the understanding of degenerative spine disorders and spinal deformities as well as for the development of new treatment strategies. Nowadays, surgeons have limited data on the segmental spinal mobility of their patients and no information concerning their biomechanical stiffness. This is not only a major problem to select the appropriate treatment strategy, but also to standardize the procedure between surgeons and to propose guidelines and recommendations concerning the appropriate treatments. In addition, new strategies, such as artificial discs, interspinous process spacers, non-fusion techniques and target-oriented conservative approaches aim at preserving spine function. However, little is known about the complex functional behavior and stiffness of the normal and degenerated spinal segment under physiological loading conditions, because the existing studies focused solely on the spinal kinematics without considering mechanical loads. Objective: The aim of this project is to determine the mechanical properties of the spine based on pre-operative tests. The main challenge will be to develop an appropriate measurement technique able to provide the surgeons with an observer independent and reproducible three-dimensional assessment of the spine flexibility suitable for daily clinical use. Previous results: During the past years, the applicants developed a method for in-vivo measurements of the segmental spine stiffness in complex pediatric deformities. This information, acquired intra-operatively, requires significant efforts from the OR staff, additional operation time, which is not suitable for use in the clinical routine, but provides gold standard direct biomechanical data. Methods: The method will be based on standing elevation of the patient. Advanced image processing techniques will be used to extract the 3D position and orientation of the patients? vertebras from planar pre-operative images. Numerical tools will be used to model spine biomechanical behavior and identify the local stiffness characteristics. The segmental spine flexibility obtained will be compared to the intra-operative stiffness measurements obtained on the same patients with the previously developed method. Therefore, developments conducted in this project will primarily focus on the stiffness assessment for pediatric deformities and will be secondarily applied to degenerative spine pathologies. Significance: The first outcome of the project is a standardized test setup for the clinician to assess spinal flexibility in an accurate and reproducible manner. Such an approach is mandatory to compare surgical techniques across surgeons working at different institutions. Furthermore, with the increasing database of patients being measured, precise guidelines could be defined for each surgical treatment. The method will also serve stiffness-adapted implants or surgical strategies and could be used to work out non-surgical approaches, standards and ?safe zones? for daily clinical use. Additionally, this information is mandatory for the development of planning solutions that consider patient-specific biomechanical information. Such tools will become increasingly important in the future due to the ever-increasing complexity of the surgical instrumentation and procedures. Infection rate of VEPTR©-Implants in children with severe spinal and thoracic deformities Research Project | 1 Project MembersBackground: Spinal and thoracic deformities in children can be treated with vertical expandable prosthetic titanium ribs (VEPTR©, Synthes GmbH®) to stimulate thoracic and spinal growth. With these implants children s symptoms and conditions can be slowed, halted or even reversed. Because of the dynamic character of the deformity and the growth of the children, the implants have to be lengthened about every half a year. With each operation there is a small risk of infection, which might increase with number of previous surgeries. Implant associated infections are often not clinical apparent and only found in microbiological analysis. To objectify the infection rate, identify potential precursors of infections and the relevance of asymptomatic infections in children with these implants a prospective study is conducted. Hypothesis: Patients with VEPTR©-implants have asymptomatic implant-associated infections. Objective: To objectify the infection rate, we will analyze, during lengthening operation, removed implant-parts microbiological. Design: Prospective case-control study. Study population: We will prospectively include all patients who undergo lengthening operation after VEPTR©-Implantation at the University Children´s Hospital Basel (UKBB). Patients will be excluded if obvious contamination of explanted components occurred in the operation room. It is expected that 4 procedures can be included per month in the study. The study may be extended if the desired patient population (>120 procedures) is not reached within the study period. Methods: All patients and the operating surgeon fill out a questionnaire analyzing clinical signs of infection. A blood sample analyzed for CRP and white blood count is taken prior to operation during anesthesia. All anyway removed implant parts are transported to a microbiology laboratory in a sterile container and treated by sonication. The resulting sonicate fluid will be used for microbial detection by culture and molecular techniques. For potentially later histologic work up, tissue probes are taken and stored in Formalin. The infection rate will be quantified and the microbiological results will be related to clinical findings, laboratory data, operation kind and numbers. Further on the germ spectrum will be analyzed. Hypothesis: We anticipate that the total infection rate lies about 5-10% and increases with number of previous surgeries. Significance: We anticipate that: we will objectify (a) the total infection rate of patients with VEPTR©-implants, and (b) risk factors for infection, especially with low-virulent germs. The natural history (c) of the infection in asymptomatic patients will be followed to analyze its relevance, and (d) treatment regimes can be developed. The public health relevance of this work is significant since these findings: (a) may influence our management of patients with these implants, and (b) may lead to the development of improved implant designs. 1 1
Patient-specific and pre-operative assessment of spine mechanical properties Research Project | 1 Project MembersBackground data: An accurate description of the biomechanical behavior of the spine is crucial for the understanding of degenerative spine disorders and spinal deformities as well as for the development of new treatment strategies. Nowadays, surgeons have limited data on the segmental spinal mobility of their patients and no information concerning their biomechanical stiffness. This is not only a major problem to select the appropriate treatment strategy, but also to standardize the procedure between surgeons and to propose guidelines and recommendations concerning the appropriate treatments. In addition, new strategies, such as artificial discs, interspinous process spacers, non-fusion techniques and target-oriented conservative approaches aim at preserving spine function. However, little is known about the complex functional behavior and stiffness of the normal and degenerated spinal segment under physiological loading conditions, because the existing studies focused solely on the spinal kinematics without considering mechanical loads. Objective: The aim of this project is to determine the mechanical properties of the spine based on pre-operative tests. The main challenge will be to develop an appropriate measurement technique able to provide the surgeons with an observer independent and reproducible three-dimensional assessment of the spine flexibility suitable for daily clinical use. Previous results: During the past years, the applicants developed a method for in-vivo measurements of the segmental spine stiffness in complex pediatric deformities. This information, acquired intra-operatively, requires significant efforts from the OR staff, additional operation time, which is not suitable for use in the clinical routine, but provides gold standard direct biomechanical data. Methods: The method will be based on standing elevation of the patient. Advanced image processing techniques will be used to extract the 3D position and orientation of the patients? vertebras from planar pre-operative images. Numerical tools will be used to model spine biomechanical behavior and identify the local stiffness characteristics. The segmental spine flexibility obtained will be compared to the intra-operative stiffness measurements obtained on the same patients with the previously developed method. Therefore, developments conducted in this project will primarily focus on the stiffness assessment for pediatric deformities and will be secondarily applied to degenerative spine pathologies. Significance: The first outcome of the project is a standardized test setup for the clinician to assess spinal flexibility in an accurate and reproducible manner. Such an approach is mandatory to compare surgical techniques across surgeons working at different institutions. Furthermore, with the increasing database of patients being measured, precise guidelines could be defined for each surgical treatment. The method will also serve stiffness-adapted implants or surgical strategies and could be used to work out non-surgical approaches, standards and ?safe zones? for daily clinical use. Additionally, this information is mandatory for the development of planning solutions that consider patient-specific biomechanical information. Such tools will become increasingly important in the future due to the ever-increasing complexity of the surgical instrumentation and procedures.
Infection rate of VEPTR©-Implants in children with severe spinal and thoracic deformities Research Project | 1 Project MembersBackground: Spinal and thoracic deformities in children can be treated with vertical expandable prosthetic titanium ribs (VEPTR©, Synthes GmbH®) to stimulate thoracic and spinal growth. With these implants children s symptoms and conditions can be slowed, halted or even reversed. Because of the dynamic character of the deformity and the growth of the children, the implants have to be lengthened about every half a year. With each operation there is a small risk of infection, which might increase with number of previous surgeries. Implant associated infections are often not clinical apparent and only found in microbiological analysis. To objectify the infection rate, identify potential precursors of infections and the relevance of asymptomatic infections in children with these implants a prospective study is conducted. Hypothesis: Patients with VEPTR©-implants have asymptomatic implant-associated infections. Objective: To objectify the infection rate, we will analyze, during lengthening operation, removed implant-parts microbiological. Design: Prospective case-control study. Study population: We will prospectively include all patients who undergo lengthening operation after VEPTR©-Implantation at the University Children´s Hospital Basel (UKBB). Patients will be excluded if obvious contamination of explanted components occurred in the operation room. It is expected that 4 procedures can be included per month in the study. The study may be extended if the desired patient population (>120 procedures) is not reached within the study period. Methods: All patients and the operating surgeon fill out a questionnaire analyzing clinical signs of infection. A blood sample analyzed for CRP and white blood count is taken prior to operation during anesthesia. All anyway removed implant parts are transported to a microbiology laboratory in a sterile container and treated by sonication. The resulting sonicate fluid will be used for microbial detection by culture and molecular techniques. For potentially later histologic work up, tissue probes are taken and stored in Formalin. The infection rate will be quantified and the microbiological results will be related to clinical findings, laboratory data, operation kind and numbers. Further on the germ spectrum will be analyzed. Hypothesis: We anticipate that the total infection rate lies about 5-10% and increases with number of previous surgeries. Significance: We anticipate that: we will objectify (a) the total infection rate of patients with VEPTR©-implants, and (b) risk factors for infection, especially with low-virulent germs. The natural history (c) of the infection in asymptomatic patients will be followed to analyze its relevance, and (d) treatment regimes can be developed. The public health relevance of this work is significant since these findings: (a) may influence our management of patients with these implants, and (b) may lead to the development of improved implant designs.
