BACKGROUND Little information has been available regarding the usefulness of Ranawat triangle method in estimating anatomical hip joint center in the Japanese population. In this study, we aimed to determine the accuracy of the method in estimating hip joint center. METHODS Using digitally reconstructed radiographs of 123 normal hips (123 patients), we measured the hip joint center coordinates (Cx, Cy) with reference to the ipsilateral lowest point of the teardrop, the pelvic width, and the pelvic height. Using these measurement values, we performed the following analyses (1) the relationship of hip joint center location with pelvic dimensions; (2) accuracy of Ranawat method in estimating hip joint center; (3) alternative methods to estimate hip joint center using pelvic height. RESULTS The mean Cx and Cy were 32 ± 3.0 mm and 13 ± 2.1 mm, respectively. Pelvic height was positively correlated with Cx (r = 0.51, p  less then  0.001) and Cy (r = 0.69, p  less then  0.001), but the correlations of pelvic width with Cx and Cy were negligible. The mean estimation error of the Ranawat method was -6.7 ± 2.6 mm in x-axis and 6.6 ± 1.9 mm in y-axis, respectively. The hip joint center was estimated within a 5 mm error in both axes in only 8 hips (6.5%). Thus, we developed two estimating methods using pelvic height, modified Ranawat method and pelvic height ratio method, and the estimation errors of these methods were within 5 mm in both axes in 118 hips (96%) and 116 hips (94%), respectively. CONCLUSIONS Ranawat method showed poor accuracy in estimating anatomical hip joint center and is not recommended for clinical use. Our alternative methods may be useful for surgeons planning the position of the acetabular component in total hip arthroplasty. BACKGROUND Several biomechanical studies on subtrochanteric femur fractures have reported that use of an intramedullary nail is superior to extramedullary implant. However, the optimal choice of intramedullary nail for the treatment of comminuted subtrochanteric femur fracture remains unclear. Here, we evaluated the biomechanical properties of comminuted subtrochanteric femur fracture treated with four different internal fixations. METHODS A comminuted subtrochanteric femur fracture model was created with a 2-cm gap below the lessor trochanter in 20 synthetic femurs. The fractures were fixed with one of four implants - Antegrade Femoral Nail (AFN), Trochanteric Fixation Nail Advanced with a femoral neck blade (TFNA blade), TFNA with a femoral neck screw (TFNA screw), and the reversed distal femoral locking compression plate (DF-LCP) - all manufactured by DePuy Synthes. Axial compression tests and torsion tests were performed and the stiffness of each implant was compared. RESULTS For compression, the TFNA blade, TFNA screw, and AFN provided significantly higher stiffness than DF-LCP (p  less then  0.001, p  less then  0.001, p = 0.001, respectively), and the TFNA blade provided significantly higher stiffness than AFN (p = 0.049). For torsion, there were no significant differences among the groups in internal rotation, while the TFNA screw had significantly lower torsional stiffness than the AFN, TFNA blade and DF-LCP in external rotation (p = 0.036, p = 0.034, p = 0.037, respectively). CONCLUSIONS These findings could help to provide biomechanical evidence regarding choice of implant for the treatment of comminuted subtrochanteric femur fracture. The TFNA blade may be more suitable for the treatment of comminuted subtrochanteric femur fracture. BACKGROUND Low cardiovascular fitness is common poststroke. Conventional subacute stroke rehabilitation does not meet Australian National Stroke Guidelines for cardiovascular exercise, particularly in mobility-dependent patients. Walking robotics can potentially achieve recommended cardiovascular exercise with these patients. AIM The primary aim was to determine whether sustained moderate intensity cardiovascular exercise can be achieved using 3 Lokomat Augmented Performance Feedback activities in mobility-dependent adults with subacute stroke. Secondary aims were to assess if cardiovascular workload was influenced by the activity completed, participants motivation or enjoyment, or changes in Lokomat settings. METHODS Ten patients with subacute stroke (mean (SD) age 63.4 (13) years) participated in 6x20-minute Lokomat study sessions. Each study session involved a warm-up and 3x5-minute APF activities presented in a random order. Metabolic data were collected using the COSMED-K5. Participants rated their perceived exertion on the BORG CR10 scale and Lokomat settings of body-weight support, guidance force, and speed were recorded. RESULTS Moderate intensity cardiovascular exercise was achieved and maintained over the 15 minutes of exercise, objectively demonstrated by a mean (SD) Metabolic Equivalent Task of 3.1 (1.3), and mean (SD) oxygen consumption of 8.0 (3.8) ml/kg/min, estimated as 52% VO2max. This was subjectively confirmed by exertion scores between 3 and 5. The cardiovascular workload was not affected by which activity was completed, participant motivation or enjoyment, or significant progression of Lokomat settings between study sessions. CONCLUSIONS Mobility-dependent patients with subacute stroke can achieve sustained moderate intensity cardiovascular exercise on the Lokomat when using APF activities. INTRODUCTION Temporary external fixation has been widely utilized in the stabilization of plateau fractures while waiting for an optimization of the soft tissue conditions before subsequent permanent internal fixation. Simultaneously, MRI is beneficial in the assessment of concomitant damage to ligaments and menisci so that these injuries could be promptly identified, and surgical planning executed at the time of definitive fixation of the bony injury. Increasing numbers of side-bars and pins have been previously suggested to increase frame rigidity, but at the same time, several studies have indicated the presence of MRI artifacts which may obscure key anatomical structures, even when MRI-compatible fixation devices are used. https://www.selleckchem.com/products/kt-413.html This study aims to identify, among six potential configurations, the construct that maximizes stability while most minimizing the number of MRI artifacts generated among different configurations commonly used. HYPOTHESIS There is one or more configurations among the others that maximize stability while preserving a clinically acceptable level of MRI quality.
BACKGROUND Little information has been available regarding the usefulness of Ranawat triangle method in estimating anatomical hip joint center in the Japanese population. In this study, we aimed to determine the accuracy of the method in estimating hip joint center. METHODS Using digitally reconstructed radiographs of 123 normal hips (123 patients), we measured the hip joint center coordinates (Cx, Cy) with reference to the ipsilateral lowest point of the teardrop, the pelvic width, and the pelvic height. Using these measurement values, we performed the following analyses (1) the relationship of hip joint center location with pelvic dimensions; (2) accuracy of Ranawat method in estimating hip joint center; (3) alternative methods to estimate hip joint center using pelvic height. RESULTS The mean Cx and Cy were 32 ± 3.0 mm and 13 ± 2.1 mm, respectively. Pelvic height was positively correlated with Cx (r = 0.51, p  less then  0.001) and Cy (r = 0.69, p  less then  0.001), but the correlations of pelvic width with Cx and Cy were negligible. The mean estimation error of the Ranawat method was -6.7 ± 2.6 mm in x-axis and 6.6 ± 1.9 mm in y-axis, respectively. The hip joint center was estimated within a 5 mm error in both axes in only 8 hips (6.5%). Thus, we developed two estimating methods using pelvic height, modified Ranawat method and pelvic height ratio method, and the estimation errors of these methods were within 5 mm in both axes in 118 hips (96%) and 116 hips (94%), respectively. CONCLUSIONS Ranawat method showed poor accuracy in estimating anatomical hip joint center and is not recommended for clinical use. Our alternative methods may be useful for surgeons planning the position of the acetabular component in total hip arthroplasty. BACKGROUND Several biomechanical studies on subtrochanteric femur fractures have reported that use of an intramedullary nail is superior to extramedullary implant. However, the optimal choice of intramedullary nail for the treatment of comminuted subtrochanteric femur fracture remains unclear. Here, we evaluated the biomechanical properties of comminuted subtrochanteric femur fracture treated with four different internal fixations. METHODS A comminuted subtrochanteric femur fracture model was created with a 2-cm gap below the lessor trochanter in 20 synthetic femurs. The fractures were fixed with one of four implants - Antegrade Femoral Nail (AFN), Trochanteric Fixation Nail Advanced with a femoral neck blade (TFNA blade), TFNA with a femoral neck screw (TFNA screw), and the reversed distal femoral locking compression plate (DF-LCP) - all manufactured by DePuy Synthes. Axial compression tests and torsion tests were performed and the stiffness of each implant was compared. RESULTS For compression, the TFNA blade, TFNA screw, and AFN provided significantly higher stiffness than DF-LCP (p  less then  0.001, p  less then  0.001, p = 0.001, respectively), and the TFNA blade provided significantly higher stiffness than AFN (p = 0.049). For torsion, there were no significant differences among the groups in internal rotation, while the TFNA screw had significantly lower torsional stiffness than the AFN, TFNA blade and DF-LCP in external rotation (p = 0.036, p = 0.034, p = 0.037, respectively). CONCLUSIONS These findings could help to provide biomechanical evidence regarding choice of implant for the treatment of comminuted subtrochanteric femur fracture. The TFNA blade may be more suitable for the treatment of comminuted subtrochanteric femur fracture. BACKGROUND Low cardiovascular fitness is common poststroke. Conventional subacute stroke rehabilitation does not meet Australian National Stroke Guidelines for cardiovascular exercise, particularly in mobility-dependent patients. Walking robotics can potentially achieve recommended cardiovascular exercise with these patients. AIM The primary aim was to determine whether sustained moderate intensity cardiovascular exercise can be achieved using 3 Lokomat Augmented Performance Feedback activities in mobility-dependent adults with subacute stroke. Secondary aims were to assess if cardiovascular workload was influenced by the activity completed, participants motivation or enjoyment, or changes in Lokomat settings. METHODS Ten patients with subacute stroke (mean (SD) age 63.4 (13) years) participated in 6x20-minute Lokomat study sessions. Each study session involved a warm-up and 3x5-minute APF activities presented in a random order. Metabolic data were collected using the COSMED-K5. Participants rated their perceived exertion on the BORG CR10 scale and Lokomat settings of body-weight support, guidance force, and speed were recorded. RESULTS Moderate intensity cardiovascular exercise was achieved and maintained over the 15 minutes of exercise, objectively demonstrated by a mean (SD) Metabolic Equivalent Task of 3.1 (1.3), and mean (SD) oxygen consumption of 8.0 (3.8) ml/kg/min, estimated as 52% VO2max. This was subjectively confirmed by exertion scores between 3 and 5. The cardiovascular workload was not affected by which activity was completed, participant motivation or enjoyment, or significant progression of Lokomat settings between study sessions. CONCLUSIONS Mobility-dependent patients with subacute stroke can achieve sustained moderate intensity cardiovascular exercise on the Lokomat when using APF activities. INTRODUCTION Temporary external fixation has been widely utilized in the stabilization of plateau fractures while waiting for an optimization of the soft tissue conditions before subsequent permanent internal fixation. Simultaneously, MRI is beneficial in the assessment of concomitant damage to ligaments and menisci so that these injuries could be promptly identified, and surgical planning executed at the time of definitive fixation of the bony injury. Increasing numbers of side-bars and pins have been previously suggested to increase frame rigidity, but at the same time, several studies have indicated the presence of MRI artifacts which may obscure key anatomical structures, even when MRI-compatible fixation devices are used. https://www.selleckchem.com/products/kt-413.html This study aims to identify, among six potential configurations, the construct that maximizes stability while most minimizing the number of MRI artifacts generated among different configurations commonly used. HYPOTHESIS There is one or more configurations among the others that maximize stability while preserving a clinically acceptable level of MRI quality.
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