The Experts below are selected from a list of 174 Experts worldwide ranked by ideXlab platform
Michael Kelly - One of the best experts on this subject based on the ideXlab platform.
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full circle 3d femoral mapping demonstrates age related changes that influence femoral implant positioning
Orthopaedic Proceedings, 2018Co-Authors: D Tucker, T Surup, A Petersik, Michael KellyAbstract:Anterior positioning of a cephomedullary nail in the distal femur occurs in up to 88% of cases. This is considered to occur because of a mismatch between the radius of curvature of the femur and that of available implants. The hypothesis for this study was that the relative thicknesses of the cortices of the femur (referenced off the Linea aspera) change with age and determine the final position of intramedullary implants.This study used the data from CT scans undertaken as part of routine clinical practice in 919 patients with intact left femora (median age 66 years, 484 male and 435 female). The Linea aspera and transverse intervals were plotted on a template femur between 25% – 60% femoral bone length (5% increments) and mapped automatically to all individual femora in the database with measurements taken in the plane of the Linea aspera.The Linea aspera was found to be internally rotated as compared to the sagittal plane referenced off the posterior femoral condyles. An age related change in the poste...
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full circle 3d femoral mapping demonstrates age related changes that influence femoral implant positioning
Injury-international Journal of The Care of The Injured, 2016Co-Authors: D Tucker, T Surup, A Petersik, Michael KellyAbstract:The geometry of the femur is important in the final position of an intramedullary implant; we hypothesised that the femoral geometry changes with age and this may predispose the elderly to anterior mal-positioning of these implants. We used CT DICOM data of 919 intact left femora and specialist software that allowed us to defined landmarks for measurement reference - such as the Linea aspera - on a template bone that could be mapped automatically to the entire database. We found that older (>80 years) cortical bone is up to 1.5 mm thinner anteriorly and 2 mm thinner posteriorly than younger (<40 years) bone but the rate of change of posterior to anterior cortex thickness is greater in the older bone. We also found the isthmus in the elderly to be more distal and less substantial than in the younger bone. This study has demonstrated femoral geometry changes with age that may explain our perception that the elderly are at increased risk for anterior mal-positioning of intramedullary implants.
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full circle 3d femoral mapping demonstrates age related changes that influence femoral implant positioning
Journal of Bone and Joint Surgery-british Volume, 2015Co-Authors: D Tucker, T Surup, A Petersik, Michael KellyAbstract:Anterior positioning of a cephomedullary nail in the distal femur occurs in up to 88% of cases. This is considered to occur because of a mismatch between the radius of curvature of the femur and that of available implants. The hypothesis for this study was that the relative thicknesses of the cortices of the femur (referenced off the Linea aspera) change with age and determine the final position of intramedullary implants. This study used the data from CT scans undertaken as part of routine clinical practice in 919 patients with intact left femora (median age 66 years, 484 male and 435 female). The Linea aspera and transverse intervals were plotted on a template femur between 25% – 60% femoral bone length (5% increments) and mapped automatically to all individual femora in the database with measurements taken in the plane of the Linea aspera. The Linea aspera was found to be internally rotated as compared to the sagittal plane referenced off the posterior femoral condyles. An age related change in the posterior/anterior cortical thickness ratio was demonstrated. The >80 year old cohort shows a significantly disproportional posterior/anterior ratio increase of 70.0% from 25–50% bone length as compared to 48.1% for the This study has shown that assessment in the sagittal plane may be inaccurate because of rotational changes in the Linea aspera. The centering influence of the corticies is lost with age with a relative thinning of the anterior cortex and thickening of the posterior cortex moving distally in the femur. This has a direct influence on the positioning of intramedullary implants explaining the preponderance of anterior malpositioning of intramedullary implants in the elderly.
D Tucker - One of the best experts on this subject based on the ideXlab platform.
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full circle 3d femoral mapping demonstrates age related changes that influence femoral implant positioning
Orthopaedic Proceedings, 2018Co-Authors: D Tucker, T Surup, A Petersik, Michael KellyAbstract:Anterior positioning of a cephomedullary nail in the distal femur occurs in up to 88% of cases. This is considered to occur because of a mismatch between the radius of curvature of the femur and that of available implants. The hypothesis for this study was that the relative thicknesses of the cortices of the femur (referenced off the Linea aspera) change with age and determine the final position of intramedullary implants.This study used the data from CT scans undertaken as part of routine clinical practice in 919 patients with intact left femora (median age 66 years, 484 male and 435 female). The Linea aspera and transverse intervals were plotted on a template femur between 25% – 60% femoral bone length (5% increments) and mapped automatically to all individual femora in the database with measurements taken in the plane of the Linea aspera.The Linea aspera was found to be internally rotated as compared to the sagittal plane referenced off the posterior femoral condyles. An age related change in the poste...
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full circle 3d femoral mapping demonstrates age related changes that influence femoral implant positioning
Injury-international Journal of The Care of The Injured, 2016Co-Authors: D Tucker, T Surup, A Petersik, Michael KellyAbstract:The geometry of the femur is important in the final position of an intramedullary implant; we hypothesised that the femoral geometry changes with age and this may predispose the elderly to anterior mal-positioning of these implants. We used CT DICOM data of 919 intact left femora and specialist software that allowed us to defined landmarks for measurement reference - such as the Linea aspera - on a template bone that could be mapped automatically to the entire database. We found that older (>80 years) cortical bone is up to 1.5 mm thinner anteriorly and 2 mm thinner posteriorly than younger (<40 years) bone but the rate of change of posterior to anterior cortex thickness is greater in the older bone. We also found the isthmus in the elderly to be more distal and less substantial than in the younger bone. This study has demonstrated femoral geometry changes with age that may explain our perception that the elderly are at increased risk for anterior mal-positioning of intramedullary implants.
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full circle 3d femoral mapping demonstrates age related changes that influence femoral implant positioning
Journal of Bone and Joint Surgery-british Volume, 2015Co-Authors: D Tucker, T Surup, A Petersik, Michael KellyAbstract:Anterior positioning of a cephomedullary nail in the distal femur occurs in up to 88% of cases. This is considered to occur because of a mismatch between the radius of curvature of the femur and that of available implants. The hypothesis for this study was that the relative thicknesses of the cortices of the femur (referenced off the Linea aspera) change with age and determine the final position of intramedullary implants. This study used the data from CT scans undertaken as part of routine clinical practice in 919 patients with intact left femora (median age 66 years, 484 male and 435 female). The Linea aspera and transverse intervals were plotted on a template femur between 25% – 60% femoral bone length (5% increments) and mapped automatically to all individual femora in the database with measurements taken in the plane of the Linea aspera. The Linea aspera was found to be internally rotated as compared to the sagittal plane referenced off the posterior femoral condyles. An age related change in the posterior/anterior cortical thickness ratio was demonstrated. The >80 year old cohort shows a significantly disproportional posterior/anterior ratio increase of 70.0% from 25–50% bone length as compared to 48.1% for the This study has shown that assessment in the sagittal plane may be inaccurate because of rotational changes in the Linea aspera. The centering influence of the corticies is lost with age with a relative thinning of the anterior cortex and thickening of the posterior cortex moving distally in the femur. This has a direct influence on the positioning of intramedullary implants explaining the preponderance of anterior malpositioning of intramedullary implants in the elderly.
T Surup - One of the best experts on this subject based on the ideXlab platform.
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full circle 3d femoral mapping demonstrates age related changes that influence femoral implant positioning
Orthopaedic Proceedings, 2018Co-Authors: D Tucker, T Surup, A Petersik, Michael KellyAbstract:Anterior positioning of a cephomedullary nail in the distal femur occurs in up to 88% of cases. This is considered to occur because of a mismatch between the radius of curvature of the femur and that of available implants. The hypothesis for this study was that the relative thicknesses of the cortices of the femur (referenced off the Linea aspera) change with age and determine the final position of intramedullary implants.This study used the data from CT scans undertaken as part of routine clinical practice in 919 patients with intact left femora (median age 66 years, 484 male and 435 female). The Linea aspera and transverse intervals were plotted on a template femur between 25% – 60% femoral bone length (5% increments) and mapped automatically to all individual femora in the database with measurements taken in the plane of the Linea aspera.The Linea aspera was found to be internally rotated as compared to the sagittal plane referenced off the posterior femoral condyles. An age related change in the poste...
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full circle 3d femoral mapping demonstrates age related changes that influence femoral implant positioning
Injury-international Journal of The Care of The Injured, 2016Co-Authors: D Tucker, T Surup, A Petersik, Michael KellyAbstract:The geometry of the femur is important in the final position of an intramedullary implant; we hypothesised that the femoral geometry changes with age and this may predispose the elderly to anterior mal-positioning of these implants. We used CT DICOM data of 919 intact left femora and specialist software that allowed us to defined landmarks for measurement reference - such as the Linea aspera - on a template bone that could be mapped automatically to the entire database. We found that older (>80 years) cortical bone is up to 1.5 mm thinner anteriorly and 2 mm thinner posteriorly than younger (<40 years) bone but the rate of change of posterior to anterior cortex thickness is greater in the older bone. We also found the isthmus in the elderly to be more distal and less substantial than in the younger bone. This study has demonstrated femoral geometry changes with age that may explain our perception that the elderly are at increased risk for anterior mal-positioning of intramedullary implants.
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full circle 3d femoral mapping demonstrates age related changes that influence femoral implant positioning
Journal of Bone and Joint Surgery-british Volume, 2015Co-Authors: D Tucker, T Surup, A Petersik, Michael KellyAbstract:Anterior positioning of a cephomedullary nail in the distal femur occurs in up to 88% of cases. This is considered to occur because of a mismatch between the radius of curvature of the femur and that of available implants. The hypothesis for this study was that the relative thicknesses of the cortices of the femur (referenced off the Linea aspera) change with age and determine the final position of intramedullary implants. This study used the data from CT scans undertaken as part of routine clinical practice in 919 patients with intact left femora (median age 66 years, 484 male and 435 female). The Linea aspera and transverse intervals were plotted on a template femur between 25% – 60% femoral bone length (5% increments) and mapped automatically to all individual femora in the database with measurements taken in the plane of the Linea aspera. The Linea aspera was found to be internally rotated as compared to the sagittal plane referenced off the posterior femoral condyles. An age related change in the posterior/anterior cortical thickness ratio was demonstrated. The >80 year old cohort shows a significantly disproportional posterior/anterior ratio increase of 70.0% from 25–50% bone length as compared to 48.1% for the This study has shown that assessment in the sagittal plane may be inaccurate because of rotational changes in the Linea aspera. The centering influence of the corticies is lost with age with a relative thinning of the anterior cortex and thickening of the posterior cortex moving distally in the femur. This has a direct influence on the positioning of intramedullary implants explaining the preponderance of anterior malpositioning of intramedullary implants in the elderly.
A Petersik - One of the best experts on this subject based on the ideXlab platform.
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full circle 3d femoral mapping demonstrates age related changes that influence femoral implant positioning
Orthopaedic Proceedings, 2018Co-Authors: D Tucker, T Surup, A Petersik, Michael KellyAbstract:Anterior positioning of a cephomedullary nail in the distal femur occurs in up to 88% of cases. This is considered to occur because of a mismatch between the radius of curvature of the femur and that of available implants. The hypothesis for this study was that the relative thicknesses of the cortices of the femur (referenced off the Linea aspera) change with age and determine the final position of intramedullary implants.This study used the data from CT scans undertaken as part of routine clinical practice in 919 patients with intact left femora (median age 66 years, 484 male and 435 female). The Linea aspera and transverse intervals were plotted on a template femur between 25% – 60% femoral bone length (5% increments) and mapped automatically to all individual femora in the database with measurements taken in the plane of the Linea aspera.The Linea aspera was found to be internally rotated as compared to the sagittal plane referenced off the posterior femoral condyles. An age related change in the poste...
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full circle 3d femoral mapping demonstrates age related changes that influence femoral implant positioning
Injury-international Journal of The Care of The Injured, 2016Co-Authors: D Tucker, T Surup, A Petersik, Michael KellyAbstract:The geometry of the femur is important in the final position of an intramedullary implant; we hypothesised that the femoral geometry changes with age and this may predispose the elderly to anterior mal-positioning of these implants. We used CT DICOM data of 919 intact left femora and specialist software that allowed us to defined landmarks for measurement reference - such as the Linea aspera - on a template bone that could be mapped automatically to the entire database. We found that older (>80 years) cortical bone is up to 1.5 mm thinner anteriorly and 2 mm thinner posteriorly than younger (<40 years) bone but the rate of change of posterior to anterior cortex thickness is greater in the older bone. We also found the isthmus in the elderly to be more distal and less substantial than in the younger bone. This study has demonstrated femoral geometry changes with age that may explain our perception that the elderly are at increased risk for anterior mal-positioning of intramedullary implants.
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full circle 3d femoral mapping demonstrates age related changes that influence femoral implant positioning
Journal of Bone and Joint Surgery-british Volume, 2015Co-Authors: D Tucker, T Surup, A Petersik, Michael KellyAbstract:Anterior positioning of a cephomedullary nail in the distal femur occurs in up to 88% of cases. This is considered to occur because of a mismatch between the radius of curvature of the femur and that of available implants. The hypothesis for this study was that the relative thicknesses of the cortices of the femur (referenced off the Linea aspera) change with age and determine the final position of intramedullary implants. This study used the data from CT scans undertaken as part of routine clinical practice in 919 patients with intact left femora (median age 66 years, 484 male and 435 female). The Linea aspera and transverse intervals were plotted on a template femur between 25% – 60% femoral bone length (5% increments) and mapped automatically to all individual femora in the database with measurements taken in the plane of the Linea aspera. The Linea aspera was found to be internally rotated as compared to the sagittal plane referenced off the posterior femoral condyles. An age related change in the posterior/anterior cortical thickness ratio was demonstrated. The >80 year old cohort shows a significantly disproportional posterior/anterior ratio increase of 70.0% from 25–50% bone length as compared to 48.1% for the This study has shown that assessment in the sagittal plane may be inaccurate because of rotational changes in the Linea aspera. The centering influence of the corticies is lost with age with a relative thinning of the anterior cortex and thickening of the posterior cortex moving distally in the femur. This has a direct influence on the positioning of intramedullary implants explaining the preponderance of anterior malpositioning of intramedullary implants in the elderly.
R P Pitto - One of the best experts on this subject based on the ideXlab platform.
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transesophageal echocardiography and clinical features of fat embolism during cemented total hip arthroplasty a randomized study in patients with a femoral neck fracture
Archives of Orthopaedic and Trauma Surgery, 2000Co-Authors: R P Pitto, J Blunk, M KosslerAbstract:Forty patients suffering from a medial femoral neck fracture participated in a prospective, randomized study. In 20 patients, the femoral component was cemented using a contemporary technique. In the patient group operated on with the bone vacuum technique, the medullary cavity was drained during the insertion of the stem. The proximal draining hole was placed in the intertrochanteric region, along the prolongation of the Linea aspera. The distal hole was placed 2 cm below the tip of the femoral component. Embolic phenomena were documented intraoperatively by continuous transesophageal echocardiographic imaging of the right atrium and ventricle. The clinical relevance of the emboli was noted simultaneously by recording hemodynamic and blood gas parameters. Patients of the control group showed severer and longer-lasting episodes of embolism than patients of the bone vacuum group. Ongoing emboli were first seen during the injection of the cement, and continued during stem insertion. Massive emboli of small particles could be verified in 19 patients (95%) of the control group and in 1 patient (5%) of the bone vacuum group (P < 0.05). During massive emboli, a distinct decrease in the arterial oxygen saturation and the end-expiratory carbon dioxide level was observed. The calculated average pulmonary shunt volume showed an increase after the insertion of the stem using the contemporary technique (36.5%; P < 0.05). These distinct hemodynamic changes were not observed in the bone vacuum group. This study was able to show a clearly reduced risk of pulmonary emboli using the bone vacuum cementing technique. The presence of pre-existing disease greatly magnified the clinical relevance of fat embolism.
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comparison of fixation of the femoral component without cement and fixation with use of a bone vacuum cementing technique for the prevention of fat embolism during total hip arthroplasty a prospective randomized clinical trial
Journal of Bone and Joint Surgery American Volume, 1999Co-Authors: R P Pitto, Matthias Koessler, Joern W KuehleAbstract:Background: Acute hypotension, hypoxemia, cardiac arrest, and sudden death are well recognized complications during total hip arthroplasty, and they have been attributed to embolization of fat and bone marrow. An increase in intramedullary pressure in the femur is the most important pathogenic factor for the development of embolic events. Intravasation of fat, bone marrow, and bone debris during the implantation of a femoral component, and the embolization of these elements through the venous system located along the Linea aspera and through the metaphyseal vessels, have been demonstrated experimentally and clinically. The purpose of the present study was to compare the effects of fixation of the femoral component without cement with those of fixation with a bone-vacuum cementing technique on the severity of embolic phenomena and cardiopulmonary impairment during total hip arthroplasty. Fixation with a conventional cementing technique was also evaluated as a control. Methods: Sixty patients (sixty hips) were entered into a prospective, randomized clinical trial. The patients were assigned to one of three groups. Group 1 consisted of twenty patients who had the femoral component inserted without cement, Group 2 comprised twenty patients who had the component inserted with a conventional cementing technique, and Group 3 included twenty patients who had fixation with the so-called bone-vacuum cementing technique. In the hips in Group 3, a suction of -800 millibars (-80,000 pascals) was applied to a proximal drainage cannula placed along the Linea aspera and a distal drainage cannula placed in the diaphysis in order to produce a vacuum in the medullary cavity of the femur during the application of cement and the insertion of the stem. Transesophageal echocardiography and hemodynamic and blood-gas analysis were performed during the operation. Results: Severe embolic events (defined as a cascade of fine echogenic particles of less than five millimeters in diameter) were observed in seventeen (85 percent) of the twenty patients during insertion of the stem with use of a conventional cementing technique but in none of the patients who had the stem inserted without cement (p < 0.05). Insertion of the femoral component with the bone-vacuum cementing technique prevented embolic phenomena in all but one patient (5 percent). Arterial oxygen saturation decreased significantly (p < 0.05) from a mean of 99.5 to 92.9 percent after insertion of the stem with a conventional cementing technique, but only slight changes were observed in the patients who had fixation of the component without cement and in those who were managed with the bone-vacuum cementing technique. Intraoperative pulmonary shunt values increased a mean of 24 percent (p < 0.05) when the femoral component was inserted with a conventional cementing technique, but with the numbers available we did not detect a significant change in those values when the component was fixed without cement or when it was inserted with use of the bone-vacuum cementing technique. Conclusions: The present study showed that severe embolic events and intraoperative pulmonary impairment are common when a femoral component is fixed with use of a conventional cementing technique. The results clearly demonstrated a low risk of embolism during total hip arthroplasty when the femoral component was fixed without cement and when it was fixed with the bone-vacuum cementing technique. The ability of a patient to withstand an embolic event should be considered before fixation of the femoral component with use of a conventional cementing technique is planned.
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relevance of the drainage along the Linea aspera for the reduction of fat embolism during cemented total hip arthroplasty
Archives of Orthopaedic and Trauma Surgery, 1999Co-Authors: R P Pitto, M Schramm, D Hohmann, M KoslerAbstract:The aim of this study was to assess the relevance of drainage placed along the Linea aspera for the prevention of fat embolism and cardiopulmonary impairment during the insertion of a cemented stem. We studied 40 patients with coxarthrosis randomly allocated to total hip arthroplasty with proximal drainage or without it. The venting hole for the drainage of the medullary cavity was placed posteriorly, between the greater and the smaller trochanter, in the prolongation of the Linea aspera. The heart was monitored intraoperatively by a echocardiography probe positioned in the patient’s oesophagus. During the operation we monitored the hemodynamics and blood gas values. Severe embolic events were observed in 85% of the control group and in 20% of the drainage group (P = 0.01). Embolism occurred during the insertion of the femoral component and continued after reduction of the hip joint. After major embolism, the pulmonary shunt values increased significantly in the control group (+22.7%), but there were no marked changes in the drainage group (+7.1%). The logical therapeutic measure to avoid intravasation of bone marrow, fat, and bone debris during the insertion of the femoral component is to prevent the rise of intraosseous pressure. The drainage of the venous system located along the Linea aspera significantly reduces the risk of intraoperative embolism and cardiopulmonary impairment.
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prophylaxis of fat and bone marrow embolism in cemented total hip arthroplasty
Clinical Orthopaedics and Related Research, 1998Co-Authors: R P Pitto, Matthias Koessler, Klaus DraenertAbstract:The efficiency of a new cementing technique developed to prevent the risk of intraoperative pulmonary embolism was assessed. Seventy patients with coxarthrosis entered into a prospective, randomized clinical trial. In the control group of 35 cases the total hip replacement was cemented conventionally. In the second group a proximal drainage placed along the Linea aspera, and a distal drainage placed in the diaphysis, created a vacuum in the medullary cavity of the femur during the insertion of the stem. The operation was performed with the patient under blood gas analysis and hemodynamic and transesophageal echocardiography monitoring. Severe transatrial embolic events were observed during the insertion of the femoral component in 94% of the cases of the control group and in 14% of the cases of the vacuum group; the difference is statistically significant. A significant decrease of arterial partial pressure of O 2 (-40.8 mm Hg) and increase of the pulmonary shunt values (+28.3%) occurred 5 minutes after the observation of embolic events in the cases operated on conventionally, but these parameters showed minimal changes in the vacuum group. The rise of intramedullary pressure in the femur is the most decisive pathogenic factor of pulmonary embolism during total hip arthroplasty. The logical prophylactic measure to prevent intravasation of fat and bone marrow is to create sufficient drainage. The cohorted investigation showed the value of the vacuum cementing technique for a substantial reduction of intraoperative embolism and pulmonary impairment.