The authors designed a study to test the hypothesis that the length of the ulna might affect the ... more The authors designed a study to test the hypothesis that the length of the ulna might affect the shape of the lunate bone because of long-term molding during life. This might then be useful to predict the presence or absence of a dynamic or static ulna plus by the shape of the lunate bone. In a prospective study, posterior-anterior wrist x-rays were taken in a standard fashion in 68 patients with a mean age of 34.5 years. Dominance, grip strength, ulnar variance and the shape of the lunate were recorded. Lunate shape, type 1, which is the least molded, was seen most frequently on both the left and right side and did not correlate with the dominant side. The most molded, type 3, was seen less frequently and almost exclusively on the nondominant side. No correlation was found between dynamic ulna plus and the type 3 lunate. Following statistical analysis, no correlation between ulnar variance and lunate shape was found, indicating that the shape of the lunate bone had no predictive va...
The wrist allows the hand to combine dorsopalmar flexion and radioulnar deviation, a unique combi... more The wrist allows the hand to combine dorsopalmar flexion and radioulnar deviation, a unique combination of functions that is made possible by a highly complex system of joints. The morphologic features of the carpal bones and of the radiocarpal and intercarpal contacts can be functionally interpreted by the mechanism that underlies the movements of the hand to the forearm. Displacements of the carpals take place in longitudinal articulation chains, with the proximal carpals having the position of an intercalated bone. The three articulation chains, radial, central, and ulnar, have interdependent movements at the radiocarpal and midcarpal levels. The linkage of movements in the longitudinal direction is associated to a transverse linkage by mutual joint contacts and by specific ligamentous interconnections. Kinematic analyses of the carpal joint motions have provided convincing evidence that each motion of the hand to the forearm demonstrates a specific motion pattern of the carpal bones. The stability of the carpus essentially depends on the integrity of the ligamentous system which consists of interwoven fiber bundles that differ in length, direction, and mechanical properties. Distinct separations into morphologic entities are difficult to make. From a functional point of view, the ligamentous interconnections can be regarded as a system that passively restricts movements of the carpals on one another and on the radius, but in a very differentiated way. The ligamentous system controls the linkage of the movements of the carpals, with the geometries of the bones and of the joint surfaces being, first of all, responsible for the kinematic behavior of the carpal joint.
Dysplasia of the hip in adults can be treated by a pelvic osteotomy. In order to assess pelvic an... more Dysplasia of the hip in adults can be treated by a pelvic osteotomy. In order to assess pelvic anatomy in relation to surgical approach and osteotomy sites, 12 cadaver hips were studied. A triple pelvic osteotomy as described by Tönnis [6] through ilium, pubis and ischium was performed, followed by an intrapelvic and anterior and posterior dissection of the hip. At the ischium, the pudendal and inferior gluteal neurovascular bundles are most at risk medially and proximally respectively. Much less in danger is the sciatic n. as it runs 1 to 3 cm lateral to the osteotomy site. At the pubis osteotomy the femoral v. lies close on the bone and is prone to damage. The artery lies further off the bone. The ilium osteotomy starts just proximal to the anterior inferior iliac spine and exits posteriorly at the sciatic notch. Here the sciatic n. and the superior gluteal neurovascular bundle may be damaged. The practical surgical implications of these three osteotomies are discussed, especially with respect to the requirement of meticulous subperiostal dissection and accurate placement of retractors. Developmental dysplasia of the hip is characterised by insufficient superolateral and anterior acetabular coverage of the femoral head due to shallowness of the acetabulum and malposition of the proximal femur. In adolescents and adults symptomatic hip dysplasia can be treated surgically by a pelvic osteotomy whereby the acetabulum is cut free from the pelvis and reoriented, to provide better lateral and anterior coverage of the femoral head. For this purpose a triple pelvic osteotomy through ilium, pubis and ischium [2, 5, 6, 7] can be performed. To perform these difficult operations one should be well informed of the pelvic anatomy in relation to the surgical approach and the bony cuts. However, we could not find any anatomic descriptions in the literature. This descriptive study was performed to define the anatomical structures at risk during surgery such as: the femoral v. and artery; the sciatic n.; the obturator, superior gluteal and pudendal neurovascular bundles. Material and methods Twelve fresh hip joints of four male and two female cadavers were studied. One hip was used as a control and 11 times a triple osteotomy was performed as described by Tönnis [6] (Fig. 1).
In biomechanical joint-motion analyses, the continuous motion to be studied is often approximated... more In biomechanical joint-motion analyses, the continuous motion to be studied is often approximated by a sequence of finite displacements, and the Finite Helical Axis (FHA) or “screw axis” for each displacement is estimated from position measurements on a number of anatomical or artificial landmarks. When FHA parameters are directly determined from raw (noisy) displacement data, both the position and the direction of the FHA are ill-determined, in particular when the sequential displacement steps are small. This implies, that under certain conditions, the continuous pathways of joint motions cannot be adequately described. The purpose of the present experimental study is to investigate the applicability of smoothing (or filtering) techniques, in those cases where FHA parameters are ill-determined. Two different quintic-spline smoothing methods were used to analyze the motion data obtained with Roentgenstereophotogrammetry in two experiments. One concerning carpal motions in a wrist-jo...
The distal radioulnar joint is functionally coupled with the proximal radioulnar joint, thus form... more The distal radioulnar joint is functionally coupled with the proximal radioulnar joint, thus forming a mechanism for the longitudinal rotation of the hand. Distal radioulnar mobility is derived from the geometry of the joint, joint surfaces, and radioulnar connections. There is a structural and functional separation between the distal radioulnar and carpal joints, giving the possibility of pronation and supination in every position of the hand to the forearm. As for the stability of the joints involved, the ulnar articular disk plays an essential role. Being part of both distal radioulnar and carpal joints, the disk has very specific morphologic features that not only are individualized to the function of both joints but also stabilize the joints in their independent movements. Developmental data give the strong impression of an architectural scheme, of which the distal radioulnar joint is only a part. Traumatic lesions at the distal radioulnar joint and disturbances in normal distal radioulnar alignment have to be viewed, therefore, in a wider context.
Pelvic osteotomies for acetabular dysplasia include an osteotomy of the ischium. The potential an... more Pelvic osteotomies for acetabular dysplasia include an osteotomy of the ischium. The potential anatomical hazards of three different osteotomies of the ischium were assessed by performing a triple osteotomy in a series of 8 fresh cadaver pelvises. An oblique osteotomy above the sacrospinous ligament using a posterior approach requires that the inferior gluteal and pudendal neurovascular bundles be mobilised and retracted. A transverse osteotomy below the sacrospinous ligament using a posterior approach can be performed in a relatively safe area between the pudendal and sciatic nerves. A transverse osteotomy from anterior can be performed through a modified Smith Peterson approach. The pudendal nerve medially, the sciatic nerve laterally and the medial circumflex artery distally are not visualised and are prone to damage.
Pelvic osteotomies for acetabular dysplasia include an osteotomy of the pubic bone. The anatomica... more Pelvic osteotomies for acetabular dysplasia include an osteotomy of the pubic bone. The anatomical consequences of two different approaches to the pubic bone were assessed by performing a triple osteotomy on a series of 12 fresh cadaver hemipelvises. The medial approach through a separate incision over the pubic symphysis was compared with the lateral approach through the incision used for the innominate osteotomy. Although the medial approach appears technically easy, there are several anatomical structures at risk, such as the femoral vein and the corona mortis. The lateral approach is safer, and it is easier to make the osteotomy close to the hip joint. The closer the osteotomy is to the hip joint, the smaller the chance of developing a non-union.
Analysis of the neural basis of olfaction has been impeded by lack of ability to deliver discrete... more Analysis of the neural basis of olfaction has been impeded by lack of ability to deliver discrete stimuli such as in the analysis of sensory mechanisms in vision 5, audition 11, and somesthesis 6. However, recently it has been possible to achieve punctate odor stimulation of the olfactory receptor surface and to obtain evidence for receptive field organization in the olfactory pathway 4. As a further advance in the control of
This study examined patterns of bone mineral density (BMD) of the wrist by computed tomography–ab... more This study examined patterns of bone mineral density (BMD) of the wrist by computed tomography–absorptiometry to evaluate force transmission patterns in vivo in patients with complaints of wrist instability requiring lunate-capitate-triquetrum-hamate (LCTH) arthrodesis. These patterns represent long-term force transmission through the wrist joint because BMD differs under different loading conditions. BMD studies of the wrist joint in vivo can evaluate the long-term force transmission through the joint under physiological and pathological conditions and before and after wrist surgery. The scaphoid fossa is relatively unloaded after LCTH arthrodesis, and a decrease in BMD is observed in the lunate fossa.
This study examined patterns of bone mineral density (BMD) of the wrist by computed tomography–ab... more This study examined patterns of bone mineral density (BMD) of the wrist by computed tomography–absorptiometry to evaluate force transmission patterns in vivo in patients with complaints of wrist instability requiring lunate-capitate-triquetrum-hamate (LCTH) arthrodesis. These patterns represent long-term force transmission through the wrist joint because BMD differs under different loading conditions. BMD studies of the wrist joint in vivo can evaluate the long-term force transmission through the joint under physiological and pathological conditions and before and after wrist surgery. The scaphoid fossa is relatively unloaded after LCTH arthrodesis, and a decrease in BMD is observed in the lunate fossa.
Triple pelvic osteotomy reorients the acetabulum relative to the pelvis in order to improve aceta... more Triple pelvic osteotomy reorients the acetabulum relative to the pelvis in order to improve acetabular coverage of the femoral head in cases of acetabular dysplasia. We undertook a radiostereometric analysis (RSA) on 6 osteotomized cadaver hips to determine the actual three-dimensional reorientation obtained. The centers of the femoral head were all translated posteriorly between 11 and 41 mm, and distally up to 13 mm. 4 were lateralized up to 8 mm, and 2 were medialized up to 5 mm. All acetabuli rotated anteriorly about the lateral to medial axis (X-axis), and 4 rotated outwards around the distal to proximal axis (Y-axis). The correlations between measurements performed on conventional anteroposterior radiographs and the RSA measurements were poor: variations in the lateral-medial direction ranged from -16 to +6 mm, and in the distal-proximal direction between -10 and +12 mm. The changes in orientations measured will significantly affect the load across the hip joint, since the dimensions of the pelvis change and the moment arms of the muscles, their lengths and lines of action are changed as well. We conclude that, with the procedures presently performed, the loads across the hip joint are bound to change, and that the reorientation can hardly be checked with conventional radiographs.
Objective. The purpose of this study was to accurately quantify three-dimensional in vivo kinemat... more Objective. The purpose of this study was to accurately quantify three-dimensional in vivo kinematics of all carpal bones in flexion and extension and radial and ulnar deviation.
The authors designed a study to test the hypothesis that the length of the ulna might affect the ... more The authors designed a study to test the hypothesis that the length of the ulna might affect the shape of the lunate bone because of long-term molding during life. This might then be useful to predict the presence or absence of a dynamic or static ulna plus by the shape of the lunate bone. In a prospective study, posterior-anterior wrist x-rays were taken in a standard fashion in 68 patients with a mean age of 34.5 years. Dominance, grip strength, ulnar variance and the shape of the lunate were recorded. Lunate shape, type 1, which is the least molded, was seen most frequently on both the left and right side and did not correlate with the dominant side. The most molded, type 3, was seen less frequently and almost exclusively on the nondominant side. No correlation was found between dynamic ulna plus and the type 3 lunate. Following statistical analysis, no correlation between ulnar variance and lunate shape was found, indicating that the shape of the lunate bone had no predictive va...
The wrist allows the hand to combine dorsopalmar flexion and radioulnar deviation, a unique combi... more The wrist allows the hand to combine dorsopalmar flexion and radioulnar deviation, a unique combination of functions that is made possible by a highly complex system of joints. The morphologic features of the carpal bones and of the radiocarpal and intercarpal contacts can be functionally interpreted by the mechanism that underlies the movements of the hand to the forearm. Displacements of the carpals take place in longitudinal articulation chains, with the proximal carpals having the position of an intercalated bone. The three articulation chains, radial, central, and ulnar, have interdependent movements at the radiocarpal and midcarpal levels. The linkage of movements in the longitudinal direction is associated to a transverse linkage by mutual joint contacts and by specific ligamentous interconnections. Kinematic analyses of the carpal joint motions have provided convincing evidence that each motion of the hand to the forearm demonstrates a specific motion pattern of the carpal bones. The stability of the carpus essentially depends on the integrity of the ligamentous system which consists of interwoven fiber bundles that differ in length, direction, and mechanical properties. Distinct separations into morphologic entities are difficult to make. From a functional point of view, the ligamentous interconnections can be regarded as a system that passively restricts movements of the carpals on one another and on the radius, but in a very differentiated way. The ligamentous system controls the linkage of the movements of the carpals, with the geometries of the bones and of the joint surfaces being, first of all, responsible for the kinematic behavior of the carpal joint.
Dysplasia of the hip in adults can be treated by a pelvic osteotomy. In order to assess pelvic an... more Dysplasia of the hip in adults can be treated by a pelvic osteotomy. In order to assess pelvic anatomy in relation to surgical approach and osteotomy sites, 12 cadaver hips were studied. A triple pelvic osteotomy as described by Tönnis [6] through ilium, pubis and ischium was performed, followed by an intrapelvic and anterior and posterior dissection of the hip. At the ischium, the pudendal and inferior gluteal neurovascular bundles are most at risk medially and proximally respectively. Much less in danger is the sciatic n. as it runs 1 to 3 cm lateral to the osteotomy site. At the pubis osteotomy the femoral v. lies close on the bone and is prone to damage. The artery lies further off the bone. The ilium osteotomy starts just proximal to the anterior inferior iliac spine and exits posteriorly at the sciatic notch. Here the sciatic n. and the superior gluteal neurovascular bundle may be damaged. The practical surgical implications of these three osteotomies are discussed, especially with respect to the requirement of meticulous subperiostal dissection and accurate placement of retractors. Developmental dysplasia of the hip is characterised by insufficient superolateral and anterior acetabular coverage of the femoral head due to shallowness of the acetabulum and malposition of the proximal femur. In adolescents and adults symptomatic hip dysplasia can be treated surgically by a pelvic osteotomy whereby the acetabulum is cut free from the pelvis and reoriented, to provide better lateral and anterior coverage of the femoral head. For this purpose a triple pelvic osteotomy through ilium, pubis and ischium [2, 5, 6, 7] can be performed. To perform these difficult operations one should be well informed of the pelvic anatomy in relation to the surgical approach and the bony cuts. However, we could not find any anatomic descriptions in the literature. This descriptive study was performed to define the anatomical structures at risk during surgery such as: the femoral v. and artery; the sciatic n.; the obturator, superior gluteal and pudendal neurovascular bundles. Material and methods Twelve fresh hip joints of four male and two female cadavers were studied. One hip was used as a control and 11 times a triple osteotomy was performed as described by Tönnis [6] (Fig. 1).
In biomechanical joint-motion analyses, the continuous motion to be studied is often approximated... more In biomechanical joint-motion analyses, the continuous motion to be studied is often approximated by a sequence of finite displacements, and the Finite Helical Axis (FHA) or “screw axis” for each displacement is estimated from position measurements on a number of anatomical or artificial landmarks. When FHA parameters are directly determined from raw (noisy) displacement data, both the position and the direction of the FHA are ill-determined, in particular when the sequential displacement steps are small. This implies, that under certain conditions, the continuous pathways of joint motions cannot be adequately described. The purpose of the present experimental study is to investigate the applicability of smoothing (or filtering) techniques, in those cases where FHA parameters are ill-determined. Two different quintic-spline smoothing methods were used to analyze the motion data obtained with Roentgenstereophotogrammetry in two experiments. One concerning carpal motions in a wrist-jo...
The distal radioulnar joint is functionally coupled with the proximal radioulnar joint, thus form... more The distal radioulnar joint is functionally coupled with the proximal radioulnar joint, thus forming a mechanism for the longitudinal rotation of the hand. Distal radioulnar mobility is derived from the geometry of the joint, joint surfaces, and radioulnar connections. There is a structural and functional separation between the distal radioulnar and carpal joints, giving the possibility of pronation and supination in every position of the hand to the forearm. As for the stability of the joints involved, the ulnar articular disk plays an essential role. Being part of both distal radioulnar and carpal joints, the disk has very specific morphologic features that not only are individualized to the function of both joints but also stabilize the joints in their independent movements. Developmental data give the strong impression of an architectural scheme, of which the distal radioulnar joint is only a part. Traumatic lesions at the distal radioulnar joint and disturbances in normal distal radioulnar alignment have to be viewed, therefore, in a wider context.
Pelvic osteotomies for acetabular dysplasia include an osteotomy of the ischium. The potential an... more Pelvic osteotomies for acetabular dysplasia include an osteotomy of the ischium. The potential anatomical hazards of three different osteotomies of the ischium were assessed by performing a triple osteotomy in a series of 8 fresh cadaver pelvises. An oblique osteotomy above the sacrospinous ligament using a posterior approach requires that the inferior gluteal and pudendal neurovascular bundles be mobilised and retracted. A transverse osteotomy below the sacrospinous ligament using a posterior approach can be performed in a relatively safe area between the pudendal and sciatic nerves. A transverse osteotomy from anterior can be performed through a modified Smith Peterson approach. The pudendal nerve medially, the sciatic nerve laterally and the medial circumflex artery distally are not visualised and are prone to damage.
Pelvic osteotomies for acetabular dysplasia include an osteotomy of the pubic bone. The anatomica... more Pelvic osteotomies for acetabular dysplasia include an osteotomy of the pubic bone. The anatomical consequences of two different approaches to the pubic bone were assessed by performing a triple osteotomy on a series of 12 fresh cadaver hemipelvises. The medial approach through a separate incision over the pubic symphysis was compared with the lateral approach through the incision used for the innominate osteotomy. Although the medial approach appears technically easy, there are several anatomical structures at risk, such as the femoral vein and the corona mortis. The lateral approach is safer, and it is easier to make the osteotomy close to the hip joint. The closer the osteotomy is to the hip joint, the smaller the chance of developing a non-union.
Analysis of the neural basis of olfaction has been impeded by lack of ability to deliver discrete... more Analysis of the neural basis of olfaction has been impeded by lack of ability to deliver discrete stimuli such as in the analysis of sensory mechanisms in vision 5, audition 11, and somesthesis 6. However, recently it has been possible to achieve punctate odor stimulation of the olfactory receptor surface and to obtain evidence for receptive field organization in the olfactory pathway 4. As a further advance in the control of
This study examined patterns of bone mineral density (BMD) of the wrist by computed tomography–ab... more This study examined patterns of bone mineral density (BMD) of the wrist by computed tomography–absorptiometry to evaluate force transmission patterns in vivo in patients with complaints of wrist instability requiring lunate-capitate-triquetrum-hamate (LCTH) arthrodesis. These patterns represent long-term force transmission through the wrist joint because BMD differs under different loading conditions. BMD studies of the wrist joint in vivo can evaluate the long-term force transmission through the joint under physiological and pathological conditions and before and after wrist surgery. The scaphoid fossa is relatively unloaded after LCTH arthrodesis, and a decrease in BMD is observed in the lunate fossa.
This study examined patterns of bone mineral density (BMD) of the wrist by computed tomography–ab... more This study examined patterns of bone mineral density (BMD) of the wrist by computed tomography–absorptiometry to evaluate force transmission patterns in vivo in patients with complaints of wrist instability requiring lunate-capitate-triquetrum-hamate (LCTH) arthrodesis. These patterns represent long-term force transmission through the wrist joint because BMD differs under different loading conditions. BMD studies of the wrist joint in vivo can evaluate the long-term force transmission through the joint under physiological and pathological conditions and before and after wrist surgery. The scaphoid fossa is relatively unloaded after LCTH arthrodesis, and a decrease in BMD is observed in the lunate fossa.
Triple pelvic osteotomy reorients the acetabulum relative to the pelvis in order to improve aceta... more Triple pelvic osteotomy reorients the acetabulum relative to the pelvis in order to improve acetabular coverage of the femoral head in cases of acetabular dysplasia. We undertook a radiostereometric analysis (RSA) on 6 osteotomized cadaver hips to determine the actual three-dimensional reorientation obtained. The centers of the femoral head were all translated posteriorly between 11 and 41 mm, and distally up to 13 mm. 4 were lateralized up to 8 mm, and 2 were medialized up to 5 mm. All acetabuli rotated anteriorly about the lateral to medial axis (X-axis), and 4 rotated outwards around the distal to proximal axis (Y-axis). The correlations between measurements performed on conventional anteroposterior radiographs and the RSA measurements were poor: variations in the lateral-medial direction ranged from -16 to +6 mm, and in the distal-proximal direction between -10 and +12 mm. The changes in orientations measured will significantly affect the load across the hip joint, since the dimensions of the pelvis change and the moment arms of the muscles, their lengths and lines of action are changed as well. We conclude that, with the procedures presently performed, the loads across the hip joint are bound to change, and that the reorientation can hardly be checked with conventional radiographs.
Objective. The purpose of this study was to accurately quantify three-dimensional in vivo kinemat... more Objective. The purpose of this study was to accurately quantify three-dimensional in vivo kinematics of all carpal bones in flexion and extension and radial and ulnar deviation.
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