Jean yves Lazennec - Academia.edu (original) (raw)
Papers by Jean yves Lazennec
Journal de radiologie, 1995
The purpose of the study is to compare normal PLC anatomy and its MRI appearance, with the variou... more The purpose of the study is to compare normal PLC anatomy and its MRI appearance, with the various lesions observed in MRI, from the simple popliteus tendinous contusion to the complete PLC rupture. For this specific work on PLC lesions, we selected 61 examinations among the traumatic knees explored during the last 3 years. Surgical correlation is obtained for the 61 patients. MRI examinations are performed on a 0.5 T. unit with gradient echo T1, T1 and T1 GD-DOTA IV. Normal PLC anatomy is compared to the dissection of 4 anatomic subjects. Normal MRI slices are evaluated with this reference analysis. The principle anatomical structures of the PLC include the lateral collateral ligament, the popliteus tendon, the arcuate ligament, the fabello fibular ligament, the posterolateral condylar capsule, and the posterior horn of the lateral meniscus. Surgical findings confirm PLC lesion for 58 patients with 3 false positive. Diagnosis of these lesions is important because chronical posterol...
International Orthopaedics
Introduction Limb-length discrepancy (LLD) is a common postoperative complication after total hip... more Introduction Limb-length discrepancy (LLD) is a common postoperative complication after total hip arthroplasty (THA). This study focuses on the correlation between patients’ perception of LLD after...
N.N. Priorov Journal of Traumatology and Orthopedics
Anterior mini-invasive approach to the spine that enables to achieve all levels from T12 to SI is... more Anterior mini-invasive approach to the spine that enables to achieve all levels from T12 to SI is described. This approach can be used both in injuries and in degenerative pathology of the spine. Surgical results were studied roentgenologically and that gave us the possibility to assess the performed osteosynthesis and the equilibrium in the sagittal plane. The suggested approach is the continuation of classical anterior approaches and it provides significant advantages for the performance of various surgical interventions at all levels of the lumbar spine without damaging the muscles. Theoretically it possesses neither neurologic risk nor the problem of blood loss which occur when intervertebral transplantation is performed via the posterior approach. Anterior extraperitoneal mini-approach enables to adjust the size of the graft and to perform the correction of sizable deformities using either rigid or semirigid graft. It can also be the only choice in case of considerable loss of ...
IntroductionThe combination of spinal fusion and THP is not exceptional. Disorders of the pelvic ... more IntroductionThe combination of spinal fusion and THP is not exceptional. Disorders of the pelvic tilt and stiffness of the lumbosacral junction modify the adaptation options while standing or sitting. Adjusting the cup can be difficult and THP instability is a potential risk. This study reports an experience with EOS® simultaneous measurements on AP and lateral views of spine and hips in THP patients.Material and methods29 men and 45 women were included in this prospective study. 21cases had bilateral THP. Patients were separated into two groups: long fusions including the thoraco-lumbar junction (group 1) and shorter fusions below L1 (group 2). We analyzed the impact of the arthrodesis on the position of the pelvis by measuring variations of the sacral slope (SS) and APP angle. Cup position was defined by coronal inclination and functional anteversion in the horizontal plane standing and sitting. We compared the data to a previous series of 150 THP patients with asymptomatic and no...
Journal of Bone and Joint Surgery-british Volume, 2016
Introduction EOS® is a low dose imaging system which allows the acquisition of coupled AP and lat... more Introduction EOS® is a low dose imaging system which allows the acquisition of coupled AP and lateral high-definition images while the patient is in standing position. HipEos has been developped to perform pre-surgical planning including hip implants selection and virtual positioning in functional weight-bearing 3D. The software takes advantage of the real size 3D patient anatomical informations obtained from the EOS exam. The aim of this preliminary study on 30 consecutive THP patients was to analyze the data obtained from HipEos planning for acetabular and femoral parameters and to compare them with pre and post-operative measurements on standing EOS images. Material and methods Full body images were used to detect spino-pelvic abnormalities (scoliosis, pelvic rotation) and lower limbs discrepancies. One surgeon performed all THP using the same type of cementless implants (anterior approach, lateral decubitus). The minimum delay for post-op EOS controls was 10 months. A simulation...
Revue De Chirurgie Orthopedique Et Reparatrice De L Appareil Moteur, 1985
Journal of Bone and Joint Surgery-british Volume, 2017
Introduction The ESP prosthesis is a one-piece deformable but cohesive interbody spacer. it provi... more Introduction The ESP prosthesis is a one-piece deformable but cohesive interbody spacer. it provides 6 full degrees of freedom about the 3 axes including shock absorption (fig1). The prosthesis geometry allows limited rotation and translation with resistance to motion (elastic return property) aimed at avoiding overload of the posterior facets. The rotation center can vary freely during motion in this “silentblock” implant. It thus differs substantially from current prostheses. Material and methods Surgeries were performed by 2 senior surgeons in 54 women and 34 men (1level in 72 cases, 2 levels in 3 cases, hybrid construct in 13 cases). Average age was 42 (SD: 7). Average BMI was 24.2kg/m2 (SD: 3,4). Clinical data and X-rays were collected at the preoperative time and at 3, 6, 12, 24, and 60 months post-op. The analysis was performed by a single observer independent from the selection of patients and from the surgical procedure. The radiological analysis at 60 months follow-up coul...
Current total disc prostheses are 2- or 3-pieces devices, including 1 or 2 bearing surfaces, and ... more Current total disc prostheses are 2- or 3-pieces devices, including 1 or 2 bearing surfaces, and providing 3 or 5 degrees of freedom but with no, or very little, resistance. The ESP® is a one-piece deformable implant made of silicon and polycarbonate polyurethane elastomer securely fixed to titanium endplates. It allows limited rotation and translation with elastic return. This cushion without fixed rotation center achieves 6 degrees of freedom including shock absorption. An earlier attempt to use elastomers (Acroflex®) failed clinically due to the polymer. This highlights the need for accurate in-vitro fatigue testing and clinical evaluations. In-vitro fatigue testing with more than 40 millions cycles were performed on different samples for compression, flexion-extension bending, lateral bending, torsion and shear. A prospective trial was initiated in 2004 for L3L4, L4L5 and L5S1 levels. Total disc replacements have been performed in 153 lumbar levels through extra-peritoneal mini-...
Purpose: Infection of a posterior fixation can lead to a therapeutic dilemma, particularly if the... more Purpose: Infection of a posterior fixation can lead to a therapeutic dilemma, particularly if the extensive fixation involves a demineralised spine. Material and methods: From 1998 to 2001, seven patients aged 19 to 76 years (mean 58) were treated with an interbody cage and an autologous graft. Four patients with scoliosis had had prior posterior surgery (mean five operations, range 3 – 9 operations). All had exhibited non-union with repeated fistulisation at each prior anterior approach, in four cases with meti-R Staphylococcus associated once with a Streptococcus and twice with an Enterococcus. Three patients suffered severe radicular pain. Three of the post-trauma patients had undergone revision procedures to remove the posterior implants. All had developed nonunion with total loss of the initial correction in two cases, one with septic instability concerning the level above the fixation. Both infections were caused by meti-R Staphylococcus, associated with an Enterococcus in one...
The Bone & Joint Journal, 2019
There remains confusion in the literature with regard to the spinopelvic relationship, and its co... more There remains confusion in the literature with regard to the spinopelvic relationship, and its contribution to ideal acetabular component position. Critical assessment of the literature has been limited by use of conflicting terminology and definitions of new concepts that further confuse the topic. In 2017, the concept of a Hip-Spine Workgroup was created with the first meeting held at the American Academy of Orthopedic Surgeons Annual Meeting in 2018. The goal of this workgroup was to first help standardize terminology across the literature so that as a topic, multiple groups could produce literature that is immediately understandable and applicable. This consensus review from the Hip-Spine Workgroup aims to simplify the spinopelvic relationship, offer hip surgeons a concise summary of available literature, and select common terminology approved by both hip surgeons and spine surgeons for future research. Cite this article: Bone Joint J 2019;101-B:808–816.
Revue de Chirurgie Orthopédique et Réparatrice de l'Appareil Moteur, 2007
Orthopaedics & Traumatology: Surgery & Research, 2016
Disc degeneration is a normal age-related process. Accelerated degeneration of discs adjacent to ... more Disc degeneration is a normal age-related process. Accelerated degeneration of discs adjacent to fused spinal levels has been observed in numerous case-series studies. The available data document this phenomenon and provide information on its time to occurrence but show huge variations in incidence rates (5% to 70%). The supra-jacent disc is involved more often than the infra-jacent disc. Studies have clarified the underlying biomechanical rationale by showing increased loading of the adjacent discs. Risk factors have been the focus of the most recent studies. They include the number of fused levels, sagittal alignment, level of fusion, stiffness of the construct, and integrity of the posterior structures. Nevertheless, the many published studies have produced somewhat conflicting results. Various radiological criteria have been used to define degeneration of the adjacent disc. Although most patients have no symptoms, adverse effects on the spine and/or nerve roots may occur and, in some cases, require revision surgery. We draw attention to the many sources of bias in the published studies, of which we provide a critical and pragmatic discussion in the light of our personal experience.
Metal-On-Metal Total Hip Replacement Devices, 2013
ABSTRACT This Metal-on-Metal hip (MOM) retrieval study of products f romfour vendors (Biomet, Dep... more ABSTRACT This Metal-on-Metal hip (MOM) retrieval study of products f romfour vendors (Biomet, Depuy, Smith & Nephew, Zimmer) demonstrated that ‘normal’ wear patterns on femoral heads (28- 54mm) were generally circular and occupied approximately 50% of the hemispherical ball area. The main wear zone (MWZ) centroid-vector averaged 16o superior to the polar axis, indicating that the wear pattern was mainly supero-medially located. Such wear patterns appeared very similar to that described on femoral heads from available simulator data. In contrast to femoral heads, the ‘normal’ wear patterns on retrieved cups were both more variable and generally larger, with 91% of MOM cases showing breakout wear averaging 206o around the cup rim. Thus the MOM retrievals demonstrated femoral wear patterns similar to those produced in simulators whereas wear patterns in retrieved cups were more extensive than patterns produced in simulator tests. There has been a major focus on “edge wear” of MOM cups but surprisingly little or no attention given to the collateral damage on the femoral heads. In this study we focused on the new definition of ‘macro grooves’, i.e. third-body wear scratches 40-100um wide and 540 mm long. The major finding was the persistent, ‘adverse’ wear patterns that were apparent as well-defined stripe damage on both femoral heads and acetabular cups. The second observation was that the macro-groove damage occurred preferentially at three sites, two of which, the basal and polar stripes, were clearly indicative of cup impingement against the femoral stem implants (made of titanium alloy). The combination of basal and polar stripes showed a 100% incidence in this study. Basal stripe damage originated at or near the base of the femoral head and generally continued in a somewhat radial direction towards the main-wear zone. The contiguous damage was the polar stripe inside the main wear zone. Confirmation of impingement damage was the presence of 100um wide tracks of metal contamination that contained elements of the alloy used in the femoral stems (Ti, Al, V). It is to be noted that the basal and polar stripes had 100% occurrence in this failed population of MOM cases. It may be that the MOM cases continuing to function well do not follow such extreme wear patterns. Combinations of basal and polar stripes were observed on all retrieved femoral heads regardless of diameter, indicating a very consistent in-vivo damage pattern for MOM bearings. Stripe wear has been frequently described on retrieved ceramic bearings but not on retrieved MOM bearings. Stripe wear was always present at sites of impingement between the cup rim and femoral neck. The dominant form of surface scratches were the ‘macro-grooves’ that varied 1-30um deep and had smooth transitioning terminuses. It could therefore be hypothesized that the trigger mechanism for adverse wear of MOM bearings came from cup-to-neck impingement episodes that released CoCr particles of size 40-100um. The circulating CoCr particles contributed t o the dominant abrasive wear process (macro grooves) until becoming finely pulverized with repeated articulations. Such particles would finally decompose down to nanometer size particulates that would number in the trillions. The result would be a combination of adverse, abrasive wear ending in the often-described “self-polishing” effect of MOM bearings. Such consistent impingement-stripe and macro- groove evidence in 100% of these MOM retrievals has implications in all hip arthroplasty designs.
Clinical neurosurgery, 1986
ABSTRACT
La Revue du praticien, Jan 15, 1998
The anatomy of the knee provides a standardised description of articular surfaces, ligament and t... more The anatomy of the knee provides a standardised description of articular surfaces, ligament and tendinous insertions in order to understand the combined action of the femoro-tibial and femoro-patellar compartments, as well as their stabilisation mechanisms. Nevertheless, the isolated vision of the articulation is insufficient; one also needs to study the global action of the limb by integrating the rotation of the whole skeletal body and its positions in the sagittal and frontal plans.
Bioceramics in Joint Arthroplasty, 2003
Conférences d'enseignement de la SOFCOT 2012, 2012
Surgical and Radiologic Anatomy, 1992
Clinical Rheumatology, 1997
Ankylosing spondylitis of the cervical spine is associated with stiff kyphosis and increased risk... more Ankylosing spondylitis of the cervical spine is associated with stiff kyphosis and increased risk of transversal unstable fracture. A spine surgeon may be involved mainly in the management of trauma cases, but in some situations, corrective surgery of a kyphotic cervical deformity is needed. Both types of cases carry specific aspects and rely on principles that differ from those associated with more common cervical surgery. This paper is a review of the literature regarding cervical surgery in cases of ankylosing spondylitis. It addresses practical technical questions.
Journal de radiologie, 1995
The purpose of the study is to compare normal PLC anatomy and its MRI appearance, with the variou... more The purpose of the study is to compare normal PLC anatomy and its MRI appearance, with the various lesions observed in MRI, from the simple popliteus tendinous contusion to the complete PLC rupture. For this specific work on PLC lesions, we selected 61 examinations among the traumatic knees explored during the last 3 years. Surgical correlation is obtained for the 61 patients. MRI examinations are performed on a 0.5 T. unit with gradient echo T1, T1 and T1 GD-DOTA IV. Normal PLC anatomy is compared to the dissection of 4 anatomic subjects. Normal MRI slices are evaluated with this reference analysis. The principle anatomical structures of the PLC include the lateral collateral ligament, the popliteus tendon, the arcuate ligament, the fabello fibular ligament, the posterolateral condylar capsule, and the posterior horn of the lateral meniscus. Surgical findings confirm PLC lesion for 58 patients with 3 false positive. Diagnosis of these lesions is important because chronical posterol...
International Orthopaedics
Introduction Limb-length discrepancy (LLD) is a common postoperative complication after total hip... more Introduction Limb-length discrepancy (LLD) is a common postoperative complication after total hip arthroplasty (THA). This study focuses on the correlation between patients’ perception of LLD after...
N.N. Priorov Journal of Traumatology and Orthopedics
Anterior mini-invasive approach to the spine that enables to achieve all levels from T12 to SI is... more Anterior mini-invasive approach to the spine that enables to achieve all levels from T12 to SI is described. This approach can be used both in injuries and in degenerative pathology of the spine. Surgical results were studied roentgenologically and that gave us the possibility to assess the performed osteosynthesis and the equilibrium in the sagittal plane. The suggested approach is the continuation of classical anterior approaches and it provides significant advantages for the performance of various surgical interventions at all levels of the lumbar spine without damaging the muscles. Theoretically it possesses neither neurologic risk nor the problem of blood loss which occur when intervertebral transplantation is performed via the posterior approach. Anterior extraperitoneal mini-approach enables to adjust the size of the graft and to perform the correction of sizable deformities using either rigid or semirigid graft. It can also be the only choice in case of considerable loss of ...
IntroductionThe combination of spinal fusion and THP is not exceptional. Disorders of the pelvic ... more IntroductionThe combination of spinal fusion and THP is not exceptional. Disorders of the pelvic tilt and stiffness of the lumbosacral junction modify the adaptation options while standing or sitting. Adjusting the cup can be difficult and THP instability is a potential risk. This study reports an experience with EOS® simultaneous measurements on AP and lateral views of spine and hips in THP patients.Material and methods29 men and 45 women were included in this prospective study. 21cases had bilateral THP. Patients were separated into two groups: long fusions including the thoraco-lumbar junction (group 1) and shorter fusions below L1 (group 2). We analyzed the impact of the arthrodesis on the position of the pelvis by measuring variations of the sacral slope (SS) and APP angle. Cup position was defined by coronal inclination and functional anteversion in the horizontal plane standing and sitting. We compared the data to a previous series of 150 THP patients with asymptomatic and no...
Journal of Bone and Joint Surgery-british Volume, 2016
Introduction EOS® is a low dose imaging system which allows the acquisition of coupled AP and lat... more Introduction EOS® is a low dose imaging system which allows the acquisition of coupled AP and lateral high-definition images while the patient is in standing position. HipEos has been developped to perform pre-surgical planning including hip implants selection and virtual positioning in functional weight-bearing 3D. The software takes advantage of the real size 3D patient anatomical informations obtained from the EOS exam. The aim of this preliminary study on 30 consecutive THP patients was to analyze the data obtained from HipEos planning for acetabular and femoral parameters and to compare them with pre and post-operative measurements on standing EOS images. Material and methods Full body images were used to detect spino-pelvic abnormalities (scoliosis, pelvic rotation) and lower limbs discrepancies. One surgeon performed all THP using the same type of cementless implants (anterior approach, lateral decubitus). The minimum delay for post-op EOS controls was 10 months. A simulation...
Revue De Chirurgie Orthopedique Et Reparatrice De L Appareil Moteur, 1985
Journal of Bone and Joint Surgery-british Volume, 2017
Introduction The ESP prosthesis is a one-piece deformable but cohesive interbody spacer. it provi... more Introduction The ESP prosthesis is a one-piece deformable but cohesive interbody spacer. it provides 6 full degrees of freedom about the 3 axes including shock absorption (fig1). The prosthesis geometry allows limited rotation and translation with resistance to motion (elastic return property) aimed at avoiding overload of the posterior facets. The rotation center can vary freely during motion in this “silentblock” implant. It thus differs substantially from current prostheses. Material and methods Surgeries were performed by 2 senior surgeons in 54 women and 34 men (1level in 72 cases, 2 levels in 3 cases, hybrid construct in 13 cases). Average age was 42 (SD: 7). Average BMI was 24.2kg/m2 (SD: 3,4). Clinical data and X-rays were collected at the preoperative time and at 3, 6, 12, 24, and 60 months post-op. The analysis was performed by a single observer independent from the selection of patients and from the surgical procedure. The radiological analysis at 60 months follow-up coul...
Current total disc prostheses are 2- or 3-pieces devices, including 1 or 2 bearing surfaces, and ... more Current total disc prostheses are 2- or 3-pieces devices, including 1 or 2 bearing surfaces, and providing 3 or 5 degrees of freedom but with no, or very little, resistance. The ESP® is a one-piece deformable implant made of silicon and polycarbonate polyurethane elastomer securely fixed to titanium endplates. It allows limited rotation and translation with elastic return. This cushion without fixed rotation center achieves 6 degrees of freedom including shock absorption. An earlier attempt to use elastomers (Acroflex®) failed clinically due to the polymer. This highlights the need for accurate in-vitro fatigue testing and clinical evaluations. In-vitro fatigue testing with more than 40 millions cycles were performed on different samples for compression, flexion-extension bending, lateral bending, torsion and shear. A prospective trial was initiated in 2004 for L3L4, L4L5 and L5S1 levels. Total disc replacements have been performed in 153 lumbar levels through extra-peritoneal mini-...
Purpose: Infection of a posterior fixation can lead to a therapeutic dilemma, particularly if the... more Purpose: Infection of a posterior fixation can lead to a therapeutic dilemma, particularly if the extensive fixation involves a demineralised spine. Material and methods: From 1998 to 2001, seven patients aged 19 to 76 years (mean 58) were treated with an interbody cage and an autologous graft. Four patients with scoliosis had had prior posterior surgery (mean five operations, range 3 – 9 operations). All had exhibited non-union with repeated fistulisation at each prior anterior approach, in four cases with meti-R Staphylococcus associated once with a Streptococcus and twice with an Enterococcus. Three patients suffered severe radicular pain. Three of the post-trauma patients had undergone revision procedures to remove the posterior implants. All had developed nonunion with total loss of the initial correction in two cases, one with septic instability concerning the level above the fixation. Both infections were caused by meti-R Staphylococcus, associated with an Enterococcus in one...
The Bone & Joint Journal, 2019
There remains confusion in the literature with regard to the spinopelvic relationship, and its co... more There remains confusion in the literature with regard to the spinopelvic relationship, and its contribution to ideal acetabular component position. Critical assessment of the literature has been limited by use of conflicting terminology and definitions of new concepts that further confuse the topic. In 2017, the concept of a Hip-Spine Workgroup was created with the first meeting held at the American Academy of Orthopedic Surgeons Annual Meeting in 2018. The goal of this workgroup was to first help standardize terminology across the literature so that as a topic, multiple groups could produce literature that is immediately understandable and applicable. This consensus review from the Hip-Spine Workgroup aims to simplify the spinopelvic relationship, offer hip surgeons a concise summary of available literature, and select common terminology approved by both hip surgeons and spine surgeons for future research. Cite this article: Bone Joint J 2019;101-B:808–816.
Revue de Chirurgie Orthopédique et Réparatrice de l'Appareil Moteur, 2007
Orthopaedics & Traumatology: Surgery & Research, 2016
Disc degeneration is a normal age-related process. Accelerated degeneration of discs adjacent to ... more Disc degeneration is a normal age-related process. Accelerated degeneration of discs adjacent to fused spinal levels has been observed in numerous case-series studies. The available data document this phenomenon and provide information on its time to occurrence but show huge variations in incidence rates (5% to 70%). The supra-jacent disc is involved more often than the infra-jacent disc. Studies have clarified the underlying biomechanical rationale by showing increased loading of the adjacent discs. Risk factors have been the focus of the most recent studies. They include the number of fused levels, sagittal alignment, level of fusion, stiffness of the construct, and integrity of the posterior structures. Nevertheless, the many published studies have produced somewhat conflicting results. Various radiological criteria have been used to define degeneration of the adjacent disc. Although most patients have no symptoms, adverse effects on the spine and/or nerve roots may occur and, in some cases, require revision surgery. We draw attention to the many sources of bias in the published studies, of which we provide a critical and pragmatic discussion in the light of our personal experience.
Metal-On-Metal Total Hip Replacement Devices, 2013
ABSTRACT This Metal-on-Metal hip (MOM) retrieval study of products f romfour vendors (Biomet, Dep... more ABSTRACT This Metal-on-Metal hip (MOM) retrieval study of products f romfour vendors (Biomet, Depuy, Smith & Nephew, Zimmer) demonstrated that ‘normal’ wear patterns on femoral heads (28- 54mm) were generally circular and occupied approximately 50% of the hemispherical ball area. The main wear zone (MWZ) centroid-vector averaged 16o superior to the polar axis, indicating that the wear pattern was mainly supero-medially located. Such wear patterns appeared very similar to that described on femoral heads from available simulator data. In contrast to femoral heads, the ‘normal’ wear patterns on retrieved cups were both more variable and generally larger, with 91% of MOM cases showing breakout wear averaging 206o around the cup rim. Thus the MOM retrievals demonstrated femoral wear patterns similar to those produced in simulators whereas wear patterns in retrieved cups were more extensive than patterns produced in simulator tests. There has been a major focus on “edge wear” of MOM cups but surprisingly little or no attention given to the collateral damage on the femoral heads. In this study we focused on the new definition of ‘macro grooves’, i.e. third-body wear scratches 40-100um wide and 540 mm long. The major finding was the persistent, ‘adverse’ wear patterns that were apparent as well-defined stripe damage on both femoral heads and acetabular cups. The second observation was that the macro-groove damage occurred preferentially at three sites, two of which, the basal and polar stripes, were clearly indicative of cup impingement against the femoral stem implants (made of titanium alloy). The combination of basal and polar stripes showed a 100% incidence in this study. Basal stripe damage originated at or near the base of the femoral head and generally continued in a somewhat radial direction towards the main-wear zone. The contiguous damage was the polar stripe inside the main wear zone. Confirmation of impingement damage was the presence of 100um wide tracks of metal contamination that contained elements of the alloy used in the femoral stems (Ti, Al, V). It is to be noted that the basal and polar stripes had 100% occurrence in this failed population of MOM cases. It may be that the MOM cases continuing to function well do not follow such extreme wear patterns. Combinations of basal and polar stripes were observed on all retrieved femoral heads regardless of diameter, indicating a very consistent in-vivo damage pattern for MOM bearings. Stripe wear has been frequently described on retrieved ceramic bearings but not on retrieved MOM bearings. Stripe wear was always present at sites of impingement between the cup rim and femoral neck. The dominant form of surface scratches were the ‘macro-grooves’ that varied 1-30um deep and had smooth transitioning terminuses. It could therefore be hypothesized that the trigger mechanism for adverse wear of MOM bearings came from cup-to-neck impingement episodes that released CoCr particles of size 40-100um. The circulating CoCr particles contributed t o the dominant abrasive wear process (macro grooves) until becoming finely pulverized with repeated articulations. Such particles would finally decompose down to nanometer size particulates that would number in the trillions. The result would be a combination of adverse, abrasive wear ending in the often-described “self-polishing” effect of MOM bearings. Such consistent impingement-stripe and macro- groove evidence in 100% of these MOM retrievals has implications in all hip arthroplasty designs.
Clinical neurosurgery, 1986
ABSTRACT
La Revue du praticien, Jan 15, 1998
The anatomy of the knee provides a standardised description of articular surfaces, ligament and t... more The anatomy of the knee provides a standardised description of articular surfaces, ligament and tendinous insertions in order to understand the combined action of the femoro-tibial and femoro-patellar compartments, as well as their stabilisation mechanisms. Nevertheless, the isolated vision of the articulation is insufficient; one also needs to study the global action of the limb by integrating the rotation of the whole skeletal body and its positions in the sagittal and frontal plans.
Bioceramics in Joint Arthroplasty, 2003
Conférences d'enseignement de la SOFCOT 2012, 2012
Surgical and Radiologic Anatomy, 1992
Clinical Rheumatology, 1997
Ankylosing spondylitis of the cervical spine is associated with stiff kyphosis and increased risk... more Ankylosing spondylitis of the cervical spine is associated with stiff kyphosis and increased risk of transversal unstable fracture. A spine surgeon may be involved mainly in the management of trauma cases, but in some situations, corrective surgery of a kyphotic cervical deformity is needed. Both types of cases carry specific aspects and rely on principles that differ from those associated with more common cervical surgery. This paper is a review of the literature regarding cervical surgery in cases of ankylosing spondylitis. It addresses practical technical questions.