Pascal Christel- MD, PhD
- Consultant at Neuro Spinal Hospital
Pascal Christel
- MD, PhD
- Consultant at Neuro Spinal Hospital
About
204
Publications
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Introduction
Former University Professor (Paris 7). Orthopaedic surgeon specialized in sports medicine and knee surgery. Fields of interest: clinical and basic research. Currently working in Riyadh, Saudi Arabia.
Current institution
Additional affiliations
March 2008 - October 2014
January 2008 - present
Πανεπιστημιακο Γενικό Νοσοκομείο Λάρισας
January 1990 - present
Université Paris Diderot - Paris 7
Publications
Publications (204)
Riassunto
La ricostruzione chirurgica del legamento crociato posteriore (LCP) ha visto recenti progressi in virtù di una migliore conoscenza della sua anatomia e della sua biomeccanica. Per ottenere un risultato anatomico soddisfacente è essenziale rispettare la posizione dei siti d’inserzione, soprattutto sul condilo mediale. L’impiego dell’artros...
This case-series outcome study presents a surgical technique for anatomic double-bundle anterior cruciate ligament (ACL) reconstruction with 4-tunnel using two interference screws. There was a 2-year minimum follow-up.
From January to December 2009, an ACL 4-tunnel, anatomic, double-bundle reconstruction was performed on 27 patients. Double-strand...
Los progresos recientes de la reconstrucción quirúrgica del ligamento cruzado posterior (LCP) se deben al mejor conocimiento de su anatomía y de su biomecánica. Para lograr un resultado anatómico satisfactorio, es esencial respetar la posición de los sitios de inserción, sobre todo en el cóndilo medial. La utilización del artroscopio y del amplific...
Graft choice for anterior cruciate ligament (ACL) reconstruction remains a debated and unsolved issue. Currently available auto- and fresh frozen allografts exhibit satisfactory mechanical properties for ACL reconstruction. The issue relates more to the outcome, in terms of residual laxity and pivot shift, harvesting morbidity, and functional outco...
Fatigue is an extrinsic factor adversely affecting joint proprioception and neuromuscular response, thereby increasing anterior cruciate ligament (ACL) strain and injury risk. The effectiveness of the single- and double-bundle techniques for ACL reconstruction to control residual rotational knee laxity under fatigue has not been examined.
Fatigue r...
The surgical treatment of osteochondral defect could have the choice between the techniques where the objectives are to obtain a repairing with a simple healing of the defect, and the techniques where the aims are to regenerate the cartilage with hyaline cartilage. In this last category, the most usual procedure is mosaicplasty, which has a limited...
The clinical diagnosis of a partial tear of the anterior cruciate ligament (ACL) is still subject to debate. Little is known about the contribution of each ACL bundle during the Lachman test. We investigated this using six fresh-frozen cadaveric lower limbs. Screws were placed in the femora and tibiae as fixed landmarks for digitisation of the bone...
Reconstruction of the anterior cruciate ligament (ACL) remains widely based on the use of the single-bundle technique. However, in the last few years, double-bundle ACL has become increasingly popular. One reason for this move is the unsatisfactory control of the tibial rotation following one bundle reconstruction. The transtibial technique, in whi...
Ultrasonic techniques have been used extensively to measure the anisotropic elastic properties of calcified tissue [1–4]. Yoon and Katz [3] have derived the equations relating the elastic constants to the technical moduli: Young's modulus, shear modulus, and the bulk modulus. In order to make these calculations they assumed that bone was transverse...
We have been involved in using several ultrasonic wave propagation techniques to study the relationship between the structure and the elastic properties of bone, both normal and pathological. Pulse through ultrasonic techniques have been used to measure the ultrasonic velocities in human, normal, osteoporotic and osteopetrotic femoral bones in vitr...
Following anatomic double-bundle anterior cruciate ligament (ACL) reconstruction with hamstring tendon autografts, 38 consecutive patients were evaluated with high-speed three-dimensional computed tomography. Scans were performed within 3 days following surgery. The length and width of the reconstructed ACL footprint were measured on axial images....
Double-bundle anterior cruciate ligament (ACL) reconstruction is a technically demanding procedure; it requires drilling 2 tibial and 2 femoral tunnels. Tunnel communication, whether intraoperative or postoperative, is a serious complication: It jeopardizes knee stability and graft function.
During double-bundle ACL reconstruction, special aimers w...
Introduction
Les laxités postérieures isolées bénéficient la plupart du temps d’un traitement fonctionnel ; cependant, lorsqu’il existe des douleurs ou une instabilité, un traitement chirurgical peut être proposé. L’objectif de cette étude était d’évaluer les résultats du traitement chirurgical des laxités postérieures isolées chroniques.
Hypothès...
Introduction
Les ruptures du ligament croisé postérieur (LCP) sont fréquemment associées à une atteinte du plan postéro-latéral (PPL). Ces lésions complexes sont très souvent mal tolérées cliniquement. Les bases biomécaniques du traitement de ces lésions complexes impliquent la nécessité d’obtenir un LCP fonctionnel et de reconstruire un PPL suffis...
Posterior cruciate ligament (PCL) injuries are frequently associated with posterolateral corner (PLC) damages. These complex lesions are most often poorly tolerated clinically. Adherence to sound biomechanical principles treating these complex lesions entails obtaining a functional PCL and reconstructing sufficient posterolateral stability.
Surgica...
Isolated posterior laxity is most often cared for with conservative functional treatment. However, when there is pain or instability, surgical treatment can legitimately be proposed. The objective of this study was to assess the results of surgical treatment for chronic isolated posterior laxity.
Surgical treatment of direct posterior laxity re-est...
Our purpose was to evaluate the radiologic orientation and length of the posterolateral (PL) femoral tunnel when drilled through the anteromedial (AM) portal at 90 degrees, 110 degrees, and 130 degrees of flexion.
In 9 fresh cadaveric knees the anterior cruciate ligament was excised and 2.4-mm guidewires were drilled through the center of the PL bu...
This study compares the positioning of femoral AM and PL tunnels obtained with specific ancillary instruments during anatomic double-bundle ACL reconstruction with the native ACL footprint using three-dimensional computed tomography (3-D CT). In 35 consecutive patients, anatomic double-bundle ACL reconstruction was performed with specific ancillary...
More than 100,000 anterior cruciate ligament reconstructions are done in the United States each year. With improvements in technology and surgical ability, the number of variables that must be considered has increased dramatically. The choice of autograft or allograft, which is one of the most important variables, has largely become a decision to b...
Graft positioning is a key issue in anterior cruciate ligament (ACL) reconstruction and even more sensitive in double-bundle reconstruction, where 2 tunnels have to be drilled within the ACL footprints at both the femoral and tibial insertion sites. Specific ancillary instruments have been developed to facilitate the positioning of the 4 sockets ne...
Specific ancillary instruments have been developed to facilitate the positioning of the 4 sockets necessary when performing anatomic double-bundle ACL reconstruction (2B-ACLR). This technical note describes both the rationale and the step-by-step way to use the specific aimers developed for this purpose. Validation of tunnel position with reference...
The purpose of this study was to determine the influence of knee flexion angle for drilling the femoral tunnel during anterior cruciate ligament (ACL) reconstruction via the anteromedial (AM) portal on resulting tunnel orientation and length.
In 8 fresh cadaveric knees, the ACL was excised and 2.4-mm guidewires were drilled through the AM bundle fo...
Rotational kinematics of the knee is not fully restored after single-bundle anterior cruciate ligament (ACL) reconstruction. Cadaveric experiments using knee testing machines have suggested anatomical reconstruction replacing the anteromedial and posterolateral bundles could restore knee kinematics more effectively than single-bundle reconstruction...
To define the positions of the attachments of the anteromedial (AM) and posterolateral (PL) bundles of the anterior cruciate ligament (ACL).
The shape and positions of the femoral and tibial attachments of the 2 bundles relative to bony landmarks were measured in 7 fresh-frozen, unpaired cadaveric knees by 6 independent observers. Metallic marker b...
Conclusion
Le traitement des gonarthroses fémoro-tibiales par ostéotomie reste actuellement une solution thérapeutique chirurgicale très utilisée dans l’attente du remplacement prothétique. Les bases théoriques de ces interventions sont de mieux en mieux connues. L’analyse radiographique, la planification préopératoire et la technique chirurgicale...
Las lesiones de los músculos esqueléticos son muy frecuentes, sobre todo en el ámbito deportivo. Se pueden encontrar lesiones de cualquier grado de afectación, pero algunas reglas diagnósticas y terapéuticas importantes permiten aportar una solución a la inmensa mayoría de los casos. Tras recordar la estructura histológica del músculo y los factore...
To review a series of tears of the posterior cruciate ligament (PCL) in order to understand its healing process, as well as to identify prognostic factors.
Prospective study.
Eighteen patients with isolated or combined PCL tears were evaluated and followed-up for 1 year after their initial injury. Magnetic resonance imaging (MRI) scans and stress r...
Anatomical observation and biomechanical studies have shown that the anterior cruciate ligament (ACL) mainly consists of 2 distinct bundles, the anteromedial bundle (AMB) and posterolateral bundle (PLB). These 2 bundles have different roles in the control of knee stability. The AMB essentially controls the anterior tibial translation, whereas the P...
Striated muscle injuries of the limbs are quite usual in sports medicine. All grades of severity can be met but several basic principles of diagnosis and treatment allow providing a solution in most of the cases. After a brief review of the histological structure of the striated muscle and the risk factors for muscle injury, this chapter will separ...
The purpose of this study was to compare the reliability and the reproducibility of both the KT-1000 arthrometer (Medmetric) and Telos for measuring anterior knee laxity. The Telos was used as the reference technique.
Criteria for inclusion were preoperative anterior knee laxity, normal contralateral knee, and intra-articular surgery to reconstruct...
Purpose of the studyThe purpose of this study was to compare the reliability and the reproducibility of both the KT-1000 arthrometer (Medmetric) and Telos for measuring anterior knee laxity. The Telos was used as the reference technique.Material and methodsCriteria for inclusion were preoperative anterior knee laxity, normal contralateral knee, and...
We worked with cadaver specimens to evaluate control of anterior knee laxity after reconstruction of the anterior cruciate ligament (ACL) comparing double two-strand anterolateral and posteromedial reconstruction with the classical four-strand technique. We hypothesized that the double reconstruction would provide better control of anterior laxity...
Le ligament croisé antérieur (LCA) est composé de deux faisceaux antéro-médial (AM) et postéro-latéral (PL) au rôle biomécanique distinct. Les techniques classiques de reconstruction du LCA par greffe à un faisceau ne remplacent que le faisceau AM. L’hypothèse de travail est que la reconstruction du LCA par greffe à un faisceau ne restaure pas une...
Current techniques for anterior cruciate ligament (ACL) reconstruction do not completely reproduce the anatomy and function of the ACL. They address only the anteromedial bundle and do not fully restore ACL function throughout the range of motion. Current grafts control anterior tibial subluxation near extension, but are less efficacious in providi...
This article describes a method for analyzing the cell distribution occurring in the membrane encapsulating cylinders of specific polymers, metals, or ceramics when implanted in the paraspinal muscles in rats for periods between 2 weeks and 1 year. Using a computer-assisted cell-counting method, it is shown that the cell distribution exhibits a non...
This article describes the various options which are available for posterior cruciate ligament (PCL) reconstruction in a chronic situation. On the femoral side, one- or two-bundle grafts may be used. In laboratory conditions, 2-bundle reconstruction makes it possible to mimic more closely the biomechanics of the native PCL. However, until now there...
This study describes a lateral extra-articular tenodesis using a short strip of ilio-tibial band. The tenodesis consists of a 12 x 75 mm strip of iliotibial band remaining attached to the Gerdy's tubercle. An isometric point in the region of Krackow's point F-9 is determined with a callipers. The strip of iliotibial band is twisted by 180 degrees t...
This study describes a lateral extra-articular tenodesis using a short strip of ilio-tibial band. The tenodesis consists of a 12 × 75 mm strip of iliotibial band remaining attached to the Gerdy's tubercle. An isometric point in the region of Krackow's point F-9 is determined with a callipers. The strip of iliotibial band is twisted by 180° to enhan...
The purpose of our study was to compare outcome at one year after anterior cruciate ligament reconstruction for chronic laxity using the patellar tendon autograft or four-strand hamstring tendon autografts.
This non-randomized study included 129 consecutive patients operated on between October 1996 and September 1998. Ninety patients were available...
Overall, the results of total knee replacement surgery are quite excellent, both with regard to pain and range of motion. Pain relief is obtained in more than 95% of the cases and more than 90% of the patients are able to bend their knee over 90 degrees. Nevertheless, in a small number of cases, stiffness can be an impairment.
Between 1992 and 1998...
This is an expanding surgical specialty and its indications are constantly evolving. Endoscopy is justified because it is less traumatic than conventional surgery. Operations are facilitated by the techniques and equipment currently available. The question has been raised whether extra-articular endoscopy is suitable for the upper or lower limb but...
This retrospective study was designed to evaluate changes in the diameter of the tibial tunnel over time following the reconstruction of the anterior cruciate ligament (ACL) with a bone-patellar tendon-bone autograft in 44 patients. The changes in the geometry of the bone tunnels were measured radiographically during the immediate postoperative per...
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...
The adsorption of plasma proteins onto biomedical polymers is an important factor in the biocompatibility of biomaterials. We identified the plasma proteins adsorbed onto four polymeric fibers used for synthetic ligament replacement: polyarylamide, polylactic acid, polyester, and polypropylene. The adsorbed proteins were eluted and analyzed by one-...
Passive hyperextension is a rare mechanism of injury of knee ligaments in clinical practice. The lesions are often complex and no consensus exists about their sequence. Our purpose was to study the mechanical behavior and the anatomical lesions of the knee following passive hyperextension until rupture.
12 pairs of fresh human cadaveric knees were...
The purpose of this study was to evaluate the influence of the graft positioning on the clinical outcome and magnetic resonance imaging (MRI) signal of the graft following anterior cruciate ligament (ACL) reconstruction using the central one-third of the patellar tendon. Twenty-two patients with a chronic anterior instability underwent a modified M...
This article analyzes the general features of the tissue response to orthopedic biomaterials when implanted in the paraspinal muscles in rats for periods between 1 week and 1 year. Using a computer-assisted cell counting method, it was shown that the membrane thickness was a stable parameter that poorly correlated with the other histomorphometric p...
The use of natural coral as a bone graft substitute is common in Europe. However, the bone-coral bonding mechanism remains elusive. A rat subcutaneous model was used to demonstrate changes at the surface of resorbable calcium carbonate in the form of natural coral. Histological results indicated in vivo formation of a calcium phosphate (CaP)-rich l...
In this paper the possibility of growing human bone marrow cells (HBMC) on dense calcium carbonate in conditions driving these cells towards osteogenesis is explored. It was observed that HBMC were able to adhere and multiply and can be driven best towards osteogenesis in the presence of Dex and 1,25(OH)D3 (as regards ALP activity). Specific morpho...
This article is a summary of the information published in the field of hip surgery in adults over the past year. It reviews the epidemiology and economic aspects of total hip replacement, which dominates adult hip surgery, and examines the long-term results and complications that occur with both cemented and uncemented arthroplasty of the hip. Asep...
For biocompatibility testing, cylindrical specimens are often inserted into drilled cortical defects. However, little attention has been paid to the drilling conditions. Our previous experience revealed that bone formation in drilled cortial defects was delayed by 5000 r.p.m. drilling due to thermal necrosis around the hole compared with 500 r.p.m....
For orthopaedic biomaterial implantation testing, specimens are often implanted into cortical bone defects. The implantation site is assumed to be one of the factors that influence the bone response to biomaterials. The aim of this study was to investigate the bone-healing process in drilled cortical defects at different sites with respect to time....
Replacing the chronic deficient anterior cruciate ligament (ACL) has been demonstrated to be a challenging surgical procedure. ACL anatomy and structure as well as its biomechanics have been extensively studied in order to understand its properties and improve its reconstruction. Currently the ACL may be replaced by different means. Autogenous graf...
In order to evaluate the potential use of polyarylamide fibers as a prosthetic material for ligament replacement, resected sheep anterior cruciate ligaments were replaced by braided devices routed through a tibial tunnel and over the top of the lateral femoral condyle. Twelve sheep were used and sacrificed between 3 and 12 months. The tissue respon...
This document has resulted from some intense debate between members of a group experienced in cruciate ligament surgery and research. Definite recommendations had the agreement of the group, while the absence of a firm viewpoint has led to recommendations for further research.
It is hoped that the recommendations will be taken up by working surgeo...
For biocompatibility evaluation, orthopaedic and dental biomaterials are often implanted into bone after drilling. Bone repair in the drilled hole may be affected by bone damage attributed to drilling, thus influencing the bone response to biomaterials. The drilling parameters (the speed of rotation and irrigation) were investigated histologically....
