Sport and early osteoarthritis: the role of sport in aetiology, progression and treatment of knee osteoarthritis.

Sports activities are considered favourable for general health; nevertheless, a possible influence of sports practice on the development of early osteoarthritis (OA) is a cause for concern. A higher incidence of OA in knees and ankles of former high-impact sports players than in those of the normal population has been shown and it is still debatable whether the cause is either to be recognized generically in the higher number of injuries or in a joint overload. The possibility to address knee OA in its early phases may be strictly connected to the modification of specific extrinsic or intrinsic factors, related to the patient in order to save the joint from further disease progression; these include sport practice, equipment and load. Non-surgical therapies such as continuative muscles reinforce and training play a strong role in the care of athletes with early OA, particularly if professional. There is an overall agreement on the need of an early restoring of a proper meniscal, ligament and cartilage integrity in order to protect the knee and resume sports safely, whereas alignment is a point still strongly debatable especially for professional athletes. Remaining questions still to be answered are the risks of different sports in relation to one another, although an actual protective effect of low-impact sports, such as walking, swimming or cycling, has been recognized on the appearance or worsening of OA, the effect of continuing or ceasing to practice a sport on the natural history of early OA, and even following appropriate treatment is still unknown.

[Femoroacetabular impingement: rehabilitation and return to sport]. / Rééducation des conflits fémoro-acétabulaires et retour au sport.

Femoroacetabular impingements (FAI) are quite frequent among young athletes. An early detection is essential in order to prevent more labral and cartilage damage. Conservative treatment should not focus on forcing the full range of motion but on restoring a good muscle balance around the joint and a better lower limb dynamic stability and control. The patient should be educated to master the end of hip range of motion during his activities. If the outcome is not satisfactory, a surgical treatment is offered. The post-operative treatment protocol is tailored to the type of repair, following several stages, from neuromuscular control to strengthening up to the return to sport. FAI prevention should be more studied in order to protect the hip of the growing athlete.

[Athletic pubalgia and hip impingement]. / Pubalgie et confit fémoro-acétabulaire.

Athletic pubalgia is a painful and complex syndrom encountered by athletes involved in pivoting and cutting sports such as hockey and soccer. To date, there is no real consensus on the criteria for a reliable diagnostic, the different investigations, and the appropriate therapy. Current literature underlines intrinsic and extrinsic factors contributing to athletic pubalgia. This review article reports upon two novelties related to the issue: the importance and efficience of prevention program and the association of femoro-acetabular impingement with the pubalgia.

[Deleterious effects of smoking on the musculoskeletal system]. / Effets délétéres du tabagisme sur l'appareil musculo-squelettique.

Tobacco smoking has important negative effects on the musculoskeletal system: decrease of bone mineral density, increase of the risk of injury, illness, and perioperative complications such as fracture-healing complications and wound complications. Orthopaedic surgeons should inform all patients of the increased risks associated with active smoking in the perioperative period and should encourage them to quit smoking four to eight weeks in advance of the proposed procedure.

[Return to sport after anterior cruciate ligament reconstruction]. / Retour au sport après reconstruction du ligament croisé antérieur.

Despite continuous advances in techniques for anterior cruciate ligament reconstruction (ACLR), return to play (RTP) after surgery remains a challenge. More than one-third of the patients are unable to return to their preinjury sport level, for most because of a fear to sustain another injury. And when a RTP is attempted, up to 20% will tear their graft and a similar % will sustain an ACL tear on the opposite side. We believe that these failures result from an incomplete recovery. Based on a literature review and on our experience, we suggest 6 objective criteria to allow a safer RTP. They rely on laxity, strength, neuromuscular function, and psychological evaluations. Rehabilitation after ACLR should focus on the deficits identified by these tests and on they specific needs of the sport that the athlete plans to return to.

Current concept in rotational laxity control and evaluation in ACL reconstruction.

Rotation combined with translation; compose the three-dimensional motion of the knee subluxation in anterior cruciate ligament deficient knee. The worldwide scientists were focused initially on the translation part of this complex 3D motion, but since the beginning of the century there was a large interest on knee rotational laxity study. Lot of paper reported new devices and results with an explosion since the beginning of the decade. The purpose of this review is to provide an extensive critical analysis of the literature and clarify the knowledge on this topic. We will start with a dismemberment of different rotational laxities reported: the rotation coupled with translation in 2D tests such as Lachman test and anterior drawer test; the rotational envelope considering the maximum internal external rotation; and the "active rotation" occurring in 3D Pivot-shift (PS) test. Then we will analyze the knee kinematics and the role of different anterior cruciate ligament (ACL) bundle on rotation. A review of different mechanical and radiological devices used to assess the different rotations on ACL deficient knees will be presented. Two groups will be analyzed, dynamic and static conditions of tests. Navigation will be described precisely; it was the starter of this recent interest in rotation studies. Opto electronic and electromagnetic navigation systems will be presented and analyzed. We will conclude with the last generation of rotational laxity assessment devices, using accelerometers, which are very promising.

Teres major muscle tear in two professional ice hockey players: cases study and literature review.

Ice hockey is a sport renowned for its numerous injuries; different studies report between 13.8 and 20 lesions per 1000 athlete exposures. Exactly 65.5% of these injuries occur during games, compared to 34.5% during training sessions. And 35.1% of all injuries involve the lower extremity and 29.7% the upper extremity (results drawn from games and training combined). Determining whether muscle injuries are extrinsic (contusions) or intrinsic (tears) is of utmost importance since the former generally require simple follow-up, whereas the latter necessitates further investigations, appropriate treatment and often prolonged absence from sports for the injured athlete. To our knowledge, no publication to date has reported isolated damage of the teres major muscle in Ice Hockey players. Seven cases were reported amongst baseball pitchers. Two cases presented after a waterskiing traction accident and a further case has been described in a tennis player. In the present study, we report two cases of isolated teres major tear in ice hockey players. These two athletes were both professional players competing at the highest level in the Swiss Ice Hockey League.

"Biological failure" of the anterior cruciate ligament graft.

Anterior cruciate ligament (ACL) reconstruction has the best chance for success when the graft undergoes extensive biologic remodeling and incorporation after implantation. There are many factors that can lead to graft failure and possible revision surgery. These include patient selection; surgical technique such as graft placement and tensioning; the use of allograft versus autograft; mechanical factors such as secondary restraint laxity; lack of a correct, carefully controlled post-operative rehabilitation program; and biological factors. When a patient presents with knee instability following ligament reconstruction and there is no history of a new trauma or identifiable technical error, biological failure should be considered. However, the biologic response of the grafted tissue is closely linked to the mechanical and biochemical environment into which the graft is placed. Thus, the "biological failure" of the ACL graft is a complex pathological entity whose cause is not fully understood. Failure may be initiated by early extensive graft necrosis, disturbances in revascularization, problems in cell repopulation and proliferation, and as well difficulties in the ligamentization process. However, further study of the biological characterization of a failed graft placed in a correct mechanical environment is warranted.

[The effect of the posterolateral bundle in the anterior cruciate ligament reconstruction]. / Le comportement du faisceau postérolatéral dans les reconstructions anatomiques du ligament croisé antérieur.

The use of new technology in 3D laxity analysis in torn anterior cruciate ligament (ACL) knee has recently improve the ability to assess the effect of reconstruction on laxity control. The aim of this study was to compare, in anatomic ACL reconstruction, the effect of each bundle, posterolateral (PL) and anteromedial (AM) on the residual laxity intraoperatively. We used an optoelectronic navigation system to measure the translation and the rotation during anterior drawer test, Lachman test and pivot shift test. Twenty-two patients were assessed with two protocols, group I with PL bundle reconstruction following the AM bundle reconstruction and group II with a reverse program. Addition of PL bundle has significantly improved the translation and rotation laxity control during the Lachman and pivot shift test, when the AM bundle was more important in the translation control during the anterior drawer test. Anatomic double bundle reconstruction improves the control of laxity intraoperatively.

[Autologous chondrocyte implantation for focal cartilage lesions: state of the art in 2007]. / Implantation de chondrocytes autologues pour les lésions cartilagineuses focales: le point en 2007.

Autologous chondrocyte implantation (ACI) is a frequently used procedure for full-thickness cartilage lesions in the knee joint. However, to date, there are just a few prospective, randomized clinical studies and most publications are case series on small and heterogenic cohorts with short-term follow-up. To date, ACI is a surgical treatment option for single traumatic lesions on the distal femur in young active subjects with a recent lesion. Lesion size should be between 3 and 8 cm2, < 6 mm in depth, tidemark preserved without penetration of the subchondral bone. Absolute contraindications for ACI include osteoarthrosis, kissing lesions, lesions size greater than 10 cm2 or deeper than 8 mm, ligament instability, partial or total meniscectomy, axis malalignment > 5. Further studies are mandatory to determine the precise indications to the technique and to show its superiority on the established treatment of chondral lesions.

[Plasticity of striated skeletal muscle: training effect and perspectives]. / Plasticité du muscle strié squelettique: effet de l'entraînement et perspectives.

The muscle's wide array of functional characteristics is mediated by the existence of fiber types, differing one from the other in terms of contractile and metabolic protein isoforms content. Numerous classification systems have evolved, describing the muscle's physical, architectural and metabolic characteristics. Nevertheless, it appears that those characteristics assemble in more or less independent modules, excluding the development of a generalized classification of muscle fiber types. The discovery of several mechanisms allowing for the muscle to adapt to training or other changes opens new interventional perspectives regarding sport performances, as well as the maintenance of an adequate musculature in patients.

Anatomy of the anterior cruciate ligament.

The anterior cruciate ligament (ACL) is a band of dense connective tissue which courses from the femur to the tibia. The ACL is a key structure in the knee joint, as it resists anterior tibial translation and rotational loads. When the knee is extended, the ACL has a mean length of 32 mm and a width of 7-12 mm. There are two components of the ACL, the anteromedial bundle (AMB) and the posterolateral bundle (PLB). They are not isometric with the main change being lengthening of the AMB and shortening of the PLB during flexion. The ACL has a microstructure of collagen bundles of multiple types (mostly type I) and a matrix made of a network of proteins, glycoproteins, elastic systems, and glycosaminoglycans with multiple functional interactions. The complex ultrastructural organization and abundant elastic system of the ACL allow it to withstand multiaxial stresses and varying tensile strains. The ACL is innervated by posterior articular branches of the tibial nerve and is vascularized by branches of the middle genicular artery.

[Patella dislocation]. / La luxation de la rotute.

Patella dislocation is a classical injury affecting teenagers. In 2/3 of cases, it occurs in sports activities. It is often a benign trauma which happens in a patello-femoral dysplasia context, leading to dislocation and reccurence if nothing is done to correct the defaults. Radiographic and scanner examinations allow to measure the dysplasia parameters and think about its correction. With MRI documentation, capsulo-ligamentous and cartilaginous lesions can be identified and their surgical repair can be discussed. When the dislocation occurs in a normal anatomical context, conservative therapy is still indicated.

[Possibilities of computer-assisted navitation in knee para-articular osteotomies]. / Möglichkeiten der computergestützten Navigation bei kniegelenknahen Osteotomien.

Osteotomies in the knee region for incipient osteoarthritis in active patients have become increasingly popular in recent years. A computer-guided navigation system should help increase the surgeon's accuracy and lower the risk of intraoperative complications for this technically demanding type of surgery. Furthermore, computer navigation might be a powerful research and educational tool. The technical principles and the clinical implications of this system for knee osteotomies are described in the following article.

Medial meniscectomy in patients over the age of fifty: a six year follow-up study.

PURPOSE: Meniscectomy in the older patient remains a controversial topic. The aim of our study is to assess the mid-term outcome of arthroscopic partial medial meniscectomy in patients over fifty years of age and attempt to retrospectively identify symptoms and/or findings on examination which can differentiate between non-degenerative medial meniscal tears versus degenerative meniscal changes. MATERIALS AND METHODS: Thirty-two patients over the age of fifty who had undergone arthroscopic medial partial meniscectomy, were reviewed. The average age was 60 (51-74 yrs) and the average follow-up was six years (3-7 yrs). Based upon the intra-operative findings, patients were divided into two groups: (1) non-degenerative meniscal tears (NDM; n = 12) and (2) degenerative meniscal changes (DM; n = 20). Our outcome measurements were with the HSS knee score, a satisfaction score, and weight-bearing X-rays. RESULTS: In the NDM group, eleven patients were rated excellent or good, and one was rated poor. In the DM group, three patients were rated as excellent or good, eight as fair, and nine as poor. The HSS score was 97 +/- 4.6 for the NDM group and 85 +/- 9.5 for the DM group. The average satisfaction score was 9.2 +/- 0.7 (very satisfied) for the NDM group and 5.8 +/- 2.6 (fairly satisfied) for the DM group. There was no significant difference between the NDM and the DM groups with regards to pre-operative symptoms and signs, except for the McMurray sign, which was found to be positive in 83% of NDM cases versus 25% of DM cases (sensitivity = 83%). Using only these data, the McMurray sign was 67% specific for NDM. CONCLUSIONS: Arthroscopic medial meniscectomy in older patients provides 90% good results six years after a non-degenerative meniscal tear, but only 20% of good results after a degenerative meniscal tear. However, based on this study, neither symptoms nor physical examination are able to differentiate between traumatic meniscal tears and degenerative meniscal changes in older patients. A positive McMurray's sign favors the diagnosis of a traumatic tear. However, a specificity of this test of only 67% as shown in our data questions its utility in clinical decision-making.

The structural GDP/GTP cycle of human Arf6.

The small GTP-binding protein Arf6 coordinates membrane traffic at the plasma membrane with aspects of cytoskeleton organization. This function does not overlap with that of other members of the ADP-ribosylation factor (Arf) family, although their switch regions, which are their major sites of interaction with regulators and effectors, have virtually identical sequences. Here we report the crystal structure of full-length, non-myristoylated human Arf6 bound to GTPgammaS. Unlike their GDP-bound forms, the active forms of Arf6 and Arf1 are very similar. Thus, the switch regions are discriminatory elements between Arf isoforms in their inactive but not in their active forms, a property that may generalize to other families of small G proteins. This suggests that GTP-bound Arfs may establish specific interactions outside the switch regions and/or be recognized in their cellular context rather than as isolated proteins. The structure also allows further insight into the lack of spontaneous GTPase activity of Arf proteins.