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  • 1
    Knee Meniscal Longitudinal Vertical Bucket Handle Tear 02:01

    Knee Meniscal Longitudinal Vertical Bucket Handle Tear

    by Medilaw.TV (12/27/11) 112 views

    KNEE MENISCAL LONGITUDINAL VERTICAL BUCKET HANDLE TEARS Knee Meniscal Longitudinal Vertical Bucket Handle Tear The two menisci are crucial to the stability of the knee during movement, and to the durability of the knee over time. Tears in a meniscus will decrease the knee’s stability and increase the wear of the articular cartilage. Tears can occur because of degenerative stiffening with aging, or through abnormal isolated or repetitive movements such as due to an acute or chronic ligament tear. Meniscal tears can also occur due to an abnormally shaped or attached meniscus that doesn’t move or distribute forces effectively. Knee Meniscal Tears. Meniscal tears can be partially or completely through the meniscus, they can be single or in multiple locations, and they can have complex shapes. Longitudinal or vertical tears occur in the periphery or substance of the meniscus. They can allow the medial flap of the meniscus to slide into the joint or they can extend and allow the flap to flip into the central part of the knee joint. This is known as a bucket handle tear. Knee Meniscal Tears informed consent graphics. A flap or oblique tear has a loose medial flap, and can occur as an acute tear, or as a progression of a longitudinal tear. They can also flip into the knee joint. Vertical tears can also be radial or transverse, or have loose tags. Horizontal or cleavage tears usually occur in the degenerate stiff meniscus. Tears may be asymptomatic, or they may cause locking, catching, giving way, pain or swelling. The outer third of the meniscus has a blood supply, so tears in this region may heal. Tears in the inner two thirds of the meniscus don’t heal, and are likely to become longer and cause worse symptoms. Knee Meniscal Tears. Over time, meniscal tears can lead to indentation of the articular surface, with fissures and erosions of the articular cartilage. This can lead to accelerated cartilage degeneration and osteo-arthritis, especially if there are also abnormal movements due to loose or torn ligaments. Knee Meniscal Tears . During movements of the knee, the menisci can be injured if they fail to follow the movements of the femoral condyles on the tibial condyles. They are 'caught unawares' in an abnormal position and are squashed. This can happen during violent extension of the knee, such as when kicking a ball. If one of the menisci fails to move forwards, it can be caught between the femoral and tibial condyles as the tibia is forcefully applied to the femur. This mechanism leads to transverse tears or detachment of the anterior horn which then becomes folded on itself. The other mechanism producing lesions of the menisci involves a twisting movement of the knee joint, which combines with lateral displacement and lateral rotation. The medial meniscus is then pulled towards the centre of the joint under the convexity of the medial femoral condyle. When the joint is extended, the meniscus can be crushed between the two condyles, leading to longitudinal splitting of the meniscus, a complete detachment of the meniscus from the capsule, or a complex tear of the meniscus. In all these longitudinal lesions, the central part of the meniscus can rear itself up into the intercondylar notch so that the meniscus assumes the shape of a bucket-handle. This type of lesion is very common among footballers (ie during falls on a flexed leg) and among miners who have to work crouched in narrow seams of coal. As soon as a meniscus is torn, the injured part fails to follow the normal movements and becomes wedged between the femoral and tibial condyles. The knee as a result 'locks' in a position of flexion, which is more marked the more posterior the rupture. Full extension is then impossible. It is unusual to see a true, fresh, isolated avulsion of a meniscus caused by a single traumatic episode. Usually this type of injury is associated with acute ligamentous disruption. Moreover, these traumatic disruptions occur at the periphery, often in the deep capsular fibers rather than in the substance of the cartilage. They a...

  • 2
    Knee Meniscus Meniscal Anatomy 01:56

    Knee Meniscus Meniscal Anatomy

    by Medilaw.TV (12/27/11) 135 views

    KNEE MENISCUS ANATOMY Knee Meniscus Meniscal Anatomy The menisci are two crescent shaped wedges in the knee joint. The menisci cover two thirds of the plateau at the top of the tibia. Each meniscus is cartilaginous and tough centrally where it is compressed between the tibia and femur. The meniscus is ligamentous and pliable at its thick peripheral attachments to the joint capsule. The meniscus' anterior and posterior tips or horns are connected to the underlying tibia. Knee Meniscal Anatomy. The outer third of each meniscus has a good blood supply from the joint capsule and synovium, allowing the possibility of healing of tears in this region. The outer quarter of each meniscus has a nerve supply that may contribute to the awareness of joint position. The menisci move and change shape as the larger rounded femoral condyles glide and roll over the smaller, flatter tibial plateau. The menisci assist joint stability via their wedge shape and mechanical spacer effect. They increase the contact surface area between the tibia and femur by one third, and have a slight meniscal shock-absorbing effect, leading to less force per unit area of the bone’s articular cartilage. The menisci also promote synovial fluid distribution within the knee joint, assisting lubrication and nutrition of the bone’s cartilage surface. Knee Meniscal Anatomy. The horns of the medial meniscus are attached further apart, it sits in a slight hollow on the tibial surface and its middle section is firmly attached to the medial collateral ligament. This makes the medial meniscus less mobile, and more susceptible to tearing during violent knee twisting. Knee Meniscal Anatomy. The blood supply of the menisci is dervied from the terminal branches of the superior and inferior medial and lateral geniculate arteries. These vessels supply the connective tissue adjacent to the periphery of the meniscus. The collateral branches perforate the outer 20 to 30% of the meniscus. This leaves an inner 70 to 80% which is the avascular segment. The central meniscus is more vascular than the superior or inferior surfaces. The anterior and posterior horns are enveloped by synovial tissue, and are therefore more highly vascularized than the middle segment. The meniscus is composed of cells which are surrounded by an extracellular matrix. The basic cell of the meniscus is the fibrochondrocyte. Two distinct types of chondrocytes have been observed, and are identified by their round or oval shape. The meniscal surface chondrocytes are usually oval, while those of the deeper layers tend to be more rounded. Both contain few mitochondria, suggesting that anerobic glycolysis is their main respiratory pathway. The extracellular matrix is composed of collagen, proteoglycans, matrix gycoproteins and elastin. The matrix is composed mainly of circumferentially arranged collagen fibres. These provide tensile strength and, to a lesser extent, radially arranged cross-links which provide shear strength. The radially-orientated fibres are more densely packed in the meniscal surface layer, which is 30 to 120 mm thick. Collagen makes up about 60 to 70% of the dry weight of the meniscus. The collagen fibres are arranged in bundles which are 50 to 150 mcm in diameter. Proteoglycans are hydrophilic negatively charged micromolecules held together by collagen fibrils. They provide the meniscus with a high capacity to resist large compressive loads. However, they do not contribute significantly to its tensile strength. The lack of congruence of the articular surfaces of the tibio-femoral joint is corrected by the interposition of the menisci or semi-lunar cartilages. The menisci are triangular in cross-section. The superior surface which is in contact with the femoral condyles, is concave. The peripheral surface which is adherent to the deep surface of the joint capsule, is cylindrical. The inferior surface, which rests on the edges of the medial and lateral tibial condyles, is almost plane. The meniscal rings are incomplete in the regions of the intercondylar tubercles of the tibia so ....

  • 3
    Knee Joint Anatomy Medical 01:50

    Knee Joint Anatomy Medical

    by Medilaw.TV (12/27/11) 225 views

    KNEE JOINT ANATOMY Knee Joint Anatomy medical legal images The knee contains two joints, the tibio-femoral joint and the patello-femoral joint. The tibio-femoral joint, is between the tibia or shin bone, and the femur or thigh bone. It is stabilized by the two collateral ligaments, the two cruciate ligaments, the two menisci and the muscles around the knee. Knee Joint Anatomy medical legal images. The patello-femoral joint is between the patellar or knee cap, and the femur. It is stabilized by the medial retinaculum, the vastus medialis oblique muscle, the patella tendon and the quadriceps tendon. The joint capsule surrounds the knee joints, keeping the synovial fluid in, and blood and adjacent tissues out. Knee Joint Anatomy medical legal images. The articulating surfaces at the ends of the tibia and the femur, and the inner surface of the patella, are covered by a smooth articular cartilage. The inner layer of the joint capsule has a thin synovial membrane that secretes synovial fluid into the knee joints to provide lubrication and nutrition. The smooth articular cartilage and the oily synovial fluid produces a durable, low friction surface that helps to distrIbute forces when the bones move against each other during knee flexion, extension and rotation. Knee Joint Anatomy medical legal images. The knee is the intermediate joint of the lower limb. It is mainly a joint with one degree of freedom which allows the end of the limb to be moved towards or away from its root or, in other words, allows the distance between the trunk and the ground to be varied. The knee has an accessory or second degree of freedom, rotation of the long axis of the leg, which only occurs when the knee is flexed. From the mechanical point of view, the knee is a compromise which sets to reconcile two mutually exclusive requirements: to have great stability in complete extension, when the knee is subjected to severe stresses resulting from the body weight and the length of the lever arms involved: to have great mobility after a certain measure of flexion has been achieved. This mobility is essential for running and the optimal orientation of the foot relative to the irregularities of the ground. The knee resolves this problem by highly ingenious mechanical devices but the poor degree of interlocking of the surfaces, essential for great mobility, renders it liable to sprains and dislocations. The first degree of freedom is related to the transverse axis, around which occur movements of flexion and extension in a sagittal plane. This axis, lying in the frontal plane, runs through the femoral condyles horizontally. Because the femoral neck overhangs the femoral shaft, the axis of the femoral shaft does not coincide with that of the leg but forms with the later an obtuse angle of 170 to 175 degrees opening outwards. This is the physiological valgus of the knee. On the other hand, the centres of the three lower limb joints, the hip, knee and ankle, lie on a straight line which is the mechanical axis of the lower limb. In the leg it coincides with that of the leg itself but in the thigh it forms an acute angle of 6 degrees with the axis of the femur. Bacause the hips are wider apart than the ankles, the mechanical axis of the lower limb runs obliquely inferiorly and medially and forms an angle of three degrees with the vertical. This angle is greater the wider the pelvis, as in the case of women. This also explains why the physiological valgus of the knee is more marked in women than in men. The axis of flexion and extension is horizontal and the angle between it and the femoral axis is 81 degrees, and the angle between it and the leg is 93 degrees. Therefore during full flexion the axis of the leg does not come to rest immediately posterior to that of the femur, but posterior and slightly medial to it so that the heel moves medially towards the plane of symmetry of the body. Full flexion brings the heel into contact with the buttock at the level of the ischial tuberosity. In addition to these sex-linked physiological variations, ...

  • 4
    Knee Meniscus Meniscal Vertical Longitudinal Tear 01:50

    Knee Meniscus Meniscal Vertical Longitudinal Tear

    by Medilaw.TV (12/27/11) 42 views

    KNEE MENISCAL VERTICAL LONGITUDINAL TEAR Knee Meniscal Vertical Longitudinal Tear The two menisci are crucial to the stability of the knee during movement, and to the durability of the knee over time. Tears in a meniscus will decrease the knee’s stability and increase the wear of the articular cartilage. Tears can occur because of degenerative stiffening with aging, or through abnormal isolated or repetitive movements such as due to an acute or chronic ligament tear. Meniscal tears can also occur due to an abnormally shaped or attached meniscus that doesn’t move or distribute forces effectively. Knee Meniscal Tears. Meniscal tears can be partially or completely through the meniscus, they can be single or in multiple locations, and they can have complex shapes. Longitudinal or vertical tears occur in the periphery or substance of the meniscus. They can allow the medial flap of the meniscus to slide into the joint or they can extend and allow the flap to flip into the central part of the knee joint. This is known as a bucket handle tear. Knee Meniscal Tears. A flap or oblique tear has a loose medial flap, and can occur as an acute tear, or as a progression of a longitudinal tear. They can also flip into the knee joint. Vertical tears can also be radial or transverse, or have loose tags. Horizontal or cleavage tears usually occur in the degenerate stiff meniscus. Tears may be asymptomatic, or they may cause locking, catching, giving way, pain or swelling. The outer third of the meniscus has a blood supply, so tears in this region may heal. Tears in the inner two thirds of the meniscus don’t heal, and are likely to become longer and cause worse symptoms. Knee Meniscal Tears. Over time, meniscal tears can lead to indentation of the articular surface, with fissures and erosions of the articular cartilage. This can lead to accelerated cartilage degeneration and osteo-arthritis, especially if there are also abnormal movements due to loose or torn ligaments. Knee Meniscal Tears informed consent graphics. During movements of the knee, the menisci can be injured if they fail to follow the movements of the femoral condyles on the tibial condyles. They are 'caught unawares' in an abnormal position and are squashed. This can happen during violent extension of the knee, such as when kicking a ball. If one of the menisci fails to move forwards, it can be caught between the femoral and tibial condyles as the tibia is forcefully applied to the femur. This mechanism leads to transverse tears or detachment of the anterior horn which then becomes folded on itself. The other mechanism producing lesions of the menisci involves a twisting movement of the knee joint, which combines with lateral displacement and lateral rotation. The medial meniscus is then pulled towards the centre of the joint under the convexity of the medial femoral condyle. When the joint is extended, the meniscus can be crushed between the two condyles, leading to longitudinal splitting of the meniscus, a complete detachment of the meniscus from the capsule, or a complex tear of the meniscus. In all these longitudinal lesions, the central part of the meniscus can rear itself up into the intercondylar notch so that the meniscus assumes the shape of a bucket-handle. This type of lesion is very common among footballers (ie during falls on a flexed leg) and among miners who have to work crouched in narrow seams of coal. As soon as a meniscus is torn, the injured part fails to follow the normal movements and becomes wedged between the femoral and tibial condyles. The knee as a result 'locks' in a position of flexion, which is more marked the more posterior the rupture. Full extension is then impossible. It is unusual to see a true, fresh, isolated avulsion of a meniscus caused by a single traumatic episode. Usually this type of injury is associated with acute ligamentous disruption. Moreover, these traumatic disruptions occur at the periphery, often in the deep capsular fibers rather than in the substance of the cartilage. They are highly vascular and suitable...

  • 5
    Knee Meniscal Meniscus Vertical Radial, Transverse, Tag Tear 01:47

    Knee Meniscal Meniscus Vertical Radial, Transverse, Tag Tear

    by Medilaw.TV (12/27/11) 57 views

    KNEE MENISCAL VERTICAL RADIAL, TRANSVERSE, TAG TEAR Knee Meniscal Meniscus Vertical Radial, Transverse, Tag Tear The two menisci are crucial to the stability of the knee during movement, and to the durability of the knee over time. Tears in a meniscus will decrease the knee’s stability and increase the wear of the articular cartilage. Tears can occur because of degenerative stiffening with aging, or through abnormal isolated or repetitive movements such as due to an acute or chronic ligament tear. Meniscal tears can also occur due to an abnormally shaped or attached meniscus that doesn’t move or distribute forces effectively. Knee Meniscal Tears. Meniscal tears can be partially or completely through the meniscus, they can be single or in multiple locations, and they can have complex shapes. Longitudinal or vertical tears occur in the periphery or substance of the meniscus. They can allow the medial flap of the meniscus to slide into the joint or they can extend and allow the flap to flip into the central part of the knee joint. This is known as a bucket handle tear. Knee Meniscal Tears. A flap or oblique tear has a loose medial flap, and can occur as an acute tear, or as a progression of a longitudinal tear. They can also flip into the knee joint. Vertical tears can also be radial or transverse, or have loose tags. Horizontal or cleavage tears usually occur in the degenerate stiff meniscus. Tears may be asymptomatic, or they may cause locking, catching, giving way, pain or swelling. The outer third of the meniscus has a blood supply, so tears in this region may heal. Tears in the inner two thirds of the meniscus don’t heal, and are likely to become longer and cause worse symptoms. Knee Meniscal Tears. Over time, meniscal tears can lead to indentation of the articular surface, with fissures and erosions of the articular cartilage. This can lead to accelerated cartilage degeneration and osteo-arthritis, especially if there are also abnormal movements due to loose or torn ligaments. Knee Meniscal Tears informed consent graphics. During movements of the knee, the menisci can be injured if they fail to follow the movements of the femoral condyles on the tibial condyles. They are 'caught unawares' in an abnormal position and are squashed. This can happen during violent extension of the knee, such as when kicking a ball. If one of the menisci fails to move forwards, it can be caught between the femoral and tibial condyles as the tibia is forcefully applied to the femur. This mechanism leads to transverse tears or detachment of the anterior horn which then becomes folded on itself. The other mechanism producing lesions of the menisci involves a twisting movement of the knee joint, which combines with lateral displacement and lateral rotation. The medial meniscus is then pulled towards the centre of the joint under the convexity of the medial femoral condyle. When the joint is extended, the meniscus can be crushed between the two condyles, leading to longitudinal splitting of the meniscus, a complete detachment of the meniscus from the capsule, or a complex tear of the meniscus. In all these longitudinal lesions, the central part of the meniscus can rear itself up into the intercondylar notch so that the meniscus assumes the shape of a bucket-handle. This type of lesion is very common among footballers (ie during falls on a flexed leg) and among miners who have to work crouched in narrow seams of coal. As soon as a meniscus is torn, the injured part fails to follow the normal movements and becomes wedged between the femoral and tibial condyles. The knee as a result 'locks' in a position of flexion, which is more marked the more posterior the rupture. Full extension is then impossible. It is unusual to see a true, fresh, isolated avulsion of a meniscus caused by a single traumatic episode. Usually this type of injury is associated with acute ligamentous disruption. Moreover, these traumatic disruptions occur at the periphery, often in the deep capsular fibers rather than in the substance of the cartilage. They a...

  • 6
    Knee Anterior Cruciate Ligament Tear Rupture Femoral Internal... 01:09

    Knee Anterior Cruciate Ligament Tear Rupture Femoral Internal...

    by Medilaw.TV (12/27/11) 77 views

    KNEE ANTERIOR CRUCIATE LIGAMENT RUPTURE INTERNAL FEMORAL ROTATION Knee Anterior Cruciate Ligament Rupture Internal Femoral Rotation demonstrative evidence graphics An intact anterior cruciate ligament is vital for knee stability and durability over time. Excess stretching forces applied to the anterior cruciate ligament can cause a partial tear or complete rupture of this ligament. A common mechanism of anterior cruciate ligament tearing is excessive internal femoral rotation, which can tear the medial collateral ligament and then the anterior cruciate ligament and the medial meniscus, such as during a side-step with the foot planted on the ground. Knee Anterior Cruciate Ligament Rupture Internal Femoral Rotation demonstrative evidence graphics. A stretched or ruptured anterior cruciate ligament results in an unstable knee that leads to increased stresses on the other supporting structures in the knee and their accelerated wear and tear. This can cause articular cartilage fissuring, erosions and osteo-arthritis, and menisci degeneration, stiffening and tears. Knee Anterior Cruciate Ligament Rupture Internal Femoral Rotation demonstrative evidence graphics. The fibres of the cruciates have different lengths and direction, so that during knee movements, they are not all stretched at the same time. The anterior cruciate ligament posses very little inherent elasticity. Application of a force straining it by more than 5% of its resting length will result in rupture. This rupture may be complete and obvious on gross inspection, or it may be partial, demonstrating failure in continuities. The anterior cruciate ligament is able to resist force of 1700N before failure. Functional instability is usually the result of acute ligament disruption or chronic attenuation superimposed on an acute injury. Nevertheless, the patient assessment must rule out the other causes that either contribute to the athlete's problem or may be the sole causes. They include meniscal lesions, chondral damage, osteo-chondral fragments, loose bodies, and patellar subluxation and dislocation. Acute and chronic injuries are discussed, but it must be realized that the acute injury is complicated by pain, and the chronic injury by internal derangement and attenuation of multiple secondary restraints. A history of pain is not always a good guide to these injuries. Some of the serious injuries may be no more painful than some of the minor injuries. Indeed, there are circumstances where partial ligament tears may produce more pain than complete third degree tears. With acute injuries, the key points are the feeling or hearing of something 'pop' or rip, the sensation of the knee going out of joint and the subsequent inability to weight bear. The report that the knee felt wobbly when attempting to walk or run is also ominous. Eight percent of individuals experiencing a painful significant pop as their knee gives way have an anterior or posterior cruciate injury or a meniscal lesion. In the presence of trauma, the main thrust of the history should be establishing whether the person complains of an effusion or hemarthrosis. An effusion is the method by which the knee joint reacts to all stress and usually takes several hours to accumulate. By contrast, an acute hemarthrosis is usually well formed after 1 to 2 hours, leaving a tense, inflamed knee. It has been shown that more than 8 percent of individuals presenting with an acute hemarthrosis have a surgically treatable lesion, the most common of which is a partial or complete tear of the Anterior Cruciate Ligament (ACL). Two thirds of these ligamentous lesions are associated with meniscal damage. The other diagnoses compatible with acute hemarthrosis are peripheral meniscal tears, osteochondral fracture or posterior cruciate injuries. It is important to stress that, whereas a hemarthrosis usually accumulates rapidly, the absence of tense swelling after the first few hours does not rule out significant injury. Occasionally the hemorrhage is contained within the synovial sheath surrounding the cruciate ...

  • 7
    Knee Meniscal Meniscus Degenerate Horizontal Cleavage Tear 01:48

    Knee Meniscal Meniscus Degenerate Horizontal Cleavage Tear

    by Medilaw.TV (12/27/11) 163 views

    KNEE MENISCAL HORIZONTAL CLEAVAGE TEAR Knee Meniscal Meniscus Degenerate Horizontal Cleavage Tear The two menisci are crucial to the stability of the knee during movement, and to the durability of the knee over time. Tears in a meniscus will decrease the knee’s stability and increase the wear of the articular cartilage. Tears can occur because of degenerative stiffening with aging, or through abnormal isolated or repetitive movements such as due to an acute or chronic ligament tear. Meniscal tears can also occur due to an abnormally shaped or attached meniscus that doesn’t move or distribute forces effectively. Knee Meniscal Tears. Meniscal tears can be partially or completely through the meniscus, they can be single or in multiple locations, and they can have complex shapes. Longitudinal or vertical tears occur in the periphery or substance of the meniscus. They can allow the medial flap of the meniscus to slide into the joint or they can extend and allow the flap to flip into the central part of the knee joint. This is known as a bucket handle tear. Knee Meniscal Tears. A flap or oblique tear has a loose medial flap, and can occur as an acute tear, or as a progression of a longitudinal tear. They can also flip into the knee joint. Vertical tears can also be radial or transverse, or have loose tags. Horizontal or cleavage tears usually occur in the degenerate stiff meniscus. Tears may be asymptomatic, or they may cause locking, catching, giving way, pain or swelling. The outer third of the meniscus has a blood supply, so tears in this region may heal. Tears in the inner two thirds of the meniscus don’t heal, and are likely to become longer and cause worse symptoms. Knee Meniscal Tears. Over time, meniscal tears can lead to indentation of the articular surface, with fissures and erosions of the articular cartilage. This can lead to accelerated cartilage degeneration and osteo-arthritis, especially if there are also abnormal movements due to loose or torn ligaments. Knee Meniscal Tears informed consent graphics. During movements of the knee, the menisci can be injured if they fail to follow the movements of the femoral condyles on the tibial condyles. They are 'caught unawares' in an abnormal position and are squashed. This can happen during violent extension of the knee, such as when kicking a ball. If one of the menisci fails to move forwards, it can be caught between the femoral and tibial condyles as the tibia is forcefully applied to the femur. This mechanism leads to transverse tears or detachment of the anterior horn which then becomes folded on itself. The other mechanism producing lesions of the menisci involves a twisting movement of the knee joint, which combines with lateral displacement and lateral rotation. The medial meniscus is then pulled towards the centre of the joint under the convexity of the medial femoral condyle. When the joint is extended, the meniscus can be crushed between the two condyles, leading to longitudinal splitting of the meniscus, a complete detachment of the meniscus from the capsule, or a complex tear of the meniscus. In all these longitudinal lesions, the central part of the meniscus can rear itself up into the intercondylar notch so that the meniscus assumes the shape of a bucket-handle. This type of lesion is very common among footballers (ie during falls on a flexed leg) and among miners who have to work crouched in narrow seams of coal. As soon as a meniscus is torn, the injured part fails to follow the normal movements and becomes wedged between the femoral and tibial condyles. The knee as a result 'locks' in a position of flexion, which is more marked the more posterior the rupture. Full extension is then impossible. It is unusual to see a true, fresh, isolated avulsion of a meniscus caused by a single traumatic episode. Usually this type of injury is associated with acute ligamentous disruption. Moreover, these traumatic disruptions occur at the periphery, often in the deep capsular fibers rather than in the substance of the cartilage. They are highly vascu...

  • 8
    Knee Meniscal Meniscus Flap, Oblique, Parrot Beak Tear 01:54

    Knee Meniscal Meniscus Flap, Oblique, Parrot Beak Tear

    by Medilaw.TV (12/27/11) 127 views

    KNEE MENISCAL FLAP, OBLIQUE, PARROT BEAK TEAR Knee Meniscal Meniscus Flap, Oblique, Parrot Beak Tear The two menisci are crucial to the stability of the knee during movement, and to the durability of the knee over time. Tears in a meniscus will decrease the knee’s stability and increase the wear of the articular cartilage. Tears can occur because of degenerative stiffening with aging, or through abnormal isolated or repetitive movements such as due to an acute or chronic ligament tear. Meniscal tears can also occur due to an abnormally shaped or attached meniscus that doesn’t move or distribute forces effectively. Knee Meniscal Tears. Meniscal tears can be partially or completely through the meniscus, they can be single or in multiple locations, and they can have complex shapes. Longitudinal or vertical tears occur in the periphery or substance of the meniscus. They can allow the medial flap of the meniscus to slide into the joint or they can extend and allow the flap to flip into the central part of the knee joint. This is known as a bucket handle tear. Knee Meniscal Tears. A flap or oblique tear has a loose medial flap, and can occur as an acute tear, or as a progression of a longitudinal tear. They can also flip into the knee joint. Vertical tears can also be radial or transverse, or have loose tags. Horizontal or cleavage tears usually occur in the degenerate stiff meniscus. Tears may be asymptomatic, or they may cause locking, catching, giving way, pain or swelling. The outer third of the meniscus has a blood supply, so tears in this region may heal. Tears in the inner two thirds of the meniscus don’t heal, and are likely to become longer and cause worse symptoms. Knee Meniscal Tears. Over time, meniscal tears can lead to indentation of the articular surface, with fissures and erosions of the articular cartilage. This can lead to accelerated cartilage degeneration and osteo-arthritis, especially if there are also abnormal movements due to loose or torn ligaments. Knee Meniscal Tears informed consent graphics. During movements of the knee, the menisci can be injured if they fail to follow the movements of the femoral condyles on the tibial condyles. They are 'caught unawares' in an abnormal position and are squashed. This can happen during violent extension of the knee, such as when kicking a ball. If one of the menisci fails to move forwards, it can be caught between the femoral and tibial condyles as the tibia is forcefully applied to the femur. This mechanism leads to transverse tears or detachment of the anterior horn which then becomes folded on itself. The other mechanism producing lesions of the menisci involves a twisting movement of the knee joint, which combines with lateral displacement and lateral rotation. The medial meniscus is then pulled towards the centre of the joint under the convexity of the medial femoral condyle. When the joint is extended, the meniscus can be crushed between the two condyles, leading to longitudinal splitting of the meniscus, a complete detachment of the meniscus from the capsule, or a complex tear of the meniscus. In all these longitudinal lesions, the central part of the meniscus can rear itself up into the intercondylar notch so that the meniscus assumes the shape of a bucket-handle. This type of lesion is very common among footballers (ie during falls on a flexed leg) and among miners who have to work crouched in narrow seams of coal. As soon as a meniscus is torn, the injured part fails to follow the normal movements and becomes wedged between the femoral and tibial condyles. The knee as a result 'locks' in a position of flexion, which is more marked the more posterior the rupture. Full extension is then impossible. It is unusual to see a true, fresh, isolated avulsion of a meniscus caused by a single traumatic episode. Usually this type of injury is associated with acute ligamentous disruption. Moreover, these traumatic disruptions occur at the periphery, often in the deep capsular fibers rather than in the substance of the cartilage. They are highly .....

  • 9
    Knee Anterior Cruciate Ligament Anatomy 01:11

    Knee Anterior Cruciate Ligament Anatomy

    by Medilaw.TV (12/27/11) 83 views

    KNEE ANTERIOR CRUCIATE LIGAMENT ANATOMY Knee Anterior Cruciate Ligament Anatomy legal movies The anterior cruciate ligament runs upwards and backwards from its tibial origin near the front of the tibial plateau, to its attachment at the posterolateral part of the intercondylar notch of the femur. The anterior cruciate ligament prevents forward movement of the tibia in relation to the femur, and with the posterior cruciate ligament, stabilizes the knee in the anteroposterior direction and allows the joint to work as a hinge while keeping the articular surfaces in contact. Knee Anterior Cruciate Ligament Anatomy legal movies. The two cruciate ligaments, along with other ligaments and muscles, cause the rolling – sliding movements of knee flexion and extension. The anterior cruciate ligament consists of closely attached ligament bundles, which spiral around each other ninety degrees. They are each taut and supportive during different knee positions. Knee Anterior Cruciate Ligament Anatomy legal movies. The cruciate ligaments lie in the centre of the joint, largely within the intercondylar notch. The anterior cruciate ligament is attached to the anterior intercondylar fossa of the tibia, along the edge of the medial condyle and between the insertion of the anterior horn of the medial meniscus anteriorly and that of the lateral meniscus posteriorly. It runs obliquely superiorly and laterally and is attached above to a narrow patch on the internal aspect of the lateral condyle of the femur which extends vertically above and along the edge of the articular cartilage. The ligament has a more anterior attachment to the tibia and a more lateral attachment to the femur than its fellow. Behind the anterior cruciate ligament is the posterior cruciate ligament. It is attached to the posterior part of the posterior intercondylar fossa of the tibia, overlapping the posterior rim of the upper surface of the tibia. Its tibial insertionis placed well posterior to the insertion of the posterior horns of the lateral and medial menisci. The ligament runs obliquely medially, anteriorly and superiorly to be inserted into the depths of the intercondylar notch and also to a patch on the edge of the lateral surface of the medial condyle along the line of the articular cartilage. This ligament has a more posterior attachment to the tibia and a more medial attachment to the femur than its fellow. The posterior cruciate ligament is constantly accompanied by the menisco-femoral ligament, which is attached below to the posterior horn of the lateral meniscus. The menisco-femoral ligament clings to the anterior surface of the posterior cruciate ligament and runs with it to a common insertion into the lateral surface of the medial condyle. Occasionally a similar ligament is present in relation to the medial meniscus, where a few fibres of the anterior cruciate ligament are inserted into the anterior horn of the medial meniscus near the insertion of the transverse ligament. The cruciate ligaments touch each other on their axial borders with the anterior running lateral to the posterior ligament.They do not lie free within the knee joint cavity, but are lined by synovium. The cruciates are so intimately related to the capsule that they can be considered as thickenings of the capsule. The joint capsule dips into the intercondylar notch to form a double-layered partition along the axis of the joint. The capsular attachment passes through the attachments of the cruciates and the thickenings of the capsule, formed by the cruciates, stand out on the capsule's external surface. The fibres of the cruciates have different lengths and direction, so that during knee movements, they are not all stretched at the same time. The anterior cruciate ligament posses very little inherent elasticity. Application of a force straining it by more than 5% of its resting length will result in rupture. This rupture may be complete and obvious on gross inspection, or it may be partial, demonstrating failure in continuities. The anterior cruciate ligament is able to ...

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    Cervical Foraminotomy Goals Orthopedic Art

    Cervical Foraminotomy Goals Orthopedic Art

    by Medilaw.TV (11/19/11) 29 views

    https://www.medilaw.tv - Shows the goals of a foraminotomy, which are to remove the tissues pressing on the spinal nerve, while maintaining spinal stability, motion and alignment. This should decrease the pain and weakness in the shoulder and arm. A cervical foraminotomy is used to decompress a spinal nerve as it passes through the intervertebral foramen by removing the medial part of the facet joint that forms the roof of the foramen, the removal of the medial part of the facet joint, the burring of the walls of the foramen and finally wound closure. orthopedic art

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