The Knee Joint 2023 PDF

THEKNEEJOINT  The knee joint is; ** a bicondylar type synovial joint, -bicondylar: if there are two condylies Which mainly allows for; ** flexion and extension -small degree of medial and lateral rotation -exclusion, only happens certain condition so that we can t say the joint is...

THEKNEEJOINT  The knee joint is; ** a bicondylar type synovial joint, -bicondylar: if there are two condylies Which mainly allows for; ** flexion and extension -small degree of medial and lateral rotation -exclusion, only happens certain condition so that we can t say the joint is biaxial. -Certain condition is flexion of hip joint It is formed by articulationsbetween **the patella, **femur **tibia. Fibula is not related with the joint. Articulating Surfaces Tibiofemoral –The medial and lateral condyles of the femur articulating with the tibialcondyles. –The weight- bearing joint of the knee like the hip joint. Patellofemoral –The anterior and distal part of the femur articulating with the patella.  The patellofemoral joint allows; the tendon of the quadriceps femoris to be inserted directly over the knee, increasing the efficiency of the muscle. The tendon of Quadriceps Femoris (the main extensor of the knee) (anterior thigh muscle) (very powerful) Quadriceps tendon muscles turn to tendon while goes down, closed the patella and changes its name as patella tendon and attaches to the tibial tuberocity in the end. Patella actually into the tendon, inside.  As the patella is both formed and resides within the quadriceps femoris tendon, it provides a fulcrum to increase power of the knee extensor, and serves as a structure that reduces frictional forces placed on femoral condyles. Both joint surfaces are lined with hyaline cartilage, and a single joint cavity. Neurovasculature This part of the body is always bending so we need some structure same with Adductor elbow joint here. We got; Canal **several both sided collaterals -Collateral; lateral to the main one The blood supply to the knee joint is through; **the genicular anastomoses They are around the knee, which are supplied by the; **genicular branches of the; -femoral artery -popliteal artery genuin: area of knee The femoral artery passes through below to the inguinal ligament and femoral artery gives the deep branch after some time. How about the surface one? It continues all the way down and gets in to the tunnel which is called ‘’Adductor Tunnel’’. It gives the passage to the femoral artery from anterior to the posterior surface. Actually; Femoral artery -gets into adductor canal -comes out of posteriorly Popliteal artery -Superior, medial, inferior medial and lateral genicular artery branches Tibial artery -out of the popliteal area it becomes POSTERIORLY  Hunter’s Canal Subsartorial Canal The adductor canal serves as a passageway from structures moving between the anterior thigh and posterior leg. It contains the femoral artery, femoral vein, nerve to the vastus medialis and the saphenous nerve (the largest cutaneous branch of the femoral nerve) Innervation The nerve supply, according to femoral nerve Hilton’s law, is by the nerves which supply the muscles which cross the joint. obturator nerve These are the; **femoral nerve, **tibial nerve **common fibular nerve. sciatic nerve Anterior and anteromedial aspects: **(1) Deep branches of the femoral nerve Posterior and inferolateral aspects: **(2) Sciatic nerve Posterior aspect: ** (3)Contribution of articular rami of the deep branch of the obturator nerve  Deep sensation can be; -Stretching -Vibration Collecting from joint. The reason why we can feel the pain at the capsule  Propriyoceptive Sensation; **Relating to stimuli that are produced and perceived within an organism, especially those connected with the position and movement of the body. **It tells our brain where the body parts of us in the spaces. **Can not be stayed alive without propriyoceptive sensation. So it is crucial. **One of the component of the propriyoceptive sensation is; ‘’THE JOINT SENSATION and INNERVATION’’. **It is also conducts different type of pain. Actually this pain is a version of stretch sensation. The initiation of proprioception is the activation of a proprioreceptor in the periphery. The proprioceptive sense is believed to be composed of information from sensory neurons located in the inner ear (motion and orientation) and in the stretch receptors located in the muscles and the joint-supporting ligaments (stance). There are specific nerve receptors for this form of perception termed "proprioreceptors", just as there are specific receptors for pressure, light, temperature, sound, and other sensory experiences. Menisci BIGGER SMALLER The medial and lateral menisci are fibrocartilage structures in the knee that serve two functions: 1-) To deepen the articular surface of the tibia, thus increasing stability of the joint. 2-) To act as shock absorbers by increasing surface area to further distrubute forces. They are C shaped, and attached atboth ends to the intercondylar area of the tibia.  In addition to the intercondylar attachment, the medial meniscus is fixed to the tibial collateral ligament and the joint capsule. Damage to the tibial collateral ligament usually results in; a medial meniscal tear. The lateral meniscus is; **smaller **does not have any extra attachments **rendering it fairly mobile. Medial Bursae A bursa is synovial fluid filled sac, found between moving structures in a joint – with the aim of reducing wear and tear on those structures. There are 4 bursae found in the knee joint. Suprapatella bursa – This is an extension of the synovial cavity of the knee, located between; -the quadriceps femoris -the femur. Prepatella bursa – Found between; -the apex of the patella -the skin.  Infrapatella bursa – Split into deep andsuperficial by ligament. – Attaches to the tibial tuberocity – There is a condition that specifically Bursitis of th – The deep bursa lies between the; - tibia - patella ligament **The superficial lies between the patellaligament and the skin. Semimembranosus bursa – Located posteriorly in the knee joint, between; -the semimembranosus muscle -the medial head ofthe gastrocnemius Ligaments The major ligaments in the knee joint are: Patellar ligament Collateralligaments CruciateLigaments 1-) Patellar ligament – a continuation of the quadriceps femoris tendon distal to the patella. It attaches to the tibial tuberosity.  2-) Collateral Ligaments They act to stabilise thehinge motion of the knee, preventing excessive medial or lateral movement Tibial (medial) Collateral Ligament A wide and flat ligament, found on the medial side of the joint. It attaches: Proximally; **the medial epicondyle of femur, Distally; **the medial condyle of the tibia. Fibular (lateral) Collateral Ligament Thinner and rounder than the tibial collateral ligament. Attaches: Proximally; Lateral epicondyle of femur, Distally; Depression on the lateral surface of the fibular head.  3-) Cruciate Ligaments These two ligaments connect the femur and the tibia. In doing so, they cross each other, hence the term; **‘cruciate’ (Latin for likea cross) Anterior cruciate ligament: ACL –it attaches at: **the anterior intercondylar region of the tibia and blends with the medial meniscus anteriorly **the femur in the intercondylar fossa posteriorly It prevents anterior dislocationof the tibia on to thefemur.  Posterior cruciate ligament: PCL attaches; **posterior intercondylar region of the tibia **anteriorly the anteromedial femoral condyle. It prevents posterior dislocation of the tibia onto thefemur. Movements Extension: Produced by the; quadriceps femoris, -which inserts into the tibial tuberosity -keeps the patella inside Flexion: Produced by the; hamstrings, gracilis, sartorius, popliteus. Lateral rotation: Produced by the; Lateral and medial biceps femoris. rotation can only occur when the knee is flexed Medial rotation: Produced by five muscles; (if the knee is not flexed, semimembranosus, the medial/lateral rotation semitendinosus, gracilis, occurs at the hip joint). sartorius, popliteus. Clinical Relevance: Injury to the KneeJoint Collateral ligaments Injury to thecollateral ligaments is the most common pathology affecting the knee joint. It is caused by a force being applied to the side of the knee when the foot is placed on the ground.  Damage to the collateral ligamentscan be assessed by asking the patient to; **medially rotate **laterally rotate the leg. We have drawer test to understand if there is movement more than what we normally expect Pain on medial rotation indicates damage to the medial ligament, pain on lateral rotation indicates damage to the lateral ligament. If the medial collateral ligament is damaged, it is more than likely that the medial meniscus is torn, due to their attachment. Cruciate ligaments The anterior cruciate ligament (ACL) can be torn by hyperextension of the knee joint, or by the application of a large force to the back of the knee with the joint partly flexed. To test for this, you can perform an anterior drawer test, where you attempt the pull the tibia forwards, if it moves, the ligament has been torn.  The most common mechanism of posterior cruciate ligament (PCL) damage is the ‘dashboard injury’. This occurs when the knee isflexed, and a large force is applied to the shins, pushing the tibia posteriorly.  This is often seen in car accidents, where the knee hits the dashboard. The posterior cruciate ligament can also be torn by hyperextension of the knee joint, or by damage to the upper part of the tibial tuberosity. To test for PCLdamage, perform the posterior draw test. This is where the clinician holds the knee in flexed position, and pushes the tibia posteriorly. If there is movement, the ligament has been torn.  Bursitis Housemaid’s knee, Superficial Infrapatellar Bursa Friction between; -the skin and thepatella Inflammation: Pus without agent can cause the prepatella bursa to become inflamed, producing a swelling on the anterior side of the knee. Clergyman’s knee, Deep Infrapatellar Bursa Similarly, friction between; -the skin and tibia can cause the infrapatella bursaeto become inflamed. (classically caused by clergymen kneeling on hard surfaces during prayer).  Unhappy Triad 3 things damaged together; 1-) Medial collateral ligament 2-) Medial meniscus 3-) Anterior criuciate ligament As the medial collateral ligament is attached to the medial menisicus, damage to either can affect both structure’s functions. A lateral force to an extended knee, such as a rugby tackle, can rupture the medial collateral ligament, damaging the medial meniscus in the process. The ACLis also affected, which completes the ‘unhappy triad’. Q) Which of the following structures can be damaged on the Unhappy Triad? -ACL -Medial Meniscus -Tibial Collateral Ligament The inflammation of the; -Skin -Bone -Tendon Choric travma of tubercle of Tibia Lesion might damage the tubercle Bony knob