knee

Knee

Anatomy

The knee is composed of four bones, two joints, and the muscles, tendons and ligaments that connect them. The four bones are the femur (thigh bone), the tibia (larger leg bone), fibula (smaller leg bone) and the patella (kneecap). The two joints are the femoral-tibial (or knee joint) and the patellofemoral (where the kneecap moves against the femur).The knee is a hinge joint made up by the thighbone and the leg bones. It contains two compartments, medial and lateral. These compartments contain the end of the femur, or condyle, the top of the tibia, or plateau, and a cartilage called a meniscus. The condyle and tibial plateau are covered in articular cartilage, which protects the end of the bone. Loss of this cartilage is termed arthritis. The meniscus sits between these bones. The meniscus, another type of cartilage, acts as a shock absorber and helps to stabilize the knee. The meniscus is named for its location in the knee. The medial meniscus is located on the inside of the knee, while the lateral meniscus is located on the outside of the knee.

Although many ligaments are found in and around the knee joint, the femur and tibia are primarily held together by four ligaments. These are the anterior cruciate ligament (ACL), the posterior cruciate ligament (PCL), the medial collateral ligament (MCL), and the lateral collateral ligament (LCL). The anterior cruciate ligament is found in the center of the knee, and acts to limit forward translation of the tibia on the femur. The posterior cruciate ligament is found in the center of the knee and acts to limit posterior translation of the tibia on the femur. The medial collateral ligament is found on the inside of the knee and holds the femur to the tibia. The lateral collateral ligament is found on the outside of the knee and holds the femur to the fibula. An injury to any of these four ligaments can leave the knee unstable.

The patellofemoral joint is made up of the patella (kneecap) and the trochlea (the groove in the femur that the kneecap travels in). The undersurface of the patella is covered with articular cartilage, as is the trochlea. Any condition that increases the pressure between these two cartilage surfaces can lead to pain in the front of the knee. The quadriceps muscles are a group of muscles that attach to the kneecap through a common tendon. They function to straighten the knee and prevent the tibia from going too far backward on the femur. The hamstring muscles are a group of muscles that attach to the tibia or fibula. They function to bend the knee and prevent the tibia from coming too far forward on the femur.

Mechanism of Injury

The knee can be injured as a result of trauma, repetitive use, or degeneration that occurs with age. Trauma is a leading cause of injury in the young. Twisting injuries, which occur with or without contact with a second person, can lead to tears of the meniscus or ligaments. Repetitive use is a common cause of knee injury. People whose occupations require a large amount of kneeling, climbing, squatting or stooping are particularly susceptible to the development of knee pain. Athletes who play sports that require sudden changes of direction, such as basketball and soccer, or jumping such as basketball and volleyball, are at increased risk of knee injuries. Finally, as the body ages, it loses flexibility. The same is true for the knee, the meniscus, and the ligaments that hold the knee together. They become stiffer and more easily torn. Normal wear and tear on the joint can accumulate over a lifetime, and lead to tears of the meniscus or damage to the articular cartilage without specific injury.

Although many ligaments are found in and around the knee joint, the femur and tibia are primarily held together by four ligaments. These are the anterior cruciate ligament (ACL), the posterior cruciate ligament (PCL), the medial collateral ligament (MCL), and the lateral collateral ligament (LCL). The anterior cruciate ligament is found in the center of the knee, and acts to limit forward translation of the tibia on the femur. The posterior cruciate ligament is found in the center of the knee and acts to limit posterior translation of the tibia on the femur. The medial collateral ligament is found on the inside of the knee and holds the femur to the tibia. The lateral collateral ligament is found on the outside of the knee and holds the femur to the fibula. An injury to any of these four ligaments can leave the knee unstable.

The patellofemoral joint is made up of the patella (kneecap) and the trochlea (the groove in the femur that the kneecap travels in). The undersurface of the patella is covered with articular cartilage, as is the trochlea. Any condition that increases the pressure between these two cartilage surfaces can lead to pain in the front of the knee. The quadriceps muscles are a group of muscles that attach to the kneecap through a common tendon. They function to straighten the knee and prevent the tibia from going too far backward on the femur. The hamstring muscles are a group of muscles that attach to the tibia or fibula. They function to bend the knee and prevent the tibia from coming too far forward on the femur.

Mechanism of Injury

The knee can be injured as a result of trauma, repetitive use, or degeneration that occurs with age. Trauma is a leading cause of injury in the young. Twisting injuries, which occur with or without contact with a second person, can lead to tears of the meniscus or ligaments. Repetitive use is a common cause of knee injury. People whose occupations require a large amount of kneeling, climbing, squatting or stooping are particularly susceptible to the development of knee pain. Athletes who play sports that require sudden changes of direction, such as basketball and soccer, or jumping such as basketball and volleyball, are at increased risk of knee injuries. Finally, as the body ages, it loses flexibility. The same is true for the knee, the meniscus, and the ligaments that hold the knee together. They become stiffer and more easily torn. Normal wear and tear on the joint can accumulate over a lifetime, and lead to tears of the meniscus or damage to the articular cartilage without specific injury.

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Dr. Subair Khan in SUN TV

Dr. Subair Khan - Chief Doctor and MD of Orthomed Hospitals was featured in Sun TV at Virunthinar Pakkam. He is Explaining about the Orthopaedic & Sports Related Issues in Current Life Style....