Understand the structure and function of the human knee in this informative article that explores the anatomy of this crucial joint.

Human knee is a complex joint that plays a vital role in a person’s ability to move, walk, run and perform various physical activities. It is the largest articulation of the body and is formed by several interconnected structures, such as bones, ligaments, tendons and cartilage.

An important bone of the knee joint is the kneecap. This small triangular bone is in front of the knee and acts as a protective cover of the joint. In addition, the femur (thigh bone) and the tibia (pimp bone) form the main bones of the knee joint. The rounded ends of the femur, called femoral condyles, rest on the upper surface of the tibia, which presents the corresponding concavities called tibial plateaus.

The knee joint is classified as a hinge joint, which allows flexion and extension movements. It also has some rotation capacity, especially during movements such as torsion or turn.

1. Ligaments provide stability to knee joint and help avoid excessive movements. The two main ligaments are the anterior cross ligament (LCA) and the posterior cross ligament (LCP), which cross inside the knee joint, creating a “x” shape.
2. The tendons, on the other hand, connect the muscles to the bones and play an essential role in the transfer of the forces generated by the muscles to produce the movement of the joint. In the knee joint, the patellar tendon connects the kneecap with the tibia, while the quadriceps tendon connects the quadriceps muscle with the kneecap.
3. The articular cartilage of the knee joint, also known as meniscus, helps reduce friction and absorb impacts during movement. There are two crescen t-shaped meniscus on each knee: the medial meniscus on the internal side and the side meniscus on the outer side.

Understanding the anatomy of the human knee is crucial to diagnose and treat various conditions and knee injuries. It provides a basis for health professionals to evaluate the individual structures involved and develop effective treatment plans to restore knee and relieve pain.

Anatomy of the Human Knee

The knee joint is made up of three main bones: the femur, tibia, and kneecap. The femur is the thigh bone, the longest and strongest in the human body. It forms the upper part of the knee joint and supports the weight of the body. The tibia, also known as the shinbone, is the larger of the two bones in the lower leg. It forms the lower part of the knee joint and supports a significant portion of the body’s weight. The kneecap is a small, triangular bone located in front of the knee joint. It acts as a protective shield for the knee and helps increase the leverage of the quadriceps muscles.

• The ligaments of the knee joint provide stability and restrict excessive movement. The four main ligaments of the knee are:
1. The anterior cruciate ligament (ACL) prevents excessive forward movement of the tibia as well as rotation.
2. The posterior cruciate ligament (PCL) prevents excessive backward movement of the tibia.
3. The medial collateral ligament (MCL) stabilizes the inner aspect of the knee, preventing it from bending inward.
4. The lateral collateral ligament (LCL) stabilizes the outside of the knee, preventing it from bending outward.

The human knee joint is a complex structure made up of bones, ligaments, tendons and muscles. Its intricate design allows for a wide range of movement while maintaining stability. Understanding the anatomy of the knee is essential to diagnosing and treating knee injuries and conditions.

The Importance of Understanding the Knee Joint

The knee joint is made up of several components: bones, ligaments, tendons and cartilage. At the center of the joint are the femur, tibia, and patella, which together form the femur, tibia, and patella, respectively. These bones are connected by a network of ligaments that provide stability and support to the joint. The ligaments include the anterior cruciate ligament (ACL), the posterior cruciate ligament (PCL), the medial collateral ligament (MCL), and the lateral collateral ligament (LCL).

Important information:

• The knee joint is a weight-bearing joint that supports a significant amount of our body weight during activities.
• The meniscus, a piece of cartilage, acts as a shock absorber within the knee joint, cushioning the bones and preventing friction.
• The knee joint is susceptible to various injuries and conditions, such as ligament tears, meniscus tears, arthritis, and patellar dislocation.

In addition to its structural components, the knee joint depends on the coordination and strength of the muscles that surround it, such as quadriceps and hamstrings, to facilitate movement and stability. Any imbalance or dysfunction of these muscles can affect the operation of the knee joint and cause limited pain or mobility.

In general, having an exhaustive knowledge of the knee joint is essential for health professionals, athletes and people who want to maintain optimal knee health. When becoming familiar with the intricate anatomy and common problems related to knee joint, they can make informed decisions about preventive measures, treatment options and rehabilitation techniques.

Table: Common knee injuries and conditions

Injury/condition	Description
Torn ligament	Partial or complete breakage of one of the knee ligaments, which causes instability.
Meniscus rupture	Meniscal rupture that causes pain, swelling and limitation of movement amplitude.
Arthritis	Inflammation and degeneration of the knee joint, which causes pain and rigidity.
Prailian dislocation	The kneecap moves from its normal position, causing serious discomfort and instability.

The Bones and Ligaments of the Knee

The knee is composed of four bones: the femur, the tibia, the fibula and the kneecap. The femur, also known as the thigh bone, is the longest and loud bone of the body. It extends from the hip joint to the knee joint and forms the upper part of it. The tibia, or spin, is the largest of the two bones of the lower leg and forms the lower part of the knee joint. The fibula, located next to the tibia, is a thinner bone that provides stability to the bottom of the leg. The kneecap is a small bone located in front of the knee joint. It acts as a protective shield of the joint and plays a role in the extension of the knee.

The knee joint is sustained and stabilized by a ligament network. Ligaments are strong connective tissue bands that connect some bones with others and help limit the movement of the joint. In the knee there are four main ligaments: the anterior cruciate ligament (LCA), the posterior cruciate ligament (LCP), the medial collateral ligament (LCM) and the lateral collateral ligament (LCL). The LCA and the LCP are located inside the knee joint and cross forming an “x”. They help stabilize the knee and prevent excessive movements forward and back. The LCM is on the inside of the knee, while the LCL is on the outer face. These ligaments provide stability to the knee joint and protect against excessive side movements.

The Role of Cartilage in Knee Function

The cartilage is a resistant and flexible connective tissue that covers the ends of the bones inside the knee joint. Its smooth and slippery surface allows a soft movement and reduces friction between the bones during the joint movement. In addition, the cartilage acts as a shock absorber, distributing evenly by the joint the forces that occur during the activities in which weight is supported. Without cartilage, the bones would touch each other, which would cause pain, inflammation and lon g-term damage in the knee joint.

• The cartilage covers the ends of the femur (thigh bone), the tibia (bone of the pimp) and the kneecap (bruit).
• It acts as a protective layer, reducing friction and avoiding joint injuries.
• The cartilage also allows a soft and painless movement of the knee joint.

It is essential to maintain the health and integrity of the knee joint cartilage to guarantee its optimal functioning and reduce the risk of developing kne e-related conditions, such as osteoarthritis.

Unfortunately, cartilage has a limited regeneration capacity, and lesions or cartilage degeneration can cause lon g-term complications. Therefore, it is essential to protect and conserve the knee cartilage through proper knee care, regular exercise and appropriate body mechanics. By understanding the paper of the cartilage in the function of the knee and taking proactive measures, people can maintain healthy knees and enjoy painless movement in the coming years.

The Muscles and Tendons Supporting the Knee

Within the human knee joint, a complex network of muscles and tendons work together to provide stability and support. These structures play a critical role in allowing a wide range of motion, while protecting the knee from excessive stress and injury.

The muscles that surround the knee joint can be classified into two large groups: the quadriceps and the hamstrings. The quadriceps, located in the front part of the thigh, are responsible for extending the knee, that is, straightening the leg. They are made up of four separate muscles: the rectus femoris, vastus lateralis, vastus intermedius, and vastus medialis. These muscles, when contracted, generate the force necessary to extend the knee and maintain stability during various activities such as walking, running and jumping.

The Quadriceps Muscles:

• Rectus femoris: This muscle originates from the ilium bone and runs down the front of the thigh, attaching to the kneecap through the quadriceps tendon. It is the only quadriceps muscle that crosses the hip and knee joints.
• Vastus lateralis: It is the largest and external muscle of the quadriceps group, it originates from the femur and attaches to the external surface of the kneecap.
• Vastus intermedius: This deep muscle lies beneath the rectus femoris and originates on the anterior and lateral surfaces of the femur, attaching to the top of the kneecap.
• Vastus medialis: Located on the inner thigh, this muscle originates from the femur and attaches to the inner part of the kneecap. Helps stabilize the kneecap during knee movements.

The Hamstrings Muscles:

1. Semimembranosus: This muscle is located at the back of the thigh and originates from the ischial tuberosity, a bony prominence of the pelvis. It attaches to the back of the tibial bone, below the knee joint.
2. Semitendinosus: This muscle, which also originates from the ischial tuberosity, is located next to the semimembranosus muscle. It crosses the hip and knee joints and attaches to the tibial bone.
3. Biceps femoris: This muscle is divided into two parts: the long head and the short head. The long head originates from the ischial tuberosity, while the short head originates from the back of the femur. The biceps femoris helps in flexion and external rotation of the knee.

Note: The quadriceps and hamstring muscles work in opposition to each other, providing dynamic stability to the knee joint. It is essential to maintain a balance between these muscle groups to avoid imbalances that can lead to knee pain and dysfunction.

The Blood Supply and Nerve Innervation of the Knee

The blood irrigation of the knee joint proceeds mainly from the genicular arteries, which form an extensive network throughout the joint. These arteries are born from various sources, such as the descending genicular artery, the upper lateral genicular artery and the upper medial genicular artery. This rich vascular supply serves to nurture knee tissues and guarantee their optimal functioning.

• The descending genicular artery: irrigate the infrapathelar fat pad and helps form the anastomotic network around the knee joint.
• The upper lateral genicular artery: irrigate the lateral collateral ligament and the lateral face of the joint.
• The upper medial genicular artery: irrigate the medial collateral ligament and the medial face of the joint.

IMPORTANT INFORMATION: Genicular arteries are anastomos, forming an periarticular arterial plexus that provides collateral circulation to the knee joint. This collateral circulation is particularly important in cases of injury or occlusion of one of the genicular arteries, since it helps maintain blood supply to the joint and prevent ischemic damage.

In addition to its blood irrigation, the knee is innervated by a complex network of nerves that provide motor and sensory functions. The innervation of the knee joint proceeds normally from branches of the femoral, shutter and sciatic nerves. These nerves not only allow the control and coordination of the muscles that surround the knee, but also provide sensory feedback, which allows us to perceive pain, touch and temperature in this area.

1. The femoral nerve: innervates the previous muscles of the thigh, including the muscular group of femoral quadriceps.
2. The obturator nerve: innervates the adductor muscles of the thigh, which contribute to the stability and movement of the knee joint.
3. The sciatic nerve: it is divided into the common tibial and fibular nerves, which provide motor innervation to the posterior muscles of the thigh and sensitive innervation to the posterior and lateral aspects of the knee joint.

In summary, blood supply and nerve innervation of the knee are critical components of its anatomical structure and its function. Understanding the intricate network of blood vessels and nerves that support the knee joint allows health professionals to diagnose and treat various conditions that affect this complex joint.

Common Knee Injuries and Conditions

One of the most frequent knee lesions is the breakage of the anterior cross ligament (LCA). The LCA is one of the main knee ligaments that connects the femur with the tibia. This injury usually occurs during sports activities that involve sudden stops or changes of direction, such as basketball or football. The symptoms of a breakage of the LCA can include a feeling of clicks at the time of injury, intense pain, swelling and knee instability.

Key point: LCA break is a common knee lesion that usually occurs during sports activities that involve sudden stops or changes. Symptoms may include a feeling of click, pain, swelling and knee instability.

Another common knee problem is patelofemoral pain syndrome, also known as runner knee. This condition is characterized by pain in the front of the knee, around or behind the kneecap. It is usually caused by a repetitive effort on the kneecap, such as running, jumping or squatting. Patelofemoral pain syndrome can be aggravated by activities that require flexing the knee for a prolonged period, such as sitting a lot of time or climbing stairs. Symptoms may include deaf or acute pain, especially with activities that involve bending the knee.

Key point: Patelofemoral pain syndrome, also known as runner knee, is a common condition characterized by pain in the anterior part of the knee. It is usually caused by a repetitive tension in the bruis and can be aggravated with activities that involve bending the knee. Symptoms may include deaf or sharp pain.

Prevention and Treatment of Knee Problems

Prevention:

• Keep a healthy weight: excess weight is an additional load for knees and increases the risk of developing knee problems such as osteoarthritis. Maintaining a healthy weight by means of a balanced diet and regular exercise can help protect your knees.
• Stay active: Regular physical activity, including low impact exercises such as swimming or cycling, can strengthen the muscles that support the knee joint. Strong muscles help stabilize the knee and reduce the probability of injuries.
• Use adequate techniques during physical activities: whether it is about running, jumping or lifting heavy objects, it is essential to use the appropriate shape and technique to avoid excessive knee tension. Going to a qualified coach can help guarantee correct movement patterns.

Important note: It is recommended to heat before performing physical activities to prepare muscles and joints for movement and reduce the risk of injury.

Treatment:

1. Rest and ice: When pain or knee inflammation is experienced, pause in activities and apply ice in the affected area can help reduce pain and swelling. This method is especially effective in acute injuries.
2. Physiotherapy: Depending on the severity and type of knee problem, physiotherapy can play a crucial role in treatment. A qualified therapist can develop an individualized program to strengthen knee, improve flexibility and relieve pain.
3. Surgical intervention: In cases where conservative treatments do not provide relief, surgical intervention may be necessary. There are several surgical options, from minimally invasive procedures to the total knee substitution, depending on the specific condition and its severity.

Important note: It is essential to consult a healthcare professional to receive an adequate diagnosis and a personalized treatment plan for knee problems. Sel f-diagnosis and sel f-treatment can cause additional complications.

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Author of the article

Dr.Greenblatt M.

Medical oncologist at the Robert Larner College of Medicine, MD, at the University of Vermont