Atlas

Knee

The knee joint is a synovial condylar joint formed by the interaction between the femur, tibia, and patella. This joint is essential for the function of the lower limb, allowing primarily flexion and extension movements, with a limited degree of internal and external rotation. Joint stability is ensured by a complex ligamentous system that includes the medial and lateral collateral ligaments, the anterior and posterior cruciate ligaments, and the joint capsule. The meniscal compartment, composed of two fibrocartilaginous menisci (medial and lateral), plays a crucial role in shock absorption and load distribution. The articular surface is covered with hyaline cartilage, which facilitates smooth movement and reduces friction between the bone surfaces. The joint is also surrounded by a series of tendons and muscles that contribute to its mobility and functional stability.

Projections

In musculoskeletal ultrasound, images are acquired through different projections that allow visualization of the knee structures from various angles.

Anterior

Anterior

The anterior projection allows visualization of the structures located at the front of the knee, such as the patellar tendon, the femoral and tibial articular cartilage, and the prepatellar bursa. This view is particularly useful for assessing the presence of joint effusions, inflammation, and tendon or cartilage lesions, which are common in joint disorders and hemophilic arthropathy.
Lateral

Lateral

The lateral projection focuses on the outer part of the knee, visualizing the lateral collateral ligament, the lateral meniscus, and the surrounding tissues. This perspective is useful for diagnosing ligament and meniscal injuries, as well as for assessing inflammation or pathological fluid accumulation in the lateral region of the joint.
Medial

Medial

The medial projection provides a view of the inner part of the knee, allowing observation of the medial collateral ligament, the medial meniscus, and the surrounding soft tissues. This projection is essential for evaluating possible ligament, meniscal, or inflammatory lesions typical of traumatic injuries or chronic conditions such as hemophilic arthropathy.
Posterior

Posterior

The posterior projection allows exploration of the structures located behind the joint, including the popliteal fat pad, the popliteal bursa, and the posterior ligaments. This view is essential for identifying fluid collections, inflammation, or lesions involving the posterior aspect of the knee.