Femur

The femur, the longest and strongest bone in the human body, is divided into three main parts: the proximal end, the shaft, and the distal end.

• Proximal End: The proximal femur includes the femoral head, neck, and the greater and lesser trochanters. The femoral head is a spherical structure that articulates with the acetabulum of the pelvis to form the hip joint. It is covered with hyaline cartilage, except at the fovea capitis where the ligamentum teres attaches. The femoral neck connects the head to the shaft and is oriented at an angle of inclination typically between 120° to 125° in adults. The greater trochanter serves as an attachment site for several muscles, including the gluteus medius and minimus, while the lesser trochanter is the attachment site for the iliopsoas muscle.[1]

• Body (Shaf)t: The body of femur (femoral shaft) is cylindrical and slightly bowed anteriorly. It contains the linea aspera, a ridge that runs longitudinally along the posterior aspect, providing attachment for muscles such as the adductor longus and vastus medialis. The shaft's cross-sectional geometry varies, with the cortex being thicker posteriorly and medially compared to anteriorly and laterally.[2]

• Distal End: The distal femur includes the medial and lateral condyles, which articulate with the tibia and patella to form the knee joint. The condyles are separated by the intercondylar fossa and are covered with articular cartilage. The medial condyle is larger and extends more distally than the lateral condyle. The patellar surface, or trochlea of femur, is located anteriorly and articulates with the patella.[3]