The Femur: Anatomy of the Thigh Bone

Overview

The femur is the thigh bone — the longest, heaviest, and strongest bone in the human body. It transmits the entire weight of the upper body to the lower leg and acts as a lever for the powerful muscles of locomotion.

Main Parts

• Head: A rounded ball that fits into the hip socket (acetabulum), forming the hip joint.
• Neck: A narrow bridge connecting the head to the shaft, set at an angle that improves the range of hip movement.
• Greater and lesser trochanters: Bony prominences that serve as attachment points for hip muscles.
• Shaft (diaphysis): The long cylindrical body of the bone.
• Condyles: The two rounded ends at the knee that articulate with the tibia.

Blood Supply

The head of the femur receives much of its blood through vessels that run along the neck. This arrangement is clinically critical: a fracture of the femoral neck can interrupt this supply and lead to death of the bone tissue (avascular necrosis).

Clinical Significance

Hip fractures, usually of the femoral neck, are common in older adults with weakened bone and often require surgery. Mid-shaft femoral fractures, by contrast, usually result from high-energy trauma and can cause significant blood loss because the bone is so vascular.

Summary

The femur combines a weight-bearing shaft, a precisely angled neck, and a ball-shaped head. Its vulnerable blood supply at the neck is what makes hip fractures such an important clinical problem.

For educational purposes only; not a substitute for medical advice.