Trochlear notch

Trochlear Notch

The trochlear notch is a large, C-shaped notch located at the proximal end of the ulna, one of the two long bones in the forearm. It is a critical component of the elbow joint, articulating with the trochlea of the humerus to allow for the flexion and extension of the forearm.

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Diagram of the elbow joint, showing the trochlear notch.

Anatomy

The trochlear notch is formed by the olecranon process and the coronoid process of the ulna. The olecranon is the prominent, pointed projection of the ulna that forms the bony tip of the elbow, while the coronoid process is a triangular eminence projecting forward from the anterior proximal portion of the ulna.

The notch is concave and smooth, allowing it to fit snugly around the trochlea of the humerus. This articulation is crucial for the hinge-like movement of the elbow, enabling the arm to bend and straighten.

Function

The primary function of the trochlear notch is to facilitate the movement of the elbow joint. It acts as a pivot point around which the ulna rotates, allowing for the flexion and extension of the forearm. This movement is essential for various daily activities, such as lifting, throwing, and pushing.

Clinical Significance

Injuries to the trochlear notch can significantly impair elbow function. Fractures of the olecranon or coronoid process can disrupt the integrity of the notch, leading to instability or limited range of motion in the elbow joint. Such injuries often require surgical intervention to restore proper alignment and function.

Related Pages

• Ulna
• Elbow joint
• Humerus
• Olecranon
• Coronoid process of the ulna

References

• Moore, K. L., Dalley, A. F., & Agur, A. M. R. (2013). Clinically Oriented Anatomy. Lippincott Williams & Wilkins.
• Standring, S. (2015). Gray's Anatomy: The Anatomical Basis of Clinical Practice. Elsevier Health Sciences.