The ulna bone, situated on the inner side of the forearm, may not receive the spotlight it deserves compared to its counterpart, the radius. However, this often-overlooked bone is integral to providing stability and support to the arm, enabling a wide range of precise movements. From its unique structure to its significant contributions in everyday activities, this article delves into the fascinating world of the ulna bone. Join us as we explore its anatomy, uncover its essential functions, and gain a deeper understanding of the ulna’s significance in our overall mobility.

Overview

The ulna is the medial bone of the forearm. It is homologous with the fibula of the lower limb. The posterior border is completely subcutaneous and crossed by no named neurovascular structures, and therefore can expose surgically. The spelling of the ‘Ulna’ bone does not have the letter R, but when you write ulnar nerve, ulnar artery, etc, it is written with the letter R because there it is used as a sort of adjective. Another thing to note is that the head of the Ulna is placed on the distal end, in contrast to the radius, which has its head on the proximal end. Both bones have their heads on the end that is smaller.

Side Determination

• 3 borders — anterior, posterior, interosseus.
• 3 surfaces — anterior, posterior, medial.
• Anterior — anterior boarder
• Posterior — Olecranon process
• Lateral — radial notch of ulna
• Superior — olecranon and coronoid processes, trochlea and radial notch
• Inferior — styloid process, head of ulna

Clinicals

Monteggia’s fracture – Fracture of the ulnar shaft with codominant dislocation of the radial head.

Quiz