What serious risk is associated with the proximity of the brachial artery in supracondylar humerus fractures?

The proximity of the brachial artery in cases of supracondylar humerus fractures poses a significant risk for developing Volkmann contracture. This condition arises from ischemia (lack of blood flow) to the muscles of the forearm due to compromised blood supply, which can occur if the brachial artery is injured or if swelling puts pressure on the artery following the fracture.

When the blood supply is insufficient to the forearm muscles, especially the flexors and pronators, the muscle tissue can become necrotic, leading to permanent muscle shortening and resulting in a characteristic claw-like hand deformity known as Volkmann contracture. This is a serious and potentially permanent complication following a supracondylar fracture, especially in the pediatric population where such fractures are common.

In contrast, while humeral avascular necrosis might be theorized due to nearby structures, it is not directly related to the brachial artery in the context of supracondylar humeral fractures. Similarly, while medial and radial nerve injuries may occur with these types of fractures, they are less directly associated with the proximity of the brachial artery compared to the risk posed by impaired vascular supply leading to Volkmann contracture.