Supracondylar Process of Humerus – Report of Two Cases

Abstract

Supracondylar process of the humerus is a congenital bone projection seen on the distal humerus on the anteromedial surface. A fibrous band called ligament of Struthers’ connects the supracondylar process of humerus with medial epicondyle. It is mainly asymptomatic but rarely can present as supracondylar process syndrome due to neurovascular compression. Although isolated median nerve injuries are most common they can also present with fractures and vascular complications. The ulnar nerve is rarely involved. The median nerve can be trapped at several sites proximal to the carpal tunnel. Potential sites where the median nerve can be trapped are bicipital aponeurosis, two heads of pronator teres, flexor digitorum superficialis, aponeurotic arch and Gantzer muscle.^[1]

Supracondylar process of the humerus is a hook-like bony process seen about 5 cm proximal to the medial epicondyle and has a pointed apex. It is curved downwards and forwards and is commonly seen in climbing mammals. Vinilla et al. published a comparison of measurements of the supracondylar process of the humerus in different studies. The length of the process varied from 0.3 cm to 1.6 cm, breadth 1cm to 1.5 cm and distance from the medial epicondyle varied from 4.4 cm to 6.5 cm. They concluded that the supracondylar process had to be differentiated from osteochondroma and myositis ossificans.^[2]