![]() On the lateral column, the articular surface of the distal humerus is the capitellum, which articulates with the radius, to form the radiocapitellar joint. ![]() Similarly, on the lateral column, the lateral collateral ligament and extensor musculature originate on the lateral epicondyle. The medial collateral ligament and flexor/pronator musculature originate from this area of the distal humerus. The medial epicondyle is the distal extent of the medial column. Ligamentous Anatomy and Articular Surface The distal articular surface is also angulated anterior to the shaft of the humerus, with approximately 30° to 40° anterior angulation of the capitellum and 25° anterior angulation of the trochlea. The medial and lateral columns diverge from the humeral shaft: the lateral column at approximately 20° and the medial column at approximately 45°. The trochlea itself is contained between the lateral and medial columns of the elbow, and it is covered with articular cartilage over 300° of its surface. The semilunar notch of the ulna engages with the trochlea and this close articulation gives bony stability. The axis of rotation of this joint is in slight external rotation (3°–9°) and valgus (4°–8°) from the humeral shaft. The ulnohumeral joint is a hinge that allows for flexion and extension of the elbow. The elbow joint is composed of three bones (radius, ulna, and humerus) and comprises the ulnohumeral, radiocapitellar, and proximal radioulnar joints. The incidence of these fractures may be increasing, especially as the population continues to age. In addition, distal humerus fractures commonly occur in two population groups: young people with a high energy mechanism and elderly people due to a low energy mechanism such as a fall, usually in association with osteoporosis. Lateral column injuries are more common than medial column injuries, and multiple types have been described. Total elbow arthroplasty is an option for management of these fractures in elderly osteoporotic patients.ĭistal humerus fractures are relatively uncommon orthopedic injuries, representing less than 7% of adult fractures, and approximately 30% of fractures about the elbow. There are multiple approaches to the elbow joint including triceps-sparing, triceps-splitting, triceps-reflecting, and olecranon osteotoy. Most intra-articular distal humerus fractures require operative fixation for an anatomic reduction and to allow for early motion to optimize outcome. Distal humerus fractures are relatively uncommon orthopedic injuries, representing less than 7% of adult fractures, and approximately 30% of fractures about the elbow.
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