The humerus of the upper arm and the paired radius and ulna of the forearm meet to form the elbow joint, a hinge joint in the upper arm. The bony prominence at the tip of the elbow is the olecranon process of the ulna. The antecubital fossa lies over the anterior aspect of the elbow.
Injuries to the elbow are common, usually occur secondary to indirect trauma and are often accompanied by injury to shoulder or wrist joints.[1]It is important to assess injuries promptly and accurately, taking into account age and the mechanism of injury, particularly because of the risk of accompanying vascular involvement. The elbow extension test is a useful screening tool for bony injury – although not infallible.
In addition to injuries listed in the table below, see also separate articles Forearm Injuries and Fractures (deals with Monteggia’s fractures), Radial Head Subluxation (nursemaid’s elbow), Epicondylitis – Lateral and Medial and Olecranon Bursitis.
Radial head and neck fractures
These are most commonly caused by a fall on to an outstretched arm. Radial head fracture is the most common fracture around the elbow joint in adults, whereas radial neck fractures occur more commonly in children.
Olecranon fractures
These are low-energy fractures which occur most commonly in the elderly and result from indirect trauma caused by a sudden pull of the triceps and brachioradialis muscles.
However, in younger patients, olecranon fractures usually follow a direct blow to the point of the elbow and are often comminuted, and there may be an associated ulnar shaft fracture.
Fractures of the coronoid process
The mechanism of injury is as for elbow dislocation and such fractures are associated with elbow dislocation in about 40% of cases
Fractures of the distal humerus
- Supracondylar/transcondylar – most are extension-type injuries from a fall on to an outstretched arm.
- Transcondylar fractures are more common in the elderly.
- Supracondylar fractures are more common in children.
Intercondylar fractures
These are T- or Y-shaped fractures with varying displacement between the condyles and the humerus.
Condylar fractures
- Lateral condyle fractures are more common than medial.
- Lateral fractures are usually due to a sudden varus stress on an elbow in extension.
- Medial fractures are due either to impact to the olecranon with a flexed elbow or sudden valgus stress on an elbow in extension
Elbow dislocation
Elbow dislocation is the second most common major joint dislocation. The ‘terrible triad of the elbow’ refers to a combination of elbow dislocation and radial head and coronoid process fracture – it is notoriously difficult to manage although a systematic review found that whilst complications are common, functional outcomes are generally satisfactory.
See full story on patient.info
Image courtesy of patient.info