The term Monteggia fracture is used to precisely refer to a dislocation of the forearm. This type of injury is extremely rare and accounts for less than 5% of all forearm fractures. The key to successfully diagnosing a Monteggia fracture is precise radiographs of the entire forearm and elbow to properly assess the nature of the injury in a timely manner. The most challenging part is to assess the extent and nature of this injury. The ulna fracture is usually in the proximal third of the ulna and may involve the olecranon, midshaft and distal shaft.
There are four main types of Monteggia fractures:
- Type 1 – This is due to direct trauma or an impact force resulting in hyperextension or hyperpronation. The most common type of hyperpronation is due to a fall on an outstretched arm.
- Type 2 – This is due to direct trauma with the forearm in supination or a rotational force in supination. This usually results in an open fracture.
- Type 3 – This is due to direct trauma over the inner aspect of the elbow, resulting in an adduction force with a lateral displacement of the radial head.
- This is due to a forced pronation of the forearm.
- Immense pain in the arm that becomes worse when using the wrist and elbow
- Swelling in the forearm
- Deformed forearm
- Swelling in the hands
- Swelling at the writ
- Tenderness in the forearm
- Numbness in the wrist
- Limited range of motion
The type of treatment administered depends on the severity of the injury. The first and most conservative step is to immobilise the arm and place it inside a protective cast. This will allow the forearm joint and ulna to properly heal. A few weeks later, the arm will be x-rayed to monitor the healing process. If there are bones that are broken, the cast will be removed and corrective actions will be taken. As the bone is a piezoelectric material, relieving it of load will result in bone resorption.
This will result in the arm with the fracture having a shorter arm than the other. The next issue is the risk of infection if the fracture is an open one. An open fracture is one that has broken skin with the broken bone protruding out of it. Some types of Monteggia fractures if occured in children, do not require an operation and can be managed with a cast.