The ulna is one of two bones of the forearm. The two bones of the forearm, the radius and the ulna, both span the distance from the elbow to the wrist joints.
How does an ulna fracture occur?
An isolated ulna fracture most commonly occurs by the forearm being struck by an object (or an the forearm striking an object). The common eponym for an isolated ulna fracture is a "nightstick fracture," although there are many other common mechanisms of this injury including falls, car accidents, and others.
What are the symptoms of an ulna fracture?
By far the most common symptom of an ulna fracture is pain. Other common symptoms include swelling and deformity of the forearm. When you suspect a forearm fracture, you should be seen by a physician and obtain x-rays to determine if there is an ulna fracture present, and if there are any associated injuries. In addition, the elbow must also be carefully examined to determine if there is a dislocation within the elbow causing an injury pattern known as a Monteggia fracture.
What is the treatment of an ulna fracture?
Isolated ulna fractures can most often be treated with a cast or fracture brace. Usually a period of immobilization will allow the bone to heal adequately.
If there is a significant amount of displacement of the ulna fracture, the fracture is considered 'unstable.' In these cases, the patient may benefit from surgical stabilization of the fracture. The usual treatment is to use a plate and screws to secure the fractured bone.
What are the complications of surgical treatment of ulna fractures?
The most common complications include:
- Painful Implants
Occasionally, the metal plate and screws can be tender and painful and require removal. This is usually done at least a year after surgery. Refracture of the bone is possible after plate removal.
Infection is an unusual complication, but possible after any surgical procedure. If infection is a problem, the metal implant will likely have to be removed.
- Non-Healing Fracture
Non-healing, called a nonunion, occurs in about 5% of patients with ulna fractures. These patients may require another surgical procedure for bone grafting to obtain healing of the ulna fracture.