The ulna is one the two bones which make up the forearm, with the other being the radius. In most cases, a forearm fractures in adults breaks both the ulna and the radius. Therefore, an ulna fracture is most likely part of a forearm fracture.
The forearm is responsible for your ability to turn your palms up and down – pronation and supination. The ulna does not move but the radius rotates around it. A forearm fracture affects your ability to rotate your arm and bend and straighten the wrist and elbow.
Ulna Fracture Causes
An ulna fracture (and radius) can occur several different ways. The bones can crack in one place or break into many pieces. The broken bones may remain in alignment or they may move out of place. In some fractures, the bones break through the skin in what is called an open fracture. This is the most serious type of fracture since the wound creates the risk of infection. Forearm fractures are commonly caused by a direct blow, falling on an outstretched arm and vehicular accidents.
Symptoms and Diagnosis
If you break your forearm, the pain will be immediate. Since both the ulna and the radius are usually affected, your forearm will also look different. It may be bent or shorter than the uninjured arm. There may also be swelling and bruising or rarely, numbness or weakness in the fingers or wrist.
Your doctor will need to know how the injury occurred, if you suffered any other injuries and if you have any illnesses. He or she will check for to see if you can move your fingers and wrists and if you have feeling in your fingers. He or she may also check your entire arm from wrist to shoulder. X-rays will be used to confirm the forearm fracture. They can show where the bone is broken, if the fragments are out of alignment and how many pieces of bone there are.
Since the radius and the ulna support each other, they need to be properly aligned during healing. If they are not, the patient may have difficulty moving their wrist and elbow. In most case, surgery is required to get broken forearm bones lined up properly.
The doctor may try to realign the bones temporarily in the emergency room without surgery. He or she will then put a splint and a sling on the arm. Ice may be applied to help reduce swelling and you will be given pain medication.
Surgery is likely if both the radius and ulna are broken or if there is an open fracture. In fact, if the bone punctured the skin, surgery may be immediate because of the risk of infection. The doctor will give you antibiotics and the wound will be cleaned. The bones are usually re-aligned during the surgery. In the case of a closed fracture, the surgery may not occur until the swelling has gone down.
The most common surgical procedure is an open reduction and internal fixation with plates and screws. The bone fragments are re-positioned and held together with metal screws and plates attached to the outer part of the bone. Rods may also be used to fix the bone. If the skin and bone were badly damaged, plates and screws can cause further problems. The surgeon would then use external fixation in which the pins or screws are placed in the bone above and below the fracture site. They are then attached to a bar outside the skin.
Recovery and Rehabilitation
In can take three to six months for an ulna fracture to fully heal. The recovery may be longer if the injury was particularly severe. Rehabilitation depends on whether the treatment was surgical or non-surgical. In the latter case, rehab begins after the arm was in a cast or brace for a few weeks. A physical therapist will guide you through exercises to help you strengthen the arm. If surgery was performed, motion exercises tend to begin shortly after surgery in an effort to prevent stiffness. If your arm was kept still for a long time, a physical therapist may be involved in your rehab.