The malleoli are specific parts of the shinbone and fibula that help make up the ankle:
- lateral malleolus
- medial malleolus
- posterior malleolus
All three are very important as an anchoring location for the ligaments that help move, control and stabilize the foot and ankle.
As there are three parts to the break, it is considered more unstable than other fractures and can be associated with a ligament injury or a dislocation.
In this article, we look at how this fracture can be treated, how long it takes to recover, and what the symptoms of such a break are.
Treatment and recovery time
Surgical repair is usually recommended for a trimalleolar fracture, which may involve screws, metal plates, and wiring.
Image credit: R.Sunset (2009, September 17).
As a trimalleolar fracture is considered unstable, doctors usually recommend surgery as treatment.
Each fracture will have to be treated separately during the surgery.
Lateral malleolus fracture
Firstly, the surgeon will realign the bone fragments, returning them to their normal position.
Screws and metals plates, which are attached to the outer surface of the bone, will hold them in place.
In some cases, a screw or rod may be inserted inside the bone to keep the bone fragments together as they heal.
Medial malleolus fracture
Surgery on the medial malleoli can reduce the risk of the fracture not healing and allow the person to start moving their ankle earlier.
There will often be impaction of the ankle joint, which is when force drives one bone into the other. This may require bone grafting, which acts as a frame for new bone to grow on and can reduce the chance of a person developing arthritis.
Bone fragments may be fixed using screws, plates, and wiring techniques.
Posterior malleolus fracture
There are different options for surgery. One option involves inserting screws running from the front to the back of the ankle or the other way round.
The other option involves placing plates and screws along the back of the shinbone.
While surgery often takes place, there are times when surgery is not appropriate. These include when the person has serious health problems, and the risk of surgery would be too great or if the person does not walk.
Immediate treatment will usually involve applying a splint to stabilize the ankle until the swelling goes down. A person may then be fitted with a short cast that can be replaced with smaller casts as the swelling continues to go down.
The person will need to have regular X-rays to ensure the ankle remains stable.
A person may not be able to put any weight on their ankle for around 6 weeks. After this time, they may be able to wear a removable brace as the ankle continues to heal.
If a person has had surgery, they will be unable to put weight on the ankle for a period of time. The amount of time will depend on several factors, including the stabilization and severity of the joint involvement.
Often, a person will experience severe swelling around the fracture. This swelling can delay further surgery, cause blisters on the skin, increase the chance of infection, and delay the healing process.
Causes, symptoms, diagnosis
A trimalleolar fracture may be diagnosed with an X-ray.
Image credit: James Heilman, MD, (2011, October 19).
A trimalleolar fracture of the ankle can often be caused by high impact, such as from a sports or car accident. However, a simple trip or fall can also cause the injury.
A severe sprain can often feel the same as a break, but there are common symptoms for a fractured ankle:
- immediate and severe pain
- tender to the touch
- unable to put weight on the damaged ankle
- the ankle is out of place in some way and looks deformed
An ankle injury needs to be examined by a doctor. After going through a person's medical history, symptoms, and how the injury occurred, they will then perform a physical examination.
If the doctor suspects that there is a fracture, then they will carry out additional tests to gain more information. They include:
- X-ray: The most common way to diagnose the fracture, an X-ray can show if a bone is broken, if there has been displacement, and how many pieces of broken bone there are.
- Stress test: A special X-ray to see if surgery is required.
- Computed tomography (CT) scan: A CT scan further evaluates the injury. It is particularly useful if the fracture has extended to the ankle joint.
- Magnetic resonance imaging (MRI) scan: This test produces high-resolution images of the anklebones and soft tissue. It is useful for evaluating the ankle ligaments.
There are also some complications associated with ankle fractures. One complication is malunion, which occurs when the bones move and heal out of place.
Malunion is usually associated with nonsurgical treatment. It can make the ankle unstable and eventually lead to arthritis.
Other complications include:
- blood clots in the leg
- damage to blood vessels, tendons, or nerves
- problems with the bone healing (non-union or delayed union)
Other similar injuries
Bimalleolar fractures are similar to trimalleolar fractures, and have similar potential causes. Physical therapy is required for both types of fractures.
The three malleolus bones can all be fractured separately without the others being affected.
There are also bimalleolar fractures, which is when two of the three parts of the malleolus are broken. In most cases of bimalleolar fractures, it is the lateral and medial malleolus that are broken.
There is also a bimalleolar equivalent, where the ligaments on the inside of the ankle are damaged as well as one of the malleoli. In most of these cases, the fibula is broken and the medial ligaments are injured.
Both bimalleolar fractures and a bimalleolar equivalent will typically make the ankle unstable and can be related to a dislocation. Surgery is usually recommended to treat them.
A trimalleolar fracture is a serious injury that will dramatically affect the person's life for the several months it takes to heal.
Rehabilitation through physical therapy and home exercise is essential for strengthening the ankle. Even after the person can walk again, it can still take months for the muscles to get strong enough for them to walk without a limp.
A person can restore full function to the ankle with proper rehabilitation, but often this will take a year or longer.