You probably know the medial malleolus as the bump that protrudes on the inner side of your ankle. It’s actually not a separate bone, but the end of your larger leg bone — the tibia, or shinbone.
The medial malleolus is the largest of the three bone segments that form your ankle. The other two are the lateral and the posterior malleolus.
When a medial malleolus fracture occurs by itself, it’s called an “isolated” fracture. But a medial malleolus fracture is more often part of a compound injury involving one or both of the other ankle parts. It may also involve injury to a ligament of the leg.
When the bone develops a crack or breaks, but the parts don’t move away from each other, it’s called a “stress” or hairline fracture.
Stress fractures of the medial malleolus can be hard to detect.
Ankle fractures are among the most common fractures in adults, and the medial malleolus is often involved. These fractures are more common in women (nearly 60 percent) than men. Slightly more than half of all adult ankle fractures are the result of falls, and 20 percent are due to auto accidents.
Ankle fractures are also a common childhood injury. The peak age for injury is 11 to 12 years. These fractures often occur in sports involving a sudden change of direction.
Symptoms of a medial malleolus fracture can include:
- immediate severe pain
- swelling around the ankle
- tenderness to pressure
- inability to put weight on the injured side
- visible displacement or deformity of the ankle bones
Your doctor will diagnose your ankle by physical examination and manipulation of the ankle, possibly followed by X-rays.
There’s some controversy over whether X-rays are needed to determine if the ankle injury is indeed a fracture.
When the swelling isn’t severe and the ankle can bear weight, it’s very unlikely to be a fracture.
A medical protocol called the Ottawa ankle rules is often used to help doctors determine if X-rays are needed.
Ottawa ankle rules
The Ottawa ankle rules were developed in the 1990s in an attempt to reduce the cost and time burden on hospital emergency rooms. Under these rules, ankle X-rays are only taken if:
- Examination shows there’s pain around the malleolus and at specific points on the tibia or fibula (leg bones).
- You can’t stand on your ankle just after the injury, and you can’t walk four steps at the time you’re examined by the doctor.
The Ottawa ankle rules also help determine whether X-rays of the foot are needed as well.
Studies have shown that following the Ottawa ankle rules catches the vast majority of ankle bone fractures, and saves money and time in the emergency room. But, a small number of fractures may be missed when the Ottawa rules are followed.
It’s important to seek emergency treatment quickly when an ankle fracture of any type is suspected.
If there is a wound, it should be covered with wet sterile gauze. Icing isn’t recommended for a serious fracture with dislocation, as the cold could injure the soft tissues. Learn more about first aid for broken bones and fractures.
If fracture is suspected, emergency medical personnel will stabilize the ankle with a splint.
If there’s obvious internal damage and dislocation of the joint, an emergency physician or paramedic may attempt to set (reduce) the joint on the spot. This is to prevent injury to the soft tissues that may cause a delay of surgery, or worse damage.
A darkening of the color of the foot, indicating restriction of blood flow, is one sign that such a measure may be needed. Time of travel to an emergency room would also be taken into account.
If a fracture is detected, it doesn’t mean you’ll need surgery. Less severe fractures will be treated by conservative (nonsurgical) treatment.
You may be treated with a short leg cast or a removable brace.
If there’s any damage to nerves or blood vessels, an orthopedic specialist will need to reset the damaged bones as soon as possible. The realigning of the bones without surgery is known as closed reduction.
A splint will then be applied to help keep the bones straight while they heal. If the fracture is more serious, you may be given a fracture brace (boot) or cast.
You may be given antibiotics to prevent infection, especially if there is an external wound.
Most medial fractures require surgery even in minimal displaced fractures (in which there is 2 millimeters or more of separation of the fracture fragments). This is because the lining of the bone, called the periosteum, will fold into the fracture site at the time of injury, which won’t be seen on an X-ray. If this membrane isn’t removed from between the bone fragments, the fracture may not heal, and a nonunion fracture could develop.
You’ll generally have either general or regional anesthesia for surgery. Such surgeries are usually done as outpatient procedures — that is, you won’t need to stay in a hospital overnight.
If the injury has pushed the bones out of place, your doctors may decide to use a type of surgery known as open reduction and internal fixation (ORIF).
Open reduction means that the surgeon repositions the fractured bone during surgery, while it’s visible.
Internal fixation means the use of special screws, rods, plates, or wires to hold the bones in place while they heal.
Bruising (hematoma) and cell death (necrosis) at the edge of the wound are the most common complications.
You have a 2 percent chance of experiencing some infection after surgery.
In the case of a serious fracture involving bone displacement, internal pressure can kill cells of the soft tissue around the ankle (necrosis). This can cause permanent damage.
Even with conservative treatment, it will take time to return to normal activity. After conservative treatment, some people are able to do a small amount of weight-bearing right away. Your doctor and physical therapist will guide you as to how much and how soon. Putting weight on the injured ankle can delay healing or cause new injury.
It takes at least six weeks for bones to heal. Your doctor will use X-rays to monitor the bone healing. These may be more frequent if the fracture was set without surgery.
If you have surgery, recovery may take longer. Most people can return to driving within 9 to 12 weeks after surgery, and return to most daily activities within 3 to 4 months. For sports, it will take a little longer.
A physical therapist may visit you in the hospital after surgery to help you get up out of bed and ambulate or walk. Your orthopedic surgeon will determine the amount of weight you can apply to your leg and may modify this as time progresses. Later, a therapist will work with you to restore motion to your ankle and strength of the involved muscles.
You’ll likely wear a cast or removable brace after the surgery.
Except in children, any screws or plates applied will be left in place unless it causes a problem.
Your doctor will guide you in pain management. This may include over-the-counter pain relievers as well as prescription painkillers.
Although a fracture of the medial malleolus can be a serious injury, the outlook for recovery is good, and complications are rare.
It’s very important to follow the directions of your doctor and physical therapist, and not overdo it. Trying to speed up your recovery could lead to new problems, and even the need for a second surgery.