Fracture Subluxation of the Ankle
A fracture subluxation of the ankle involves great forces onto the ankle that results in both a fracture and a partial dislocation of the ankle.
Table of Contents
- Anatomy of the Ankle
- Fracture Subluxation of the Ankle
- Causes of a Fracture Subluxation of the Ankle
- Symptoms of Fracture/Subluxation of the Ankle
- Diagnosis of a Fracture/Subluxation of the Ankle
- Treatment of Fracture/Subluxation of the Ankle
- Complications of Fracture/Subluxation of the Ankle
The ankle is the large distal joint made up of three bones. It begins with the tibia, which is the “shin” bone. Next to the tibia is another long bone, the fibula. The tibia and the fibula form the medial malleolus and the lateral malleolus, respectfully. These are the bumps on either side of the ankle. The part of the foot that makes up the ankle joint is the heel bone or the talus. The ankle allows for dorsiflexion and plantar flexion of the foot as well as side to side motion of the ankle.
When we think of the “ankle joint”, we are really thinking of two joints: there is the true ankle joint and the subtalar joint. The subtalar joint is beneath the true ankle joint and consists of the talus above the calcaneus bone. This allows for the side to side motion of the foot. It is the true ankle joint that allows for the up and down motion of the foot. It is made from the tibia, fibula and the talus. All the bones are covered with articular cartilage where they approximate one another.
There are ligaments that hold the joint together. If they are disrupted, you get subluxation or dislocation of the joint. These are the anterior tibiofibular ligament that connects the tibia to the fibula and the lateral collateral ligaments, which attach the calcaneus to the fibula. These ligaments stabilize the joint. There are also deltoid ligaments that aid in stability by connecting the talus to the tibia and provide medial stability to the joint.Fracture Subluxation of the Ankle
If the foot is forcefully rotated externally, there is fracture of the bone with disruption of the ligaments so that the ankle has one or more bones fractures with subluxation of the joint. There are several classifications of an ankle fracture that identify where the fractured bones are and what is dislocated or subluxed. These classifications include:
- Weber A. There is a transverse fracture of the fibula at the level of the ankle joint and a transverse vertical fracture of the medial malleolus of the tibia. The posterior malleolus is intact and the syndesmosis is intact.
- Weber B. The fibula has a spiral fracture that begins at the level of the ankle joint. The medial malleolus is either intact or has an avulsion fracture of the posterior tibial-fibular ligament. The anterior syndesmosis is intact as is the anterior tibial fibular ligament. The lateral aspect is the last part to rupture.
- Weber C. Weber C fractures are also known as the Dupytren’s fracture and the Maisonneuve fracture, which is a high fibular fracture. The fibula shows a spiral fracture above the syndesmosis. The medial malleolus is fractured along with the possibility of a rupture of the deltoid ligament. The posterior malleolus has an avulsion fracture with rupture of the posterior syndesmosis.
There are many causes of a fracture subluxation of the ankle. Car accidents are common causes of this type of injury because there can be crush injuries to the foot and ankle and the ankle can be driven into the front of the car in front-end collisions.
Falls are common causes of ankle fractures. You can fracture your ankle simply by tripping and falling. You can also fall from a great height and can cause a fracture/dislocation of the ankle. Depending on the height of the fall, the fracture can be very severe or even open.
You can misstep and put your foot down in the wrong position, leading to a broken ankle. You can twist your ankle on uneven pavement or while going up or down stairs and can fracture your ankle. Ankle fractures are common in the winter months when people slip on the ice.
Overuse of the ankle can cause a fractured ankle in the weight bearing bones but rarely would they result in subluxation of the ankle.
People with osteoporosis are at greater risk for ankle fracture/subluxations. Their bones have become weakened so that they fracture more easily than bones not affected by osteoporosis.Symptoms of Fracture/Subluxation of the Ankle
There are several symptoms of an ankle fracture/subluxation that you need to pay attention to. These include:
- Hearing a snap or crack in your ankle when you are initially injured.
- Having extreme pain, especially with movement of the ankle.
- Swelling of the joint
- Severe ankle deformity.
- If it’s an open fracture, there will be bony edges sticking out of the skin
- Bruising around the ankle
- Tenderness to palpation of the ankle
- Inability to move the ankle as much as you normally could
- Inability to completely bear weight on the affected ankle
Even if you don’t have all of the symptoms, you can still have a fractured ankle so you need to be seen by an emergency physician or your family physician to have an x-ray and further medical evaluation.Diagnosis of a Fracture/Subluxation of the Ankle
In diagnosing a fracture/subluxation of the ankle, the doctor will ask you about your symptoms and will ask you about when and how the injury happened. He or she will ask you if the bruising and swelling developed immediately or took several hours to develop. You will be asked whether you had difficulty putting your weight on the foot immediately following the injury.
The doctor will examine your lower leg, ankle and foot, looking for areas of tenderness, swelling and bruising. Areas of concern include the lateral malleolus, which is the distal end of the fibula, and the medial malleolus, the distal end of the tibia. The malleoli are the bony knobs on either side of the ankle. The doctor will look for evidence that the fractures are open and will assess the stability of the ankle. In a fracture/subluxation, the bony ankle will be unstable.
Range of motion will be assessed and compared to the normal ankle. The pulse will be checked for in the foot to make sure there hasn’t been any vascular compromise. A brief neurological examination will be checked to make sure major nerves haven’t been injured.
A plain film x-ray may be enough to say that the bone or bones have been fractured. A dislocation may also be able to be seen on plain film. Subluxations may not be seen on plain film and instead, you may have to go under general anesthesia with films done while stressing the joint. This is the best way to determine which ligaments have been torn.Treatment of Fracture/Subluxation of the Ankle
Surgery is necessary to treat a fracture/subluxation of the ankle. These are unstable fractures that need repair in the operating room to make stable again. Usually, both the tibia and fibula are fractured, sometimes in more than one place. The ankle, in general, does not tolerate any displacement at all because it leads to an uneven load onto the ankle joint and arthritis will later occur in such a situation.
One aspect of surgery is fixing the disruption of the syndesmosis, the fibrous ligament that holds the tibia and fibula together at the level of the ankle joint. If this isn’t fixed, the ankle will continue to be unstable.
If the lateral malleolus needs fixing, it is often treated with plates and screws. Ideally the bony fragments are put together in exactly the same place that they were in before the injury.
Fractures of the medial malleolus are fractures of the distal end of the tibia. An incision is made along the medial aspect of the ankle and any blood clot is removed. The fracture is generally held together with two screws.
If both the medial and lateral malleoli are involved, they are repaired in the same procedure with two incisions made. At all times, the bones are put together in the same way as they existed before the fracture. A trimalleolar fracture is treated much like a bimalleolar fracture. The broken posterior fragment off the distal tibia needs to be approximated but only if it represents greater than 20 percent of the joint surface. It is usually fixed with one or two screws from the front to the back of the ankle.
If the syndesmosis is partially or totally torn, the doctor determines this by stressing the ankle under fluoroscopy. The syndesmosis is not sutured but rather two screws are place that hold the tibia and fibula together to make sure the syndesmosis can heal over time. It takes 3-6 months for this to happen and, after that, the screws are removed.
It takes about 6 weeks for the bones to heal. The patient is in a cast boot or postoperative type of shoe and is non-weight bearing. At about twelve weeks post operatively, the patient can increase weight bearing depending on the level of pain. The patient can begin using a regular show and can attend physical therapy for rehabilitation.Complications of Fracture/Subluxation of the Ankle
There are several complications of a fracture/subluxation of the ankle. There can be a nerve injury, particularly with the superficial peroneal nerve. This occurs during surgery and depends on the placement of the incisions, especially when repairing the lateral malleolus. Nerve damage can happen from accidently cutting the nerve, from retraction during surgery or from the buildup of scar tissue as the injury heals. The end result is pain or numbness along the path that the nerve travels.
There can be calf muscle atrophy from lack of ability to move those muscles during the recovery period. Usually this muscle can strengthen following a good period of time with physical therapy and exercise. It may not, however, come back to its full potential.
Even when the fracture was repaired correctly, there may be stiffness of the joint capsule, which subsequently decreases the range of motion in the ankle joint. The stiffness can lead to ankle arthritis that can last a lifetime. Most people with arthritis of the ankle have suffered some kind of injury in the past to the ankle.
There can be increased pain associated with the plates and screws used in the repair of the fractures. About 15-20 percent of patients with internal fixation need to have the screws and plates removed after the bone has healed.
There can be a failure or fracture of the screws used to hold together the tibia and fibula while the syndesmosis heals. This happens if the screws are removed too late. Fortunately, this sort of failure is not painful and does not change the way a person recovers from this type of surgery.
Postoperative infection following open reduction and internal fixation happens about 40 percent of the time. The infection risk is higher in those that are diabetic and in those who have poor control of their diabetes. In some cases of infection, the entire surgery must be repeated.
There can be wound complications that need to be treated with special dressings such as vacuum dressings. Even so, there can be wound margin necrosis which will extend the length of the hospital stay.
There can be poor reduction of the syndesmosis. This is very important because the syndesmosis must heal together and must heal tightly. If this does not happen, there can be stress on the joint and inability to place full weight on the foot.
If you or a loved one has suffered an ankle injury as a result of someone else's negligence and would like to discuss your legal options with an experienced Sacramento Personal Injury Attorney, contact us online or call us at 916.921.6400 to set up a FREE consultation.