The tibia (shin bone) and the fibula are the bones of the lower leg. Pilon fractures are injuries that occur at the lower end of the tibia and involve the weightbearing surface of the ankle joint. The fibula also may be broken. These injuries were first described more than 100 years ago and remain one of the most challenging problems for orthopaedic surgeons to treat.
The word “pilon” comes from the French and means pestle. A pestle is a tool used for crushing or pounding things. This crushing describes what happens to the tibia and fibula bones at the ankle joint due to the high-energy impact of the injury.
Pilon fractures occur when the talus (ankle bone) is driven into the leg with such force that the leg bones break at the ankle joint. Common causes of pilon fractures are falls from heights and car accidents.
Pilon fractures are very painful and debilitating injuries. Symptoms include pain and inability to bear weight on the leg. They often result in an obvious deformity of the ankle joint. Swelling occurs quickly and can be followed by bruising.
Your foot and ankle orthopaedic surgeon will take your medical history and perform a physical examination of your leg and ankle. The results of this exam will help the surgeon to determine how best to treat the pilon fracture. Your surgeon will be watchful for other injuries that may be present.
In addition, your surgeon will take X-rays of your leg and ankle to see how badly the tibia and fibula are broken. The bones may be broken in multiple places. The surgeon also may get a CT scan of your ankle to view all of the broken areas of the tibia and fibula.
Some pilon fractures do not need surgical treatment. These are typically lower-energy injuries to the tibia and fibula at the ankle joint. The bones are broken but simply shifted out of place and these injuries tend to be less severe. These lower-energy pilon fractures can be treated with a leg cast.
Most pilon fractures have multiple breaks. There often are large separations between fractured fragments and instability in the tibia and fibula at the ankle joint. These fractured bones often benefit from surgery.
The goals of pilon fracture surgery are to restore alignment and stability and allow healing of the tibia and fibula at the ankle joint. Once the fractures are healed, the goals are to restore your ankle’s movement and strength.
Pilon fracture surgery usually is done in two steps to protect the skin and soft tissue. Orthopaedic surgeons do not routinely perform incisions through areas of damaged skin because doing so may result in wound healing problems. Surgeons often must wait until a patient’s soft tissue improves before incisions can be made. A notable exception would be an open fracture where the bone has penetrated through the skin during the initial bone break.
In many cases the first stage in treating pilon fractures is by surgically applying an external fixator to the patient’s leg. This fixator is a frame applied outside of the leg that holds the leg and ankle in proper position. This allows both the patient and surgeon to regularly inspect the soft tissue of the leg and ankle without frequent splint changes. The fibula fracture may be treated at the same time the external fixator is placed. This part of the procedure is known as open reduction and internal fixation of the fibula (ORIF).
It may take several weeks after the first surgery before the patient’s soft tissues improve and the leg is ready for the second stage of surgical treatment. This delay can be frustrating for the patient, but it may be necessary to minimize the risk of a wound healing problem. The wait does not affect overall results. In some cases the external fixator is used as the final treatment and is kept in place for many weeks to months. Patients often are asked to elevate their leg to quickly reduce their swelling to prepare for the second stage.
The second stage of surgical treatment is to remove the external fixator and fix the tibia fracture using plates and screws. The fibula may also receive an ORIF if it was not fixed in the first stage.
When an external fixator is applied surgically to the patient’s leg, steel pins are placed in the tibia far above the fracture and also in the heel (calcaneus) and foot (metatarsals) bones far below the fracture. The pins are placed through small incisions that minimize damage to the soft tissues. They attach to metal bars outside the skin. The external fixator helps to hold the leg and ankle in proper position while the patient’s soft tissues improve.
The fibula may be fixed at the same time if the skin is not damaged. ORIF of the broken fibula involves an open incision over the bone. The broken fragments are put back together and held in place with a metal plate and screws. Special care is taken to restore the length of the fibula. The incision is then sewn together in layers. Deep tissue over the bone is closed with sutures and the skin is closed with sutures or staples.
This next step is an ORIF of the tibia bone. This step may be delayed several days or even weeks after the initial surgery. The incisions typically are at the front or the inner side of the ankle. Other incisions may be made depending on the injury. The broken fragments are put back together and held in place with metal plates and screws. Special care is taken to restore the shape and stability of the ankle joint. The fibula may be fixed with an ORIF if it was not previously treated. The incisions are then sewn together. The external fixator is typically removed and the leg is placed in a splint. This involves slabs of plaster that are applied to the rear and sides of the leg, ankle and foot. Special care is taken to cushion the leg with appropriate padding.
It often takes 3-6 months for the breaks in the tibia and fibula bones to heal. Until the bones fully heal, the patient’s leg and ankle cannot be stressed or worked too hard. Advancing activity too soon before the tibia and fibula bones are healed can jeopardize the repair and ultimately bone healing.
The surgeon also must schedule regular visits to monitor healing of the fracture and advance the patient’s activity accordingly. Many surgeons have a specific schedule for patients to see them in the office for post-surgical follow-up until the pilon fracture is fully healed.
The patient’s first post-surgical visit is usually about two weeks after surgery. The splint is removed and the patient’s leg is examined. The sutures/staples are removed if the incisions are healing well. If there is more severe leg swelling, the surgeon may wait longer before removing the sutures/staples. X-rays of the leg and ankle are performed to confirm that the tibia and fibula fractures are still in place. The leg in then placed in either a cast or a removable boot.
Patients usually received monthly follow-up with their surgeon. At each of these regular visits, the surgeon checks on the patient’s leg’s soft tissue, bones and ankle joint. The soft tissue is checked for swelling and wound problems, while the bones are checked on X-rays for the progression of healing. The ankle joint is checked for movement, strength, and stability.
Patients are restricted from full weight bearing on their operated leg until there is complete healing of the tibia and fibula bones. Patients are not allowed to bear weight on their leg in their post-surgical splint. Patients are not allowed to bear any weight on their operated leg until there is evidence of bone healing. This period of non-weight bearing is with the leg in either a cast or boot. It usually takes 6-12 weeks to see initial bone healing on X-rays.
So long as the patient’s tibia and fibula are healing with each subsequent visit, weight bearing activity gradually can be increased in the protective boot. Patients ultimately can remove the boot and gradually resume activities in normal shoes.
The time to achieve full bone healing of a pilon fracture typically occurs 3-6 months after surgery, but it often takes patients 12 months or more to fully recover from the injury. These are serious ankle injuries. Most patients do not return to the same function that they had before getting hurt. It is common for patients to have residual aches, swelling, stiffness, and weakness even after the tibia and fibula bones are healed. Some patients may need physical therapy to help in their recovery.
Early potential complications are problems that can occur within the first few weeks after surgery. Many of these are wound-related, whether these are healing problems or infection. Some of these are superficial problems or infections that can improve with wound care and oral antibiotics. Deeper wound problems or infections can occur and are more severe. These problems often need further surgery or stronger antibiotics to eliminate the infection.
Other potential complications can occur within several months after surgery. Many of these involve difficulties with bone healing at the fractured areas. Some patients experience “delayed unions” in which the bones ultimately heal but take longer than six months to do so. Many delayed unions can improve by immobilizing the leg and limiting full activities for the longer amount of time it needs to heal. Some surgeons may recommend that the patient use a bone stimulator. This is a removable device that is worn on the patient’s leg that uses ultrasound or electrical impulses to help stimulate bone healing.
Another potential problem is a nonunion. This is when the bones do not fully heal. Some nonunions develop when the blood supply to the bones has been damaged from the injury. Other nonunions occur if there is too much movement between fractured pieces of bone. Some of these can be treated in the same way as delayed unions. Other nonunions may need surgery. The surgery to treat the nonunion depends on an individual’s situation. It may involve procedures like adding healthy bone from other parts of the body or chemicals to help stimulate bone healing.
Long-term complications can occur many years after the patient’s pilon fracture is healed. The most common is ankle arthritis. Restoring tibia and fibula bone and ankle joint alignment lessens the chances of patients developing ankle arthritis. However, the cartilage at the tibia that helps to cushion the ankle joint can be irreversibly damaged during the initial injury. Arthritis can result in pain, swelling, stiffness, and weakness at the leg and ankle.