The goals of treating fractures of the talus are to:
- Maximize the movement of the ankle and subtalar joints
- Restore the anatomic dimensions of the bone
- Prevent arthritis of either of the above joints
This is not easy because of the magnitude of the fracture that commonly occurs in the most serious injuries. Arthritis may develop, or even worse, there may be a loss of blood supply to the bone. This loss of blood supply is one of the more devastating problems associated with fractures of the talus. In order for the bone to survive and heal after a fracture, it needs blood circulation. One of the problems commonly associated with certain severe fractures of the talus is that the blood circulation to this bone is damaged, leading to partial death of the bone (called avascular necrosis).
Not all fractures of the talus lead to the development avascular necrosis. However, if this does occur, it is commonly associated with the development of arthritis of both the ankle and/or the subtalar joint, as well as the collapse of the bone.
Treatment options of fractures of the talus are quite varied. They range from immobilization of the foot in a cast or boot to surgery. If surgery is performed it is usually done with incisions and then the bone is put back together with a procedure called open reduction and internal fixation. Pins and/or screws are used to reduce and hold the bone in place.
Fractures of the talus can be quite devastating. These are difficult fractures to treat, and even with good correction and fixation of the fracture, numerous complications can occur. Some of these are as a result of deformity, some from arthritis, and some occurring when the blood supply to the talus bone is damaged.
- Ankle arthritis. Arthritis of the ankle can occur. The ankle joint moves in the up and down direction, and if arthritis of the ankle occurs, this will affect the ability of the ankle to move.
- Subtalar arthritis. The joint underneath the talus bone is called the subtalar joint. This is the joint which joins the talus to the heel bone called the calcaneus, and is responsible for the in and out movement of the back of the foot. This movement is called inversion and eversion. If arthritis of the subtalar joint occurs, then there will be more pain on in and out movement of the foot than the up and down movement. If arthritis of the subtalar joint occurs, then the most common operation to correct this is a fusion (gluing together) of the subtalar joint. This operation results in correction of the pain in the back of the foot, but the foot is stiffer, and little if any in and outward movement of the foot remains. Provided that the bone is healthy, the fusion is not too complicated. Unfortunately, the talus can collapse in size, and if this occurs, then special types of bone graft need to be used to correct the deformity and make sure that healing occurs without losing more height of the back of the foot.
- Deformity of the foot. One of the problems with talus fractures is that in addition to the main fracture, there are often additional smaller fractures on the inside of the bone. When the fracture is fixed, it can be difficult to reposition the bone correctly, and deformity occurs. Typically, the foot turns inward and what happens is that more weight is placed on the outside of the foot, which can be terribly painful. Some doctors have tried to correct the deformity by cutting the talus bone and inserting a bone graft, but this rarely works, and pain and stiffness of the foot and ankle continues. The only reliable way to correct this deformity (called a varus deformity) is to fuse three joints in the back of the foot. This operation is called a triple arthrodesis.
- Avascular necrosis of the talus (AVN). The talus bone as every other bone depends on a blood supply to remain alive. When the talus is fractured, this blood supply can be torn, leading to death of the talus. This dead bone can be total, and include the entire talus, or patchy, without much destruction to the bone.
Recovery after fractures of the talus can be prolonged. Walking and weight bearing on the foot cannot occur for eight to 12 weeks. Once the bone is healed, however, exercise and physical therapy is initiated to maximize the function of the ankle. If avascular necrosis of the bone occurs then one has to be more careful with the type of exercise and activities that are initiated.