Injuries of the talus or broken fracture may therefore affect multiple joints and multiple planes of movement of the foot and ankle. These injuries range from relatively minor chips or fragments that are broken off the edges of the talus to very serious talus neck or talus dome fractures that can be quite disabling.
Most injuries to the talus result from motor vehicle accidents, although falls from heights also can injure the talus. These are serious injuries are often associated with injuries to the lower back. Talus fracture is associated with other injuries in about 50% of cases.
Aim of treatment in talus fracture is to restore the bone shape and alignment. This in turn leads to realignment of its connecting joints which prevent arthritis and maintain movements in these joints. This is not always possible especially when the injury is severe and there are multiple small bone fragments. In such cases arthritis can develop. Blood supply to the bone can also be damaged at the time of injury leading to a condition called avascular necrosis of talus. Not all fractures of the talus lead to the development of avascular necrosis. However, if it does occur it is commonly associated with the development of arthritis in both the ankle and/or the subtalar joint, as well as the collapse of the bone. All this can happen despite treatment but proper treatment does substantially decrease chances of all this happening.
Treatment of fracture depends upon whether they are displaced or not. If in doubt a CT Scan will confirm the displacement. All displaced talus fractures are best treated with surgery. Surgery includes open reduction internal fixation with screws and pins.
Recovery after fractures of the talus can be prolonged. Walking and weight bearing on the foot cannot occur for eight to twelve 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. Walking and exercise are still permitted. There are surgical procedures that can be performed if avascular necrosis develops to try to improve the blood circulation to the talus bone.
Talus fracture is a disabling and difficult fracture. About 80% of these fractures can develop one or other complications. They should be treated by doctors who are confident in dealing with complications of this fracture and have good knowledge of mechanics of foot and ankle joints.You should contact Dr Bhargava if you have ongoing pain after talus fracture.
Common problems after fracture of talus:
1. Avascular necrosis
Avascular necrosis means that part of the talus bone becomes diseased due to disruption of its blood supply. Once avascular necrosis is established it can lead to arthritis of subtalar and ankle joints causing permanent pain and disability. Details of this condition are described separately.2. Subtalar Arthritis
Subtalar joint is the joint between talus and the heel bone calcaneus. It is responsible for inward outward movement of the heel. Subtalar joint arthritis occurs if there is damage to the subtalar joint surface at the time of injury or secondary to avascular necrosis. If it occurs patient will complain of pain in the outside of the ankle, and stiffness of the back of the foot. Walking on uneven ground surfaces is difficult since the inversion and eversion movement of the subtalar joint is missing. The treatments can consist of pain-killer tablets, injection of the subtalar joint with cortisone, special arch supports and orthotics and surgery. If joint is severely damaged and has developed arthritis than subtalar joint fusion is the best option.
- 3. Ankle Arthritis
Ankle joint is the joint between the talus and lower end of leg bones called tibia and fibula. Ankle is responsible for up and down movement of the foot. These movements are called dorsiflexion and plantar flexion. Ankle arthritis can occur if there is damage to the ankle joint surface at the time of injury or it can occur secondary to avascular necrosis of talus. If ankle arthritis occurs, it will treated by ankle replacement or fusion operation. Details of these are discussed later in avascular necrosis section.
- 4. Fracture malunion leading to deformity of the foot
Fractures of the talus are commonly associated with smaller fractures. This is called fracture comminution. This can lead to collapse of bone while healing leading to development of malunion and secondary deformity. Varus malunion is the most common deformity. In this deformity the foot is turned inwards putting more pressure and pain on the outside of the foot. If this occurs this need operation. Type of operation depends upon the severity of deformity and status of underlying joint. It can either be treated by bone grafting and deformity correction or triple arthrodesis.
- Avascular Necrosis of Talus
MRI scans pictures of hindfoot showing black and white areas of avascular necrosis in the talus. These areas indicate portions of talus without blood supply. MRI scan is useful to diagnose Avascular necrosis.
Avascular necrosis of the talus can be quite difficult problem. It can lead to cause damage to the ankle joint resulting in ankle arthritis, deformity and pain. It commonly occurs following fractures of the talar neck and has been reported in 10–100% of cases.
CT Scan picture of the hindfoot on the left showing undisplaced fracture of talus. CT Scan is a good diagnostic tool when xrays are not clearly showing the fracture. Compare it with the displaced fracture on the right. AVN is more likely in the displaced fracture
There is an increased incidence of avascular necrosis with increasing fracture displacement as predicted by the Hawkins classification. Open traumatic wounds have been shown to be associated with an increased rate of avascular necrosis in both talar body and talar neck injuries, with reported incidences ranging from 69% to 86%.
Displaced fracture of Talus neck with body of talus dislocating out of Ankle joint. Chances of AVN reach up to 100 % in such cases.
Whether AVN or avascular necrosis will develop or not really depends upon the type of the fracture and not on how it is managed. This is because as seen above in the pictures the more displaced the fracture is it more likely that it will damage the blood supply to the talus. It is important to know that healing of fracture usually occurs despite avascular necrosis. On x-rays While the majority of patients will have some evidence of increased density on x-ray evaluations following a neck fracture, this finding does not predict talar collapse or a poor result. A significant percentage of these cases will undergo revascularization with resolution of the sclerosis, while others will have persistence of sclerosis without collapse.
Avascular necrosis with talar body collapse is a very serious complication that results in pain and associated ankle and subtalar joint arthritis. Complex secondary reconstructive procedures are needed.
For patients with isolated subtalar arthritis subtalar fusion is a good operation for relieving pain and improving walking.
Traditionally, when arthritis of the ankle joint occurs after AVN and talus fracture, a fusion of the ankle has been recommended. This fusion is a complicated operation, and the results of the fusion are not always predictable. This also results in profound stiffness of the hindfoot especially when both subtalar and ankle joints are involved.
The problem with fusion, is that there is limited blood supply into the talus, and the success of the fusion is not always that good. For this reason, alternative treatments are desirable. In particular, instead of the fusion of both the ankle and the subtalar joint which is illustrated above, following a fusion of the subtalar joint, an ankle joint replacement can be performed. Also ankle replacement can be done in isolation especially if the subtalar joint is not symptomatic.