Keys To Diagnosis of Foot and Ankle Injuries
Missed or delayed diagnoses of peritalar injuries can leave a patient limping for the rest of his or her life. To help orthopedic surgeons quickly and accurately diagnose these injuries, orthopedic specialists have written this article reviewing these rare and often subtle foot and ankle injuries.
Peritalar refers to the talus and the soft tissues and bones around that bone. The talus is one of the large bones in the back part of the foot that helps form the ankle joint. It sits just above the calcaneus, or heelbone. The two bones make up the back part of the foot (sometimes referred to as the hindfoot). The talus is connected to the calcaneus at the subtalar joint. The ankle joint allows the foot to bend up and down. The subtalar joint allows the foot to rock from side to side.
Diagnosis can be difficult because the hindfoot and ankle is a very complex structure. Flat, two-dimensional X-rays don't always show what's really going on. It isn't until the injury doesn't heal and the patient continues to report pain and difficulty walking that additional imaging studies are done to find the real problem. By that time, it could be too late to save the natural biomechanics of the subtalar joint. Surgery may be needed to fuse the joint together to reduce pain and stabilize the joint. But fusion means a loss of motion and possibly, function.
Specific injuries covered in this article include bone fractures, joint dislocations, and ligament tears/ruptures affecting any of the periarticular joints. The talus articulates (moves against) the calcaneus, tibia (shin bone), and navicular bones. The calcaneus articulates against the talus and the cuboid.
So, injury to any of the following joints can result in peritalar instability: the tibiotalar joint, subtalar, calcaneocuboid, and talonavicular. That covers a lot of territory in the foot/ankle structure. And it makes up quite a bit of foot and ankle motion as we walk. The calcaneus hits the ground first, then the leg rocks over the foot until we push off with the toes to swing the leg through and start the cycle over again. Any disruption of the bones, joints, and ligaments can impair motion and function creating significant disability.
Pictures drawn of the foot/ankle anatomy along with X-rays and CT scans help illustrate what happens when any of these areas are injured. Descriptions are given for each injury and the most common mechanisms for those injuries. This information can help physicians recognize the history and clinical presentation of peritalar disruptions, thus making the diagnosis sooner than later. Things to watch out for include:
a history of trauma to the foot and ankle
presence of tenderness to touch in specific areas
plain and/or stress or weight-bearing X-rays when trauma is a factor
CT scans when patients fail to improve
Physicians are encouraged to look at both the foot and ankle, all the joints, and all of the soft tissue structures in between. The area where the foot meets the ankle is called the transitional zone. Ignoring any points in the transitional zone during the exam and imaging studies can contribute to the delay in diagnosis.
Treatment suggestions are given for transverse tarsal joint injuries, ligamentous chopart injuries, talar head fractures, navicular fractures, cuboid fractures, talar dome injuries, lateral talar process fractures, posterior talar process fractures, and a variety of different calcaneal fractures. Treatment can range from cast immobilization to surgery. The goal is to limit pain and restore function. Instrumentation with plates and screws may be needed to accomplish this. Fusion called arthrodesis is a last resort but may be necessary.
The authors conclude that loss of any of the strong, supportive soft tissue structures of the peritalar region can lead to collapse of the surrounding joints. Early recognition, diagnosis, and treatment can mean the difference between an uneventful recovery and permanent disability. Even though these injuries are rare, the physician who keeps in mind the keys to diagnosis will have no trouble recognizing these problems.
Joseph X. Kou, MD, and Paul T. Fortin, MD. Commonly Missed Peritalar Injuries. In Journal of the American Academy of Orthopaedic Surgeons. December 2009. Vol. 17. No. 2. Pp. 775-786.