Ankle Injury Basics for the Physician Assistant Exam
Injuries to the ankle are a common reason why people go to the emergency room. The Physician Assistant Exam (PANCE) will ask you about the common cause of these ankle injuries. Many of these injuries are sports injuries or secondary to sports-related injuries.
The soft tissues of the ankle
The most common ankle injury is the ankle sprain. Sometimes you may see a diagnosis, especially in the ER, of an “ankle sprain and strain,” but strains and sprains differ:
Strain: In general, a strain is an injury to a muscle or tendon, usually caused by pulling or pushing or twisting the wrong way.
Sprain: An ankle sprain refers to an injury that affects the ligaments. During an activity that involves running and jumping, the person lands on his or her ankle the wrong way, causing abnormal stretching and/or possibly a ligamentous tear, usually in the lateral ligaments. In the most common type of ankle injury, the ankle inverts — that is, the bottom of the foot turns inward, injuring the anterior talofibular ligament.
A radiograph is often ordered to evaluate an ankle injury for a possible fracture. However, the Ottawa ankle rules, which help clinicians determine whether a radiograph is needed, were designed to reduce unnecessary radiographs and to cut down on patient waiting time, especially in the ER. In short, you order a radiograph if the affected person
Can’t bear weight on the ankle immediately after the injury (or at the time of examination by a medical professional)
Has bone tenderness in one of the following places:
Along the distal 6 cm of the posterior edge of the tibia or tip of the medial malleolus
Along the distal 6 cm of the posterior edge of the fibula or tip of the lateral malleolus
At the base of the fifth metatarsal
At the navicular bone
Just to make life even more difficult, there are three grades of ankle sprains — Grades 1, 2, and 3. The grading depends on the severity of the sprain (mild, moderate, or severe). Thus, Grade 1 is a mild sprain, and Grade 3 is a severe sprain. The more severe the sprain, the more rehabilitation the patient needs and the more time to recover.
Most of the time, the treatment is temporarily not bearing weight on the ankle, applying intermittent ice and heat, and elevating the leg. An ankle splint and/or brace may be prescribed.
The Achilles tendon is vital because it connects the calf muscle to the heel. This tendon is important for walking, for activities like running and jumping, and for standing up on your tippy-toes. Achilles tendon injuries include strain and rupture. One of the most common patients to suffer with tendon injury is the weekend warrior, someone who’s sedentary during the week and goes wild with athletics on the weekend.
In addition to the lack of physical conditioning, failure to warm up, stretch properly, and wear proper footwear all play an important role in Achilles tendon injuries. The most common mechanisms of injury include sudden forced plantar flexion of the foot, unexpected dorsiflexion of the foot, and violent dorsiflexion of a plantar flexed foot.
Clinically, the most common presentation is the affected person’s yelling “Ow!” and pointing to his or her calf area. The calf area right above the insertion site to the heel is tender. The MRI is the diagnostic test of choice. Treatment is conservative and consists of anti-inflammatories, pain medication, and rehabilitation. Surgery may be required for full-thickness tears.
The class of antibiotics called the fluoroquinolones has been reported to increase risk of tendon rupture. The Achilles tendon remains the most common site of quinolone-induced rupture.
Take an ankle and push, pull, rotate, invert, or evert it in any one significant direction, and you can fracture it. Most of the time, ankle fractures occur with ligamentous tears.
Presenting symptoms of an ankle fracture can include ecchymosis over the area of injury and an inability to bear weight. The ankle can be cold to palpation. The ankle can’t be moved at all or can’t be moved without significant pain.
Radiographs need to be done pronto. If the patient has a fracture, initial treatment can involve splinting and/or casting. The key is to avoid weight-bearing (by using crutches) and to keep the area as stable as possible. Some ankle fractures require immediate surgery.