American Board of Surgical Assistants (ABSA) Orthopedic Practice Test

A young man experiences severe pain and has an edematous, discolored area around his ankle. What is the diagnosis if he cannot plantar flex his foot?

1. Fractured ankle

2. Ruptured Achilles tendon

3. Ankle sprain

4. Distracted ankle

The correct answer is: Ruptured Achilles tendon

The presentation of severe pain, edema, discoloration around the ankle, and the inability to plantar flex the foot strongly suggests a ruptured Achilles tendon. The Achilles tendon is crucial for the patellar tendon, as it allows for the primary movements associated with plantar flexion—raising the heel off the ground and contributing to walking and running. When this tendon is ruptured, individuals typically experience a sudden, sharp pain in the back of the ankle, followed by significant swelling and bruising. The inability to plantar flex the foot is a hallmark sign, as the muscles responsible for this action (the gastrocnemius and soleus) are no longer able to effectively pull on the Achilles tendon. Other conditions, such as a fractured ankle or an ankle sprain, can lead to swelling and pain as well, but these would not typically result in an absolute inability to plantar flex the foot. Instead, a fractured ankle might present with acute pain localized to the bone area, and an ankle sprain would generally allow for some range of motion despite pain. The term “distracted ankle” does not correlate with typical orthopedic terminology and is unlikely to be the correct answer. Thus, the combination of symptoms and functional loss points directly to a rupt