Hey Woody Paige! There's no such thing as an Achilles' heel injury. An Achilles' heel is a literary allusion to a weak link in a chain or a chink in the armor. What you mean is an Achilles' tendon injury, or an Achilles' tendon rupture.
"An Achilles’ heel is a deadly weakness in spite of overall strength, that can actually or potentially lead to downfall. While the mythological origin refers to a physical vulnerability, metaphorical references to other attributes or qualities that can lead to downfall are common."
as opposed to
"The Achilles tendon (or occasionally Achilles’ tendon), also known as the calcaneal tendon or the tendo calcaneus, is a tendon of the posterior leg. It serves to attach the plantaris, gastrocnemius (calf) and soleus muscles to the calcaneus (heel) bone."