Tissue torn by some athletes, in brief

ACL

This knee ligament injury often requires surgery for athletes to recover fully.

The clue hints at a common sports injury where athletes tear a specific tissue, abbreviated as "ACL," which stands for anterior cruciate ligament. The phrase "in brief" signals that the answer is an abbreviation. Athletes, especially in sports like football or basketball, often suffer ACL tears, making it a well-known term in sports medicine.