Cаse Study:Chief Cоmplаint Greg, а 68 y/о male, presents tо his family doctor c/o bilateral knee pain that worsens prior to a heavy rainstorm. He states that his "arthritis" is not getting any better. He has been taking NSAIDs but is not obtaining relief at this point. His family physician referred him to an orthopedic surgeon for further evaluation.Past Medical History Greg was active in sports in high school and college. He tore his ACL while playing football his junior year in college, at which time he retired from intercollegiate athletics. His only other physical complaint involves mild stiffness in his right shoulder, which he attributes to pitching while playing baseball in high school. What does the abbreviation ACL mean?