If you stand and twist your leg and it hurts does that mean that you either of a meniscus or acl problem? a displacment means a tear of the meniscus?

Knee problems: Yes, you could damage your meniscus and/or acl by standing and twisting your leg. Displacement means the state of being out of place. Meniscus or bone fracture fragments are displaced when they are out of place.

Meniscus.: It's probably more meniscus than ACL. See a sports medicine trained orthopedic specialist for an accurate diagnosis.