Pit Bull 101: Torn Ligaments

“A torn cranial cruciate ligament is one of the most common orthopedic disorders among dogs,” says Dr. Harari. Dogs knees are very similar to humans knees, and the cranial cruciate ligament is the same as the anterior cruciate ligament (ACL) in humans. Like human athletes who tear their ACLs, dogs tear their cranial cruciate ligaments during athletic activities.”

Source http://www.cvm.uiuc.edu/petcolumns/showarticle.cfm?id=43