Final answer:
An ACL tear causing instability, popping, and hemarthrosis in the knee is best treated with arthroscopic surgery and physical therapy for a full recovery.
Step-by-step explanation:
A female with knee instability, popping, and hemarthrosis is most likely experiencing an injury related to the ligaments of the knee. Based on the symptoms described, the most probable cause is an anterior cruciate ligament (ACL) tear. This injury often occurs following a forceful blow to the anterior knee resulting in hyperextension or when there is a rapid change in direction causing twisting as well as hyperextension of the knee. The appropriate treatment for an ACL tear typically includes surgery followed by physical therapy to regain function and stability. Arthroscopic surgery is the preferred method, as it involves a minimally invasive procedure with more rapid recovery times, using a graft, commonly from the patellar ligament, to reconstruct the torn ACL.