Which injury is commonly associated with knee locking?

Knee locking is typically associated with a meniscal tear. This occurs when the meniscus, which is the cartilage that acts as a cushion between the femur and tibia in the knee joint, is damaged. A tear can cause a piece of the cartilage to become trapped within the joint, leading to a sensation of the knee getting stuck or locked in place during movement.

Patients often describe the feeling that their knee won’t move freely, particularly when bending or straightening the leg. This symptom is most prevalent with certain types of meniscal tears, especially those that are bucket handle tears, where a fragment of the meniscus flips into the joint and prevents movement.

In contrast, an ACL tear primarily results in instability of the knee but is not typically associated with locking. A patellar fracture usually leads to significant pain and swelling, impairing motion but not causing a locking sensation. Quadriceps strains primarily affect muscle and flexibility, leading to pain but not mechanical locking of the knee joint. Thus, the meniscal tear is the injury most directly linked to the phenomenon of knee locking.