Differential Diagnosis for Knee Locking
Single Most Likely Diagnosis
- Meniscal Tear: This is the most common cause of knee locking, where a tear in the meniscus (cartilage) can cause it to become trapped between the bones, leading to locking or catching sensations in the knee.
Other Likely Diagnoses
- Loose Body: A loose fragment of bone or cartilage within the knee joint can cause locking or catching sensations.
- Osteochondritis Dissecans: A condition where a piece of cartilage and bone becomes detached from the surrounding bone, leading to locking or pain in the knee.
- Ligamentous Injury: Injuries to the ligaments surrounding the knee, such as the anterior cruciate ligament (ACL), can cause instability and locking sensations.
Do Not Miss Diagnoses
- Septic Arthritis: A bacterial infection within the knee joint, which can cause severe pain, swelling, and locking, and requires prompt medical attention to prevent long-term damage.
- Tumor: A rare but potentially life-threatening cause of knee locking, where a tumor grows within the knee joint or surrounding bone.
Rare Diagnoses
- Synovial Chondromatosis: A rare condition where cartilage grows within the synovial lining of the knee joint, leading to loose bodies and potential locking sensations.
- Discoid Meniscus: A rare congenital condition where the meniscus is abnormally shaped, leading to increased risk of tearing and locking sensations.
- Osteonecrosis: A rare condition where the bone within the knee joint dies due to lack of blood supply, leading to pain and potential locking sensations.