Differential Diagnosis for Sudden Onset Knee Pain
Single Most Likely Diagnosis
- Meniscal Tear: A meniscal tear is a common cause of sudden onset knee pain, often resulting from a twisting injury or direct blow to the knee. The menisci are cartilage structures in the knee joint that can be damaged, leading to pain, swelling, and limited mobility.
Other Likely Diagnoses
- Ligament Sprain: Ligament sprains, such as those affecting the anterior cruciate ligament (ACL) or medial collateral ligament (MCL), can cause sudden knee pain due to overstretching or tearing of the ligaments.
- Patellar Dislocation: Patellar dislocation occurs when the kneecap (patella) slips out of place, often causing sudden pain and swelling in the knee.
- Osteochondritis Dissecans: Osteochondritis dissecans is a condition where a piece of cartilage and bone in the knee joint becomes damaged, leading to pain and swelling.
Do Not Miss Diagnoses
- Septic Arthritis: Septic arthritis is a serious infection within the knee joint that requires prompt medical attention. It can cause sudden onset of severe knee pain, swelling, and fever.
- Fracture: A fracture of the knee, such as a tibial plateau fracture, can cause sudden onset knee pain and requires immediate medical evaluation.
- Osteonecrosis: Osteonecrosis, also known as avascular necrosis, is a condition where the bone tissue dies due to lack of blood supply, leading to sudden onset knee pain.
Rare Diagnoses
- Pigmented Villonodular Synovitis (PVNS): PVNS is a rare condition characterized by the growth of abnormal tissue in the knee joint, leading to pain, swelling, and limited mobility.
- Synovial Chondromatosis: Synovial chondromatosis is a rare condition where cartilage grows in the synovial membrane of the knee joint, causing pain, swelling, and stiffness.
- Knee Hemarthrosis: Knee hemarthrosis is a rare condition where blood accumulates in the knee joint, often due to a bleeding disorder or trauma, leading to sudden onset knee pain and swelling.