Differential Diagnosis for Posterior Knee Pain
- Single Most Likely Diagnosis
- Baker's Cyst: A fluid-filled cyst that causes pain and swelling in the posterior knee, often associated with knee arthritis or injury. This is a common cause of posterior knee pain, especially in older adults.
- Other Likely Diagnoses
- Hamstring Strain: A muscle strain in the back of the thigh can cause posterior knee pain, especially with activities that involve bending or straightening the knee.
- Gastrocnemius Strain: A strain in the calf muscle can also cause pain in the posterior knee, particularly with activities that involve ankle movement.
- Popliteus Tendinitis: Inflammation of the popliteus tendon, which connects the popliteus muscle to the lateral femur, can cause posterior knee pain, especially with rotational movements.
- Do Not Miss Diagnoses
- Deep Vein Thrombosis (DVT): A blood clot in the deep veins of the leg can cause posterior knee pain, swelling, and warmth. This is a medical emergency that requires prompt treatment.
- Popliteal Artery Aneurysm: A bulge in the popliteal artery can cause posterior knee pain, swelling, and weakness in the leg. This is a rare but potentially life-threatening condition.
- Tumor or Cyst: A tumor or cyst in the posterior knee, such as a synovial sarcoma or a ganglion cyst, can cause pain and swelling. Although rare, these conditions can be serious and require prompt evaluation.
- Rare Diagnoses
- Popliteal Cystic Adventitial Disease: A rare condition characterized by the formation of cysts in the adventitia of the popliteal artery, which can cause posterior knee pain and claudication.
- Fabella Syndrome: A rare condition where a small bone in the posterior knee, the fabella, causes pain and inflammation due to friction or impingement.
- Neurogenic Causes: Rarely, posterior knee pain can be caused by neurogenic conditions such as a lumbar radiculopathy or a peripheral neuropathy.