Differential Diagnosis for Knee Pain When Walking Down Stairs
Single Most Likely Diagnosis
- Patellofemoral Pain Syndrome (PFPS): This condition is characterized by pain around or behind the patella, often exacerbated by activities that put stress on the knee, such as walking down stairs. The pain is usually due to abnormal tracking of the patella within the femoral groove, leading to increased stress on the patellofemoral joint.
Other Likely Diagnoses
- Osteoarthritis (OA) of the Knee: OA can cause pain in the knee, especially with weight-bearing activities like walking down stairs. The pain is typically worse with activity and relieved by rest.
- Meniscal Tears: Tears in the menisci, which are cartilage structures within the knee joint, can cause pain, especially with twisting or bending movements, such as those involved in walking down stairs.
- Ligament Sprains: Sprains of the ligaments around the knee, such as the medial or lateral collateral ligaments, can cause pain and instability, particularly with activities that involve bending or twisting the knee.
Do Not Miss Diagnoses
- Septic Arthritis: Although less common, septic arthritis is a serious condition that requires prompt diagnosis and treatment. It can cause severe pain, swelling, and warmth of the affected joint, and can be life-threatening if not treated promptly.
- Osteonecrosis (Avascular Necrosis): This condition, which involves the death of bone tissue due to lack of blood supply, can cause severe pain in the knee, especially with weight-bearing activities. It is a serious condition that can lead to collapse of the bone and require surgical intervention.
Rare Diagnoses
- Tumor or Cyst: Rarely, a tumor or cyst within or around the knee joint can cause pain, especially with activity. Examples include osteoid osteomas, synovial chondromatosis, or ganglion cysts.
- Complex Regional Pain Syndrome (CRPS): This is a rare condition characterized by chronic pain, inflammation, and hypersensitivity, usually following an injury. It can affect the knee and cause significant pain and disability.