Differential Diagnosis for Intraosseous/Subchondral Cyst on X-ray
Single Most Likely Diagnosis
- Osteoarthritis (OA): This is the most common cause of intraosseous or subchondral cysts, especially in weight-bearing joints like the hips and knees. These cysts are a hallmark of OA and are thought to result from the abnormal stress and bone remodeling associated with the disease.
Other Likely Diagnoses
- Rheumatoid Arthritis (RA): While less common than OA, RA can also lead to the formation of subchondral cysts due to the inflammatory process and associated bone erosion.
- Gout: Gouty arthritis can cause subchondral cysts, particularly in the context of chronic tophaceous gout, where urate crystals deposit in the joints and surrounding bone.
- Trauma: Previous trauma to a joint can lead to the development of subchondral cysts, possibly due to altered joint mechanics and stress distribution.
Do Not Miss Diagnoses
- Infection (Osteomyelitis or Septic Arthritis): Although less common, an infectious process can lead to cystic changes within bone. Missing this diagnosis could lead to severe consequences, including joint destruction and systemic infection.
- Tumor (e.g., Chondroblastoma, Giant Cell Tumor): Certain bone tumors can present with cystic lesions. While rare, these conditions require prompt diagnosis and treatment to prevent significant morbidity.
Rare Diagnoses
- Synovial Chondromatosis: A rare condition characterized by the growth of cartilage in the synovium, which can lead to the formation of subchondral cysts.
- Hemophilia: Repeated hemarthroses in patients with hemophilia can lead to joint damage, including the formation of subchondral cysts.
- Sickle Cell Disease: Bone infarcts associated with sickle cell disease can sometimes present as cystic lesions on X-ray, although this is less common in the subchondral region.