Differential Diagnosis for Hip Pain with Labrochondral Junction Separation

• Single most likely diagnosis:
  • Femoroacetabular Impingement (FAI): This condition is characterized by abnormal contact between the femoral head and the acetabulum, leading to labral tears and cartilage damage, which matches the findings of superior and posterosuperior partial-thickness acetabular labrochondral junction separation.
• Other Likely diagnoses:
  • Labral tear: The partial-thickness articular surface labral chondral junction detachment is consistent with a labral tear, which can be caused by trauma, overuse, or underlying hip conditions.
  • Hip instability: The blunting of the left hip anterosuperior acetabular free edge and the labrochondral junction separation may indicate hip instability, which can cause pain and limited mobility.
• Do Not Miss diagnoses:
  • Osteonecrosis: Although the report mentions no femoral avascular necrosis, it is essential to consider this condition, as it can be devastating if missed. However, the absence of marrow signal abnormality makes this less likely.
  • Infection or septic arthritis: Although there is no hip effusion or significant osteoarthritis, infection or septic arthritis can cause rapid deterioration and must be considered, especially if the patient presents with systemic symptoms like fever or chills.
• Rare diagnoses:
  • Synovial chondromatosis: This rare condition is characterized by the formation of cartilaginous nodules in the synovial membrane, which can cause hip pain and limited mobility. However, the absence of significant osteoarthritis or joint effusion makes this less likely.
  • Pigmented villonodular synovitis (PVNS): This rare condition is characterized by the proliferation of synovial tissue, leading to joint pain and swelling. Although the report does not mention significant joint effusion or synovial thickening, PVNS should be considered in cases of unexplained hip pain.