Differential Diagnosis for Prominent Patellar Spurring and Patellofemoral Joint Space Narrowing

• Single Most Likely Diagnosis
  • Osteoarthritis (OA) of the patellofemoral joint: This is the most likely diagnosis due to the presence of patellar spurring and joint space narrowing, which are hallmark signs of OA. The lateral predominance of joint space narrowing is consistent with the typical pattern seen in patellofemoral OA.
• Other Likely Diagnoses
  • Patellofemoral pain syndrome (PFPS): Although PFPS is more commonly associated with soft tissue and alignment issues, chronic conditions can lead to degenerative changes, including spurring and joint space narrowing.
  • Chondromalacia patellae: This condition involves the softening of cartilage on the underside of the patella, which can lead to pain and degenerative changes similar to those described.
• Do Not Miss Diagnoses
  • Septic arthritis: Although less likely, septic arthritis of the patellofemoral joint could present with joint space narrowing and could be deadly if missed due to the potential for rapid joint destruction and systemic infection.
  • Crystal arthropathy (gout or pseudogout): These conditions can cause acute or chronic joint inflammation and degeneration, including the formation of spurs and joint space narrowing, and require specific treatment.
• Rare Diagnoses
  • Wilson's disease: A rare genetic disorder that can lead to copper accumulation in joints, causing degenerative changes.
  • Hemochromatosis: A condition characterized by excessive iron storage, which can lead to joint degeneration, including the patellofemoral joint.
  • Neuropathic arthropathy: Although more commonly associated with other joints, neuropathic arthropathy due to various causes (e.g., diabetes, syphilis) could potentially affect the patellofemoral joint, leading to rapid degeneration.