- Stage I: Soft-tissue swelling from hemarthrosis or bleeding into the periarticular soft tissues. No skeletal abnormality.
- Stage II: Osteoporosis and overgrowth of the epiphysis without bone cysts or narrowing of the cartilage space.
- Stage III: Early subchondral bone cysts, squaring of patella, widening of intercondylar notch of distal femur or humerus, preserved cartilage space. This is the final stage at which hemophilic arthropathy is reversible with treatment.
- Stage IV: Characterized by narrowing of cartilage space. More advanced findings of stage III are also seen.
- Stage V (shown above): Fibrous joint contracture (as seen in the attempted frontal view), loss of joint cartilage space, marked enlargement of epiphyses, and substantial disorganization of the joint.
- Arnold WD, Hilgartner MW. Hemophilic arthropathy. Current concepts of pathogenesis and management. J Bone Joint Surg Am. 1977 Apr;59(3):287-305.
- Ng WH, Chu WC, Shing MK, Lam WW, Chik KW, Li CK, Li CK, Ling SC. Role of imaging in management of hemophilic patients. AJR Am J Roentgenol. 2005 May;184(5):1619-23.