- Discussion:
- disease is most crippling when repeated bleeding into joint produces arthritis;
- left untreated most severe hemophiliacs will suffer crippling arthritis in one or more joints by early adolescence;
- after joint bleed, or hemarthrosis, synovium must absorb degradation products of the blood;
- repeated hemarthroses will cause synovial hypertrophy and inflammation;
- some hemophiliacs develop florid synovial hypertrophy after only two or three joint bleeds, whereas others seem to be more resistant and require more hemarthroses to develop significant synovial changes;
- early stage:
- arthropathy is characterized by synovial hypertrophy;
- it is similar to that of rheumatoid arthritis;
- synovium shows marked vascular hyperplasia, hemosiderin deposits, infiltration by chronic inflammatory cells (lymphocytes, plasma cells, & giant cells), & gradual development of fibrous tissue;
- hemosiderin-stained pannus begins to creep over the joint surfaces;
- constant oozing of blood from the highly vascular and friable synovium tends to perpetuate the synovial inflammation;
- hypertrophied synovium also produces large quantities of hydrolytic enzymes which promote fibrillation & erosion of articular cartilage;
- late stage:
- degenerative changes similar to those seen in osteoarthritis;
- thinning & erosion of articular cartilage are caused by altered configuration and mechanics of the joint;
- progressive fibrosis of synovium may contribute to joint contracture and restriction of joint motion