Joints, haemorrhage in (haemarthrosis)

Discharge of blood in a joint cavity, usually the consequence of damage to the capsule caused by a sprain, dislocation or an injury. Such blood usually remains fluid and is broken down slowly and the breakdown products re-absorbed in the bloodstream. In the case of large quantities of blood removal by surgery may be necessary, because the enzymes released could affect the cartilage of the joint; damaged tissue may be repaired at the same time. Patients with diabetes mellitus or those using anticoagulants to treat thrombosis, for example, can cause haemorrhage by normal pressure on the joint; ultimately this can cause damage, and lead to immobility of the joint.