Final answer:
Hemarthrosis is bleeding into a joint, and a mixing study is a test used to evaluate abnormal bleeding. If a mixing study doesn't correct hemarthrosis, it suggests an intrinsic factor as the cause. The ddx for hemarthrosis includes conditions like hemophilia and von Willebrand disease.
Step-by-step explanation:
Hemarthrosis refers to bleeding into a joint, which can cause pain, swelling, and limited mobility.
A mixing study is a laboratory test used to evaluate the coagulation system and determine the cause of abnormal bleeding. If a mixing study does not correct hemarthrosis, it suggests that there is an intrinsic factor causing the bleeding, such as a clotting factor deficiency or a clotting factor inhibitor.
The differential diagnosis (ddx) for hemarthrosis includes conditions such as hemophilia, von Willebrand disease, and other rare bleeding disorders.