[NOVEL CONCEPTS AND CHANGES IN TOTAL JOINT ARTHROPLASTY IN THE 21ST CENTURY].

Total joint arthroplasty (TJA) is amongst the most common elective orthopedic surgeries. Since their introduction in 1951 there have been changes not only in prosthesis design and surgical approaches, but also in patient management, anesthesia, drug regimen and robotic arm assistance. These changes led to advancement in patient safety and shorter hospitalization.

A novel role for factor VIII and thrombin/PAR1 in regulating hematopoiesis and its interplay with the bone structure.

Analysis of hematopoietic stem cells (HSCs) in factor VIII knockout (FVIIIKO) mice revealed a novel regulatory role for the coagulation cascade in hematopoiesis. Thus, HSCs in FVIIIKO mice had reduced proportions of CD34(low) cells within Lin(-)Sca(+)Kit(+) progenitors, and exhibited reduced long-term repopulating capacity as well as hyper granulocyte-colony-stimulating factor (G-CSF)-induced mobilization. This disregulation of HSCs is likely caused by reduced levels of thrombin, and is associated with altered protease-activated receptor 1 (PAR1) signaling, as PAR1 KO mice also exhibited enhanced G-CSF-induced mobilization.