In the standard total joint replacement surgery complication list which includes infection, pain, dislocation (for hip replacement), pulmonary embolus, death and stiffness. It has received most attention after heart surgery but has been found after all kinds of major surgery. It occurs more often in the elderly and it is unclear why it occurs. An article here describes that short term cognitive deficits persisted in 8% of patients 3 months after joint replacement. In many it will be permanent. Joint replacement surgery when necessary produces many benefits. POCD is just one more example of why this, or any surgery, should be avoided if it is not truly necessary and if other satisfactory treatment alternatives exist.