Is there a role for low dose aspirin in a patient with AVN in four large joints who has underlying well-controlled SLE and positive APLs but no history of clots?  

AVN in SLE patients is common, most often in the context of glucocorticoid use. Thus, in this case, there is no evidence that APLAs are the etiology. Moreover, to the best of my knowledge, there is no evidence that primary prevention with aspirin in the setting of APLAs is effective. So I would not ...