title: Is VIII worse than IX?
abstract: In this issue of Blood, Tagariello and colleagues report that patients with severe hemophilia A are more likely to undergo hip or knee arthroplasty than those with severe hemophilia B and suggest that there is a difference in the severity of the 2 hemophilias.
authors.affiliation: University of Sheffield.
authors.forename: Michael
authors.initials: M
authors.lastname: Makris