In the clinic, for those of us who treat PWBD with advanced stage joint disease of the ankle, pain is greatly reduced following ankle fusion. However, what still remains unclear about these patients, and yet is available through the Center for Disease Control's Universal Data Collection project, are the following variables: current overall activity level; use of cane, crutches or walker (in the last year); number of days missed from work due to LE bleeds (in the last year); use of a wheelchair (in the last year); ankle ROM and report of additional lower extremity target joints post ankle fusion. We plan to perform a retrospective analysis of the above data points in patients who have undergone ankle fusion. Data will be pulled from one annual visit prior to the ankle fusion, and two successive annual visits following the fusion. The purpose for pulling data from two successive annual visits following the procedure is to allow for adequate recovery time in patients. Additionally, the same data points will be pulled for a group of patients with similar range of motion as the experimental group, but who do not undergo ankle fusion. The intent of this study is to provide FVIII/FIX deficiency patients with a better sense of their expected outcomes following ankle fusion, based on the data gathered from the bleeding disorders community via the UDC.