what is the number of times that patient 10425 had received a appl ext fix-tib/fibula on their last hospital encounter?
select count(*) from procedures_icd where procedures_icd.icd9_code = ( select d_icd_procedures.icd9_code from d_icd_procedures where d_icd_procedures.short_title = 'appl ext fix-tib/fibula' ) and procedures_icd.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 10425 and admissions.dischtime is not null order by admissions.admittime desc limit 1 )