let's count the number of times patient 28277 has received a fus/refus 9 vertebrae procedure since 4 years ago.
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 = 'fus/refus 9 vertebrae' ) and procedures_icd.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 28277 ) and datetime(procedures_icd.charttime) >= datetime(current_time,'-4 year')