instruction: how many patients whose admission location is transfer from hosp/extram and procedure long title is open reduction of fracture with internal fixation, femur?
response: SELECT COUNT(DISTINCT demographic.subject_id) FROM demographic INNER JOIN procedures ON demographic.hadm_id = procedures.hadm_id WHERE demographic.admission_location = "TRANSFER FROM HOSP/EXTRAM" AND procedures.long_title = "Open reduction of fracture with internal fixation, femur"