Aim: To understand family caregiver involvement in delirium prevention care for older adults hospitalized for orthopedic surgery hospitals and family caregiver integration by nurses.; Design: Multiple-case study.; Methods: The model of Care Partner Engagement was selected as theoretical framework. Eight cases will comprise an older adult hospitalized a family caregiver and a ward nurse. They will be recruited with a non-probability sampling on two orthopedic surgery wards in two hospitals.