RecruitingEarly Cognitive Changes After Same-day Discharge Hip and Knee ArthroplastyThe goal of this observational study is to explore early cognitive changes in patients aged 70 years or older undergoing same-day discharge after hip or knee replacement surgery. The main question it aims to answer is: Does patients experience cognitive changes in cognitive test performance from before surgery to the first day after surgery? Participants will: * Complete a cognitive test battery virtually about 14 days before surgery, and on the first and seventh day after their operation. * Record pain levels and pain medicine use during the first week after surgery