Persistent post-surgical pain, postoperative cognitive dysfunction, and resilience in older people undergoing elective knee surgery: A mixed method project to explore associations and underlying mechanisms

Many older adults undergoing different types of non-cardiac surgeries (including orthopedic surgeries) present with a significant decline in cognition one-year post-surgery. This postoperative cognitive dysfunction (POCD) is significantly more frequent (as many as 30% of patients aged 65 or older) than what we would expect in non-surgical patients with similar ages and comorbidities. The causes and mechanisms of POCD are poorly understood. Persistent post-surgical pain (PPSP) is also frequent and can persist for a long time, requiring chronic medication use. Older patients with osteoarthritis often receive knee surgery after a long history of pain and impaired mobility and often experience PPSP. This research will examine 200 people between 55 and 85 years of age who are undergoing elective knee surgery, to evaluate the association between PPSP (and its treatment) and POCD. This study will also explore how cognition can interfere with coping strategies and expectations, which are also thought to influence the persistence of pain, satisfaction, and functional recovery after surgery.