The role of pain catastrophising on subjective function and pain following total hip arthroplasty: a prospective comparative study of 531 patients with 2-year follow-up

Background and purpose: Considering dissatisfaction rates of around 10% after total hip arthroplasty (THA), this study aimed to investigate the role of pain catastrophising (PC) on functional outcomes, pain, and quality of life following THA in a large prospective study. PC is the tendency to focus on and exaggerate painful stimuli combined with a decreased ability to deal with pain. Patients and methods: A prospective comparative study was performed with 531 patients undergoing primary unilateral THA between 2019 and 2020. Patients were considered PC with a preoperative score >= 30 on the PC Scale, resulting in 57 (11%) PC-patients. Patient-reported outcome measures (PROMs) were collected preoperatively, at 3 months, 1 year, and 2 years postoperatively and consisted of Hip disability and Osteoarthritis Outcome Score-Physical Function (HOOS-PS), Oxford Hip Score (OHS), pain (NRS), and quality of life (EQ-5D), including minimal clinical important differences (MCIDs) and patient acceptable symptom state (PASS), as well as length of stay and aseptic revisions. Results: PC-patients reported inferior preoperative scores on all PROMs and had longer hospital stay (p = 0.02). Although PC-patients had more improvement in all scores and a higher proportion generally reached MCID, they still reported lower OHS, more pain, and lower EQ-5D at 2-year follow-up (all p < 0.03), and fewer PC-patients reached PASS for OHS and EQ-5D at final follow-up. No difference in aseptic revisions was seen (p = 0.95). Conclusions: PC-patients had worse preoperative subjective function and more pain. Although they showed more improvement than non-PC patients at all outcomes, less patients reached PASS for OHS and EQ-5D at 2-year follow-up.