Erlenwein J, et al. - The authors performed this observational cohort study to investigate whether the prevalence of persistent pain after total hip replacement differs depending on the definition of persistent pain and to assess the effect of ongoing pain on the patient’s quality of life 6 months after surgery. They supported a high prevalence of persistent postoperative pain following total hip replacement and a large variability depending on the definition used. They found a close association between physical functioning and pain as well as the relevance of the patient’s psychological state at the time of the operation.