Prevalence of chronic postsurgical pain after thoracotomy and total knee arthroplasty: a retrospective multicenter study in Japan (Japanese Study Group of Subacute Postoperative Pain).

We performed a multicenter observational study to assess the prevalence and risk factors of persistent pain after lung cancer surgery and total knee arthroplasty (TKA) in the Japanese population. After receiving Ethics Committee approval, a retrospective chart review was performed for patients who underwent surgery at seven university hospitals in Japan in 2013. A total of 511 patients who underwent lung cancer surgery and 298 patients who underwent TKA were included. The prevalence of chronic postsurgical pain (CPSP) at 3 and 6 months was 18 and 12% after lung surgery and 49 and 33% after TKA, respectively. The prevalence of analgesic use at 3 and 6 months was 16 and 9% after lung surgery and 34 and 22% after TKA, respectively. In both groups, preoperative analgesic use was associated with CPSP. Anesthetic methods or techniques during both types of surgery did not significantly affect the prevalence of CPSP. This is the first study in which the prevalence of CPSP after lung surgery and TKA in Japanese population was extensively evaluated in a multicenter trial. Further prospective studies are needed to confirm the prevalence of CPSP in the Japanese population and to identify risk factors and prevention methods.