Persistent postoperative pain at 1 year after orthopedic surgery and its association with functional disability.

The mean score for persistent pain at 1 year after surgery on the numerical rating scale was 1.2. Worse preoperative bodily pain, higher preoperative serum CRP level, and spine and spinal cord surgeries increased the persistent pain score at 1 year after surgery, which was associated with functional disability CLINICAL TRIAL REGISTRATION: This prospective observational study was registered on the University Hospital Medical Information Network (31 December 2015; UMIN000021671).