Characteristics of and Factors Contributing to Immediate Postoperative Pain After Ankle Fracture Surgery

To build an appropriate strategy of pain management after ankle fracture surgery, surgeons need to know the characteristics of postoperative ankle pain and its contributing factors. The aim of the present study was to investigate the maximum pain period after ankle fracture surgery and the factors affecting postoperative pain using a linear mixed model when patient-controlled analgesia (PCA) was used as a basic modality. A total of 219 adult patients (108 males and 111 females; mean age 51.2 ± 15.9 years) who had undergone operative treatment for ankle fractures were included. Data on fracture severity, causes of injury, interval between injury and surgery, anesthesia method, American Society of Anesthesiologists classification, and operative time were collected. Pain intensity was measured using an 11-point pain intensity numerical rating scale preoperatively and postoperatively every 8 hours. Intravenous PCA was prescribed to all patients. The chronologic pattern of postoperative pain and factors affecting it were statistically analyzed using a linear mixed model. Maximum postoperative pain was observed at 8 hours postoperatively, and the maximum pain numerical rating scale score was 3.92, measured at 8-hour intervals. The severity of fracture (p = .01) was the only significant factor contributing to postoperative pain after ankle fracture surgery on multivariate analysis. Clinicians should consider the chronologic pattern of postoperative pain after ankle fracture surgery during postoperative pain management. Interventions for pain control, in addition to PCA, might be needed at ~8 hours postoperatively, especially for those with severe ankle fractures.