Abstract: BACKGROUND: At present, dexamethasone is widely used in hip and knee arthroplasties to reduce postoperative pain, nausea and vomiting, and speed up the recovery of patients. However, domestic and foreign studies on the role of dexamethasone in the perioperative period of unicondylar arthroplasty have not been reported. 
OBJECTIVE: To investigate the effect of intravenous dexamethasone on the perioperative period of unicondylar arthroplasty.   
METHODS: Sixty-nine knee osteoarthritis patients who underwent primary unicondylar arthroplasty in Department of Orthopedics, The First Affiliated Hospital of Soochow University from January 2020 to May 2021 were randomly divided into two groups. Patients in the trial group (n=35) were given dexamethasone 8 mg intravenously before skin incision. Patients in the control group (n=34) were given an equal volume of normal saline intravenously. Before surgery and 1, 2, and 3 days after surgery, the visual analogue scale scores of the patients at rest and walking were evaluated; the occurrences of nausea and vomiting at the corresponding time points after the surgery were recorded. Before surgery and 1 and 3 days after surgery, leukocyte count and C-reactive protein value were detected. The postoperative follow-up was conducted for 3 months to record the presence of complications such as wound infection, joint prosthesis infection, peptic ulcer bleeding and so on. 
RESULTS AND CONCLUSION: (1) The visual analogue scale scores of pain in the trial group were significantly lower than those in the control group when walking on the 1st and 2nd day after the operation and resting on the 1st day after the operation (P < 0.05). (2) The incidence of nausea and vomiting at 0-6 and 6-24 hours after operation was significantly lower in the trial group than that of the control group (P < 0.05). (3) The leukocyte count and C-reactive protein value were significantly lower in the trial group than those of the control group on the 1st postoperative day (P < 0.05). (4) The patients in the two groups were followed up for 3 months without complications such as wound infection, joint prosthesis infection, or peptic ulcer bleeding. (5) The results suggest that intravenous injection of dexamethasone used during unicondylar arthroplasty can effectively relieve early postoperative pain, reduce postoperative nausea and vomiting, inhibit early inflammation, and is beneficial for patient recovery. 

Key words: unicondylar arthroplasty, artificial joint, dexamethasone, glucocorticoid, postoperative nausea and vomiting, postoperative pain, perioperative period, intravenous injection