A systematic review and meta-analysis on the effects of intravenous dexamethasone on postoperative outcomes in patients undergoing total knee arthroplasty.

Purpose: Dexamethasone has shown promising efficacy in alleviating pain and enhancing outcomes undergoing TKA. However, an optimal route of administration, dosage, and treatment duration have not yet been established. This study is to assess the effects of intravenous dexamethasone administration on postoperative pain management and prognosis in patients undergoing TKA.

Methods: Data were retrieved from PubMed, Embase, the Cochrane Library, and Web of Science to compare the effects of intravenous dexamethasone administration versus non-administration on outcomes following TKA. Primary endpoints included pain scores and morphine consumption. Secondary endpoints comprised walking distance, ROM, patients requiring rescue analgesics and antiemetics, LOS, levels of CRP and IL-6, QoR, and the incidence of adverse events.

Results: This meta-analysis included 15 RCTs involving 2,584 patients. The study indicated that intravenous dexamethasone can decrease VAS scores at rest (24 h, 95% CI: -0.71 [-0.86, -0.55], I²=66%, P < 0.00001; 48 h, 95% CI: -0.30 [-0.43, -0.18], I²=46%, P < 0.00001) and movement (24 h, 95% CI: -0.89 [-1.23, -0.55], I²=91%,P < 0.00001; 48 h, 95% CI: -0.42 [-0.62, -0.23], I²=84%, P < 0.0001). Moreover, it can reduce morphine consumption (24 h, 95% CI: -3.06 [-4.82, -1.30], I²=46%, P = 0.0006; 48 h, 95% CI: -5.23 [-8.28, -2.18], I²=76%, P = 0.0008) and increase walking distances on postoperative days 1 to 3, and improve the ROM on postoperative day 1 to 2. Furthermore, intravenous dexamethasone reduced the need for requiring rescue analgesics and antiemetics, shortened LOS, lowered CRP and IL-6 levels, and improved the quality of life after TKA. The incidence of infection, gastrointestinal hemorrhage, wound healing, or deep vein thrombosis/pulmonary embolism did not differ significantly. Subgroup analyses revealed no significant differences between single-administration and repeat-administration groups, except in the context of rescue antiemetic requirements.

Conclusion: Our study revealed that a single intravenous dose of dexamethasone, ranging from 8 to 16 mg administered before or after the induction of anesthesia or one hour prior to surgery, is efficacious in diminishing postoperative pain and cumulative morphine consumption, reducing the necessity for rescue analgesics and antiemetics, and shorten LOS for TKA. Additionally, it contributed to an increase in postoperative walking distance, ROM, and overall quality of postoperative recovery.

Trial registration: We conducted literature selection, eligibility criteria evaluation, data extraction and analysis on the research program registered in Prospero (CRD42024521224) in January 2025.