Effects of Low-Dose Dexamethasone Regimens on Early Clinical Outcomes After Unicompartmental Knee Arthroplasty: A Retrospective Cohort Study

Objective To compare four perioperative low-dose dexamethasone regimens for early recovery after unicompartmental knee arthroplasty (UKA) and to identify an optimal regimen. Methods In this retrospective cohort study, a total of 247 patients who underwent UKA were allocated to four groups according to perioperative low-dose dexamethasone use: (1) IVDPAD, preoperative and postoperative intravenous dexamethasone plus intraoperative periarticular dexamethasone; (2) IVD, preoperative and postoperative intravenous dexamethasone; (3) PAD, intraoperative periarticular dexamethasone alone; and (4) CON, without dexamethasone. Outcomes within 72 h included visual analog scale pain scores at rest, during passive flexion and ambulation; postoperative nausea and vomiting; opioid consumption; knee range of motion; C-reactive protein; white blood cell count; and neutrophil percentage. Knee Society function score, knee swelling, recovery-15 quality, length of stay and complications were also recorded. Results Compared with the CON group, the IVDPAD and PAD groups presented lower VAS pain at rest on postoperative days 1–2, lower passive flexion pain on days 1–3 and lower ambulation pain on day 3. Compared with IVDs, IVDPADs are associated with less pain at rest and passive flexion pain on days 1–2. PONV incidence in the IVDPAD and IVD groups was significantly lower than that in the CON and PAD groups, with no significant difference between the PAD and CON groups. Knee ROM on days 1–3 was greater in the IVDPAD group than in the CON group. CRP was significantly lower in the IVDPAD and IVD groups than in the CON and PAD groups, whereas the WBC and neutrophil percentages increased in the IVDPAD and PAD groups. The length of stay was shorter in the IVDPAD and PAD groups. No serious adverse events occurred. Changes in blood glucose levels, the KSS function score, knee swelling, the QoR-15 score and overall complications did not differ significantly among the groups. Conclusions Under a standardized enhanced recovery after surgery pathway, the combined intravenous–periarticular low-dose dexamethasone regimen provides early benefits, likely through complementary systemic antiemetic and local anti-inflammatory effects. Overall, IVDPAD achieved a favorable balance between efficacy and safety and may help optimize dexamethasone pathways and stratify perioperative management after UKA.