股関節全置換術におけるオピオイド系鎮痛 vs. オピオイドフリー鎮痛：系統的レビューとメタアナリシス

Hip arthroplasty is a standard surgical procedure to decrease joint pain. Opioid-based regimens have historically been used to treat postoperative pain; however, opioid-free regimens are increasingly employed due to the increased risk of dependence and adverse events. This systematic review aimed to compare patient outcomes following opioid-based and opioid-free perioperative regimens in hip arthroplasty.

We systematically searched PubMed, Web of Science, Scopus, and Cochrane Central from inception to December 2024 and updated the search in May 2025. Only clinical trials comparing opioid-based and opioid-free regimens in which adult patients underwent total hip arthroplasty were included. The co-primary outcomes were the rest visual analog scale (VAS) pain score and the movement VAS pain score. The secondary outcomes were nausea, vomiting, pruritus, cumulative opioid consumption at 24 h, antiemetic administration, headache, urinary retention, operation time, and blood loss. We used the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) framework to assess the quality of evidence for the main outcomes.

We identified 6,354 articles, with 28 trials involving 1,787 patients (opioid-based group: 889, opioid-free group: 898) that met the inclusion criteria. For the co-primary outcomes, the opioid-free group experienced lower scores on the movement VAS at both 12 and 24 hours compared to the opioid-based group, showing a mean difference (MD -1.43, 95% CI: -2.66 to -0.20, p =  0.022) and (MD -1.18, 95% CI: [-2.25 to -0.10], p =  0.032), respectively. Furthermore, the opioid-free group had lower scores on the resting VAS at 12 and 24 hours compared to the opioid-based group (MD -1.51, 95% CI: -2.89 to -0.13, p =  0.032) and (MD -1.12, 95% CI: -1.94 to -0.29, p =  0.008), respectively.

This study found that the opioid-free regimens, compared to the opioid-based, were associated with lower VAS pain scores, though with considerable variability. Also, opioid-free analgesia decreased postoperative side effects, especially opioid side effects like nausea and pruritus. However, there was no difference in outcomes, including vomiting, headache, urinary retention, antiemetic use, and overall satisfaction. For the VAS scores, the GARDE assessment ranged from very low to low certainty; on the other hand, the certainty of evidence for vomiting, nausea, and pruritus ranged from moderate to high.

PROSPERO (CRD420250637286).