Postoperative Analgesic and Rehabilitation Outcomes After Implementation of a Kampo Plus Acetaminophen Pathway for Cervical Laminoplasty: A Retrospective Historical Control Study

Background: Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used for acute postoperative pain but may be limited by adverse effects.In November 2023, our institution introduced a postoperative analgesic pathway using regular Kampo medicines plus acetaminophen, with NSAIDs administered as needed.This study compared postoperative pain, rescue NSAID use, and acute-phase rehabilitation outcomes after implementation of this pathway with those of the preceding scheduled-NSAID pathway.Methods: This single-center retrospective historical-control study included 34 of 38 patients who underwent cervical laminoplasty at Chiba Aoba Municipal Hospital, Japan, between January 2022 and September 2025.The Kampo (K) group comprised 19 patients treated from November 2023 through September 2025 with Saireito (TJ-114), Keishibukuryogankayokuinin (TJ-125), and scheduled acetaminophen, with NSAIDs as needed.The historical NSAID (N) group comprised 15 patients treated from January 2022 through October 2023 with scheduled NSAIDs.Outcomes included Barthel Index (BI), time to first out-of-bed mobilization, postoperative length of stay, maximum postoperative and discharge Numerical Rating Scale (NRS) scores, maximum-to-discharge NRS change, and as-needed NSAID administrations.Exploratory regression analyses adjusted BI at discharge for age and baseline BI and adjusted NRS outcomes for age and preoperative neck pain Visual Analog Scale score.Results: The K group was older than the N group (72 ± 11 vs. 65 ± 9 years; p = 0.033).Time to first out-of-bed mobilization and postoperative length of stay did not show statistically significant between-group differences.BI at discharge was lower in the K group in the unadjusted analysis (85 (75-90) vs. 100 (90-100); p = 0.030), whereas the adjusted difference (K minus N) was -2.78 points (95% CI, -19.22 to 13.66; p = 0.741).Maximum postoperative NRS (4 (3-5) vs. 3 (2.5-4.5);p = 0.159) and discharge NRS (0 (0-0.5) vs. 0 (0-2); p = 0.217) did not differ significantly.The exploratory maximum-to-discharge NRS change was larger in the K group (4 (3-4) vs. 2 (1.5-3); p = 0.004); the adjusted difference was 1.88 points (95% CI, 0.50-3.26;p = 0.008).As-needed NSAID administrations were 0 (0-1) and 0 (0-0), respectively (p = 0.259).Conclusions: Implementation of the Kampo plus acetaminophen-based pathway was associated with a larger exploratory maximum-to-discharge NRS change, but not with lower as-needed NSAID use or clear differences in absolute maximum or discharge NRS scores.Because this was a small, noncontemporaneous historical-control study and the pathways differed in more than Kampo exposure, the findings do not establish an independent analgesic effect of Kampo medicines or equivalence in functional recovery.Prospective contemporaneous studies are warranted.