Abstract
OBJECTIVE: To investigate the trajectories of acute postsurgical pain (APSP) following total knee arthroplasty (TKA), its influencing factors, and its impact on knee function recovery at 3 months postoperatively. METHODS: A convenience sample of patients undergoing TKA at a tertiary hospital in Panzhihua City between June 2024 and February 2025 was recruited. Preoperatively (T0), baseline data including demographics, anxiety, depression, family care index, pain level, and pain catastrophizing were collected. Postoperative pain levels were assessed on days 1 (T1), 2 (T2), 3 (T3), and 5 (T4), while joint functional outcomes were evaluated at 3 months postoperatively (T5). Growth mixture modeling (GMM) was used to identify distinct APSP trajectory subgroups, logistic regression was used to analyze influencing factors, and multiple linear regression was used to examine the association between APSP trajectories and joint functional outcomes. RESULTS: Among 227 enrolled patients, two APSP trajectory subgroups were identified: a moderate-high persistent pain group (45.16%) and a moderate-low rapid relief group (54.84%). Logistic regression revealed that age, preoperative pain level, pain catastrophizing, and family care index significantly influenced APSP trajectories. APSP trajectory membership positively predicted 3-month knee joint functional outcomes. CONCLUSION: TKA patients exhibit two distinct APSP trajectory patterns, which serve as significant predictors of joint functional outcomes. Clinicians should identify the persistent pain subgroup and implement enhanced multimodal analgesia to prevent chronic postsurgical pain and optimize rehabilitation outcomes.