Table 1_The dual association of serum uric acid with the functional outcomes of patients after hip arthroplasty: 1-year follow-up study.xlsx

BackgroundSerum uric acid (UA) exhibits dual biological roles as both an antioxidant and a pro-oxidant, yet its impact on functional recovery after hip arthroplasty remains unclear. This study investigated the nonlinear relationship between UA levels and 1-year postoperative outcomes in patients undergoing hip arthroplasty.
MethodsIn this single-center observational study, 468 hip arthroplasty patients (September 2018–September 2023) were stratified into functional independence (FIM ≥108) and non-independence groups. Serum UA was categorized as low, middle, or high. Functional outcomes were assessed using the UCLA Activity Scale (UCLAAS) and Patient-Reported Satisfaction (PRS) metrics. Restricted cubic splines (RCS) and multivariable regression models evaluated nonlinear and linear associations, adjusted for age, comorbidities, and laboratory parameters.
ResultsA U-shaped relationship emerged between UA levels and functional independence (p < 0.01 for nonlinearity). Both low UA (OR = 2.09, 95% CI:1.14–3.85) and high UA (OR = 3.74, 95% CI:1.89–7.41) independently predicted reduced functional independence. Secondary outcomes exhibited domain-specific effects: only high UA correlated with poorer mobility (UCLAAS: β = −0.53, p = 0.015). Multivariable adjustments confirmed the robustness of these associations.
ConclusionSerum UA demonstrates a dual, nonlinear association with functional recovery after hip arthroplasty, where extremes perturb redox balance and bone remodeling. Monitoring perioperative UA levels and targeting individualized thresholds may optimize rehabilitation strategies.

背景：血清尿酸（Serum uric acid, UA）兼具抗氧化与促氧化的双重生物学功能，但其对髋关节置换术后功能恢复的影响尚不明确。本研究旨在探讨UA水平与髋关节置换患者术后1年预后之间的非线性关联。方法：本项单中心观察性研究纳入2018年9月至2023年9月期间的468例髋关节置换患者，将其划分为功能独立（功能独立性评定量表（Functional Independence Measure, FIM）≥108）与功能非独立两组。将血清UA水平分为低、中、高三个等级。采用加州大学洛杉矶分校活动量表（UCLA Activity Scale, UCLAAS）及患者报告满意度（Patient-Reported Satisfaction, PRS）指标评估功能结局。通过限制性立方样条（Restricted Cubic Splines, RCS）与多变量回归模型分析非线性及线性关联，并校正年龄、合并症及实验室参数等混杂因素。结果：研究发现UA水平与功能独立性之间呈U型关联（非线性检验p<0.01）。低UA组（优势比（OR）=2.09，95%置信区间（CI）：1.14~3.85）与高UA组（OR=3.74，95%CI：1.89~7.41）均独立预测功能独立性降低。次要结局呈现领域特异性效应：仅高UA水平与较差的运动功能相关（UCLAAS：β=-0.53，p=0.015）。多变量校正后证实上述关联具有稳健性。结论：血清UA与髋关节置换术后功能恢复呈双重非线性关联，极端UA水平会扰动氧化还原平衡与骨重塑。监测围手术期UA水平并制定个体化阈值或可优化康复策略。