预后营养指数在老年髋部骨折预后评估中的 应用：从预测到干预的研究进展

The Application of Prognostic Nutritional Index in the Prognosis Evaluation of Elderly Hip Fractures: Research Progress from Prediction to Intervention

摘要: 髋部骨折是老年人群最常见的严重创伤之一，术后死亡率高、功能恢复差，给医疗系统带来沉重负担。营养不良在老年髋部骨折患者中普遍存在，是影响预后的关键可修饰因素。预后营养指数(Prognostic Nutritional Index, PNI)作为基于血清白蛋白和外周血淋巴细胞计数计算的复合指标，近年来在骨科领域受到广泛关注。本文系统综述PNI在老年髋部骨折预后评估中的研究进展，重点阐述PNI对术后死亡率、功能恢复、并发症的预测价值及其量效关系特征，探讨PNI从预测工具向临床干预指导策略转化的可行路径。现有证据表明，PNI是老年髋部骨折患者术后长期死亡率的独立预测因子(OR = 0.75, 95%CI: 0.66~0.85)，且与术后日常生活活动能力依赖风险(OR = 0.90)、早期行走功能恢复显著相关。值得注意的是，PNI与死亡率之间存在非线性阈值效应，当PNI < 50.3时，每增加1个单位死亡率下降6%，而超过该阈值后死亡率趋于稳定。基于PNI构建的列线图预测模型及术前营养优化策略代表了从风险评估到精准干预的转化方向。未来研究需通过大样本前瞻性试验确立PNI的最佳干预阈值，并验证营养支持治疗改善预后的临床效益。

Abstract: Hip fractures are one of the most common severe traumas among the elderly population, with high postoperative mortality and poor functional recovery, imposing a heavy burden on the medical system. Malnutrition is prevalent among elderly patients with hip fractures and is a key modifiable factor affecting prognosis. The Prognostic Nutritional Index (PNI), a composite indicator calculated based on serum albumin and peripheral blood lymphocyte counts, has received extensive attention in the field of orthopedics in recent years. This article systematically reviews the research progress of PNI in the prognostic assessment of elderly hip fractures, focusing on the predictive value of PNI for postoperative mortality, functional recovery, and complications, as well as its dose-response characteristics. It also explores the feasible path for the transformation of PNI from a predictive tool to a clinical intervention guidance strategy. Current evidence indicates that PNI is an independent predictor of long-term postoperative mortality in elderly hip fracture patients (OR = 0.75, 95% CI: 0.66~0.85), and is significantly associated with postoperative dependence on daily living activities (OR = 0.90) and early walking function recovery. It is noteworthy that there is a non-linear threshold effect between PNI and mortality. When PNI is less than 50.3, each increase of 1 unit in PNI leads to a 6% decrease in mortality, and after exceeding this threshold, the mortality tends to stabilize. The nomogram prediction model constructed based on PNI and the preoperative nutritional optimization strategy represent the transformation direction from risk assessment to precise intervention. Future research needs to establish the optimal intervention threshold of PNI through large-sample prospective trials and verify the clinical benefits of nutritional support treatment in improving prognosis.