Construction and evaluation of risk stratification prediction model of hip joint dysfunction after PFNA in elderly patients with intertrochanteric fracture

WU Zhigang; ZHANG Haidong; LIU Haiyang

doi:10.3969/j.issn.1002-3429.2026.01.008

Abstract：Objective To construct a risk stratification prediction model for hip joint dysfunction following proximal femoral nail antirotation(PFNA)in elderly patients with intertrochanteric fractures,and to evaluate its performance.Methods A total of 208 elderly patients with intertrochanteric fractures admitted from January 2021 to June 2023 were selected as the research subjects.A questionnaire survey was conducted through the general data questionnaire,hospital electronic medical record system,Harris hip function scoring system,and Tampa Scale for Kinesiophobia.Univariate and multivariate logistic regression analyses were used to analyze the influencing factors of hip joint dysfunction after PFNA in elderly patients with intertrochanteric fractures.Significant variables from logistic regression analysis were included in the nomogram model,and the receiver operating characteristic(ROC)curve was used to verify its efficacy.According to the risk factors carried by individuals,the total risk score and risk probability of hip joint dysfunction after PFNA in elderly patients were calculated using a nomogram model,and the risk stratification was performed based on the total risk scores.Results The follow-up and data collection of 206 elderly patients with intertrochanteric fractures were finally completed.The Harris hip function score was(86.12±7.32)scores,the good prognosis rate of hip function was 75.24％(155/206),and the poor prognosis rate was 24.76％(51/206).Univariate and multivariate logistic regression analyses showed that overweight/obesity,unstable fracture,time to operation≥7 d,Clavien-Dindo classification,kinesiophobia,malnutrition,osteoporosis,serum N-terminal propeptide of type I collagen,and serum osteocalcin were all independent risk factors for hip dysfunction after PFNA in elderly patients with intertrochanteric fracture,while functional exercise compliance and serum 25-hydroxyvitamin D3 were protective factors(P＜0.01).Based on the above influencing factors,the area under the ROC curve of the nomogram model for predicting hip joint dysfunction after PFNA was 0.861(95％CI:0.793,0.928).According to the nomogram model,the total risk score and predicted risk probability of hip joint dysfunction were calculated.According to the total score,patients were stratified into three risk levels:low risk(≤ 160 scores),medium risk(＞160-200 scores)and high risk(＞200 scores),with the corresponding probabilities of ≤ 10％,＞10％-50％and＞50％,respectively.Conclusion Overweight/obesity,malnutrition and osteoporosis are the influencing factors of hip joint dysfunction after PFNA in elderly patients with intertrochanteric fracture.The nomogram model constructed on this basis has good clinical predictive utility and can guide the clinical establishment of risk warning model.