Correlation between C-reactive protein/albumin and contralateral hip refracture after total hip arthroplasty in elderly patients with hip fractures

Abstract

Background: There is still a risk of refracture of the contralateral hip after total hip replacement, to analyze the expression of C-reactive protein (CRP) and albumin (Alb) in elderly patients with contralateral hip refracture after total hip arthroplasty (THA), and to determine its correlation with the risk of post-surgery refracture and guide the prediction of the risk of contralateral hip fracture in the future. Methods: The medical records of elderly patients who suffered hip fracture and underwent THA at our hospital between July 2016 and July 2019 were reviewed, and 224 eligible patients were finally enrolled. The patients were divided into the refracture group and the control group according to the incidence of contralateral hip refracture. The baseline data of the two groups were compared, and all relevant laboratory tests were performed before surgery. The serum levels of CRP and Alb were compared, along with the CRP/Alb ratio, between the two groups to establish whether CRP/Alb is a predictor for post-surgery contralateral hip refracture in elderly patients. Results: Twenty (8.93%) of the 224 patients suffered post-surgery contralateral hip refracture. There were no significant differences in the baseline data of the refracture and control groups (P>0.05). However, the patients who experienced refracture had significantly higher CRP levels and lower Alb levels compared with the controls, resulting in an elevated CRP/Alb ratio in the patients with refracture (P<0.05). Serum CRP level was negatively correlated to that of Alb (r=-0.443, P<0.001). The linear regression equation was Y=2.718-0.598X, indicating that the CRP/Alb ratio is a risk factor for contralateral hip refracture in elderly hip fracture patients following THA (P<0.05). The area under the receiver operating characteristic (ROC) curve of the CRP/Alb ratio as a predictor for post-THA contralateral hip refracture was 0.841 (95% CI: 0.702-0.914). The optimal cutoffvalue was 1.12, which corresponded to high specificity and sensitivity of 0.782 and 0.945, respectively, and the Youden index was 0.727. Conclusions: Serum CRP level is closely associated with Alb level in elderly hip fracture patients, and the CRP/Alb ratio is a risk factor for post-THA contralateral hip refracture. Therefore, preoperative measurement of serum CRP/Alb level can assist with predicting the risk of post-THA refracture in elderly hip fracture patients.