Study on causes of angle error of femoral prosthesis on coronal plane in patients with hip osteoarthritis after total hip arthroplasty
FENG Xiao,JIANG Jian,WANG Long
Department of Orthopedics, Affiliated Hospital of Xuzhou Medical University, Jiangsu Xuzhou 221000, China
Abstract:
To investigate the causes of angle error of femoral prosthesis on coronal plane in patients with hip osteoarthritis after total hip arthroplasty. Methods Perspective study, a total of 122 patients with hip osteoarthritis diagnosed and treated in our hospital from March 2017 to February 2022 were collected and treated with THA. The femoral prosthesis valgus angle (FPVA), mechanical lateral distal femoral angle, femoral shaft-neck angle, femur neck length, femoral side bending angle were measured by Image-Pro Plus software on the PACS system before and after operation. According to the coronal FPVA of the full-length film 6 months after operation, the patients were divided into two groups: when FPVA > 3°or <-3°, they were included in the poor force line group, otherwise they were included in the good force line group. The general clinical data and imaging parameters of patients in each group were compared. The influencing factors of predicting the angle error of the prosthesis on the coronal plane were obtained by multiple linear regression analysis of variance. Construct the Nomogram prediction model and verify the model. Spearman correlation was used to analyze the correlation between FPVA and other factors. Results Mechanical lateral distal femoral angle, femoral shaft-neck angle, femur neck length, femoral side bending angle were the influencing factors of prosthesis angle error in patients with osteoarthritis after THA. The Nomogram model constructed on the coronal plane to predict the angle error of the prosthesis has good discrimination and internal verification results. FPVA was negatively correlated with lateral bending angle of femur (r=-0.381, P<0.001), lateral angle of mechanical axis of femur (r=-0.519, P<0.001) and length of femoral neck (r=-0.422, P<0.001), but positively correlated with dry angle of femoral neck (r=0.761, P<0.001). Conclusion Mechanical lateral distal femoral angle, femoral shaft-neck angle, femur neck length, femoral side bending angle have great influence on the coronal angle of femoral prosthesis in patients with hip osteoarthritis.
