Abstract:

BACKGROUND: A good press-fit between the femoral component and the cross-section of medullary cavity of proximal femur is very important. The accuracy of preoperative templating of noncemented femoral prostheses is low. It is necessary to search a new method for preoperative prediction of total hip arthroplasty (THA).
OBJECTIVE: To analyze the application of preoperative medial-dimension measurement method of femoral neck to predict the size of suitable femoral prosthesis in THA.
METHODS: Clinical data of 58 patients (65 hips) undergoing primary total hip arthroplasty were collected. Prediction to select femoral stem was based on the medial dimension of medullary cavity of femoral neck accurately measured from preoperative CT film. Conventional preoperative templating served as control.
RESULTS AND CONCLUSION: The medial dimension of medullary cavity of femoral neck was correlated fairly well with sizes of the stems (r=0.84-0.85, P < 0.05), suggesting that the application of the medial dimension of medullary cavity of femoral neck was feasible for prediction of femoral component in THA. The excellent rate of predicted femoral stem and the excellent and good rate in the medial-dimension measurement method of femoral neck were greater than the preoperative templating (P < 0.01, P < 0.05). Particularly, the excellent rate of medial-dimension measurement method of femoral neck was 66% in the group more than 45 years of age, greater than the preoperative templating method (32%, P=0). As a measurement to predict the appropriate femoral implant in total hip arthroplasty, the medial-dimension measurement method of femoral neck has better accuracy than the conventional preoperative templating, particularly for the elderly.