The Correlation Bween The Anteversion Of Acetabular And Acetabular Transverse Ligament

Objective Accurate positioning of the acetabular component in total hip arthroplasty is essential to minimise the risk of dislocation and preserve the range of movement of the hip. It also affects polyethylene wear and the rate of osteolysis. However, ensuring the accuracy of the intraoperative orientation of the acetabular component during a total hip replacement can be difficult. Nowadays, although there are many tools available to the surgeon to aid placement of the acetabular component, errors still occur. There is a need to develop and validate a method for establishing cup orientation that is patient specific and independent of the anterior pelvic plane. Using the transverse acetabular ligament to determine the anteversion of the acetabular component is a good and reproducible technique. The objective of this paper is to evaluate the correlation between the transverse acetabular ligament and acetabular bony opening plane and to examine whether the transverse acetabular ligament could be the orientation landmark during implanting the acetabular cup correctly.Materials and Methods Twenty patients, who were being investigated with a CT3D-reconstruction of the hip, were enrolled in this study. The anteversion angle of the transverse acetabular ligament was determined by manually selecting end point on the transverse acetabular ligament. The acetabular bony opening plane was determined through manually selecting the midpoint of the anterior, posterior and superior wall. The anteversion angle of the transverse acetabular ligament and the anteversion angle of acetabular bony opening plane were evaluated with respect to the sagital plane. All Data were presented as the mean±standard deviation (SD) and an t test was performed to evaluate the differences between the anteversion angle of the transverse acetabular ligament and the anteversion angle of acetabular bony opening plane.Results The anteversion angle of the transverse acetabular ligament is15.2°±5.2°.The anteversion angle of acetabular bony opening plane17.8°±4.0°.There is a significant difference between the anteversion angle of the transverse acetabular ligament and the anteversion angle of acetabular bony opening plane, but they are correlated (r=0.8526).Conclusions The anteversion angle of the transverse acetabular ligament and the anteversion angle of acetabular bony opening plane is not always the same, but they are correlated. The transverse acetabular ligament offer a possible solution to the many difficulties involved in cup placement during total hip arhroplasty...