Hip dislocation is a common complication in patients who undergo reconstruction surgery after periacetabular tumor resection and most of these cases are anterior dislocations. Studies suggest that this type of dislocation may be closely related to the position and anteversion angle of the acetabular component. Therefore, properly reducing the anteversion angle of the acetabular cup during reconstruction might effectively prevent possible collisions between the cup and the femoral component, thereby reducing the potential risk of dislocation. Based on this theory, we aim to investigate whether patients who receive modified anteversion angle (( α-15°)±10°) of the acetabular cup have a lower risk of dislocation within one year after surgery, compared to patients who receive conventional anteversion angle ( α±10°) of the acetabular cup.~PS: α refers to the preoperative anteversion angle of the affected hip. α equals to the anteversion angle of the contralateral limb if it cannot be accurately measured on the affected size. A standard error within 10° is accepted.
The purpose of this clinical study is to investigate whether patients who receive modified anteversion angle (( α-15°)±10°) of the acetabular cup have a lower risk of dislocation within one year after surgery, compared to patients who receive conventional anteversion angle ( α±10°) of the acetabular cup.~The hypothesis is that patients with placement of the modified (( α-15°)±10°) anteversion angle of the acetabular component will have decreased risk of dislocation 1 year after surgery compared to patients with conventional anteversion angle ( α±10°) placement.~PS: α refers to the preoperative anteversion angle of the affected hip. α equals to the anteversion angle of the contralateral limb if it cannot be accurately measured on the affected limb. A standard error within 10° is accepted