Relationship Between Preoperative Pelvic Sagittal Position Parameters And The Position Of Acetabular Prosthesis After Total Hip Arthroplasty

Objective:The purpose of this study was to investigate the relationship between preoperative pelvic sagittal position parameters and the position of acetabular prosthesis after total hip arthroplasty.Method:A retrospective study was conducted on 60 patients who met the inclusion and exclusion criteria in the first affiliated Hospital of Nanchang University from June2022 to December 2022.All patients underwent unilateral total hip arthroplasty,The range of motion,Harris hip score and VAS score were recorded before and 3 months after operation.The hip joint CT,standing pelvic lateral radiographs and bilateral hip radiographs were examined before and after operation,and bilateral hip radiographs and standing pelvic lateral radiographs were performed at 1 and 3 months after operation.The pelvic incidence angle(pelvicincidence,PI),sharp angle,pelvic inclination angle(pelvictilt,PT),acetabular anteversion angle(AVA)and acetabular abduction angle(ABA)were recorded before and after operation.The relationship between PI,PT before operation and AVA and ABA of acetabular prosthesis after operation,1 month and 3 months after operation was compared,and then the differences of AVA and ABA of acetabular prosthesis after operation and 3 months after operation were compared.Results:At the last follow-up,the range of motion of hip joint was flexion(51.6 ±17.5)°,extension(5.9 ±3.9)°,adduction(13.2 ±3.7)°,abduction(40.5±5.8)°,internal rotation(11.8 ±3.7)°,external rotation(37.1 ±5.7)°.The range of motion of hip joint in flexion,extension,adduction,abduction,internal rotation and external rotation were significantly higher than those before operation(flexion,extension,adduction,abduction,internal rotation and external rotation,respectively).There was significant difference between the two groups(P < 0.05).The postoperative acetabular prosthesis AVA was not correlated with preoperative PI,but positively correlated with preoperative PT.(correlation coefficient = 0.898,P<0.01).The AVA of acetabular prosthesis after total hip arthroplasty was significantly different from that before operation.There were differences in AVA and ABA of acetabular prosthesis after operation and 3 months after operation(P< 0.05).Conclusions:After total hip arthroplasty,the position of acetabular prosthesis changes with the recovery of motor function to maintain sagittal balance of the body.The sagittal position parameter of the pelvis that may affect the position of the acetabular prosthesis after surgery is the pelvic tilt Angle PT,which may be positively correlated with the position of the acetabular prosthesis.Patients with low PI who underwent posterior approach THA had greater hip discomfort....