Influence of pelvic obliquity in lateral position to acetabular component orientation during total hip arthroplasty / 中华骨科杂志

ABSTRACT

Objective To explore the influence of pelvis obliquity in lateral position to acetabular component orientation during total hip arthroplasty (THA),and the method to correct.Methods Fifty patients (62 hips) were performed THA with posterolateral incision in lateral position by the same team.The patients were randomized and divided into experimental group (EX,with 25 cases,34 hips) and control group (CON,with 25 cases,28 hips).In EX group,the acetabular components were placed by means of the gradienter and plumb correcting technique during THA.While in CON group,the acetabular components were placed by traditional method during THA.The acetabular abduction angles were measured postoperatively,and compared between the two groups.Results The average obliquity of pelvis was-1.647°±4.512°in EX group when putting the patient in lateral position before correcting.Through the application of gradienter and plumb,the average abduction angle of acetabular component was 42.685°±3.355° postoperatively,with the difference of 1.962°±1.515° compared with the preoperative angles.And in CON group,the average abduction angle of acetabular component was 44.534°±4.844° postoperatively,with the difference of 4.244°±3.042°.The difference of abduction angle in CON group was much higher than that in EX group (P＜0.05).Conclusion The pelvic obliquity when putting the patient under lateral position will affect the surgeons'judgments of placing acetabular component during THA,furthermore,lead to inconsistency among the abduction angles obtained preoperatively,intraoperatively and postoperatively.By applying the correcting method with gradienter and plumb,the discrepancy can reduce obviously between the abduction angle measured postoperatively and that of measured during operation comparing with traditional method.