Post-operative hip centre restoration and migration after impaction bone grafting in revision and complex primary hip arthroplasty

Introduction/objectives Although impaction grafting proved efficacy in the reconstruction of acetabular defects in primary and revision hip arthroplasty, its role in large segmental defects is still debatable. Our objective is to determine hip centre restoration and last follow-up migration after acetabular reconstruction with impaction grafting in different types of acetabular defects. Methods This is a single-centre retrospective radiographic study of (107) total hip arthroplasty (42 primary and 65 revision) in (104) patients using impaction grafting. The available radiographs were examined for normal, preoperative, immediate postoperative, and last follow-up vertical ( Y ) and horizontal ( X ) hip centre. Maximum acetabular defect distance (MADD), presence, and size of the mesh were recorded. Results In type I and II AAOS defects, the post-operative hip centre was not significantly different from the normal hip centre on the contralateral healthy side. In type III defects, there was a significant variation between the normal hip centre and the post-operative hip centre ( P value 0.034 and 0.001 for Y and X , respectively). At 44-month follow-up of 36 hips, 31 (86%) hips migrated. The mean migration ± SD was 5.72 ± 3.7, 2, 4.15 ± 1.2, and 11.26 ± 3.9 mm for types I, II, and III, respectively ( P value 0.211). Hips with MADD > 15 mm, especially with large mesh sizes migrate significantly more ( P value = 0.042, 0.037, and 0.039, respectively). Conclusion Hip centre restoration was better, and migration was less for type I and II AAOS rather than for type III. Other options for reconstruction should be considered.