Long-term results of the uncemented acetabular component in a primary total hip arthroplasty performed for protrusio acetabuli: a fifteen year median follow-up.
OBJECTIVE
Protrusio acetabuli is an uncommon finding that can be seen in patients undergoing primary total hip arthroplasty for arthritis. Uncemented fixation of the acetabular component and bone grafting of the protrusio defect is commonly used as a reconstruction method and has shown good mid-term results. The long-term outcome of these reconstructions warrants further study. The objective of this study was to determine the results of primary total hip arthroplasty (THA) with use of an uncemented acetabular component for protrusio acetabuli in patients followed for a minimum of ten years.


METHODS
Sixty-five hips in 53 patients had a primary THA with uncemented acetabular component for the protrusio acetabuli between 1984 and 2001. There were 53 procedures performed in females (82%) and 12 in males (18%). The mean age at the procedure was 66 years. Acetabular floor reconstruction with use of bone graft was performed in 58 hips (89%). Four patients (five hips) were lost to follow-up less than ten years after the procedure and 25 patients (31 hips) had died during the follow-up period. The median follow-up of living patients that did not have revisions for acetabular component was 15.4 years (range, ten to 24 years).


RESULTS
During the study duration, six hips underwent acetabular component revision: aseptic loosening (three hips), polyethylene wear (two hips), and recurrent instability (one hip). The median Harris hip score for the living patients who did not have an acetabular component revision improved from 55 points pre-operatively to 82 points at the latest follow-up. At 15 years, the estimated survival rate from revision was 70% for the THA: 85.4% for the acetabular component, and 83% for the femoral component. Five unrevised acetabular components had evidence of non-progressive radiolucency.


CONCLUSIONS
In patients undergoing THA with acetabular protrusio, fixation of an uncemented hemispherical shell and use of bone graft as necessary provided satisfactory clinical and radiographic results as well as satisfactory survivorship rates at a median follow-up of 15 years.
Department of Orthopaedic Surgery, Mayo Clinic, 200 1st Street SW, Rochester, MN, 55905, USA.
Yaser M K
YM
Baghdadi
A Noelle
AN
Larson
Rafael J
RJ
Sierra
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000379:methods; D016025:Bone Transplantation; D002484:Cementation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007592:Joint Diseases / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D012086:Reoperation; D016896:Treatment Outcome