Background: This study was undertaken to provide
a basis for decision-making when a well-fixed cemented cup is encountered
at the time of a revision of a femoral component of a total hip replacement.
It may be beneficial to retain the cup in some instances and thus
reduce morbidity, complications, blood loss, operative time, and
Methods: All patients who had a revision of the
femoral component and retention of an all-polyethylene acetabular
component from 1971 to 1996 were identified. Three hundred and seventy-four patients
with a total of 395 cemented total hip replacements fit the inclusion
criteria. The gender, date of and age at the index surgery, type
of acetabular implant, and time of and reason for the revision of
the femoral component were reviewed. The time to subsequent cup
revision or latest surveillance was noted. The average age (and
standard deviation) was 66.5 ± 11.8 years at the
time of the femoral revision, which was performed at an average
of 8.0 ± 4.4 years after the primary arthroplasty.
For the purposes of this study, the end point for survival of the
acetabular component was cup revision for any reason.
Results: At the time of the latest follow-up, at
an average of nine years after the femoral revision and 17.3 years
after the primary arthroplasty, 342 (86.6%) of the 395
cups remained in situ. Fifty-three cups (13.4%) in fifty-two
patients had been revised, at an average of 10.0 ±
5.7 years after the femoral revision and 16.7 ±
5.3 years after the primary arthroplasty. The rate of survival of
the retained acetabular components was 96.9% at five years,
89.3% at ten years, and 78.7% at fifteen years
after the femoral revision and was 95.1% at fifteen years
and 87.1% at twenty years after the primary arthroplasty.
Increased age (p < 0.0001) and a shorter time-interval
(less than 7.5 years) between the primary arthroplasty and the femoral
revision (p = 0.05) were significantly associated with
an increased likelihood of survival free of cup revision. Femoral
head size, acetabular component design, gender, and primary diagnosis
did not affect prosthetic survival in this sample of patients.
Conclusions: The likelihood of survival of the unrevised
cup was associated with patient age and duration of implantation,
with the age of the patient being the more dominant factor predicting failure
of the acetabular component.