Background: Removal of a well-fixed cementless acetabular component
can result in increased operative time and postoperative morbidity. The
objectives of this retrospective study were to determine whether retention of
a well-fixed acetabular component at the time of isolated femoral revision was
compatible with long-term socket survival.
Methods: The records of eighty-three consecutive patients (ninety
hips) in whom a well-fixed cementless socket had been retained during revision
of a femoral component were reviewed. The mean age of the patients was 48.7
years at the time of the primary arthroplasty and 54.1 years at the time of
femoral revision. The radiographic analysis was based on anteroposterior
radiographs and was performed by a single independent reviewer. The
intraoperative criterion for stability of the socket was the absence of
movement at the bone-implant interface during the application of direct
pressure to the edges of the socket in four quadrants with use of a metallic
pusher.
Results: At the time of the isolated femoral revision, no socket
demonstrated a radiolucent line measuring >1 mm in any two zones and forty
of the ninety hips had periacetabular osteolysis. The mean size of the
osteolytic lesions was 5.71 cm2 (range, 0.4 to 24.2
cm2), and twenty-eight of the forty hips underwent bone-grafting.
The mean duration of follow-up was 9.7 years after the isolated femoral
revision and 14.9 years after the primary arthroplasty. Five acetabular
sockets were revised at a mean of 6.8 years after the femoral revision. Only
one of these sockets had failed because of aseptic loosening. With revision of
the acetabular component for any reason as the end point, the survival rate
was 98.7% at five years and 93.5% at ten years after the femoral revision and
100% at ten years and 93.9% at fifteen years after the primary arthroplasty.
No hip showed recurrence or expansion of periacetabular osteolysis. The
prevalence of dislocation was 16% (fourteen of ninety).
Conclusions: Revision of a stable, cementless acetabular component
solely on the basis of its duration in vivo or the presence of periacetabular
osteolysis does not appear to be warranted. Retention of the socket with
grafting of larger periacetabular osteolytic lesions appears to be consistent
with satisfactory socket longevity.
Level of Evidence: Therapeutic study, Level IV (case
series [no, or historical, control group]). See Instructions to Authors for a
complete description of levels of evidence.