Background:
Aseptic loosening of the cemented stem is the most common cause
of revision of total hip arthroplasties. The loosening is often
associated with substantial lysis of the surrounding bone. The surface
finish of femoral components is suspected as a contributing factor
to this bone lysis. The purpose of this study was to compare the
results associated with a rough surface and those associated with
a polished surface in a consecutive series of cemented stems with
essentially the same geometry.
Methods:
The study included 244 consecutive total hip arthroplasties with
a cemented femoral component performed by one surgeon. There was
no difference in patient selection criteria or surgical techniques
between the group treated with a polished stem and that treated
with a grit-blasted stem. All arthroplasties were hybrid, with an
uncemented acetabular component. Generally, patients were over the
age of sixty years (mean age, 70.6 years). The stems inserted in
the initial 122 hips had a grit-blasted surface with a roughness
of 2.1 mm. The stem surface in the second 122 hips was polished
(roughness, 0.1 mm). The results of clinical and radiographic assessments performed
immediately after surgery were compared with those performed at
the most recent visit. The average duration of clinical follow-up
for the patients treated with the grit-blasted and polished stems
was 5.98 years and 5.32 years, respectively.
Results:
Four hips treated with the grit-blasted stem had aseptic loosening
with substantial surrounding lysis and required revision. An additional
two hips in this group had radiographic evidence of substantial
lysis and were judged to have an impending need for revision. In
contrast, no hip treated with the polished stem required revision,
and only one had minimal lysis. This difference regarding failures
and impending failures was significant (p = 0.05). The clinical
results were comparable, with an Iowa hip rating of 98 points at
the time of follow-up in both groups.
Conclusions:
There was a significant difference between grit-blasted and polished
stems with respect to the prevalence of revisions and impending
revisions, all of which were identified in a relatively short follow-up
period. The results in this series favor the use of a polished stem
when cement is employed for fixation of the femoral component.