Background: Highly cross-linked polyethylene is currently the most
common articulation surface used for total hip arthroplasty. The hypothesis of
the present study was that the Durasul highly cross-linked polyethylene
acetabular liner would have less wear at five years than would a conventional
polyethylene liner used in association with the same total hip replacement
Methods: Forty-three consecutive patients (fifty hips) underwent
total hip replacement with an uncemented titanium porous-coated metal cup and
a Durasul liner that was mated with a 28-mm cobalt-chromium femoral head.
Thirty-one patients (thirty-seven hips) were followed for at least five years.
Thirty-five other patients (thirty-seven hips) underwent total hip
arthroplasty with the same system but with a conventional polyethylene liner,
and these patients also were followed for five years. Clinical assessment was
performed with use of the Harris hip score and a patient self-assessment
examination. Radiographic analysis included measurements of acetabular
component position, fixation, and osteolysis. Femoral head penetration of the
Durasul liners was compared with that of the conventional liners.
Results: The clinical results as determined on the basis of Harris
hip scores and patient self-assessment examinations did not differ between the
Durasul group and the control group. The mean bedding-in penetration was 0.054
± 0.07 mm for the Durasul group and 0.059 ± 0.154 mm for the
control group. The subsequent penetration, with elimination of the bedding-in
wear, resulted in a linear wear rate of 0.029 ± 0.02 mm per year for
the Durasul group, compared with 0.065 ± 0.03 mm per year for the
control group (p < 0.005). The annual penetration at one and five years was
0.074 mm and 0.011 mm, respectively, for the Durasul group, compared with
0.151 mm and 0.04 mm, respectively, for the control group.
Conclusions: While the qualitative wear pattern of the highly
cross-linked polyethylene liner was the same as that of the conventional
polyethylene liner, the annual linear wear rate was 45% of that seen with the
conventional polyethylene liner. Therefore, we believe that these early data
support the continued use of this highly cross-linked polyethylene liner for
total hip arthroplasty.
Level of Evidence: Therapeutic Level III. See
Instructions to Authors for a complete description of levels of evidence.