The aim of this prospective randomised study
was to compare the clinical and radiological results of a cemented
all-polyethylene Ultima acetabular component with those of a cementless
porous-coated acetabular component (PFC) following total hip replacement
(THR). A total of 287 patients received either a polyethylene acetabular
component (group A) or a cobalt–chromium porous-coated component
(group B) with an identical cemented femoral component and 28 mm
cobalt-chromium head, thus making it the largest study of its type.
Patients were evaluated radiologically and clinically using the
Harris hip score (HHS). Group A comprised 183 patients (73 male,
110 female) with a mean age of
71.3 years (55 to 89). Group B comprised 104 patients (48 male,
56 female) with a mean age of 69.8 years (56 to 89). A total of
16 patients (13 in Group A, three in Group B) did not have post-operative
data for analysis. The mean follow-up in group A was 7.52 years
(0.4 to 15.0) and in Group B 7.87 years (0.5 to 14.0). At final follow-up the mean HHS was similar between groups A
and B (74.5 (25 to 100) and 78.0 (37 to 100), respectively; p =
0.068). The total number of revisions for any cause was 28, 17 of
which were in group A and 11 in group B. The ten-year survivorship
was 86.8% (95% confidence interval (CI) 78.4 to 92.1) and 89.2%
(95% CI 78.3 to 94.8) for groups A and B, respectively (log-rank
p-value = 0.938). A total of 20 cemented and two cementless acetabular
components had evidence of acetabular radiolucencies or acetabular
component migration at last follow-up (p = 0.001). These results indicate that patients with a cemented all-polyethylene
and cementless porous-coated polyethylene lined acetabular component
have similar long-term clinical outcomes.
We report a case of iatrogenic sciatic nerve injury caused by pre-operative intraneural injection of local anaesthetic at total hip replacement. To our knowledge, this is unreported in the orthopaedic literature. We consider sacral nerve blockade in patients undergoing total hip replacement to be undesirable and present guidelines for the management of peri-operative sciatic nerve injury.