We studied 80 patients (83 hips) who underwent cemented Total Hip Arthroplasty using MS-30? & distal centralizer(Protek, Switzerland) at the Dept. of Orthopaedic surgery, National Medical Center from January 1992 to May 1994. The
purpose
of
this study was to evaluate the effecr of centralizer on cement mantle. These cases were divided into three groups according to femoral geometry and use of the centralizer. Groupl had a normal femora1 geometry using centralizer, group2 had a
deformed femoral geometry using centralizer and group3 had a deformed femoral geometry not using centralizer.
We assessed centralizing effect, demarcation line, cement mantle thickness, canal fit ratio, axis alignment, bubble formation and plgging failure on the immediately postoperative x-ray film (anteroposterial, lateral) after
standardization
with
head template. Group1 & group2 showed well centrally aligned in both ant-posterial & lateral view. when compared to group3(p<0.01). Demarcation line in three groups showed no differences and it observed mainly in distal zone, however,
none of
grade3(more than 2mm) were observed in anteroposterial view. Mantle thickness more than 3mm in distal zones(desirable thickness) were achieved more in groupl & group2 than group3(p<0.01) Canal fit ratio showed about 65% proximally,80%^ in
the
middle, adn 40% distally. Perfect neutral aligment were achieved 46% in group1, 47% in groupl, 47% in group2, however 25%, in gorup3. Bubbles in cement was observed mainly in zone4 and more in group3(55%) than groupl(39%). Cement
plugging
failure were observed in group1 & group2
|