E. Ebramzadeh et al., THE CEMENT MANTLE IN TOTAL HIP-ARTHROPLASTY - ANALYSIS OF LONG-TERM RADIOGRAPHIC RESULTS, Journal of bone and joint surgery. American volume, 76A(1), 1994, pp. 77-87
The correlation between the thickness of the cement mantle, the medull
ary canal fill, and the orientation of the stem and the long-term radi
ographic outcome of 836 cemented femoral components in patients who ha
d a primary total hip replacement was assessed with use of survival an
alysis over a twenty-one-year follow-up period. The femoral stems of h
ips that had a two to five-millimeter-thick cement mantle in the proxi
mal medial region had a better outcome than stems implanted with a thi
cker or thinner cement mantle. Stems in femora with less than two mill
imeters of proximal medial cancellous bone had a better outcome than s
tems in femora with thicker cancellous bone. Stems that filled more th
an half of the medullary canal had better radiographic results than th
ose that filled half or less. Progressive loosening, fracture of the c
ement, and radiolucent lines at the stem-cement or bone-cement interfa
ces were more likely to develop in stems that were oriented in more th
an 5 degrees of varus than in those in neutral or valgus. The noted co
rrelations were true whether the stem was made of titanium alloy or of
stainless steel. The results of this study emphasize the importance o
f careful preoperative planning in total hip arthroplasty done with ce
ment and provide guidelines for the selection of the shape, size, and
position of the stem.