The Journal of Bone and Joint Surgery, Vol 76, Issue 1 77-87, Copyright © 1994 by Journal of Bone and Joint Surgery, Inc
The cement mantle in total hip arthroplasty. Analysis of long-term radiographic results
E Ebramzadeh, A Sarmiento, HA McKellop, A Llinas and W Gogan
Orthopaedic Biomechanics Laboratory, J. Vernon Luck, Sr., Orthopaedic Research Center, Los Angeles Orthopaedic Hospital, California.
The correlation between the thickness of the cement mantle, the medullary
canal fill, and the orientation of the stem and the long-term radiographic
outcome of 836 cemented femoral components in patients who had a primary
total hip replacement was assessed with use of survival analysis over a
twenty-one-year follow-up period. The femoral stems of hips that had a two
to five-millimeter-thick cement mantle in the proximal medial region had a
better outcome than stems implanted with a thicker or thinner cement
mantle. Stems in femora with less than two millimeters of proximal medial
cancellous bone had a better outcome than stems in femora with thicker
cancellous bone. Stems that filled more than half of the medullary canal
had better radiographic results than those that filled half or less.
Progressive loosening, fracture of the cement, and radiolucent lines at the
stem-cement or bone-cement interfaces were more likely to develop in stems
that were oriented in more than 5 degrees of varus than in those in neutral
or valgus. The noted correlations were true whether the stem was made of
titanium alloy or of stainless steel. The results of this study emphasize
the importance of careful preoperative planning in total hip arthroplasty
done with cement and provide guidelines for the selection of the shape,
size, and position of the stem.
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