Deficient cement mantles may he detrimental with regard to long-term outcom
e of cemented femoral stems. We performed a cadaver Study oil 48 left femor
a with 4 different stem designs (1 anatomic, 3 straight) to study the influ
ence of stem design, centralizer, and femur type on cement mantle thickness
. A radiographic and microradiograhic analysis was done. Overall, 88% of st
ems were aligned within 1 degrees of neutral in the frontal plane. In Gruen
Zones 1 through 7, we measured 24 thin cement mantles (<2 mm) in 19 specim
ens with no correlation to stem design or zone. In the sagittal plane, typi
cal areas of thin cement mantles were identified in Gruen zones 8 and 9 (n
= 39) and 12 (n = 21). The anatomic stem design carried the lowest risk (54
%) of producing a thin cement mantle proximally ill Gruen zones 8 and 9. Th
e risk for straight stem designs was >90%. Straight Steins Without centrali
zer showed the highest risk of thin cement mantles ill Gruen zone 12 (93%).
Centralizers were efficient to prevent thin cement mantles in zone 12 but
had [to effect proximally. Lateral radiographs are essential to allow for a
dequate radiographic assessment of the cement mantle and stem alignment. Th
ere is a high risk of producing thin cement mantles in Gruen zones 8 and 9,
in particular when straight stems are used. Posterior canal entry and low
neck osteotomies are essential. Anatomic stems respect the anatomy, allow f
or more even cement mantles, minimize the risk of thin cement mantles Witho
ut the use of centralizers, and may be considered in the femur with marked
proximal bow.