Pull-Out Strength of a Polished Tapered Stem is Improved by Placing Bone Cement Over the Shoulder of the Implant

Femoral Stem Displacement in a Patient Suffering Recurrent Dislocations After Hip Hemiarthroplasty: Case Report

“…This has been proven to offer mechanical stability and is strongly recommended in the case of highly polished stems, such as the Exeter design, which are inherently more susceptible to displacement [7, 13]. We also argue that simple reinsertion of the polished component in the cement mantle is a safe procedure, and does not result in loss of mechanical stability.…”

Dislodgement of a cemented exeter femoral stem during closed manipulative reduction of a dislocated total hip replacement

“…It has been recommended that there should be a continuous cement mantle covering the shoulder of the stem in continuity with the cement mantle in the lateral femur. Incorporating the cement in to the cancellous bone of the greater trochanter may increase its mechanical strength and prevent displacement of the stem [9] , [16] . In our case there was no cementation over the shoulder of the prosthesis which may be one of the reasons for stem dislodgement.…”

“…Yun et al observed the displacement of a cemented femoral stem in a bipolar hemiarthroplasty [19] . Even though the polished stems are wedge shaped and depend on the hoop stress generated in the femur for stability [20] ; it is unprotected against traction forces [16] .…”

Displacement of a cemented femoral implant. A complication of manipulation of a dislocated total hip replacement

“…Smooth-polished tapered stems do not have a permanent bond with the cement and allow controlled subsidence in the cement in order to maintain stability while being placed under load 8. It has been recommended that cement should be applied over the shoulder of the polished stem thereby increasing the pull-out force required 9. This, however, is not routine practice.…”