Stemmed femoral knee prostheses: Effects of prosthetic design and fixation on bone loss

Cruciate-retaining TKA Using a Third-generation System with a Four-pegged Tibial Component: A Minimum 10-year Followup Note

“…The system described in this series is unique in that it incorporates the use of a four-pegged tibial design. Potential advantages of this design include preservation of proximal tibial bone, ease of preparation and component insertion, and the potential for reduced stress shielding of the proximal tibia by avoiding fixation deep in the tibial metaphysis [5,11,29,32,51]. Although the use of polymethylmethacrylate precoating has been associated with problems when used for a cemented femoral stem of a THA [36,48], in this series aseptic loosening of precoated tibial and femoral components was not seen.…”

Experimental Evaluation of Strain Shielding in Distal Femur in Revision TKA

“…However, there are finite element studies simulating bone-remodelling processes using the strain-adaptive theory [11], where four types of knee prostheses were compared. The results of their study indicate that press-fit stem prostheses induce an augment or maintain the density in the anterior femur (ROI 3), while for the posterior region (ROI 7) it provokes a reduction or maintains, depending on the boundary conditions of the femoral component-cement interface.…”

“…For instance, Turner et al [7] showed that the average amount of femoral bone loss in a dog model was related to stem stiffness and attributed this effect to the greater degree of periprosthetic bone stress-shielding engendered by stiffer stems. A reduction of mechanical stress was also predicted in the distal femur due the placement of knee prosthesis using finite element models [8][9][10][11]. Radiological studies have shown distal femoral bone resorption; particularly behind the anterior flange [12].…”

“…These abnormal stresses can promote the effect of stress shielding, and may contribute to bone loss. Stems increase initial stability but can then reduce later stability due to abnormal bone stresses that can lead to bone resorption [11]. This is a classical dilemma in implant fixation.…”

Management of Bone Loss in Primary and Revision Knee Replacement Surgery

“…Brooks et al used stems in conjunction with various bone augmentation techniques for defect in the proximal tibia: they suggested that a 70-mm stem carried from 23% to 38% of the axial load (Brooks et al, 1984). A finite element analysis has revealed that the predicted bone loss is even greater in stemmed components compared to stemless ones; this may have consequences to discouraged routine use of stems in revision TKA (van Lenthe et al, 2002). Nevertheless Stern and Insall (Stern & Insall, 1992) advocates routine use of stemmed components in revision TKA.…”