Biomechanical Performance of the Cemented Hip Stem with Different Surface Finish

Abstract

The integrity of the cemented fixation interface is responsible for the long-term longevity of artificial hip prostheses. Metallic stems with roughened surfaces are considered to provide stronger adhesion with cement. However, clinical studies have reported that roughened stems show a lower survival rate than polished stems. These studies clearly reveal that the causes of artificial stem loosening are very complicated and multifaceted. Therefore, this study was conducted to investigate the mechanical effect of stem surface finish in cemented hip replacement. To accomplish this, a series of cement–metal specimens were tested configurations to assess the mechanical characteristics of the cement–metal interface specimens. A finite elemental model of cemented femoral prostheses was then created, in which the cement–stem interface was assumed to be in different bonding states according to the experimentally measured interface properties. The failure probabilities of the cement mantle and cemented interface under physiological loadings were evaluated. Experimental results indicate that the polished metal produced higher interfacial tensile and lower shearing strengths than the roughened metal. The polished stems were predicted to induce a lower failure probability of cement mantle and higher integrity of the cement–stem interface when compared to the roughened stem. Overall, current results provide significant evidence to support the clinical outcomes of cemented hip prostheses with different stem surface finishes.

Comparison of the Clinical Results of Identically Designed Total Knee Prostheses with Different Surface Roughnesses

“…In the present study, a roughened surface was associated with osteolysis at the tibial baseplate, but not with osteolysis of the femoral component. We think that this difference was because the femur with a femoral component had a higher portion of cortical bone than tibia with tibial baseplate [9]. Therefore, our results indicate that strengthening bonding at the prosthesis-cement interface by increasing surface roughness is a better clinical option when a prosthesis is fixed in cancellous bone.…”

“…Various surface treatments in orthopaedic prosthesis have been employed to enhance the ability of prostheses to bond with cement; polishing, porous coatings, and roughening of textures by sand-blasting [9]. Pittman et al [5] reported a mechanical study about surface roughness of total knee prosthesis and demonstrated that prosthesis-cement bonding strength increased with increasing surface roughness.…”

“…The influence of prosthesis surface texture on the stability of the prosthesis-cement interface have been studied, and several mechanical studies have demonstrated that bonding strength between prosthesis and cement increase with increasing surface roughness of the prosthesis [5][6][7]. However, it is debatable whether roughened prostheses are clinically desirable [8,9]. In hip arthroplasty, rough surfaced femoral stems produced more wear debris caused by tension between cement and bone, resulting in more stem loosening through osteolysis than polished femoral stem [8][9][10][11].…”

“…However, it is debatable whether roughened prostheses are clinically desirable [8,9]. In hip arthroplasty, rough surfaced femoral stems produced more wear debris caused by tension between cement and bone, resulting in more stem loosening through osteolysis than polished femoral stem [8][9][10][11]. But to our knowledge, no study has compared the clinical results of total knee prostheses with different undersurface roughness.…”

Finite Element analysis of stress state in the cement of total hip prosthesis with elastomeric stress barrier

“…M Mahmoud et al [3] analyzed revision of the well-fixed broken stem of cemented hemiarthroplasty using anterolateral proximal femoral window. Also, the polished stems were predicted to induce a lower failure probability of cement mantle and higher integrity of the cement-stem interface when compared to the roughened stem and notable developments have included ceramic hip resurfacing and mini hip stems treated by [4]- [6] while topology and lattice in the optimized hip prosthesis design were performed to reduce stress shielding as shown by He et al [7]. The Finite Element Method (FEM) is very suitable technique to interrelate these aspects quantitatively as shown by Huiskes and Chao [8] while Huiskes and Boeklagen [9] introduce a method of numerical shape optimization for prosthetic designs to minimize interface stresses.…”