No benefit of a proximal stem centralizer in cementing of a femoral prosthesis in human cadavers

Abstract

Background and purposeA proximal stem centralizer may be beneficial regarding cementing pressures, cement penetration, and stem alignment. We measured these parameters when cementing a mat-surfaced femoral component with and without the use of a proximal stem centralizer.Material and methods8 femoral prostheses with proximal centralizers and 8 femoral prostheses without proximal centralizers were cemented according to third-generation cementing technique in 8 pairs of embalmed cadaveric femora. We recorded intramedullary pressures (peak levels, the area under the pressure curves and mean pressure) with 6 pressure transducers during stem cementation. Computer tomographic scanning of specimens was performed to evaluate stem alignment after surgery. Thickness of the cement mantle, cement penetration, and stem centralization at the metaphyseal part of the femur were measured on cross sections using stereology.ResultsThere were no statistically significant differences in measured pressure and cement penetration values between the groups. There was similar cement distribution around the stems; however, in using a proximal centralizer, the cement mantle tended to be thinner laterally. Moreover, we found a larger variation in stem alignment on lateral projection in the proximal centralizer group.InterpretationNo benefits regarding intramedullary pressures and cement penetration were obtained from cementation of a straight stem with a proximal stem centralizer. However, there was an increased risk of inferior stem positioning in the reamed medullary cavity using the centralizing device.

Comparison of Two Pressurisers for Cementation of the Proximal Femur

“…The maximum pressures in this study were similar to those reported in previous studies. 7,10,11 Pressurisation of cement influences the cement-bone interface. Pressures during stem implantation can be much higher than pressures during cementation, but do not affect cement interdigitation or blood displacement, as the cement is too viscous at this time point.…”

“…Studies of proximal cement pressurisers mainly focus on pressures generated (rather than pressures generated in each Gruen zone). [6][7][8] Two commonly used types of cement pressurisers are the Exeter MIS half-moon femoral cement seal (Stryker Orthopedics, Mahwah [NJ], USA) and the femoral canal pressuriser (Stryker Orthopedics, Mahwah [NJ], USA). The latter is designed to fit into the medullary canal of the proximal femur ( Fig.…”

Femoral Stem Cementation in Primary Total Hip Arthroplasty

“…Comparatively, despite the lack of impact on stem alignment, it was noted that a distal centralizer allows for less variation in the circumferential cement mantle compared with stems inserted without centralizers 123 . Petruskevicius et al assessed the impact of proximal stem centralizers on cementing pressure, penetration, and stem alignment and found no benefit in cement penetration and pressurization while posing an increased risk of stem malpositioning with the use of a proximal centralizing device 124 . These combined findings question the need for a centralizer, and surgeons are advised to pay close attention to stem positioning when using these devices, without relying on self-correction of erroneous stem alignment.…”