Comparison of the Primary Stability of Porous Tantalum and Titanium Acetabular Revision Constructs

Abstract

Adequate primary stability of the acetabular revision construct is necessary for long-term implant survival. The difference in primary stability between tantalum and titanium components is unclear. Six composite hemipelvises with an acetabular defect were implanted with a tantalum augment and cup, using cement fixation between cup and augment. Relative motion was measured at cup/bone, cup/augment and bone/augment interfaces at three load levels; the results were compared to the relative motion measured at the same interfaces of a titanium cup/augment construct of identical dimensions, also implanted into composite bone. The implants showed little relative motion at all load levels between the augment and cup. At the bone/augment and bone/cup interfaces the titanium implants showed less relative motion than tantalum at 30% load (p < 0.001), but more relative motion at 50% (p = n.s.) and 100% (p < 0001) load. The load did not have a significant effect at the augment/cup interface (p = 0.086); it did have a significant effect on relative motion of both implant materials at bone/cup and bone/augment interfaces (p < 0.001). All interfaces of both constructs displayed relative motion that should permit osseointegration. Tantalum, however, may provide a greater degree of primary stability at higher loads than titanium. The clinical implication is yet to be seen

Cemented acetabular components combined with trabecular metal augments provide excellent long-term survivorship for severe acetabular bone loss

“…Advances in the material coating of shells and augments have given surgeons great confidence in using these implants due to their improved bone purchase and faster osseous integration. 13 Cadaveric studies have demonstrated significant improved when combining porous coated shells (Gription) with trabecular metal augments compared to traditional uncemented shells (Porocoat) and trabecular metal augments. 14 However, they are not without their disadvantages.…”

Preparation, modification, and clinical application of porous tantalum scaffolds

“…For THA revision, modular and revision multi-hole porous Ta shells are available ( Figure 10 ). Owing to their low elastic modulus, high friction coefficient, and superior osteoconductivity, porous Ta shells are beneficial for maintaining or even increasing the bone mass of the adjacent acetabulum and contribute to revision surgery, when needed ( Vutescu et al, 2017 ; Beckmann et al, 2020 ). In a prospective study ( Macheras et al, 2008 ) with 8–10 years of follow-up of 151 hips after primary THA, although the periacetabular gaps of length 1–5 mm were found in the early 25 acetabular cups, the aforementioned gaps disappeared after 24 weeks.…”

Accuracy measurement of different marker based motion analysis systems for biomechanical applications: A round robin study

“…For this purpose, markers are attached to the implant as well as to the bone to measure the micromotions between the components under loading conditions. The translational motions between the implant and the bone are often below 100 μm and rotations far below one degree can occur [ 12 – 14 ]. Due to improvements of marker-based measurement systems in the last decades, these systems were also used for these biomechanical research areas, where high accuracies are needed.…”