Biomechanical qualities of threaded acetabular cups

Klanke, J.; Partenheimer, A.; Westermann, K.

doi:10.1007/s00264-002-0368-y

Cited by 12 publications

(2 citation statements)

References 10 publications

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“…In addition to investigations using bone (cadavers or corpse donation) [41,42], closed-cell rigid plastic foams are increasingly being used to assess fixation strength [36,43]. Although closed-cell rigid foams deviate from the properties of acetabular bone, they are very convenient for the evaluation of primary fixation strength due to the mechanical properties resulting from the uniform cell structure.…”

Section: Introductionmentioning

confidence: 99%

Influence of Synthetic Bone Substitutes on the Anchorage Behavior of Open-Porous Acetabular Cup

Weißmann

Ramskogler²,

Schulze

et al. 2019

Materials

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Background: The development in implants such as acetabular cups using additive manufacturing techniques is playing an increasingly important role in the healthcare industry. Method: This study compared the primary stability of four selectively laser-melted press-fit cups (Ti6Al4V) with open-porous, load-bearing structural elements on the surface. The aim was to assess whether the material of the artificial bone stock affects the primary stability of the acetabular cup. The surface structures consist of repeated open-porous, load-bearing elements orthogonal to the acetabular surface. Experimental pull-out and lever-out tests were performed on exact-fit and press-fit cups to evaluate the primary stability of the cups in different synthetic bone substitutes. The acetabular components were placed in three different commercially available synthetic materials (ROHACELL-IGF 110, SikaBlock M330, Sawbones Solid Rigid). Results & conclusions: Within the scope of the study, it was possible to show the differences in fixation strength between the tested acetabular cups depending on their design, the structural elements used, and the different bone substitute material. In addition, functional correlations could be found which provide a qualitative reference to the material density of the bone stock and the press-fit volume of the acetabular cups.

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Section: Introductionmentioning

confidence: 99%

Influence of Synthetic Bone Substitutes on the Anchorage Behavior of Open-Porous Acetabular Cup

Weißmann

Ramskogler²,

Schulze

et al. 2019

Materials

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“…Primary stability as a prerequisite for good osseointegration significantly influences the success of an implantation [29].In the field of press-fit cups, experimental work evaluating the pull-out and lever-out behavior in preclinical as well as in post-clinical investigations is of particular interest for the assessment of anchoring strength [38][39][40][41][42][43]. Besides bones (cadavers) closed-cell foams are being used more and more often in their function as an artificial bone bed [37,[44][45][46]. In addition to different PU (polyurethane) foams, EP-DUR polyurethane foams, polymethacrylamide (PMI) foams and a combination of a polyvinyl chloride (PVC) layer and a PMI foam have served as bone substitutes [47][48][49].…”

mentioning

confidence: 99%

Experimental Characterization of the Primary Stability of Acetabular Press-Fit Cups with Open-Porous Load-Bearing Structures on the Surface Layer

Weißmann

Boss²,

Schulze

et al. 2018

Metals

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Background: Nowadays, hip cups are being used in a wide range of design versions and in an increasing number of units. Their development is progressing steadily. In contrast to conventional methods of manufacturing acetabular cups, additive methods play an increasingly central role in the development progress. Method: A series of eight modified cups were developed on the basis of a standard press-fit cup with a pole flattening and in a reduced version. The surface structures consist of repetitive open-pore load-bearing textural elements aligned right-angled to the cup surface. We used three different types of unit cells (twisted, combined and combined open structures) for constructing of the surface structure. All cups were manufactured using selective laser melting (SLM) of titanium powder (Ti6Al4V). To evaluate the primary stability of the press fit cups in the artificial bone cavity, pull-out and lever-out tests were conducted. All tests were carried out under exact fit conditions. The closed-cell polyurethane (PU) foam, which was used as an artificial bone cavity, was characterized mechanically in order to preempt any potential impact on the test results. Results and conclusions: The pull-out forces as well as the lever moments of the examined cups differ significantly depending on the elementary cells used. The best results in pull-out forces and lever-out moments are shown by the press-fit cups with a combined structure. The results for the assessment of primary stability are related to the geometry used (unit cell), the dimensions of the unit cell, and the volume and porosity responsible for the press fit. Corresponding functional relationships could be identified. The findings show that the implementation of reduced cups in a press-fit design makes sense as part of the development work.beyond the current state of the art, for example in the field of orthopedics, is an interesting task for development engineers. Due to their outstanding mechanical and biocompatible properties, titanium and titanium alloys, in addition to other materials, are at the center of development work [5][6][7].Of major interest is the implementation of open-porous structures in orthopedic implants. These structural elements provide excellent conditions to fulfil structural and functional requirements. Open-porous structures meet the mechanical requirements regarding surface quality as well as those regarding design conditions [8][9][10]. In addition, such structures offer a potential for solving the problems of different stiffnesses between human bone and full implants [11,12]. As a result of their geometry, open-pore structures offer the cells good conditions for nutrient supply, and consequently, the possibility to grow well into the pores. Characteristic features of open-pore structures like pore size and distribution as well as connectivity affect biological processes like cell migration and proliferation and as a result the regeneration process [3,13].The applications of open-porous and load-bearing structures in orthopedic ap...

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