Abstract：
:Tripolar systems have been implanted to reduce the risk of recurrent dislocation. However, there is little known about the dynamic behavior of tripolar hip endoprostheses under daily life conditions and achieved joint stability. Hence, the objective of this biomechanical study was to examine the in vivo dynamics and dislocation behavior of two types of tripolar systems compared to a standard total hip replacement (THR) with the same outer head diameter. Several load cases of daily life activities were applied to an eccentric and a concentric tripolar system by an industrial robot. During testing, the motion of the intermediate component was measured using a stereo camera system. Additionally, their behavior under different dislocation scenarios was investigated in comparison to a standard THR. For the eccentric tripolar system, the intermediate component demonstrated the shifting into moderate valgus-positions, regardless of the type of movement. This implant showed the highest resisting torque against dislocation in combination with a large range of motion. In contrast, the concentric tripolar system tended to remain in varus-positions and was primarily moved after stem contact. According to the results, eccentric tripolar systems can work well under in vivo conditions and increase hip joint stability in comparison to standard THRs.
journal_name
Med Eng Physjournal_title
Medical engineering & physicsauthors
Fabry C,Kaehler M,Herrmann S,Woernle C,Bader Rdoi
10.1016/j.medengphy.2013.09.007subject
Has Abstractpub_date
2014-01-01 00:00:00pages
65-71issue
1eissn
1350-4533issn
1873-4030pii
S1350-4533(13)00216-6journal_volume
36pub_type
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