Standardized Loads Acting in Hip Implants

• DOI: 10.1371/journal.pone.0155612
• Publication Date: 2016-05-20T04:58:50Z
• Authors: Georg Bergmann; Alwina Bender; Jörn Dymke; Georg Duda; Philipp Damm
• Keywords: Stair climbing; Biomechanics

With the increasing success of hip joint replacements, average age patients has decreased, have become more active and their expectations implant durability risen. Thus, pre-clinical endurance tests on implants require defining realistic in vivo loads from younger patients. These simplifications to be applicable for simulator numerical analyses. Here, contact forces were measured with instrumented ten subjects during nine most physically demanding frequent activities daily living. Typical levels directions high extracted intra- inter-individually widely varying individual data. data can also used analyse bone remodelling at implant-bone interface, evaluate tissue straining finite element studies or validate analytical loading predictions, among other uses. The current ISO standards stems necks are based historic 1970s. Comparisons these test unveiled that unidirectional orientations deviate time-dependent walking activities. force testing stem is substantially too low while neck better matches typical magnitudes. Because magnitudes peak vary activities, load scenarios reflect a collection should applied rather than using forces. Based patients, proposals time courses required cycle numbers given here. Friction moments addition moment standardized wear implant. It was shown friction only very slightly influences stresses shaft.