The influence of cycling loading force on the substrate made of frozen bone grafts was investigated. Three layers of bone grafts were compacted in a spherical model of hip joint acetabulum and then subjected to a sinusoidal loading force. For each layer a series of N = 30 loading cycles were performed. The least impacted grafts were located in the upper part of the acetabulum, close to its opening, whereas the bed is the most compacted part. Compacting is a non-linear process which quickly loses its dynamics during subsequent cycles. Most of the compacting was observed during the first cycles and the deformation of bone grafts has clearly plastic character. Bone grafts initially compacted by orthopedist undergo further compacting when exposed to a cyclic load.
2
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
The stability of the polyethylene acetabulum cemented on a substrate made of frozen bone grafts was investigated. The force was applied to the edge of the acetabulum and the magnitude of the force and resulting displacement were recorded. These tests were preceded by stress testing, during which the acetabulum was subjected to loading forces of 1 or 3 kN through 100,000 cycles. Additionally the influence of the thickness of grafts layer on the overall stability of an implant was also determined. The experiments proved that such factors as initial compacting of bone grafts, magnitude of the loading force and thickness of grafts layer greatly affect the stability of the artificial acetabulum.
3
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
W referacie przedstawiono problematykę stabilności zamocowania panewki sztucznego stawu biodrowego po zabiegu rewizyjnym. Wykonano badania eksperymentalne na modelach cielęcego stawu biodrowego z zacementowaną na warstwie ubitych przeszczepów kostnych panewką polietylenową. Po zacementowaniu panewki obciążano ją siłą 1kN przez 100000 cykli a następnie sprawdzano jej stabilność przykładając na jej krawędź siłę ścinającą. Badano wpływ grubości warstwy przeszczepów oraz kierunku działania siły obciążającej na stabilność panewki.
EN
The paper deals with the problem of stability of artificial acetabulum after revision hip arthroplasty. Experimental tests on calf joint with artificial acetabulum cemented into it were performed. Cemented acetabulum was subjected to a cyclic load of 1 kN through 100000 cycles and then the fixing stability was verified by applying a shearing force to its edge. The influence of thickness of bone grafts layer and the direction of loading force on the overall stability was investigated.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.