Stem taper mismatch has a critical effect on ceramic head fracture risk in modular hip arthroplasty

Publikationstyp
Journal Article
Publikationsdatum
2017-01
Sprache
English
Author
Gührs, Julian 
Körner, Mandy 
Bechstedt, Maren 
Krull, Annika 
Morlock, Michael 
Institut
Biomechanik M-3 
TORE-URI
http://hdl.handle.net/11420/2773
Enthalten in
Clinical biomechanics 
Volume
41
Start Page
106
End Page
110
Citation
Clinical Biomechanics (41): 106-110 (2017-01)
Publisher DOI
10.1016/j.clinbiomech.2016.12.009
Scopus ID
2-s2.0-85007424238
Background Modular total hip prostheses with ceramic heads are well established in orthopedic surgery and widely used. With the variety of different manufacturers and available designs, components are at risk for mismatch. Several case studies show the potentially devastating effects of mismatch. Methods The aim of this study was to investigate the outcome of one arbitrary component mismatch with commercially available components that appear to provide a stable fixation during assembly. A biomechanical in-vitro analysis of fracture strength (n = 5) was carried out in accordance with ISO 7206-10. “Type1” Bi-Metric®-stems were mismatched with “V40” Al2O3 ceramic heads. Findings Mean fracture strength was reduced to about 50% of the recommended FDA minimum by the mismatch (Mean 23.68 kN, SD 2.35 kN). A small contact area between head and stem taper was identified as a potential key parameter. Interpretation Mixing and matching components can put a patient at greater risk for ceramic head fracture and must be avoided.