scholarly journals Titanium neck-titanium stem taper corrosion in a modular neck stem

2019 ◽  
Vol 5 (2) ◽  
pp. 145-147 ◽  
Author(s):  
Ronit Shah ◽  
Carl Talmo ◽  
Sumon Nandi
Keyword(s):  
Modular Neck ◽  
Stem Taper ◽  
Titanium Stem

scholarly journals Modelling changes in modular taper micromechanics due to surgeon assembly technique in total hip arthroplasty

2020 ◽  
Vol 102-B (7_Supple_B) ◽  
pp. 33-40
Author(s):  
Jonathan A. Gustafson ◽  
Robin Pourzal ◽  
Brett R. Levine ◽  
Joshua J. Jacobs ◽  
Hannah J. Lundberg
Keyword(s):  
Contact Mechanics ◽  
Permanent Deformation ◽  
Implant Design ◽  
Cobalt Chromium ◽  
Stem Taper ◽  
Assembly Technique ◽  
Dynamic Assembly ◽  
Titanium Stem ◽  
Contact Pressures

Aims The aim of this study was to develop a novel computational model for estimating head/stem taper mechanics during different simulated assembly conditions. Methods Finite element models of generic cobalt-chromium (CoCr) heads on a titanium stem taper were developed and driven using dynamic assembly loads collected from clinicians. To verify contact mechanics at the taper interface, comparisons of deformed microgroove characteristics (height and width of microgrooves) were made between model estimates with those measured from five retrieved implants. Additionally, these models were used to assess the role of assembly technique—one-hit versus three-hits—on the taper interlock mechanical behaviour. Results The model compared well to deformed microgrooves from the retrieved implants, predicting changes in microgroove height (mean 1.1 μm (0.2 to 1.3)) and width (mean 7.5 μm (1.0 to 18.5)) within the range of measured changes in height (mean 1.4 μm (0.4 to 2.3); p = 0.109) and width (mean 12.0 μm (1.5 to 25.4); p = 0.470). Consistent with benchtop studies, our model found that increasing assembly load magnitude led to increased taper engagement, contact pressure, and permanent deformation of the stem taper microgrooves. Interestingly, our model found assemblies using three hits at low loads (4 kN) led to decreased taper engagement, contact pressures and microgroove deformations throughout the stem taper compared with tapers assembled with one hit at the same magnitude. Conclusion These findings suggest additional assembly hits at low loads lead to inferior taper interlock strength compared with one firm hit, which may be influenced by loading rate or material strain hardening. These unique models can estimate microgroove deformations representative of real contact mechanics seen on retrievals, which will enable us to better understand how both surgeon assembly techniques and implant design affect taper interlock strength. Cite this article: Bone Joint J 2020;102-B(7 Supple B):33–40.

Assessment of Carbon Stock and Uptake by Estimation of Stem Taper Equation for Pinus densiflora in Korea

2017 ◽  
Vol 8 (4) ◽  
pp. 415-424 ◽  
Author(s):  
Jin-Taek Kang ◽  
Yeong-Mo Son ◽  
Ju-Hyeon Jeon ◽  
Sun-Jeoung Lee
Keyword(s):  
Carbon Stock ◽  
Pinus Densiflora ◽  
Stem Taper ◽  
Taper Equation

Catastrophic Stem Taper Wear in Ceramic on Polyethylene Bearing Couple: A Case Report

2014 ◽  
Vol 24 (2-3) ◽  
pp. 185-188 ◽  
Author(s):  
Atsushi Kusaba ◽  
Mariko Katsui ◽  
Naoyuki Hakuta ◽  
Masashi Tsuchida ◽  
Akihiko Maeda ◽  
...  
Keyword(s):  
Case Report ◽  
Stem Taper ◽  
Bearing Couple

The Estimation of Stem Volume for Pinus thunbergii by Coast using Kozak’s Stem Taper Model in Korea

2017 ◽  
Vol 29 (4) ◽  
pp. 225-244 ◽  
Author(s):  
Yeongmo Son ◽  
Jinteak Kang ◽  
Juhyeon Jeon ◽  
Chiung Ko
Keyword(s):  
Pinus Thunbergii ◽  
Stem Volume ◽  
Stem Taper ◽  
Taper Model

Influence of climate on annual changes in Douglas-fir stem taper

Trees ◽  
2022 ◽  
Author(s):  
D. A. Jones ◽  
C. A. Harrington ◽  
J. B. St. Clair
Keyword(s):  
Douglas Fir ◽  
Stem Taper ◽  
Annual Changes

scholarly journals Evaluation of the Relative Stem Taper Curves Estimated Only from Tree Height and Diameter at Breast Height:

2012 ◽  
Vol 94 (4) ◽  
pp. 188-191 ◽  
Author(s):  
Megumi Ishida ◽  
Satoshi Naoi ◽  
Yasumasa Watanabe ◽  
Akinori Tsuzuku ◽  
Masaya Aoki
Keyword(s):  
Tree Height ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Stem Taper

scholarly journals Modular Necks and Corrosion - Review of Five Cases

2016 ◽  
Vol 6 (3) ◽  
Author(s):  
Timothy McTighe ◽  
Declan Brazil
Keyword(s):  
Study Group ◽  
Cobalt Chromium ◽  
Cementless Stem ◽  
Modular Neck ◽  
Metal Titanium ◽  
Tissue Sparing ◽  
Plasma Sprayed ◽  
Late Instability ◽  
Arthroplasty Revision

This report updates previous articles and commentary presented on Modular Necks from our Tissue Sparing Implant Study Group. In July 2012 we reported that at two years post-op we had encountered no modular neck taper failures or any signs of fretting corrosion, or pseudo tumors associated with the ARC™ Stem.Today we describe five patients out of five hundred and forty-two who had total hip arthroplasty revision [titanium alloy stem, cobalt-chromium modular neck (c.c.) and c.c. modular head (32 mm or 36 mm), highly-cross-linked polyethylene liner, metal titanium plasma sprayed cementless metal cup]. All patients’ were female and all demonstrated progressive hip pain or late instability. All  had debridement of the periarticular soft tissue, stem extraction with new primary length cementless stem replacement. At revision and early follow up all patients are doing well, however, we recommend heighten awareness in all active female patients with modular neck stem junctions.

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