Abstract
Fatigue damage in the cement mantle surrounding hip stems has been studied in the past. However, so far no quantitative method has been validated for assessing ex-vivo damage and for predicting the in-vitro risk of cement fracture. This work presents a method for measuring cement damage; the cement mantle was sliced and sections were inspected with dye penetrants and an optical microscope. Cracks were counted, measured, and classified by type in each region of the cement mantle. Statistical indicators (in total and per unit volume of cement) were proposed that allow quantitative comparison. The method was first validated on two implant types with known clinical success rate, which were tested in vitro using a physiological loading profile (described in Part 1 of this work). The most relevant indicators were able to detect statistical differences between the two designs. Retrieved cement mantles (the same design as one of the in-vitro stems) from revision surgery were also processed with the same inspection method. Excellent qualitative and quantitative agreement was found between the in-vitro generated fatigue damage and the cracking pattern found in the ex-vivo retrieved cement mantles. This demonstrated the effectiveness of the cement inspection protocol and provided a further validation to the in-vitro testing method.
| Original language | English |
|---|---|
| Pages (from-to) | 585-599 |
| Number of pages | 15 |
| Journal | Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine |
| Volume | 221 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - 2007 |
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Keywords
- Cemented stem
- Ex-vivo retrievals
- Fatigue cracks
- Fatigue testing
- Hip prostheses
- Long-term stability
- Micromotions
- Physiological loading
- Validation
ASJC Scopus subject areas
- Biomedical Engineering
- Mechanical Engineering
- Medicine(all)
Cite this
Preclinical assessment of the long-term endurance of cemented hip stems. Part 2 : In-vitro and ex-vivo fatigue damage of the cement mantle. / Cristofolini, L.; Erani, P.; Savigni, P.; Bordini, B.; Vicenconti, M.
In: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Vol. 221, No. 6, 2007, p. 585-599.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Preclinical assessment of the long-term endurance of cemented hip stems. Part 2
T2 - In-vitro and ex-vivo fatigue damage of the cement mantle
AU - Cristofolini, L.
AU - Erani, P.
AU - Savigni, P.
AU - Bordini, B.
AU - Vicenconti, M.
PY - 2007
Y1 - 2007
N2 - Fatigue damage in the cement mantle surrounding hip stems has been studied in the past. However, so far no quantitative method has been validated for assessing ex-vivo damage and for predicting the in-vitro risk of cement fracture. This work presents a method for measuring cement damage; the cement mantle was sliced and sections were inspected with dye penetrants and an optical microscope. Cracks were counted, measured, and classified by type in each region of the cement mantle. Statistical indicators (in total and per unit volume of cement) were proposed that allow quantitative comparison. The method was first validated on two implant types with known clinical success rate, which were tested in vitro using a physiological loading profile (described in Part 1 of this work). The most relevant indicators were able to detect statistical differences between the two designs. Retrieved cement mantles (the same design as one of the in-vitro stems) from revision surgery were also processed with the same inspection method. Excellent qualitative and quantitative agreement was found between the in-vitro generated fatigue damage and the cracking pattern found in the ex-vivo retrieved cement mantles. This demonstrated the effectiveness of the cement inspection protocol and provided a further validation to the in-vitro testing method.
AB - Fatigue damage in the cement mantle surrounding hip stems has been studied in the past. However, so far no quantitative method has been validated for assessing ex-vivo damage and for predicting the in-vitro risk of cement fracture. This work presents a method for measuring cement damage; the cement mantle was sliced and sections were inspected with dye penetrants and an optical microscope. Cracks were counted, measured, and classified by type in each region of the cement mantle. Statistical indicators (in total and per unit volume of cement) were proposed that allow quantitative comparison. The method was first validated on two implant types with known clinical success rate, which were tested in vitro using a physiological loading profile (described in Part 1 of this work). The most relevant indicators were able to detect statistical differences between the two designs. Retrieved cement mantles (the same design as one of the in-vitro stems) from revision surgery were also processed with the same inspection method. Excellent qualitative and quantitative agreement was found between the in-vitro generated fatigue damage and the cracking pattern found in the ex-vivo retrieved cement mantles. This demonstrated the effectiveness of the cement inspection protocol and provided a further validation to the in-vitro testing method.
KW - Cemented stem
KW - Ex-vivo retrievals
KW - Fatigue cracks
KW - Fatigue testing
KW - Hip prostheses
KW - Long-term stability
KW - Micromotions
KW - Physiological loading
KW - Validation
UR - http://www.scopus.com/inward/record.url?scp=34548167626&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=34548167626&partnerID=8YFLogxK
U2 - 10.1243/09544119JEIM184
DO - 10.1243/09544119JEIM184
M3 - Article
C2 - 17937198
AN - SCOPUS:34548167626
VL - 221
SP - 585
EP - 599
JO - Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
JF - Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
SN - 0954-4119
IS - 6
ER -