Limits...
Influence of clearance on the time-dependent performance of the hip following hemiarthroplasty: a finite element study with biphasic acetabular cartilage properties.

Li J, Hua X, Jin Z, Fisher J, Wilcox RK - Med Eng Phys (2014)

Bottom Line: Both a prolonged loading period of 4000 s and dynamic gait load of 10 cycles were considered.It was found that a larger clearance led to a higher stress level, a faster reduction in load supported by the fluid and a faster cartilage consolidation process.The results demonstrated that a larger clearance in hip hemiarthroplasty is more harmful to the acetabular cartilage and prosthesis heads with more available dimensions (i.e. smaller increments in diameter) could be manufactured for surgeons to achieve a lower clearance, and reduced contact stress in hemiarthroplasty surgeries.

View Article: PubMed Central - PubMed

Affiliation: Institute of Medical and Biological Engineering, School of Mechanical Engineering, University of Leeds, UK. Electronic address: ljyjerry@gmail.com.

Show MeSH

Related in: MedlinePlus

Results over 4000 s period for the natural hip model and the hip models in hemiarthroplasty with different head dimensions in the static loading case.
© Copyright Policy - CC BY
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4644988&req=5

fig0015: Results over 4000 s period for the natural hip model and the hip models in hemiarthroplasty with different head dimensions in the static loading case.

Mentions: Results of the models under the static load over 4000 s period are summarised in Fig. 3. The hemiarthroplasty model with larger clearance had higher peak contact stress, higher peak fluid pressure, smaller contact area and greater changes in these results over the 4000 s. The peak contact stress decreased by 20.5% for the hemiarthroplasty model with 2 mm clearance, while there was almost no change (<1%) in the peak contact stress for the model with no clearance over the 4000 s period. The fluid support ratio was above 90% over the 4000 s period for all the models, and was slightly higher but decreased faster for models with larger clearances. The decrease in fluid support ratio was 6.9% and 4.5% for the model with a clearance of 2 mm and 0 mm, respectively. Comparable results were found between the natural hip model and the hemiarthroplasty model with no clearance.


Influence of clearance on the time-dependent performance of the hip following hemiarthroplasty: a finite element study with biphasic acetabular cartilage properties.

Li J, Hua X, Jin Z, Fisher J, Wilcox RK - Med Eng Phys (2014)

Results over 4000 s period for the natural hip model and the hip models in hemiarthroplasty with different head dimensions in the static loading case.
© Copyright Policy - CC BY
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4644988&req=5

fig0015: Results over 4000 s period for the natural hip model and the hip models in hemiarthroplasty with different head dimensions in the static loading case.
Mentions: Results of the models under the static load over 4000 s period are summarised in Fig. 3. The hemiarthroplasty model with larger clearance had higher peak contact stress, higher peak fluid pressure, smaller contact area and greater changes in these results over the 4000 s. The peak contact stress decreased by 20.5% for the hemiarthroplasty model with 2 mm clearance, while there was almost no change (<1%) in the peak contact stress for the model with no clearance over the 4000 s period. The fluid support ratio was above 90% over the 4000 s period for all the models, and was slightly higher but decreased faster for models with larger clearances. The decrease in fluid support ratio was 6.9% and 4.5% for the model with a clearance of 2 mm and 0 mm, respectively. Comparable results were found between the natural hip model and the hemiarthroplasty model with no clearance.

Bottom Line: Both a prolonged loading period of 4000 s and dynamic gait load of 10 cycles were considered.It was found that a larger clearance led to a higher stress level, a faster reduction in load supported by the fluid and a faster cartilage consolidation process.The results demonstrated that a larger clearance in hip hemiarthroplasty is more harmful to the acetabular cartilage and prosthesis heads with more available dimensions (i.e. smaller increments in diameter) could be manufactured for surgeons to achieve a lower clearance, and reduced contact stress in hemiarthroplasty surgeries.

View Article: PubMed Central - PubMed

Affiliation: Institute of Medical and Biological Engineering, School of Mechanical Engineering, University of Leeds, UK. Electronic address: ljyjerry@gmail.com.

Show MeSH
Related in: MedlinePlus