Analysis of biomechanical effect of stem-end design in revision TKA using Digital Korean model.
BACKGROUND
The stem-end pain after revision total knee arthroplasty has been clinically reported around the diaphyseal region of the tibia, and the stem-end design has been recognized as one of the causes of the stem-end pain. But there are few reports about the biomechanical characteristics of different stem-end designs on revision total knee arthroplasty. The objective of this study is to investigate the biomechanical effect of the stem-end design in revision total knee arthroplasty.


METHODS
Three-dimensional finite element models of a tibia and implants for revision total knee arthroplasty with various stem-end design parameters were developed. The tibia model was chosen from 50 male cadavers to represent the standard Korean male. The contact pressures and von Mises stresses around the stem-end were calculated under axial loading.


RESULTS
The longer stem length, the bigger stem diameter, the stronger press-fit, and no slot shape increased both peak contact pressures and von Mises stresses. The location of peak contact pressures coincided with the location of stem-end pain reported in clinical studies.


CONCLUSIONS
Different stem-end designs altered the contact pressures or stress concentrations to the tip of the stem. The location of peak contact pressures or von Mises stresses suggested there may be a biomechanical factor to transfer load or generate stress concentration at the location of the stem-end pain in the diaphysis.
Kim
Yoon Hyuk
YH
School of Advanced Technology and Industrial Liaison Research Institute, Kyung Hee University, Republic of Korea. yoonhkim@khu.ac.kr
Kwon
Oh Soo
OS
Kim
Kyungsoo
K
D001696:Biomechanical Phenomena / Q000379:methods; D003198:Computer Simulation; D017076:Computer-Aided Design; D019544:Equipment Failure Analysis / Q000379:methods*; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology* / Q000601:surgery*; D007720:Knee Prosthesis; D007723:Korea; D008297:Male; D008954:Models, Biological; D011474:Prosthesis Design / Q000379:methods*; D013314:Stress, Mechanical