Abstract
Objective The longevity of a knee prosthesis is influenced by the wear of the tibial insert due to its posture and movement. In this study, we assumed that the strain on the tibial insert is one of the main reasons for its wear and investigated the influence of the knee varus-valgus angles on the mechanical stress of the tibial insert. Methods Knee prosthesis motion was simulated using a knee motion simulator based on a parallel-link six degrees-of-freedom actuator and the principal strain and pressure distribution of the tibial insert were measured. In particular, the early stance phase obtained from in vivo X-ray images was examined because the knee is applied to the largest load during extension/flexion movement. The knee varus-valgus angles were 0° (neutral alignment), 3°, and 5° malalignment. Results Under a neutral orientation, the pressure was higher at the middle and posterior condyles. The first and second principal strains were larger at the high and low pressure areas, respectively. Even for a 3° malalignment, the load was concentrated at one condyle and the positive first principal strain increased dramatically at the high pressure area. The negative second principal strain was large at the low pressure area on the other condyle. The maximum equivalent strain was 1.3–2.1 times larger at the high pressure area. For a 5° malalignment, the maximum equivalent strain increased slightly. Conclusion These strain and pressure measurements can provide the mechanical stress of the tibial insert in detail for determining the longevity of an artificial knee joint.
| Original language | English |
|---|---|
| Pages (from-to) | 495-500 |
| Number of pages | 6 |
| Journal | Journal of Orthopaedics |
| Volume | 14 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - Dec 1 2017 |
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All Science Journal Classification (ASJC) codes
- Orthopedics and Sports Medicine
Cite this
Strain measurements of the tibial insert of a knee prosthesis using a knee motion simulator. / Sera, Toshihiro; Iwai, Yuya; Yamazaki, Takaharu; Tomita, Tetsuya; Yoshikawa, Hideki; Naito, Hisahi; Matsumoto, Takeshi; Tanaka, Masao.
In: Journal of Orthopaedics, Vol. 14, No. 4, 01.12.2017, p. 495-500.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Strain measurements of the tibial insert of a knee prosthesis using a knee motion simulator
AU - Sera, Toshihiro
AU - Iwai, Yuya
AU - Yamazaki, Takaharu
AU - Tomita, Tetsuya
AU - Yoshikawa, Hideki
AU - Naito, Hisahi
AU - Matsumoto, Takeshi
AU - Tanaka, Masao
PY - 2017/12/1
Y1 - 2017/12/1
N2 - Objective The longevity of a knee prosthesis is influenced by the wear of the tibial insert due to its posture and movement. In this study, we assumed that the strain on the tibial insert is one of the main reasons for its wear and investigated the influence of the knee varus-valgus angles on the mechanical stress of the tibial insert. Methods Knee prosthesis motion was simulated using a knee motion simulator based on a parallel-link six degrees-of-freedom actuator and the principal strain and pressure distribution of the tibial insert were measured. In particular, the early stance phase obtained from in vivo X-ray images was examined because the knee is applied to the largest load during extension/flexion movement. The knee varus-valgus angles were 0° (neutral alignment), 3°, and 5° malalignment. Results Under a neutral orientation, the pressure was higher at the middle and posterior condyles. The first and second principal strains were larger at the high and low pressure areas, respectively. Even for a 3° malalignment, the load was concentrated at one condyle and the positive first principal strain increased dramatically at the high pressure area. The negative second principal strain was large at the low pressure area on the other condyle. The maximum equivalent strain was 1.3–2.1 times larger at the high pressure area. For a 5° malalignment, the maximum equivalent strain increased slightly. Conclusion These strain and pressure measurements can provide the mechanical stress of the tibial insert in detail for determining the longevity of an artificial knee joint.
AB - Objective The longevity of a knee prosthesis is influenced by the wear of the tibial insert due to its posture and movement. In this study, we assumed that the strain on the tibial insert is one of the main reasons for its wear and investigated the influence of the knee varus-valgus angles on the mechanical stress of the tibial insert. Methods Knee prosthesis motion was simulated using a knee motion simulator based on a parallel-link six degrees-of-freedom actuator and the principal strain and pressure distribution of the tibial insert were measured. In particular, the early stance phase obtained from in vivo X-ray images was examined because the knee is applied to the largest load during extension/flexion movement. The knee varus-valgus angles were 0° (neutral alignment), 3°, and 5° malalignment. Results Under a neutral orientation, the pressure was higher at the middle and posterior condyles. The first and second principal strains were larger at the high and low pressure areas, respectively. Even for a 3° malalignment, the load was concentrated at one condyle and the positive first principal strain increased dramatically at the high pressure area. The negative second principal strain was large at the low pressure area on the other condyle. The maximum equivalent strain was 1.3–2.1 times larger at the high pressure area. For a 5° malalignment, the maximum equivalent strain increased slightly. Conclusion These strain and pressure measurements can provide the mechanical stress of the tibial insert in detail for determining the longevity of an artificial knee joint.
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U2 - 10.1016/j.jor.2017.08.003
DO - 10.1016/j.jor.2017.08.003
M3 - Article
AN - SCOPUS:85034852302
VL - 14
SP - 495
EP - 500
JO - Journal of Orthopaedics
JF - Journal of Orthopaedics
SN - 0972-978X
IS - 4
ER -