TY - JOUR
T1 - Effect of sagittal pelvic tilt on joint stress distribution in hip dysplasia
T2 - A finite element analysis
AU - Kitamura, Kenji
AU - Fujii, Masanori
AU - Utsunomiya, Takeshi
AU - Iwamoto, Miho
AU - Ikemura, Satoshi
AU - Hamai, Satoshi
AU - Motomura, Goro
AU - Todo, Mitsugu
AU - Nakashima, Yasuharu
N1 - Funding Information:
This work was supported by a Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science , Grant Number JP18K09109 .
Publisher Copyright:
© 2020 Elsevier Ltd
PY - 2020/4
Y1 - 2020/4
N2 - Background: Physiologic pelvic tilt can change acetabular orientation and coverage in patients with hip dysplasia. In this study, we aimed to clarify the impact of change in sagittal pelvic tilt on joint stress distribution in dysplastic hips. Methods: We developed patient-specific finite element models of 21 dysplastic hips and 21 normal hips. The joint contact area, contact pressure, and equivalent stress of the acetabular cartilage were assessed at three pelvic tilt positions relative to the functional pelvic plane: 10° anterior tilt, no tilt, and 10° posterior tilt. Findings: The mean contact area was 0.6–0.7 times smaller, the mean maximum contact pressure was 1.8–1.9 times higher, and the mean maximum equivalent stress was 1.3–2.8 times higher in dysplastic hips than in normal hips at all three pelvic positions. As the pelvis tilted from 10° anterior to 10° posterior, the mean contact area decreased, and the mean maximum contact pressure and median maximum equivalent stress increased. The latter two changes were more significant in dysplastic hips than in normal hips (total increment was 1.3 MPa vs. 0.4 MPa, P = 0.001, and 3.6 MPa vs. 0.4 MPa, P < 0.001, respectively). The mean equivalent stress increased in the anterosuperior acetabulum during posterior pelvic tilt in dysplastic and normal hips, while the change was not significant in the superior and posterosuperior acetabulum in both groups. Interpretation: Sagittal pelvic tilt alters the loading environment and joint stress distribution of the hip joint and may impact the degeneration process in dysplastic hips.
AB - Background: Physiologic pelvic tilt can change acetabular orientation and coverage in patients with hip dysplasia. In this study, we aimed to clarify the impact of change in sagittal pelvic tilt on joint stress distribution in dysplastic hips. Methods: We developed patient-specific finite element models of 21 dysplastic hips and 21 normal hips. The joint contact area, contact pressure, and equivalent stress of the acetabular cartilage were assessed at three pelvic tilt positions relative to the functional pelvic plane: 10° anterior tilt, no tilt, and 10° posterior tilt. Findings: The mean contact area was 0.6–0.7 times smaller, the mean maximum contact pressure was 1.8–1.9 times higher, and the mean maximum equivalent stress was 1.3–2.8 times higher in dysplastic hips than in normal hips at all three pelvic positions. As the pelvis tilted from 10° anterior to 10° posterior, the mean contact area decreased, and the mean maximum contact pressure and median maximum equivalent stress increased. The latter two changes were more significant in dysplastic hips than in normal hips (total increment was 1.3 MPa vs. 0.4 MPa, P = 0.001, and 3.6 MPa vs. 0.4 MPa, P < 0.001, respectively). The mean equivalent stress increased in the anterosuperior acetabulum during posterior pelvic tilt in dysplastic and normal hips, while the change was not significant in the superior and posterosuperior acetabulum in both groups. Interpretation: Sagittal pelvic tilt alters the loading environment and joint stress distribution of the hip joint and may impact the degeneration process in dysplastic hips.
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U2 - 10.1016/j.clinbiomech.2020.02.011
DO - 10.1016/j.clinbiomech.2020.02.011
M3 - Article
C2 - 32114278
AN - SCOPUS:85080061058
VL - 74
SP - 34
EP - 41
JO - Clinical Biomechanics
JF - Clinical Biomechanics
SN - 0268-0033
ER -