植入金属对聚乙烯、金属对金属和弹性人造椎间盘假体的颈椎的应变行为-有限元分析。

PubMed ID
G H
发表日期 2018年11月

原始出处 临床生物力学(布里斯托尔,雅芳)
Clinical biomechanics (Bristol, Avon)
作者 Chen  Wen-Ming  Jin  Jie  Park  Taehyung  Ryu  Kyeong-Sik  Lee  Sung-Jae 

文献标题 植入金属对聚乙烯、金属对金属和弹性人造椎间盘假体的颈椎的应变行为-有限元分析。
Strain behavior of malaligned cervical spine implanted with metal-on-polyethylene, metal-on-metal, and elastomeric artificial disc prostheses - A finite element analysis.
Strain behavior of malaligned cervical spine implanted with metal-on-polyethylene, metal-on-metal, and elastomeric artificial disc prostheses - A finite element analysis.

文献摘要 BACKGROUND

全椎间盘置换术后颈椎曲度的改变(即前凸角的丧失)经常被观察到。然而,这种前凸角度的变化是否是由于术前脊柱畸形和/或假体设计的局限性,目前尚不清楚。目的探讨颈椎间盘置换术后的生物力学问题。

METHODS

在金属假体和金属假体上分别选择了一种几何特征和金属材质,即金属假体和金属假体。所有椎间盘均建模并植入多节段颈椎有限元模型(C3-C7)中,颈椎各节段正常、平直和后凸对齐。采用混合方案进行比较分析。

FINDINGS

结果表明,当脊柱失去前凸对准时,具有弹性核心的假体比金属对聚乙烯和金属对金属假体产生更大的屈曲运动范围(差异达6.1°)。相比之下,当脊柱前凸正常排列时,不同假体的运动范围相当相似(差异在1.9°以内)。弹性假体的局部大应变高达84.8%,在屈曲载荷下导致椎间盘前间隙塌陷。

INTERPRETATION

椎间盘置换术后,颈椎排列的改变会显著影响手术水平范围内的运动行为,其原位性能在很大程度上取决于人工椎间盘装置的设计,尤其是材料性能。


BACKGROUND

Postoperative alterations in cervical spine curvature (i.e. loss of lordotic angle) are frequently observed following total disc replacement surgery. However, it remains unclear whether such changes in lordotic angle are due to preoperative spinal deformities and/or prostheses design limitations. The objective of the study is to investigate strain and segmental biomechanics of the malaligned cervical spine following total disc replacement.

METHODS

Three disc prostheses were chosen, namely a metal-on-polyethylene, a metal-on-metal, and an elastomeric prosthesis, which feature different geometrical and material design characteristics. All discs were modelled and implanted into multi-segmental cervical spine finite element model (C3-C7) with normal, straight and kyphotic alignments. Comparative analyses were performed by using a hybrid protocol.

FINDINGS

The results indicated that as the spine loses lordotic alignment, the prosthesis with elastomeric core tends to produce significantly larger flexion range of motion (difference up to 6.1°) than metal-on-polyethylene and metal-on-metal prostheses. In contrast, when the treated spine had normal lordotic alignment, the range of motion behaviors of different prostheses are rather similar (difference within 1.9°). Large localized strains up to 84.8% were found with the elastomeric prosthesis, causing a collapsed anterior disc space under flexion loads.

INTERPRETATION

Changes in cervical spinal alignments could significantly affect the surgical-level range of motion behaviors following disc arthroplasty; the in situ performance was largely dependent on the designs of the artificial disc devices in particular to the material properties.

BACKGROUND

Postoperative alterations in cervical spine curvature (i.e. loss of lordotic angle) are frequently observed following total disc replacement surgery. However, it remains unclear whether such changes in lordotic angle are due to preoperative spinal deformities and/or prostheses design limitations. The objective of the study is to investigate strain and segmental biomechanics of the malaligned cervical spine following total disc replacement.

METHODS

Three disc prostheses were chosen, namely a metal-on-polyethylene, a metal-on-metal, and an elastomeric prosthesis, which feature different geometrical and material design characteristics. All discs were modelled and implanted into multi-segmental cervical spine finite element model (C3-C7) with normal, straight and kyphotic alignments. Comparative analyses were performed by using a hybrid protocol.

FINDINGS

The results indicated that as the spine loses lordotic alignment, the prosthesis with elastomeric core tends to produce significantly larger flexion range of motion (difference up to 6.1°) than metal-on-polyethylene and metal-on-metal prostheses. In contrast, when the treated spine had normal lordotic alignment, the range of motion behaviors of different prostheses are rather similar (difference within 1.9°). Large localized strains up to 84.8% were found with the elastomeric prosthesis, causing a collapsed anterior disc space under flexion loads.

INTERPRETATION

Changes in cervical spinal alignments could significantly affect the surgical-level range of motion behaviors following disc arthroplasty; the in situ performance was largely dependent on the designs of the artificial disc devices in particular to the material properties.


获取全文 10.1016/j.clinbiomech.2018.08.005