Abstract：
BACKGROUND: This study aims to investigate the impact of varying coronal alignments of femoral prostheses on stress and strain distributions within the lateral compartment following unicompartmental knee arthroplasty (UKA) in patients with normal bone density and osteoporosis using finite element analysis. Additionally, it examines the relationship between osteoporosis and the progression of osteoarthritis in the lateral compartment postoperatively.
METHODS: UKA models were developed for both normal bone and osteoporotic conditions using a validated finite element model of the knee. Seven alignment conditions for the femoral prosthesis were simulated: 0° (neutral alignment), varus angles of 3°, 6°, and 9°, and valgus angles of 3°, 6°, and 9°, resulting in a total of 14 scenarios. Stress and strain distributions in the meniscus, tibial cartilage, and femoral cartilage of the lateral compartment were evaluated.
RESULTS: The results indicated that stress and strain in the meniscus, tibial cartilage, and femoral cartilage of the lateral compartment increased with greater varus alignment and decreased with greater valgus alignment in both normal and osteoporotic models. At equivalent alignment angles, stress and strain were consistently higher in the osteoporotic model (M2) compared to the normal bone model (M1), although the peak equivalent stress in the tibial cartilage was lower in the M2 model than in the M1 model.
CONCLUSIONS: In patients with osteoporosis undergoing fixed-bearing medial UKA, varus malalignment of the femoral prosthesis can lead to increased stress and strain in the lateral compartment\'s meniscus, tibial cartilage, and femoral cartilage. These findings suggest that osteoporosis may contribute to abnormal stress and strain distributions in the lateral compartment following UKA, potentially accelerating the progression of osteoarthritis in this region postoperatively.
METHODS: UKA models were developed for both normal bone and osteoporotic conditions using a validated finite element model of the knee. Seven alignment conditions for the femoral prosthesis were simulated: 0° (neutral alignment), varus angles of 3°, 6°, and 9°, and valgus angles of 3°, 6°, and 9°, resulting in a total of 14 scenarios. Stress and strain distributions in the meniscus, tibial cartilage, and femoral cartilage of the lateral compartment were evaluated.
RESULTS: The results indicated that stress and strain in the meniscus, tibial cartilage, and femoral cartilage of the lateral compartment increased with greater varus alignment and decreased with greater valgus alignment in both normal and osteoporotic models. At equivalent alignment angles, stress and strain were consistently higher in the osteoporotic model (M2) compared to the normal bone model (M1), although the peak equivalent stress in the tibial cartilage was lower in the M2 model than in the M1 model.
CONCLUSIONS: In patients with osteoporosis undergoing fixed-bearing medial UKA, varus malalignment of the femoral prosthesis can lead to increased stress and strain in the lateral compartment\'s meniscus, tibial cartilage, and femoral cartilage. These findings suggest that osteoporosis may contribute to abnormal stress and strain distributions in the lateral compartment following UKA, potentially accelerating the progression of osteoarthritis in this region postoperatively.
摘要：
背景：本研究旨在利用有限元分析研究正常骨密度和骨质疏松患者单室膝关节置换术（UKA）后股骨假体冠状排列变化对外侧室应力和应变分布的影响。此外,它研究了骨质疏松症与术后侧室骨关节炎进展之间的关系。
方法：使用经过验证的膝关节有限元模型，针对正常骨骼和骨质疏松状况开发了UKA模型。模拟了股骨假体的七个对准条件：0°（中性对准），3°的内翻角度，6°,9°,外翻角度为3°，6°,9°,总共有14种场景。弯月面中的应力和应变分布，胫骨软骨,评估外侧区室的股骨软骨。
结果：结果表明，弯月面的应力和应变，胫骨软骨,在正常模型和骨质疏松模型中，外侧室的股骨软骨随内翻排列的增加而增加，并随外翻排列的增加而减少。在相等的对齐角度下，与正常骨模型（M1）相比，骨质疏松模型（M2）中的应力和应变始终较高，尽管M2模型中胫骨软骨的峰值等效应力低于M1模型。
结论：在接受内侧UKA固定轴承的骨质疏松症患者中，股骨假体内翻不对齐可导致侧室半月板应力和应变增加，胫骨软骨,和股骨软骨。这些发现表明，骨质疏松症可能导致UKA术后侧室应力和应变分布异常，术后可能加速该地区骨关节炎的进展。
方法：使用经过验证的膝关节有限元模型，针对正常骨骼和骨质疏松状况开发了UKA模型。模拟了股骨假体的七个对准条件：0°（中性对准），3°的内翻角度，6°,9°,外翻角度为3°，6°,9°,总共有14种场景。弯月面中的应力和应变分布，胫骨软骨,评估外侧区室的股骨软骨。
结果：结果表明，弯月面的应力和应变，胫骨软骨,在正常模型和骨质疏松模型中，外侧室的股骨软骨随内翻排列的增加而增加，并随外翻排列的增加而减少。在相等的对齐角度下，与正常骨模型（M1）相比，骨质疏松模型（M2）中的应力和应变始终较高，尽管M2模型中胫骨软骨的峰值等效应力低于M1模型。
结论：在接受内侧UKA固定轴承的骨质疏松症患者中，股骨假体内翻不对齐可导致侧室半月板应力和应变增加，胫骨软骨,和股骨软骨。这些发现表明，骨质疏松症可能导致UKA术后侧室应力和应变分布异常，术后可能加速该地区骨关节炎的进展。
