■髌股和胫股关节承重增加与全膝关节置换术(TKA)并发症有关。因此,本研究的目的是量化髌股和胫股关节的生物力学特征,并模拟后交叉韧带保留(CR)和后稳定(PS)TKAs后不同的负重需求.
■八个新鲜冷冻的尸体膝盖(平均年龄,68.4年;范围,40-86岁)使用具有肌肉负荷能力的自定义膝盖系统进行了测试。用CR和PSTKA植入物测试TKA膝盖,并以15°至90°的6个不同弯曲角度加载,并逐渐增加载荷。独立变量是植入物类型(CR和PSTKA),逐渐增加的负载,和膝关节屈曲角度(KFA)。因变量为髌股和胫股运动学和接触特征。
■结果表明,在较高的KFA下,与PS植入物相比,CR植入物的股骨位置明显向后平移(36.6±5.2mm和32.5±5.7mm,分别)。在较高的KFA和载荷(102.4±12.5N和88.1±10.9N,分别)。最后,在弯曲角度为45°时,CR的胫骨股接触力明显大于PS植入物,60°,75°,和90°KFA,对于CR和PS植入物,测试的所有载荷在这些弯曲角度下的平均值为246.1±42.1N和192.8±54.8N,分别。
■在这项生物力学研究中,CRTKA显示髌股接触力较小,但胫骨股接触力比PSTKA更大。对于跨关节的较高载荷和增加的弯曲角度,在保留后交叉韧带的CR设计中,股骨后平移明显多于PS设计,因此髌股接触面积和力明显少于PS设计.对于医生来说,负载对植入物的不同影响是一个重要的考虑因素,因为负载要求较高的患者应考虑比CR设计明显更大的髌股接触力和PS面积。
UNASSIGNED: Increased load bearing across the patellofemoral and tibiofemoral articulations has been associated with total knee arthroplasty (TKA) complications. Therefore, the purpose of this study was to quantify the biomechanical characteristics of the patellofemoral and tibiofemoral joints and simulate varying weight-bearing demands after posterior cruciate ligament-retaining (CR) and posterior-stabilized (PS) TKAs.
UNASSIGNED: Eight fresh-frozen cadaveric knees (average age, 68.4 years; range, 40-86 years) were tested using a custom knee system with muscle-loading capabilities. The TKA knees were tested with a CR and then a PS TKA implant and were loaded at 6 different flexion angles from 15° to 90° with progressively increasing loads. The independent variables were the implant types (CR and PS TKA), progressively increased loading, and knee flexion angle (KFA). The dependent variables were the patellofemoral and tibiofemoral kinematics and contact characteristics.
UNASSIGNED: The results showed that at higher KFAs, the position of the femur translated significantly more posterior in CR implants than in PS implants (36.6 ± 5.2 mm and 32.5 ± 5.7 mm, respectively). The patellofemoral contact force and contact area were significantly greater in PS than in CR implants at higher KFAs and loads (102.4 ± 12.5 N and 88.1 ± 10.9 N, respectively). Lastly, the tibiofemoral contact force was significantly greater in the CR than the PS implant at flexion angles of 45°, 60°, 75°, and 90° KFA, the average at these flexion angles for all loads tested being 246.1 ± 42.1 N and 192.8 ± 54.8 N for CR and PS implants, respectively.
UNASSIGNED: In this biomechanical study, CR TKAs showed less patellofemoral contact force, but more tibiofemoral contact force than PS TKAs. For higher loads across the joint and at increased flexion angles, there was significantly more posterior femur translation in the CR design with a preserved posterior cruciate ligament and therefore significantly less patellofemoral contact area and force than in the PS design. The different effects of loading on implants are an important consideration for physicians as patients with higher load demands should consider the significantly greater patellofemoral contact force and area of the PS over the CR design.