目前盆腔恶性肿瘤的主要治疗方法包括肿瘤切除后的半骨盆假体重建。在EnnekingII+III型骨盆肿瘤的病例中,假体需要固定在剩余的髂骨上。假体固定的常用方法包括鞍座假体,冰淇淋假体,模块化半骨盆假体,和使用三维打印的个性化假肢。为了防止半骨盆假体的失败,设计了一种新颖的固定方法,并进行了有限元分析。在临床病例中,第三个和第四个骶骨螺钉断裂,在有限元分析的结果中也观察到了这种现象。在原有手术模式的基础上,设计是为辅助背髂关节设计的,辅助髂底,辅助骶骨螺钉,和辅助耻骨支固定。然后在步态周期的最大载荷下进行了非线性准静态有限元分析,结果表明,辅助骶骨背侧固定显著降低了骶骨螺钉上的应力和超过28μm的相对微动。耻骨支的固定进一步增加了假体的初始稳定性及其界面骨整合能力。因此,对于半骨盆假体,合并耻骨支支撑和髂背固定是可取的,为半骨盆肿瘤假体的应用提供了新的选择。
The current primary treatment approach for malignant pelvic tumors involves hemipelvic
prosthesis reconstruction following tumor resection. In cases of Enneking type II + III pelvic tumors, the
prosthesis necessitates fixation to the remaining iliac bone. Prevailing methods for
prosthesis fixation include the saddle
prosthesis, ice cream
prosthesis, modular hemipelvic
prosthesis, and personalized prosthetics using three-dimensional printing. To prevent failure of hemipelvic arthroplasty protheses, a novel fixation method was designed and finite element analysis was conducted. In clinical cases, the third and fourth sacral screws broke, a phenomenon also observed in the results of finite element analysis. Based on the original surgical model, designs were created for auxiliary dorsal iliac, auxiliary iliac bottom, auxiliary sacral screw, and auxiliary pubic ramus fixation. A nonlinear quasi-static finite element analysis was then performed under the maximum load of the gait cycle, and the results indicated that assisted sacral dorsal fixation significantly reduces stress on the sacral screws and relative micromotion exceeding 28 μm. The fixation of the pubic ramus further increased the initial stability of the
prosthesis and its interface osseointegration ability. Therefore, for hemipelvic prostheses, incorporating pubic ramus support and iliac back fixation is advisable, as it provides new options for the application of hemipelvic tumor prostheses.