中文摘要：

目的分析髂骨肿瘤Ⅰ型切除后骨盆的稳定性。方法选择健康成人尸体骨盆标本6具，按照Ennecking对骨盆肿瘤Ⅰ型切除标准行髂骨大部分切除，模拟双足站立位，施加0～500N垂直分级载荷，CCD采集骨盆图像，基于ImageJ软件采用数字标记点质心跟踪法对缺损骨盆位移进行检测，并与正常骨盆的相同载荷下位移进行对照分析。结果双足站立位，垂直载荷下缺损骨盆以健侧股骨头为支点在冠状面向患侧产生下移及旋转运动。500N垂直载荷下，S1椎体垂直位移为（7±3）mm，是正常组骨盆的8．3倍，在冠状面上的旋转角度为（4．0±1．8）°，是正常骨盆的12．5倍，缺损骨盆存在严重不稳。结论建立了人体双足站立位髂骨肿瘤Ⅰ型切除的生物力学模型，髂骨肿瘤Ⅰ型切除后，骨盆存在严重不稳，必须进行修复重建。

英文摘要：

Objective To analyze the pelvic stability after type Ⅰ resection of iliac tumor. Methods Six adult cadaveric specimens were tested. The iliac subtotal resection models were established according to Ennecking＇s type Ⅰ resection. Markers were affixed to the key region of the pelves. Axial loading from the proximal lumbar was applied by MTS load cell in the gradient of 0 - 500 N in the double feet standing state. Images in front view were obtained using CCD camera. Based on Image J software, displacements of the first sacral vertebrae （ S1 ） of the resected pelves and the intact pelves were calculated using digital marker tracing method with center-of-mass algorithm. Results Serious instabilities were found in the resected pelves. S1 rotational movements around the normal side femoral head of the resected pelvis were found. The average vertical displacement of S1 of the resected pelvis was （7 ±3） mm under vertical load of 500 newtons, which were 8.3 times compared to the intact pelvis. The average angle of S1 rotation around the normal side femoral head of the resected pelvis was （4. 0±1.8 ）°, which were 12. 5 times compared to the intact pelvis. Conclusions Biomechanical model of type Ⅰ resection of iliac tumor are established. Essential pelvic reconstruction must be introduced because of the serious instability of the bone defection after tumor resection.