Humphrey Catherine A, Liu Qi, Templeman David C, Ellis Thomas J
Department of Orthopaedics and Rehabilitation, University of Rochester, Rochester, New York, USA.
J Trauma. 2010 Nov;69(5):1230-4. doi: 10.1097/TA.0b013e3181d3cc07.
The purpose of this study is to compare a locked screw construct to a single iliosacral screw for fixation of a vertically unstable pelvic ring injury in a transforaminal sacral fracture model.
Orthopaedic Trauma Association type 61-C1.3a2c5 fractures were created in 10 fresh frozen cadaveric pelvis specimens. Specimens were divided into two groups of five. In both groups, the anterior ring was stabilized with a six-hole 3.5-mm reconstruction plate. In the locked plate (LP) group, the posterior injury was stabilized using a two-hole locking plate with one solid 5.0-mm locking iliosacral screw directed onto the S1 body and a second locking screw directed into the lateral sacral ala. In the iliosacral screw group, the posterior injury was stabilized using a single cannulated 7.3-mm screw. Testing was conducted on a Materials Testing System. Values for displacement and rotation were recorded. Each pelvis was axially loaded with a compressive sine wave from 175 N to 350 N for 10,000 cycles to simulate limited weight bearing, with data recorded at 1,000 cycle increments.
Two specimens in the iliosacral screw group displaced more than 1 cm during the first 1,000 cycles. These two specimens displayed gross fracture motion in all planes. All five specimens in the LP group completed 10,000 cycles of testing with less than 1 cm of displacement. A vector displacement calculation from the plane displacement data revealed that the LP group had significantly less displacement (median 1.9 mm) than the specimens in the iliosacral group (median 6.7 mm; p = 0.008) after 10,000 cycles.
A two-hole plate locked head screw construct resulted in less displacement than a single iliosacral screw in a transforaminal sacral fracture model.
本研究的目的是在经椎间孔骶骨骨折模型中，比较锁定螺钉结构与单根髂骶螺钉用于固定垂直不稳定骨盆环损伤的效果。
在10个新鲜冷冻的尸体骨盆标本上制造出骨科创伤协会61-C1.3a2c5型骨折。标本被分为两组，每组5个。两组均使用一块六孔3.5毫米重建钢板固定前环。在锁定钢板（LP）组中，使用一块双孔锁定钢板固定后环损伤，其中一枚实心5.0毫米锁定髂骶螺钉打入S1椎体，另一枚锁定螺钉打入骶骨翼外侧。在髂骶螺钉组中，使用一枚7.3毫米空心螺钉固定后环损伤。在材料测试系统上进行测试。记录位移和旋转值。每个骨盆轴向加载175牛至350牛的压缩正弦波，持续10000个周期以模拟有限负重，每1000个周期记录一次数据。
髂骶螺钉组中有两个标本在最初的1000个周期内位移超过1厘米。这两个标本在所有平面均出现明显的骨折移位。LP组的所有五个标本均完成了10000个周期的测试，位移小于1厘米。根据平面位移数据进行的矢量位移计算显示，在10000个周期后，LP组的位移（中位数1.9毫米）明显小于髂骶螺钉组的标本（中位数6.7毫米；p = 0.008）。
在经椎间孔骶骨骨折模型中，双孔钢板锁定头螺钉结构比单根髂骶螺钉产生的位移更小。
