Jazini Ehsan, Klocke Noelle, Tannous Oliver, Johal Herman S, Hao John, Salloum Kanaan, Gelb Daniel E, Nascone Jason W, Belin Eric, Hoshino C Max, Hussain Mir, OʼToole Robert V, Bucklen Brandon, Ludwig Steven C
*R Adams Cowley Shock Trauma Center, Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, MD; and †Globus Medical, Inc, Audubon, PA.
J Orthop Trauma. 2017 Jan;31(1):37-46. doi: 10.1097/BOT.0000000000000703.
We sought to determine the role of lumbopelvic fixation (LPF) in the treatment of zone II sacral fractures with varying levels of sacral comminution combined with anterior pelvic ring (PR) instability. We also sought to determine the proximal extent of LPF necessary for adequate stabilization and the role of LPF in complex sacral fractures when only 1 transiliac-transsacral (TI-TS) screw is feasible.
Fifteen L4 to pelvis fresh-frozen cadaveric specimens were tested intact in flexion-extension (FE) and axial rotation (AR) in a bilateral stance gliding hip model. Two comminution severities were simulated through the sacral foramen using an oscillating saw, with either a single vertical fracture (small gap, 1 mm) or 2 vertical fractures 10 mm apart with the intermediary bone removed (large gap). We assessed sacral fracture zone (SZ), PR, and total lumbopelvic (TL) stability during FE and AR. The following variables were tested: (1) presence of transverse cross-connector, (2) presence of anterior plate, (3) extent of LPF (L4 vs. L5), (4) fracture gap size (small vs. large), (5) number of TI-TS screws (1 vs. 2).
The transverse cross-connector and anterior plate significantly increased PR stability during AR (P = 0.02 and P = 0.01, respectively). Increased sacral comminution significantly affected SZ stability during FE (P = 0.01). Two versus 1 TI-TS screw in a large-gap model significantly affected TL stability (P = 0.04) and trended toward increased SZ stabilization during FE (P = 0.08). Addition of LPF (L4 and L5) significantly improved SZ and TL stability during AR and FE (P < 0.05). LPF in combination with TI-TS screws resulted in the least amount of motion across all 3 zones (SZ, PR, and TL) compared with all other constructs in both small-gap and large-gap models.
The role of LPF in the treatment of complex sacral fractures is supported, especially in the setting of sacral comminution. LPF with proximal fixation at L4 in a hybrid approach might be needed in highly comminuted cases and when only 1 TI-TS screw is feasible to obtain maximum biomechanical support across the fracture zone.
我们试图确定腰骶固定（LPF）在治疗伴有不同程度骶骨粉碎且合并骨盆前环（PR）不稳定的Ⅱ区骶骨骨折中的作用。我们还试图确定实现充分稳定所需的LPF近端范围，以及在仅1枚经髂骨 - 经骶骨（TI - TS）螺钉可行时LPF在复杂骶骨骨折中的作用。
15个L4至骨盆的新鲜冷冻尸体标本在双侧站立滑动髋部模型中进行屈伸（FE）和轴向旋转（AR）测试。使用摆动锯通过骶孔模拟两种粉碎程度，一种是单一垂直骨折（小间隙，1毫米），另一种是两条垂直骨折，间距10毫米且中间骨块去除（大间隙）。我们评估了FE和AR过程中的骶骨骨折区（SZ）、PR和全腰骶（TL）稳定性。测试了以下变量：（1）横向交叉连接器的存在；（2）前路钢板的存在；（3）LPF的范围（L4与L5）；（4）骨折间隙大小（小与大）；（5）TI - TS螺钉数量（1枚与2枚）。
横向交叉连接器和前路钢板在AR过程中显著提高了PR稳定性（分别为P = 0.02和P = 0.01）。骶骨粉碎程度增加在FE过程中显著影响SZ稳定性（P = 0.01）。在大间隙模型中，2枚与1枚TI - TS螺钉显著影响TL稳定性（P = 0.04），并且在FE过程中SZ稳定有增加趋势（P = 0.08）。添加LPF（L4和L5）在AR和FE过程中显著改善了SZ和TL稳定性（P < 0.05）。与小间隙和大间隙模型中的所有其他结构相比，LPF与TI - TS螺钉组合在所有3个区域（SZ、PR和TL）产生的运动最少。
LPF在治疗复杂骶骨骨折中的作用得到支持，特别是在骶骨粉碎的情况下。在高度粉碎的病例以及仅1枚TI - TS螺钉可行时，可能需要采用近端固定在L4的混合方法进行LPF，以在骨折区域获得最大生物力学支持。
