Krettek C, Mannss J, Miclau T, Schandelmaier P, Linnemann I, Tscherne H
Trauma Department, Hannover Medical School, Germany.
J Orthop Res. 1998 Sep;16(5):572-5. doi: 10.1002/jor.1100160508.
Current methods of distal interlocking of intramedullary femoral nails are dependent on image intensification. However, radiation exposure to the patient, the operating room staff, and the surgeon remains a concern. Proximally mounted, radiation-free aiming systems for distal interlocking of femoral nails have reportedly failed because of nail deformation with insertion. To better understand this deformation, a three-dimensional magnetic motion tracking system was used to determine the position of the distal interlocking hole following nail insertion. The amount and direction of deformation of commercially available small-diameter implants (unslotted 9-mm nails inserted without reaming) and large-diameter implants (slotted 13-mm nails inserted with reaming) from a single manufacturer were analyzed. Measurements of deformation (three translations and three angles), based on the center of the distal transverse locking hole, were performed on 10 paired intact human cadaveric femora before and after insertion. The technique produced the following results for the small and large-diameter nails, respectively: lateral translations of 18.1+/-10.0 mm (mean+/-SD, range: 47.8 mm) and 21.5+/-7.9 mm (range: 26.4 mm), dorsal translations of -3.1+/-4.3 mm (range: 15.2 mm) and 0.4+/-9.8 mm (range: 30.1 mm), and rotation about the longitudinal axes of -0.1+/-0.2 degrees (range: 0.7 degrees) and 10.0+/-3.1 degrees (range: 7.8 degrees). This technique is useful for measuring insertion-related femoral nail deformation. The data for the nails tested suggest that a simple aiming arm, mounted on the proximal end of the femoral nail alone, will not sufficiently provide accurate distal aiming.
目前股骨髓内钉远端交锁的方法依赖于影像增强。然而，患者、手术室工作人员及外科医生所遭受的辐射暴露仍是一个问题。据报道，用于股骨钉远端交锁的近端安装式无辐射瞄准系统因插入时钉子变形而失败。为了更好地理解这种变形，使用三维磁运动跟踪系统来确定钉子插入后远端交锁孔的位置。分析了来自单一制造商的市售小直径植入物（未开槽的9毫米钉子，插入时未扩髓）和大直径植入物（开槽的13毫米钉子，插入时扩髓）的变形量和方向。基于远端横向锁定孔的中心，在插入前后对10对完整的人体尸体股骨进行了变形测量（三个平移和三个角度）。该技术分别对小直径和大直径钉子产生了以下结果：横向平移分别为18.1±10.0毫米（平均值±标准差，范围：47.8毫米）和21.5±7.9毫米（范围：26.4毫米），背侧平移分别为-3.1±4.3毫米（范围：15.2毫米）和0.4±9.8毫米（范围：30.1毫米），以及绕纵轴的旋转分别为-0.1±0.2度（范围：0.7度）和10.0±3.1度（范围：7.8度）。该技术可用于测量与插入相关的股骨钉变形。所测试钉子的数据表明，仅安装在股骨钉近端的简单瞄准臂不足以提供准确的远端瞄准。
