Kyle R F
Orthopedics. 1985 Nov;8(11):1356-9. doi: 10.3928/0147-7447-19851101-08.
Intramedullary rodding allows excellent control of bending forces on long bone fractures when adequate sized rods are used. This is made possible by reaming when necessary. Torsional stability is poor if adequate bone nail contact is not obtained and there is little bone fragment interdigitation. This can be optimized with the interlocking system, especially with proximal and distal fractures. Intramedullary rods allow transmission of compressive load so there must be adequate bone to bone contact without comminution to prevent shortening. If a great deal of comminution is present, an interlocking system must be used to resist compressive loads. The interlocked devices have not been proven to be a detriment to union and indeed are a semi-rigid fixation system when used in comminuted shaft fractures. The strength of an osteosynthesis with an intramedullary rod depends on the geometry of the rod and the geometry of the fracture complex. Both locked and nonlocked intramedullary rods perform extremely well when one understands the mechanical principles involved in intramedullary rodding and pays close attention to detail.
当使用尺寸合适的髓内钉时，髓内钉固定能够很好地控制长骨骨折上的弯曲力。必要时通过扩髓可以实现这一点。如果没有获得足够的骨与钉接触且骨碎片相互交错很少，则扭转稳定性较差。这可以通过交锁系统进行优化，尤其是对于近端和远端骨折。髓内钉允许传递压缩载荷，因此必须有足够的骨与骨接触且无粉碎，以防止缩短。如果存在大量粉碎，则必须使用交锁系统来抵抗压缩载荷。交锁装置尚未被证明对骨折愈合有不利影响，实际上在粉碎性骨干骨折中使用时是一种半刚性固定系统。髓内钉接骨术的强度取决于髓内钉的几何形状和骨折复合体的几何形状。当了解髓内钉固定所涉及的力学原理并密切关注细节时，锁定和非锁定髓内钉的表现都非常出色。
