Claes L, Laule J, Wenger K, Suger G, Liener U, Kinzl L
Department of Orthopaedic Research and Biomechanics, University of Ulm, Germany.
J Bone Joint Surg Br. 2000 Jan;82(1):142-8.
The treatment of large bony defects by callus distraction is well accepted, but the duration of treatment is long and the rate of complications increases accordingly. We have examined the effect of the stiffness of the axial fixator on reducing the time for maturation of callus. We created a mid-diaphyseal defect of 15 mm in the metatarsal bone in sheep and stabilised it with a ring fixator. After four days a bony segment was transported for 16 days at 1 mm per day. After 64 days the animals were divided into four groups, three with axial interfragmentary movement (IFM) of 0.5, 1.2 and 3.0 mm, respectively, and a control group. The 3.0 mm IFM group had the smallest bone density (p = 0.001) and area of callus and the largest IFM after 12 weeks; it also had typical clinical signs of hypertrophic nonunion. The most rapid stiffening of the callus was in the 0.5 mm group which had the smallest IFM (p = 0.04) after 12 weeks and radiological signs of bridging of the defect. These results indicate that suitable dynamic axial stimulation can enhance maturation of distraction callus when the initial amplitude is small, but that a large IFM can lead to delayed union.
骨痂延长术治疗大的骨缺损已被广泛接受，但治疗时间长且并发症发生率相应增加。我们研究了轴向固定器的刚度对缩短骨痂成熟时间的影响。我们在绵羊跖骨中制造了一个15毫米的骨干中段缺损，并用环形固定器进行固定。四天后，将一段骨块以每天1毫米的速度运输16天。64天后，将动物分为四组，三组分别进行0.5、1.2和3.0毫米的轴向骨折块间移动（IFM），另一组为对照组。3.0毫米IFM组在12周后骨密度最小（p = 0.001）、骨痂面积最小且IFM最大；它还具有肥大性骨不连的典型临床症状。骨痂最快速硬化的是0.5毫米组，该组在12周后IFM最小（p = 0.04）且有缺损桥接的放射学征象。这些结果表明，当初始幅度较小时，合适的动态轴向刺激可促进牵张骨痂的成熟，但较大的IFM会导致骨愈合延迟。
