Mueller C A, Rahn B A
Clinic for Traumatology, University Clinic Freiburg, Germany.
J Trauma. 2003 Sep;55(3):495-503; discussion 503. doi: 10.1097/01.TA.0000075919.53201.7D.
Reaming is regarded as the most adverse aspect of the intramedullary nailing procedure since it leads not only to impairment of the vessels but also to an increase in intramedullary pressure and cortical temperatures which may in turn lead to aseptic cortical necroses and pulmonary dysfunction. Intramedullary pressure increase is considered to be the most detrimental of these factors.
The aim of this study was to investigate the effect on intramedullary pressure and cortical temperature of removing the medullary fat before reaming. The fat was removed through a suction tube inserted proximally. The measurements were made on pairs of human femora whereby in one group the contents of the medulla were drained by suction before reaming. The pressure was measured in the mid diaphysis and in the metaphysis. The temperature was measured in the mid diaphysis. The femora were reamed in a water bath at 37 degrees C and at a constant insertion force.
In comparison to the group which was not drained, the pressure for the 9.0 mm reamer in previously drained femora was reduced as follows: positive diaphyseal pressure by 88% (reamer insertion); positive metaphyseal pressure by 78% (reamer insertion); negative diaphyseal pressure by 84% (reamer withdrawal); negative metaphyseal pressure by 65% (reamer withdrawal). No significant difference was determined for temperature increase (median suction, 39.7 degrees C; median without suction, 39.4 degrees C).
The removal of the medullary contents by suction before inserting reaming instruments leads to a considerable and statistically significant pressure reduction. If the medullary contents are not sucked out before reaming or insertion of unreamed nails, high intramedullary pressure and the risk of embolization is unaltered. Consequently new instruments should be developed to facilitate the removal of the medullary contents before commencing the reaming procedure or insertion of unreamed nails.
扩髓被认为是髓内钉固定手术中最不利的环节，因为它不仅会损伤血管，还会导致髓内压力升高和皮质温度上升，进而可能导致无菌性皮质坏死和肺功能障碍。髓内压力升高被认为是这些因素中最有害的。
本研究的目的是探讨在扩髓前清除髓内脂肪对髓内压力和皮质温度的影响。通过近端插入的吸管清除脂肪。对成对的人体股骨进行测量，其中一组在扩髓前通过抽吸排出髓内容物。在骨干中部和干骺端测量压力。在骨干中部测量温度。股骨在37℃的水浴中以恒定的插入力进行扩髓。
与未进行抽吸的组相比，在先前已抽吸的股骨中，9.0mm扩髓器产生的压力降低如下：骨干正压降低88%（扩髓器插入时）；干骺端正压降低78%（扩髓器插入时）；骨干负压降低84%（扩髓器退出时）；干骺端负压降低65%（扩髓器退出时）。温度升高方面未确定有显著差异（抽吸组中位数为39.7℃；未抽吸组中位数为39.4℃）。
在插入扩髓器械前通过抽吸清除髓内容物可导致压力显著降低且具有统计学意义。如果在扩髓或插入未扩髓的髓内钉之前不吸出髓内容物，髓内高压和栓塞风险将不会改变。因此，应开发新器械以方便在开始扩髓手术或插入未扩髓的髓内钉之前清除髓内容物。
