Stern S H, Sharrock N, Kahn R, Insall J N
Department of Orthopedic Surgery, Northwestern University, Chicago, Illinois 60611.
Clin Orthop Relat Res. 1994 Feb(299):179-89.
This study evaluated the effects of intramedullary instrumentation when used on the femur and tibia. Twenty-six patients (52 knees) undergoing bilateral index cemented total knee arthroplasty were analyzed. Bilateral knee arthroplasties were chosen because the increased surgery would theoretically maximize any perioperative hemodynamic or hematologic changes. Patients were randomized into one of two groups depending on the exact form of surgical instrumentation used. Group I (intramedullary) knees were implanted with standard intramedullary fluted instruments. No special measures to vent the entrance holes were made. Group II (extramedullary) knees were implanted with an extramedullary tibial guide, in conjunction with an intramedullary femoral guide placed through a vented femoral hole. All patients manifested significant changes in their hematologic and hemodynamic values after arthroplasty. Leukocytes increased 85% on average, whereas fibrinogen (106%) and erythrocyte sedimentation rates (145%) also showed significant increases. Conversely, patients exhibited a relative thrombocytopenia (63%) nadiring on the second postoperative day. However, there was no significant differences seen between the two instrumentation groups. Hemodynamically, all patients exhibited rises in cardiac index (52%) and pulmonary artery pressures (64%). Analysis of the hemodynamic results in this study does demonstrate subtle evidence of increased pulmonary vascular resistance in the intramedullary group. Specifically, the intramedullary group had lower cardiac indexes, in association with higher pulmonary pressures. This increase in pulmonary vascular resistance with the use of intramedullary instrumentation may represent subtle evidence of increased lung injury in this group. Results point to the continued use of fluted intramedullary rods and vented entrance holes as a reasonable surgical technique in patients undergoing knee arthroplasty.
本研究评估了髓内器械应用于股骨和胫骨时的效果。对26例（52膝）接受双侧初次骨水泥全膝关节置换术的患者进行了分析。选择双侧膝关节置换术是因为手术量增加理论上会使围手术期的任何血流动力学或血液学变化最大化。根据所使用的手术器械的确切形式，患者被随机分为两组之一。第一组（髓内）膝关节植入标准的带槽髓内器械，未采取特殊措施对入口孔进行排气。第二组（髓外）膝关节植入髓外胫骨导向器，并通过一个有排气孔的股骨孔放置髓内股骨导向器。所有患者在关节置换术后血液学和血流动力学值均出现显著变化。白细胞平均增加85%，而纤维蛋白原（106%）和红细胞沉降率（145%）也显著升高。相反，患者术后第二天出现相对血小板减少（63%）。然而，两组器械组之间未见显著差异。血流动力学方面，所有患者的心指数（52%）和肺动脉压（64%）均升高。本研究对血流动力学结果的分析确实显示了髓内组肺血管阻力增加的细微证据。具体而言，髓内组的心指数较低，同时肺动脉压较高。使用髓内器械时肺血管阻力的增加可能是该组肺损伤增加的细微证据。结果表明，对于接受膝关节置换术的患者，继续使用带槽髓内棒和有排气孔的入口孔是一种合理的手术技术。
