Honl M, Rentzsch R, Müller G, Brandt C, Bluhm A, Hille E, Louis H, Morlock M
Barmbek General Hospital, Department of Orthopedic Surgery, Rübenkamp 148, 22291 Hamburg, Germany.
J Biomed Mater Res. 2000;53(6):781-90. doi: 10.1002/1097-4636(2000)53:6<781::aid-jbm20>3.0.co;2-g.
Water-jet cutting techniques have been used in industrial applications for many different materials. Recently these techniques have been developed into a revolutionary cutting tool for soft tissues in visceral surgery. The present study investigates the usage of this cutting technology for the revision surgery of endoprostheses. In the first part of the study, samples of bovine bone and acrylic bone cement (PMMA) were cut using an industrial jet cutting device with pure water. Below 400 bar, only PMMA was cut; above 400 bar, bone was also cut, but only pressures above 800 bar resulted in clinically useful rates of material removal (cut depth 2. 4 mm at 10 mm/min traverse speed). In the second part of the study, the effect of adding biocompatible abrasives to the water in order to reduce the required pressure was investigated, resulting in a significantly higher removal of material. At 600 bar, PMMA was cut 5. 2 mm deep with plain water and 15.2 mm deep with added abrasives. The quality of the cuts was increased by the abrasive. Though there was no clear selectivity between bone and PMMA any more, the rate of material removal at similar pressures was significantly higher for PMMA than for bone (600 bar: 1.6 mm cut depth for bone samples, 15.2 mm for PMMA). The measured cut depths with either method were not influenced by a change of the cutting direction with respect to the main direction of the osteons in the bone. However, a reduction of the jet surface angle (90 degrees to 23 degrees ) resulted for bone in a significantly lower cut depth at 600 bar (plain water: 0.62 mm vs. 0.06 mm; abrasive: 1.61 mm vs. 0.60 mm). The laboratory experiments indicate that abrasive water jets may be suitable for cutting biomaterials like bone and bone cement.
水刀切割技术已在工业应用中用于多种不同材料。最近，这些技术已发展成为一种用于内脏手术中软组织的革命性切割工具。本研究调查了这种切割技术在内植物翻修手术中的应用。在研究的第一部分，使用工业水刀切割设备用纯水切割牛骨和丙烯酸骨水泥（PMMA）样本。在400巴以下，仅PMMA被切割；在400巴以上，骨头也能被切割，但只有压力高于800巴时才能达到临床可用的材料去除率（在10毫米/分钟的横向速度下切割深度为2.4毫米）。在研究的第二部分，研究了向水中添加生物相容性磨料以降低所需压力的效果，结果材料去除率显著提高。在600巴时，用纯水切割PMMA的深度为5.2毫米，添加磨料后为15.2毫米。磨料提高了切割质量。虽然骨头和PMMA之间不再有明显的选择性，但在相似压力下，PMMA的材料去除率明显高于骨头（600巴：骨样本切割深度为1.6毫米，PMMA为15.2毫米）。两种方法测量的切割深度不受切割方向相对于骨中骨单位主方向变化的影响。然而，对于骨头，将水刀表面角度从90度减小到23度会导致在600巴时切割深度显著降低（纯水：0.62毫米对0.06毫米；磨料：1.61毫米对0.60毫米）。实验室实验表明，磨料水刀可能适用于切割骨头和骨水泥等生物材料。
