Masterson E L, Masri B A, Duncan C P, Rosenberg A, Cabanela M, Gross M
University of British Columbia, Vancouver, Canada.
J Bone Joint Surg Br. 1997 Nov;79(6):908-13. doi: 10.1302/0301-620x.79b6.7690.
An analysis of the cement mantle obtained with the Exeter impaction allografting system at one centre showed that it was either deficient or absent in almost 47% of Gruen zones. We therefore examined the mantle obtained using this system at another hospital and compared the results with those from the CPT and Harris Precoat Systems at other centres. The surgical indications for the procedure and the patient details were broadly similar in all four hospitals. There was some variation in the frequency of use of cortical strut allografts, cerclage wires and wire mesh to supplement the impaction allograft. Analysis of the cement mantles showed that when uncertain Gruen zones were excluded, the incidence of zones with areas of absence or deficiency of the cement was 47% and 50%, respectively, for the two centres using the Exeter system, 21% for the CPT system and 18% for the Harris Precoat system. We measured the difference in size between the proximal allograft impactors and the definitive prosthesis for each system. The Exeter system impactors are shorter than the definitive prosthesis and taper sharply so that the cavity created is inadequate, especially distally. The CPT proximal impactors are considerably longer than the definitive prosthesis and are designed to give a mantle of approximately 2 mm medially and laterally and 1.5 mm anteriorly and posteriorly. The Harris Precoat proximal impactors allow for a mantle with a circumference of 0.75 mm in the smaller sizes and 1 mm in the larger. Many reports link the longevity of a cemented implant to the adequacy of the cement mantle. For this reason, femoral impaction systems require careful design to achieve a cement mantle which is uninterrupted in its length and adequate in its thickness. Our results suggest that some current systems require modification.
在一个中心对使用埃克塞特嵌压式同种异体骨移植系统获得的骨水泥壳进行的分析表明，在格鲁恩分区中，近47%的区域骨水泥壳存在不足或缺失。因此，我们在另一家医院检查了使用该系统获得的骨水泥壳，并将结果与其他中心使用CPT和哈里斯预涂层系统的结果进行了比较。在所有四家医院中，该手术的手术指征和患者详细信息大致相似。在使用皮质支撑同种异体骨、环扎钢丝和钢丝网来补充嵌压式同种异体骨的频率上存在一些差异。对骨水泥壳的分析表明，排除不确定的格鲁恩分区后，使用埃克塞特系统的两个中心骨水泥缺失或不足区域的发生率分别为47%和50%，CPT系统为21%，哈里斯预涂层系统为18%。我们测量了每个系统近端同种异体骨冲击器与最终假体之间的尺寸差异。埃克塞特系统的冲击器比最终假体短，并且急剧变细，因此形成的腔不合适，尤其是在远端。CPT近端冲击器比最终假体长得多，设计用于在内侧和外侧形成约2毫米、在前侧和后侧形成1.5毫米的骨水泥壳。哈里斯预涂层近端冲击器在较小尺寸时允许形成周长为0.75毫米的骨水泥壳，在较大尺寸时为1毫米。许多报告将骨水泥固定植入物的使用寿命与骨水泥壳的充分性联系起来。因此，股骨嵌压系统需要精心设计，以获得长度不间断且厚度合适的骨水泥壳。我们的结果表明，一些当前的系统需要改进。
