Mumith A, Coathup M, Chimutengwende-Gordon M, Aston W, Briggs T, Blunn G
University College London, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore, Middlesex HA7 4LP, UK.
Bone Joint J. 2017 Feb;99-B(2):276-282. doi: 10.1302/0301-620X.99B2.BJJ-2016-0584.R1.
Massive endoprostheses rely on extra-cortical bone bridging (ECBB) to enhance fixation. The aim of this study was to investigate the role of selective laser sintered (SLS) porous collars in augmenting the osseointegration of these prostheses.
The two novel designs of porous SLS collars, one with small pores (Ø700 μm, SP) and one with large pores (Ø1500 μm, LP), were compared in an ovine tibial diaphyseal model. Osseointegration of these collars was compared with that of a clinically used solid, grooved design (G). At six months post-operatively, the ovine tibias were retrieved and underwent radiological and histological analysis.
Porous collars provided a significantly greater surface (p < 0.001) for the ingrowth of bone than the standard grooved design. Significantly greater extracortical pedicle formation was seen radiologically around the grooved design (length p = 0.002, thickness p < 0.001, surface area p = 0.002) than around the porous collars. However, the ingrowth of bone occurred from the transection site into the porous structure of both types of collar. A fivefold increase in integration was seen with the SP and a threefold increase in the LP design when compared with G (p < 0.001).
SLS porous collars allow the direct ingrowth of more bone and are better than current designs which rely on surface ongrowth and ECBB. Cite this article: Bone Joint J 2017;99-B:276-82.
大型内置假体依靠皮质外骨桥接（ECBB）来增强固定。本研究的目的是调查选择性激光烧结（SLS）多孔颈圈在增强这些假体骨整合方面的作用。
在绵羊胫骨干模型中比较了两种新型多孔SLS颈圈设计，一种是小孔径（Ø700μm，SP），另一种是大孔径（Ø1500μm，LP）。将这些颈圈的骨整合与临床使用的实心带槽设计（G）的骨整合进行比较。术后六个月，取出绵羊胫骨并进行放射学和组织学分析。
与标准带槽设计相比，多孔颈圈为骨长入提供了显著更大的表面积（p < 0.001）。放射学检查显示，带槽设计周围的皮质外蒂形成明显大于多孔颈圈周围（长度p = 0.002，厚度p < 0.001，表面积p = 0.002）。然而，骨长入从横断部位发生到两种颈圈的多孔结构中。与G相比，SP设计的整合增加了五倍，LP设计增加了三倍（p < 0.001）。
SLS多孔颈圈能使更多的骨直接长入，比目前依赖表面长入和ECBB的设计更好。引用本文：《骨与关节杂志》2017年；99 - B：276 - 82。
