Lin P P, Roe S, Kay M, Abrams C F, Jones A
Department of Orthopaedic Surgery, University of North Carolina, Chapel Hill, USA.
Clin Orthop Relat Res. 1998 Jul(352):194-201.
Current methods of treating calcaneus fractures vary greatly, and many techniques of internal fixation have been described. The study of these fractures has been limited in part by the lack of a suitable laboratory model. In this study, a new cadaveric model of calcaneus fractures was developed, using a combination of osteotomies and impaction. The model allows a pattern of intraarticular injury to be reproduced consistently. The model was used to examine one aspect of internal fixation. It was hypothesized that fixation would be more stable if the screws supporting the posterior facet were incorporated into the lateral plate, as opposed to being separate from the plate. Six pairs of anatomic specimen legs were used, and each pair was divided randomly between two experimental groups. In Group A (screws out), the posterior facet screws were outside the plate, and in Group B (screws in), the screws were incorporated into the plate. The strength of the reconstructed calcanei were evaluated by axial loading of the limb through the tibia. Stiffness and energy to failure were significantly greater and Bohler's angle significantly less compromised in Group B. It was concluded that the position of the articular fragment of comminuted calcaneal fractures will be maintained at higher loads when the screws in the posterior facet are incorporated into the lateral plate. The model of calcaneal fractures described in this study may be suitable for examining other aspects of fixation.
目前治疗跟骨骨折的方法差异很大，并且已经描述了许多内固定技术。对这些骨折的研究部分受到缺乏合适实验室模型的限制。在本研究中，通过截骨术和撞击相结合的方式，开发了一种新的跟骨骨折尸体模型。该模型能够一致地再现关节内损伤模式。该模型用于研究内固定的一个方面。研究假设，与与侧板分离相比，如果支撑后关节面的螺钉并入侧板，固定会更稳定。使用了六对解剖标本腿，每对随机分为两个实验组。在A组（螺钉外置）中，后关节面螺钉位于板外，而在B组（螺钉内置）中，螺钉并入板内。通过经胫骨对肢体进行轴向加载来评估重建跟骨的强度。B组的刚度和破坏能量明显更大，而Bohler角的受损明显更小。得出的结论是，当后关节面的螺钉并入侧板时，粉碎性跟骨骨折关节碎片的位置在更高负荷下将得以维持。本研究中描述的跟骨骨折模型可能适用于研究固定的其他方面。
