Three-dimensional osseous micro-architecture of the distal humerus: implications for internal fixation of osteoporotic fracture.

BACKGROUND: The purpose of this study is to analyze 3-dimensional structural parameters of cortical and trabecular bone in the distal humerus using quantitative CT and to find regional variations and differences according to age.

METHODS: We collected 14 cadaveric distal humeri with an average age of 58.4 years. The specimens were examined at 3 different levels: 1) distal trans-epicondylar section, 2) mid trans-olecranon fossa section, and 3) proximal supra-olecranon fossa section.

RESULTS: In the distal section, bone volume was the greatest in the anterior part of the lateral condyle and the least in the posterior part of the lateral condyle. Cortical thickness in the distal section was the thickest in the posterior medial and the thinnest in the anterior aspect followed by lateral aspect. The changes in cortical thickness with aging were obvious in the posterior side and trabecular bone on the medial condyle.

CONCLUSION: This study evaluated the differences in cortical and trabecular bone parameters in each different region of the distal humerus. We found a potential weakness of plate fixation in the posterolateral aspect of the distal condyle because of relative insufficient osseous micro-architecture, which may affect the treatment of osteoporotic distal humerus fractures especially in elderly patients.