骨折成角移位的方向及度量应以凸角为准
Convex is more accurate in describing the direction andmeasurements of fractures with angular displacement

我国本科教材《外科学》已连续四版将骨折成角移位的方向表述为以顶角为准。临床医学必须遵循凹凸定律，应当以凸角为准。本文就其几何学中三角的基本概念、骨折成角移位的生物力学和临床操作的规范性提出了建议，供同行商榷。
Vertex is used in describing the direction and measurements of fractures with angular displacement inSurgery of consecutive four editions, which is undergraduate textbook of our country. The convex-concave rule must befollowed in clinical medicine, so convex is more accurate in describing the fractures. This paper discussed the basic conceptsof triangle in geometry, the biomechanics in fracture displacement and the normalization in clinical operation