Provided are a bone plate and a bone plate system optimized for hybrid HTO. This bone plate is provided with: a main section 1a that is fixed, along the longitudinal direction of a tibia X, to an obliquely anterior medial surface of the tibia below a bone cutting surface of the tibia X； a wide section 1b that is wider than the main section 1a and fixed above the bone cutting surface along the peripheral surface of the tibia X； a connecting section 1c connecting the main section 1a and the wide section 1b； and a plurality of screw holes 4, 4a, 4b, 4c formed in the main section 1a, the wide section 1b and the connecting section 1c. The inner surface extending from the wide section 1b to the connecting section 1c, which faces the tibia X, has a continuously curved shape that is twisted around the axis along the longitudinal direction of the tibia X. The wide section 1b is offset from the main section 1a outwardly in the thickness direction. A side surface of the connecting section 1c that extends along the posterior surface of the tibia X when the bone plate is mounted on the tibia X has a curvature that is greater than the curvature of a side surface of the connecting section 1c that extends along the anterior surface of the tibia X.L'invention concerne une plaque pour os et un système de plaque pour os optimisés pour HTO hybride. Cette plaque pour os est pourvue : d'une section principale 1a qui est fixée, le long de la direction longitudinale d'un tibia X, à une surface médiane oblique antérieure du tibia au-dessous d'une surface de coupe osseuse du tibia X ； d'une section large 1b qui est plus large que la section principale 1a et fixée au-dessus de la surface de coupe osseuse le long de la surface périphérique du tibia X ； d'une section de connexion 1c reliant la section principale 1a et la section large 1b ； et d'une pluralité de trous de vis 4, 4a, 4b, 4c formées dans la section principale 1a, la section large 1b et la section de connexion 1c. La surface interne
