The invention relates to a bone plate assembly for use in orthopaedic or trauma surgery. The bone plate assembly includes a plate member (1, 1', 1") having a top side (1a) and a bottom side (1b) at least one passage (2) extending from the top side (1a) to the bottom side (1b)； wherein the at least one passage (2) includes a first bore (2a) with a first end open towards the top side (1a) and a second end, a seat portion (2c) configured to receive the head (7) of the bone anchor (6)； and wherein the first bore (2a) comprises a first central axis (C1) and the seat portion comprises a second central axis (C3), and wherein the first central axis (C1) and the second central axis (C3) intersect each other within the passage (2)； and a second bore (2b) open towards the bottom side (1b)； and wherein the first bore (2a) comprises an internal thread (5).
