is not tightened a passage is formed for the shaft of the anchoring screw 62 over the length of the elongated hole 61 with this arrangement the diaphyseal anchor 4 can optionally be fixed in three catch positions that determine its height at the diaphysis 72 in the embodiment of fig2 to 4 the screw head is seated in the central catch seat each catch seat protects the fixed diaphyseal anchor 4 in a simple manner against movement directed away from the epiphysis 71 along the diaphysis 72 at the desired height particularly effective support in a direction transversely to the shaft of the anchoring screw 62 is obtained other suitable catch connections or similar locking connections which adjust the height of support can be set up in this case the connecting anchoring elements are designed and dimensioned in such a way that the arrangement at the diaphysis 72 corresponding to the flat dimension of the flat web 41 remains particularly flat the fixation pins 3 as can be seen from fig1 to 4 are designed as screws with a thread extending over its length full thread appropriately as cannulated banjo screws these are in each case passed through internally threaded transverse through bores 24 which are provided exclusively in the main body 21 of the supporting body 2 this being in such a way that the screws 3 come to lie in a crossing arrangement each screw each fixation pin 3 is attached by means of the screw connection at a fixed angle to the.