DEVICE FOR FIXATION OF BONE FRAGMENTS AT BONE FRACTURES

摘要

The present invention relates to a device for fixation of bone fragments at bone fractures. The device comprises at least two fixation means (1) and a securing plate (17). The securing plate (17) has threaded holes (19). The fixation means consist of bone nails (1) which each comprises a sleeve (5) with a displaceable pin (7) inside the sleeve. A forward portion (9) of the (7) pin defines a first fixing portion for fixing the bone nail (1) in an inner bone fragment (3). A threaded rear end portion (18) of the sleeve (5) defines a second fixing portion for locking the bone nail (1) to the securing plate (17). The sleeve (5) has a middle portion (32) along which the outer bone fragment (2) can slide inwards towards the Inner bone fragment (3). The thread of each threaded hole (19) in the securing plate (17) is configured such that after screwing of the threaded rear end portion (18) of the sleeve (5) into the threaded hole until it reaches a surface in the hole against which said threaded rear end portion can abut, a side aperture for the pin (7) in the sleeve is oriented in a predetermined direction in the inner bone fragment (3).

主权项

1. A device for fixation of bone fragments at bone fractures,
wherein the device comprises at least two fixation means (1) and a securing plate (4), wherein the securing plate (17) is configured with a threaded hole (19) for each fixation means (1), wherein the fixation means each takes the form of a bone nail (1) which comprises a sleeve (5) and, disposed therein, a pin (7) arranged for movement in the sleeve so that at least a forward portion (9) of the pin can he driven outwards through at least one side aperture (13) in the sleeve, wherein the forward portion of the pin (7) constitutes a first fixing portion in the form of at least one hook (9) which engages in an inner bone fragment (3) for fixing the bone nail (1) therein, wherein the rear end portion (18) of the sleeve (5) is threaded and defines a second fixing portion for locking the bone nail (1) to the securing plate (17) which is disposed on the outside of an outer bone fragment (2) without fixed connection therewith such that movement of the outer bone fragment relative to the securing plate is allowed and change of the angular position of the bone nails relative to the securing plate and relative to one another is prevented, wherein a middle portion (32) of the sleeve (5) is situated between the side aperture (13) in the sleeve and the second fixing portion (18) thereof and runs through the outer bone fragment (2), said middle portion being configured such that the outer bone fragment during secondary compression can slide inwards therealong away from the securing plate (17) and towards the inner bone fragment (3) in which the bone nail (1) is fixed, and wherein the thread of each threaded hole (19) in the securing plate (17) is configured such that after screwing of the threaded rear end portion (18) of the sleeve (5) into the threaded hole until the said threaded rear end portion reaches a surface in the hole against which said threaded rear end portion can abut, the side aperture (13) in the sleeve is oriented in a predetermined direction in the inner bone fragment (3).