FR2885027A1 - Bone plate for performing e.g. cervical arthrodesis, has holes, each with one end having covering unit to house, in cooperation with countersunk hole, part of drilled head of fixation screw to immobilize head in axial direction of screw - Google Patents

Abstract

The plate has holes for the passage of a fixation screw (3). Each of the holes has an oblong shape and is drilled in its circumference. Each hole has an end (21) conformed for coupling a drilled head (30) of the screw in the end, and an end (22) with a covering unit (23) extending to the right of a countersunk hole (20). The unit (23) allows to house, in cooperation with the countersunk hole, a part of the head to immobilize the head in an axial direction of the screw after axial translational movement of the plate to pass the head from the end (21) to the end (22).

Description

The present invention relates to an osteosynthesis plate device

  intended in particular for performing arthrodesis, in particular cervical arthrodesis.

  The currently known osteosynthesis plate devices consist of flat and elongate pieces, comprising at least two holes to allow the passage of fixing screws.

  However, it is common that one or other of the screws loosens and unscrews in an undesired manner, so that the plate is no longer perfectly maintained, which can be detrimental to the desired connection, and therefore to the patient.

  The present invention aims to provide a plate device to overcome this disadvantage.

  The osteosynthesis plate device according to the invention is of the type consisting of an elongated and flat element, comprising holes for the passage of fixing screws, and it is essentially characterized in that each of the holes has an oblong shape and is milled around its circumference, and comprises a first end shaped to allow coupling the countersunk head of a screw, and a second end which comprises elements extending to the right of the countersink, so as to constitute with the latter means adapted to immobilize said head in the axial direction of said screw after displacement in axial translation of said flat member so as to pass said head from the first to the second end.

  The passage of the screw head from one end to the other of a hole is obtained by translational movement of the plate.

  According to an additional feature of the device according to the invention, the elements which extend to the right of the countersink so as to constitute with the latter means adapted to immobilize the head in the axial direction of the screw, are provided suitable for s' extending over only a portion of said head so as to allow access to the maneuvering footprint of the latter with a clamping tool.

  It is thus possible, after immobilization of the screw head in the axial direction, to tighten and lock the latter.

  In case of loosening of a screw, the plate remains secured to it and continues to ensure the desired joining.

  The advantages and characteristics of the device according to the invention will emerge more clearly from the description which follows and which refers to the appended drawing, which represents a non-limiting embodiment thereof.

  In the accompanying drawing: - Figure 1 shows a schematic plan view of a plate device according to the invention.

  FIG. 2 represents a schematic sectional view along the axis XX 'of FIG.

  With reference to these figures, it can be seen that an osteosynthesis plate 1 according to the invention comprises oblong holes 2 each comprising a countersink 20.

  Each hole 2 has two ends 21 and 22, the end 21 allowing the passage of the countersunk head 30 of a screw 3, while the end 22 has above a portion of its periphery, in line with the countersink 20, a covering element 23 which is adapted, in cooperation with the countersink 20, to fit a portion of the head 30 tightly so as to immobilize the screw 30 in the axial direction thereof.

  The cover member 23 centrally has a recess 24 to allow access to a maneuvering footprint 31 that includes the head 30.

  After screwing screws 3, only one of which is shown, in the ends 21 of the holes 2, the plate 1 is moved longitudinally so as to engage the heads 30 under the cover members 23, then the screws 3 can be tightened by means of of a tool, not shown, through the recess 24.

Claims (2)

  1) Osteosynthesis plate device, of the type consisting of an elongated and flat element (1), and comprising holes (2) for the passage of fixing screws (3), characterized in that each of the holes (2) has an oblong shape and is milled around its periphery, and has a first end (21) shaped to enable the countersunk head (30) to be coupled with a screw (3), and a second end (22) which comprises elements (23) extending to the right of the countersink (20), so as to constitute with the latter means adapted to immobilize said head (30) in the axial direction of said screw (3) after displacement in axial translation said flat member (1) so as to pass said head (30) from the first (21) to the second (22) end.   2) Osteosynthesis plate device according to claim 1, characterized in that the elements (23) which extend to the right of the countersink (20) so as to constitute with the latter means able to immobilize the head (30). ) in the axial direction of the screw (3), are provided capable of extending over only a portion of said head so as to allow access to the footprint of maneuvement of the latter with a tool of Tightening.