Orthopedic implant consisting of a support structure provided with at least an orifice for passing through a fixing screw associated with a nut

• US 20040267261A1
• Filed: 05/24/2004
• Published: 12/30/2004
• Est. Priority Date: 11/22/2001
• Status: Active Grant

• Current Assignee: Bio Quest, DLM Incorporated (Medtronic Plc)
• Original Assignee: DLM Incorporated (Medtronic Plc)
• Inventors: Derouet, Guillaume
• Granted Patent: US 7,410,496 B2
• Time in Patent Office: Days
• US Class Current: 606/70
• CPC Class Codes: A61B 17/8047 wherein the additional element surrounds the screw head in the plate hole A61B17/8052 takes precedence
• CPC Class Codes: A61B 17/8605 Heads, i.e. proximal ends projecting from bone
• CPC Class Codes: A61B 17/8665 Nuts
• CPC Class Codes: A61B 17/8695 Washers surrounding screw head in plate hole A61B17/8047, between bone plate and bone A61B17/8028

Abstract

An orthopedic device having a support structure provided with at least an orifice for a fixing screw associated with a nut; the head of the screw to be pressed on one side of the support, and the nut adapted to be pressed on the other side of the support, in a housing enabling its being integrated at least partly, so as to enable the support structure to be clamped between the screw head and the nut when the screw body has been completely screwed in the receiving bone material. The implantable device includes elements for maintaining the nut in its housing opposite the orifice, and elements for locking the nut in rotation. The contours of the housing and of the nut are dimensioned to provide at least one degree of freedom to the nut in the housing enabling self-centering of the screw and nut.

Claims

1-14. -14. (cancelled)

15. An implantable orthopaedic device formed of a supporting structure (1), at least one fastening screw (5) and a nut (10), which supporting structure (1) is fitted with at least one orifice (3) to let through the fastening screw (5) associated with said nut (10), the head (6) of said screw (5) being intended for resting on one side of said support (1), and said nut (10) being intended for resting on the other side of said support (1), in a housing (12) which enables at least partial integration, to allow clamping said supporting structure (1) between the head (6) of the screw and the nut (10) upon complete screwing of the screw body in the receiving bone material, which implantable device includes means for holding said nut (10) in its reception housing (12) facing the orifice (3) of the supporting structure (1), and means for locking said nut (10) in rotation, characterised in that the contours of the housing (12) of the supporting structure (1) and the contours of the nut (10) are sized to confer at least one degree of freedom to said nut (10) when integrated and held in its housing (12), enabling self-centring of the nut (10) with respect to the associated fastening screw (5) regardless of the admissible orientation of the axis of said screw (5) relative to the axis (16) of the orifice (3) of the supporting structure (1), when presenting said screw (5) facing said nut (10) integrated in hits housing (12), and also in order to allow selection of an accurate spatial orientation of said screw (5) with respect to the axis (16) of the orifice (3), within an admissible orientation amplitude, when screwing the latter in the reception bone material, whereas the contact surfaces of the nut (10)/supporting structure (1) and of the screw head (6)/supporting structure (1) are adapted for correct locking of said supporting structure (1) between said screw head (6) and said nut (10), upon complete clamping, regardless of the screw orientation selected.

16. An implantable device according to claim 15, characterised in that the holding means (13) of the nut (10) in its reception housing (12) are composed of a material rebound closing partially said housing (12).

17. An implantable device according to claim 15, characterised in that the holding means of the nut (10) in its housing (12) are formed of an added-on clip (13) closing partially said housing (12).

18. An implantable device according to claim 17, characterised in that it includes a clip (13) for holding a nut (10) in the form of an open circular loop, which loop (13) comprises a snap-on groove (39) co-operating with a throat (33) of appropriate shape provided in the integration housing (12) of the nut (10).

19. An implantable device according to claim 15, characterised in that the means (14) for locking the nut (10) in rotation in the reception housing (12) of the supporting structure (1) are formed of at least one relief (34) laid out on one of said parts (1, 10), co-operating with an adapted notch (37) provided on the other one of said parts (10, 1).

20. An implantable device according to claim 15, characterised in that it includes cylindrical contact surfaces between the screw head (6) and the supporting structure (1), on the one hand, and cylindrical contact surfaces between the supporting structure (1) and the nut (10), on the other hand, adapted to confer to the fastening screw (5) a possibility of orientation relative to the supporting structure (1), while keeping contacts between said surfaces.

21. An implantable device according to claim 20, characterised in that it includes cylindrical contact surfaces between the screw head (6) and the supporting structure (1), on the one hand, and cylindrical contact surfaces between the supporting structure (1) and the nut (10), on the other hand, which surfaces have the same axis (21, 22, 23).

22. An implantable device according to claim 15, characterised in that it includes spherical contact surfaces (7, 31) between the screw head (6) and the supporting structure (1), on the one hand, and cylindrical contact surfaces (32, 35) between the supporting structure (1) and the nut (10), on the other hand, which surfaces are adapted to confer to the fastening screw (5) a possibility of orientation relative to the supporting structure (1), while keeping contacts between surfaces.

23. An implantable device according to claim 22, characterised in that it includes spherical contact surfaces (7, 31 ;

32, 35) between the screw head (6) and the supporting structure (1), on the one hand, and between the supporting structure (1) and the nut (10), on the other hand, which have the same centre (21, 22, 23).

24. An implantable device according to claim 21, characterised in that it includes cylindrical or spherical contact surfaces whereof the position of the axis, or of the centre (23) as the case may be, is situated in the vicinity of the upper plane of the supporting structure (1), let alone confused with this plane.

25. An implantable device according to claim 22, characterised in that it includes a nut (10) containing a cylindrical shaft (100) fitted with a female thread (30), and a spherical crown (356) situated at the periphery of said cylindrical shaft (100).

26. An implantable device according to claim 15, characterised in that the fastening screw (5) is fitted with a body thread (25) able to co-operate with the bone material, and with a head thread (27), different, able to co-operate with the associated nut (10), the outer diameter of the body thread (25) being smaller than or equal to the outer diameter of the head thread (27).

27. An implantable device according to claim 26, characterised in that it includes at least one fastening screw (5) whereof the head thread (27) is composed of n threads (28) offset by 1/n turn, whereof the pitch corresponds to that of the thread (30) of the nut (10) and to that of the body thread (25).

28. An implantable device according to claim 23, characterised in that it includes cylindrical or spherical contact surfaces whereof the position of the axis, or of the centre (23) as the case may be, is situated in the vicinity of the upper plane of the supporting structure (1), let alone confused with this plane.