Hook for an occipito-cervical rod or plate of an occipito-cervical osteosynthesis instrumentation

• US 5,542,946 A
• Filed: 05/27/1994
• Issued: 08/06/1996
• Est. Priority Date: 05/27/1994
• Status: Expired due to Term

• Current Assignee: Sofamor S.N.C.
• Original Assignee: Sofamor S.N.C.
• Inventors: Logroscino, Carlo, Goube, Michel
• Primary Examiner(s): TUCKER, GUY V
• Application Number:
  US08/250,580
• Time in Patent Office: 802 Days
• Field of Search: 606/61, 606/69, 606/70, 606/71, 606/72, 606/73, 606/60, 606/54, 606/59, 606/101
• US Class Current: 606/276
• CPC Class Codes: A61B 17/7002 Longitudinal elements, e.g. rods
• CPC Class Codes: A61B 17/7032 Screws or hooks with U-shaped head or back through which longitudinal rods pass
• CPC Class Codes: A61B 17/7055 connected to sacrum, pelvis or skull
• CPC Class Codes: A61B 17/7056 Hooks with specially-designed bone-contacting part

Abstract

The hook (32) comprises a body (33) and a laminar portion (37) which is suitably profiled and adapted to penetrate a foramen opening at the base of the occiput against which it bears. The body is arranged to receive an osteosynthesis rod or plate and has a plane of symmetry (P). The laminar portion (37) has a curvature adapted to the thickness of the occipito-cervical shell and is inclined relative to one side or the other of the plane of symmetry (P) so as to be adaptable to the anatomy of the edge of the occiput in the region of the foramen. This inclination may be for example substantially 45°. This asymmetry of the laminar portion (37) relative to the body (33) of the hook (32) enables the surgeon to avoid having to previously remove a piece of the edge of the occiput of the patient and consequently damage the occiput.

Claims

1. Hook for an occipito-cervical rod or plate of an occipito-cervical osteosynthesis instrumentation, said hook comprising a generally U-shaped body with opposite side branches having a laminar portion defined by a strip suitably profiled and adapted to penetrate a foramen opening at the base of the occiput, said body being adapted to receive an osteosynthesis rod or plate and having a median plane of symmetry extending between said side branches, said strip being inclined relative to either side of said median plane of symmetry so as to adapt itself to the anatomy of the edge of the occiput in the region of the foramen.

2. Hook according to claim 1, wherein said strip has an inclination of substantially 45°

relative to said median plane of symmetry.

3. Occipito-cervical osteosynthesis instrumentation comprising two separate similarly configured parts, namely a right part and a left part, each part including a cervical rod having asperities and an elongate occipital plate which is in one piece with said rod and extends said rod toward said occiput in the position of use, and adjustable means for anchoring said rod to the vertebrae C1-C3 and for anchoring said plate to said occiput, each of said parts being pre-angulated and so profiled as to be adapted to the anatomy of the occipito-cervical connection of the human spine, said adjustable means for anchoring said plate to said occiput comprising hooks adapted to penetrate the foramen openings at the base of said occiput against which they bear, each hook including a laminar portion and a generally U-shaped body with opposite side branches adapted to receive the rod or plate and having a median plane extending between said side branches and said laminar portion is inclined relative to either side of said plane of symmetry.

4. Instrumentation according to claim 3, wherein said laminar portion has an inclination of substantially 45°

relative to said median plane of symmetry.