Anterior osteosynthesis plate for lumbar vertebrae or sacral lumbar vertebra and instrument for positioning same

An anterior osteosynthesis plate for lumbar-lumbar or lumbar-sacral vertebrae, the plate being of the type comprising:

• an elongated body:
• adapted to cover at least part of the anterior portions of two consecutive vertebrae;
• possessing an anterior face and an opposite posterior face designed to be pressed against the anterior faces of the vertebrae;
• presenting first and second end zones that are interconnected by a connection zone;
• and
• provided with two through holes for anchoring screws, each formed in a respective one of the end zones;
• wherein the posterior face of the body of the plate presents a first bearing surface in said first end zone, and a second bearing surface in said second end zone, each bearing surface being designed to come into contact with the anterior face of the corresponding vertebrae, the bearing surfaces extending on separate planes and being firstly inclined to define an obtuse angle between said planes matching the relative angle between the anterior portions of the two vertebrae, and second being interconnected in the connection zone by a concave extension such that at least the posterior face of the body presents a profile that is concave in the sagittal plane;
• and
• wherein each bearing surface is provided with a roughnesses to encourage anchoring of the plate on the anterior portions of the vertebrae.