Receiving part for receiving a rod for coupling the rod to a bone anchoring element

A bone anchoring device comprising:

• a bone anchoring element comprising a shaft and a head;
• a receiving part for receiving a rod for coupling the rod to the bone anchoring element, the receiving part comprising:
• a receiving part body having a first end, a second end, an axis extending through the first end and the second end, a substantially U-shaped recess at the first end forming a channel for receiving the rod, and an accommodation space for accommodating the head of the bone anchoring element, the accommodation space having an opening at the second end for introducing the head;
• and
• a pressure element configured to be arranged at least partially in the accommodation space, the pressure element comprising a first section having a second recess for receiving the rod, and a second section having an expandable portion to insert and clamp the head, the pressure element having a slit extending from a free end of the second section and having an opposite end spaced apart from a free end of the first section, wherein the first section and the second section are axially connected to one another;
• and
• a closure element,
• wherein the first and second sections of the pressure element are insertable through the opening at the second end of the receiving part body toward the first end of the receiving part body, and wherein the first section of the pressure element is configured to abut against a stop in the receiving part body to position the expandable portion in the accommodation space.

A method for coupling a rod to a bone anchoring element via a receiving part, the receiving part comprising a receiving part body having a first end, second end, an axis extending through the first end and the second end, a substantially U-shaped recess at the first end forming a channel for receiving the rod, and an accommodation space for accommodating a head of the bone anchoring element, the accommodation space having an opening at the second end for introducing the head, and a pressure element configured to be arranged at least partially in the accommodation space, the pressure element comprising a first section having a second recess for receiving the rod, and a second section having an expandable portion to insert and clamp the head, the pressure element having a slit extending from a free end of the second section and having an opposite end spaced apart from a free end of the first section, wherein the first section and the second section are axially connected to one another, the method comprising:

• inserting the first and second sections of the pressure element through the opening at the second end of the receiving part body toward the first end of the receiving part body until the first section of the pressure element abuts against a stop in the receiving part body to position the expandable portion in the accommodation space;
• introducing the head through the opening into the pressure element, wherein the expandable portion of the pressure element expands in the accommodation space to accommodate the head;
• inserting the rod into the channel;
• adjusting an angular position of the receiving part with respect to the bone anchoring element to be aligned with the rod;
• and
• advancing a closure element in the substantially U-shaped recess towards the second end of the receiving part body, the closure element advancing the rod towards the second end, the rod advancing the pressure element towards the second end,
• wherein the closure element is advanced until it locks the relative positions of the rod and the bone anchoring element with respect to the receiving part.