Adapter device and system including an adapter device and a bone anchor

An adapter device for connecting an instrument to a bone anchor that comprises a shank and a head and that defines a channel that extends through the head and at least a portion of the shank, the adapter device comprising:

• an elongate main portion having a longitudinal axis, a first end with a surface that is directly engageable with the head, an opposite second end, and a channel that extends longitudinally through the main portion;
• a holding member comprising an inner surface forming a seat for the head;
• and
• a supply cannula configured to move through the entire channel of the main portion, the supply cannula comprising a first portion and a second portion extending from a first end of the first portion in a direction away from the first portion, wherein the first end of the first portion is positionable at a same axial height as the first end of the main portion, and wherein an outer width of the second portion is smaller than an outer width of the first portion.

A kit, comprising:

• a bone anchor comprising a shank and a head, wherein the bone anchor defines a channel extending through the head and at least a portion of the shank;
• and
• an adapter device, comprising:
• an elongate main portion having a longitudinal axis, a first end with a surface that is directly engageable with the head, an opposite second end, and a channel that extends longitudinally through the main portion,
• a holding member having an inner surface forming a seat for the head, and
• a supply cannula insertable into the channel of the main portion,
• wherein, when the head is in the seat, the supply cannula is configured to move through the first end of the main portion to the head, and to directly engage with an abutment of the head such that axial movement of the supply cannula relative to the bone anchor is limited by the abutment.