Template for positioning interbody fusion devices

摘要

A template assembly is provided for marking locations on the disc annulus for the implantation of an interbody fusion device or the introduction of a working instrument. The template assembly includes a tubular body sized for percutaneous introduction into a patient and advancement to an affected intervertebral disc. An elongated shaft slidably extends through the tubular body and is threadedly engaged to the tubular body at its proximal end so that rotation of the shaft relative to the tubular body advances the shaft through the body. A guide foot is pivotably connected to the distal end of the tubular body to be pivoted from a first position aligned with the tubular body to a second deployed position oriented substantially perpendicular to the tubular body. The guide body is pivoted from the first position to the second position by advancement of the elongated shaft through the tubular body. The guide body in one embodiment defines a bore through which the working tip of an electrocautery instrument extends to mark the disc annulus. In another embodiment, the guide body itself defines an electrocautery projection. The template assembly can be anchored to the affected disc by a guide wire extending through the tubular body and about which the template assembly can be rotated to make an additional mark on the annulus at a predetermined distance from the first mark.