US Patent 7717919 Application of therapy aligned to an internal target path

An alignment jig that creates a plurality of parallelograms may be used to align an external alignment line with an internal target path. The internal target path is within the patient's body and may be defined by two guide pin tips. The alignment jig may be created so that it creates the external alignment line to be co-linear with the internal target path or the external alignment line may be parallel to the internal target path by offset a distance from being co-linear. The external alignment line may be used in the provision of therapy such as the delivery of a screw to a precise location in the provision of therapy to a portion of the spine.