An improved low cost, preferably disposable instrument guide adapted to carry an access instrument used in accessing a compromised portion of a bone structure has a single piece guide body. The guide body has a first referencing arm and second referencing arm. The first referencing arm has a first end portion, wherein the first end portion of the first referencing arm has a reference structure integral therewith and wherein the reference structure defines a virtual axis. The second referencing arm is integral to the first reference arm and has at least one guide opening with a guide axis extending to intersect the virtual axis. The at least one guide opening is located at a fixed angle on the second referencing arm.