CPT® Code 20931

Add-On Code

The CPT® Code 20931 refers to the use of a structural allograft specifically for spine surgery. In this context, an allograft is a type of bone graft that utilizes donor bone, typically harvested from a cadaver. This procedure is distinct in that it involves the placement of an intact piece of donor bone, which has been carefully shaped or sculpted to fit into a specific bone defect within the spine. Unlike other grafts, such as those that may contain living cells or growth factors, a structural allograft primarily serves as a calcium scaffold. This scaffold allows for the natural process of bone growth to occur around it, a phenomenon known as bone conduction. Additionally, the term 'osteopromotive material' is often associated with this procedure. These materials are designed to promote bone growth and may include substances that contain natural growth factors, which can stimulate the differentiation of cells into bone-forming cells. One notable example is bone morphogenic proteins (BMP), which are combined with absorbable collagen sponges to enhance the graft's effectiveness in inducing new bone formation. It is important to note that CPT® Code 20931 is used exclusively for reporting the placement of structural allografts in spine surgery and should be listed separately in addition to the primary procedure code, ensuring accurate billing and documentation of the surgical intervention.