ICD-10-PCS Billable Code

0NU307Z

Supplement Parietal Bone, Right to No Qualifier with Autologous Tissue Substitute, Open Approach

Procedural Specifications

Clinical Axis Detail Definition
Section0 Medical and Surgical
Body SystemN Head and Facial Bones
OperationU Supplement
Body Part3 Parietal Bone, Right
Approach0 Open
Device7 Autologous Tissue Substitute
QualifierZ No Qualifier

Operation Definition

Putting in or on biological or synthetic material that physically reinforces and/or augments the function of a portion of a body part

Procedure Overview

Supplement procedures add material, either the patient's own tissue, donor tissue, or a synthetic substitute, onto or into a facial or cranial bone to reinforce it or restore its bulk and contour without removing the bone that is already there. This differs from replacing a bone outright; the native bone stays in place and the added material simply strengthens or builds up its form. It is commonly performed to fill a bony defect left by prior trauma or tumor surgery, to augment thin or deficient bone before dental implants, or to reconstruct the contour of the orbit, cheek, or skull after an injury.

Materials used range from titanium mesh and hydroxyapatite cement to bone graft harvested from the patient's hip or rib, or processed allograft bone from a tissue bank. The choice depends on the size of the defect, the load the area must bear, and whether the reconstruction needs to support surrounding soft tissue or restore symmetry.

These procedures are often staged well after the original injury or cancer surgery, once healing has stabilized and the reconstructive plan is finalized.

Anatomy & Axis Detail

Parietal Bone, Right

The right parietal bone forms much of the lateral and superior skull roof on that side, directly overlying the parietal lobe of the brain. Supplement involves reinforcing this bone with graft, mesh, or synthetic material without full-thickness replacement, typically performed to correct a residual contour irregularity after craniotomy closure, to strengthen thinned bone from a prior infection or radiation, or to fill small defects left after burr holes or minor bone removal. Since the parietal bone contains the sagittal suture along its medial border and lies near the superior sagittal sinus, care in shaping and securing the supplement material is important to avoid impinging on venous structures. This procedure is distinguished from replacement, which would apply when a larger segment of bone is substituted rather than merely augmented.

Approach: Open

Open approach means the surgeon cuts through skin, mucous membrane, or other tissue layers to physically expose the target site to view before performing the procedure. It gives direct visualization and hands-on access, distinguishing it from Percutaneous approaches where instruments pass through a small puncture without exposing the site. Open is typical for procedures needing wide access, such as most laparotomies.

Device: Autologous Tissue Substitute

Autologous Tissue Substitute identifies a device value where material harvested from the patient's own body, such as an autograft, is used to replace or reconstruct a body part. Its defining feature is tissue origin from the patient, setting it apart from Nonautologous Tissue Substitute, sourced from a donor or animal, and Synthetic Substitute, made of manufactured material.

Coding & Documentation

A supplement code is appropriate when the documentation describes reinforcing or augmenting an existing facial or cranial bone with graft material or a synthetic substitute, while the underlying native bone remains largely intact. Look for terms such as onlay bone graft, cranioplasty with mesh, or orbital floor reconstruction with implant material, along with a clear statement of what substance was used, since that determines the device or substance value in the code.

The most common documentation gap is failing to specify whether the material is autologous, nonautologous, or synthetic, each of which maps to a different qualifier and can change reimbursement. Coders also frequently mistake a graft placed to fill a defect left after removal of a body part for Supplement when it should be Replacement, or vice versa; the rule of thumb is that Supplement reinforces a body part that is still present in some form, whereas Replacement substitutes for a body part that has been taken out entirely.

Commonly Confused With

ReplacementSupplement is easily confused with Replacement, since both involve putting material into the body, but Replacement takes the place of a body part that has been removed or is nonfunctional, while Supplement reinforces a body part that remains in place.
InsertionIt also overlaps conceptually with Insertion, which places a device that monitors, assists, or prevents but does not physically reinforce the body part's structure.