> ## Documentation Index
> Fetch the complete documentation index at: https://docs.navnx.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Graft Path

> Configuring graft geometry with spline control points, diameter, and live 3D preview.

## Graft Path

For ligament reconstruction procedures, NavNX allows you to define and visualise the graft path — the trajectory the graft tissue will follow through the tunnels and across the joint.

## Graft Configuration

Open the graft tool by clicking **Graft** in the toolbar or pressing **G**. The properties panel displays graft parameters:

| Parameter      | Description                                              |
| -------------- | -------------------------------------------------------- |
| **Graft type** | Autograft or allograft label                             |
| **Diameter**   | Graft diameter in mm (adjustable)                        |
| **Length**     | Total graft length in mm (auto-calculated from the path) |

## Spline Control Points

The graft path is defined as a smooth spline curve through a series of control points:

<Steps>
  <Step title="Switch to Graft view">
    Select the **Graft** tab in the toolbar. The viewport shows the 3D bone model with tunnels.
  </Step>

  <Step title="Review auto-generated points">
    If tunnels have been placed, NavNX automatically generates an initial graft path through the tunnel entry and exit points.
  </Step>

  <Step title="Add or adjust control points">
    Click on the path to add intermediate control points. Drag existing points to refine the curve. The spline updates smoothly in real time.
  </Step>

  <Step title="Set the diameter">
    Adjust the graft diameter using the slider or input field in the properties panel.
  </Step>
</Steps>

## Live 3D Preview

The graft is rendered as a semi-transparent tube in the 3D viewport. As you adjust control points or diameter, the preview updates immediately:

* The tube follows the spline curve through the tunnels
* Colour indicates fit: **green** for adequate clearance, **amber** when the graft diameter approaches the tunnel diameter

<Tip>
  Increase the graft diameter incrementally to check tunnel clearance. If the graft preview turns amber, consider increasing the tunnel diameter.
</Tip>

## Removing the Graft

To remove the graft path from the plan, click **Remove Graft** in the properties panel and confirm.

<Note>
  The graft path is included in the pre-op report, showing the planned trajectory, diameter, and total length.
</Note>