Staging and Deciphering Your Imaging Reports

Deciphering a radiology report can feel like learning a new language. For Kienböck disease, doctors use specific measurements and a classification system called Lichtman Staging to describe exactly how much the lunate bone has changed and how those changes are affecting the rest of your wrist ^[1][2].

The Lichtman Staging System

This system categorizes the disease into stages based on what can be seen on X-rays, CT scans, and MRIs.

[Insert diagram illustrating the Lichtman Stages I-IV here]

• Stage I: The bone looks structurally normal on X-rays, but an MRI shows “stress” or swelling (edema) inside the bone. This is the earliest stage of blood flow loss ^[3][4].
• Stage II: The bone begins to harden. On an X-ray, the lunate will look whiter and denser than the bones around it. This hardening is called sclerosis ^[5].
• Stage III: The bone begins to flatten or break apart (collapse). This stage is further divided:
  • Stage IIIA: The lunate has collapsed, but the other wrist bones are still in their normal alignment ^[1].
  • Stage IIIB: The “foundation” of the wrist has become unstable. Other bones, specifically the scaphoid, begin to tilt or rotate out of place ^[6][7].
  • Stage IIIC: This denotes a coronal fracture, which is a vertical split through the lunate bone. This fracture makes the bone much harder to heal and often requires a different surgical approach ^[8][9].
• Stage IV: The collapse has caused the protective cartilage in the wrist to wear away, leading to osteoarthritis throughout the joint ^[10].

A Guide to Report Terminology

When reading your report, you may encounter these technical terms:

• Ulnar Variance: This is the difference in length between the two bones of your forearm (the radius and ulna). Negative ulnar variance means your ulna is shorter, which shifts extra pressure onto the lunate ^[11][12].
• Carpal Height Ratio: A calculation doctors use to see if your wrist bones are “sinking” toward your arm. A decreasing ratio means the wrist is collapsing ^[13][14].
• Gadolinium Enhancement: This refers to the use of a contrast dye during an MRI. If the lunate “enhances,” it means blood is still reaching the bone (it is viable). If it does not enhance, the bone tissue is likely dead (necrotic) ^[15].
• Scapholunate Angle: This measures the relationship between two wrist bones. A normal angle is between 30 and 60 degrees. An angle larger than 60 degrees often signals the shift into Stage IIIB instability, meaning the wrist bones are shifting out of place ^[16].

Your Report Checklist

When reviewing your imaging results with your doctor, ensure the following information is clear:

1. Lichtman Stage: Has a specific stage been assigned (e.g., IIIA vs. IIIB)?
2. Bone Viability: Does the MRI show blood flow (gadolinium enhancement)?
3. Fracture Status: Is there any mention of a coronal or vertical fracture?
4. Anatomy: Is there negative ulnar variance, and if so, how many millimeters?
5. Alignment: Is the scaphoid bone tilted or rotated (flexed)?
6. Arthritis: Are there signs of “joint space narrowing” or “osteophytes” (bone spurs)?