Radiology Coding Alert

Question: A patient presents for a visit two months following a vertebroplasty procedure for a pathological fracture of the C2 spine. The fracture is a result of spinal metastases originating from a primary liver malignancy. The physician reviews a recent magnetic resonance imaging (MRI) exam and concludes the patient's fracture is healing well. What diagnosis code should I apply?

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Answer: As it stands, this diagnosis does not offer a high degree of specificity, which may limit your ability to identify the most appropriate diagnosis code. You should check the provider's notes to make sure the etiology behind the pathologic fracture is definitively documented as a result of the metastases. If not, you may want to consider referring the claim back to the provider for further clarification.

In this scenario, there are three diagnosis codes you want to consider. You will apply a diagnosis code for the pathological fracture of the C2 vertebrae, a code for the secondary malignancy to the spine, and lastly a code for the primary liver malignancy.

Pathological fracture coding, despite the fact that you know the underlying disease, does not offer a high degree of specificity. Under the ICD-10 index, you will find Fracture ⇒ pathological (pathologic) ⇒ vertebrae, which leads you to code M84.48XD (Pathological fracture, other site, subsequent encounter for fracture with routine healing). Since the surgical procedure for the fracture occurred two months ago and the physician documented that the fracture is healing well, you will apply a D (Subsequent encounter) seventh digit to the diagnosis code.

Next, you will apply code C79.51 (Secondary malignant neoplasm of bone) for the secondary spinal malignancy. Lastly, you will apply code C22.8 (Malignant neoplasm of liver, primary, unspecified as to type) for the malignancy of the liver. Even though the provider does not document term "primary," the fact that the provider documents the liver as the originating site is enough to code with a primary malignancy diagnosis.

Now, your final task is to identify which diagnosis is primary. While it might make sense to some to code the fracture as the primary diagnosis, ICD-10 guidelines are clear when it comes to assigning a principal diagnosis.

According to Section 1.C.6.b. in the ICD-10 guidelines, "When an admission or encounter is for a procedure aimed at treating the underlying condition (e.g., spinal fusion, kyphoplasty), a code for the underlying condition (e.g., vertebral fracture, spinal stenosis) should be assigned as the principal diagnosis." Additionally, according to Section 1.C.2.a. in the ICD-10 guidelines, "If the treatment is directed at the malignancy, designate the malignancy as the principal diagnosis."

Based on this information, you can confidently apply C79.51 as the primary diagnosis followed by M84.48XD and C22.8. Even though the surgeon performed the vertebroplasty to treat the pathologic fracture, the underlying cause for the fracture is the malignancy, which you must code as the principal diagnosis.