Procedure Coding (CPT®):

31287 – Nasal/sinus endoscopy, surgical; with sphenoidotomy

Correct because the surgeon performed a surgical endoscopic sphenoidotomy to evaluate and treat sphenoid sinus injury.

No CSF leak repair was performed, so codes 31290–31291 are not appropriate.

31231-59 – Nasal endoscopy, diagnostic

Diagnostic endoscopy is separately reportable because:

It was performed to evaluate traumatic injury

It is not bundled into the surgical service when it provides distinct diagnostic information

Modifier -59 indicates a separate and distinct service per NCCI edits.

Diagnosis Coding (ICD-10-CM):

S02.109A – Unspecified fracture of base of skull, initial encounter for closed fracture

The anterior cranial fossa fracture with sphenoid sinus involvement qualifies as a skull base fracture

No CSF leak is documented

Correct 7th character “A” for initial encounter

Why Other Options Are Incorrect:

A – Incorrect format and duplicated CPT logic

B – 31267 = maxillary sinus, wrong sinus

D – 31291 includes CSF leak repair, which was not performed