ICD-10 Diagnosis Code for Trimalleolar Fracture
The diagnosis code for a trimalleolar ankle fracture is S82.85- (trimalleolar fracture of lower leg), with the 7th character extension indicating the episode of care and fracture characteristics.
Understanding the Coding Structure
The ICD-10 code S82.85- requires a 7th character to complete the code:
- S82.851-: Displaced trimalleolar fracture of right lower leg
- S82.852-: Displaced trimalleolar fracture of left lower leg
- S82.853-: Displaced trimalleolar fracture of unspecified lower leg
- S82.854-: Nondisplaced trimalleolar fracture of right lower leg
- S82.855-: Nondisplaced trimalleolar fracture of left lower leg
- S82.856-: Nondisplaced trimalleolar fracture of unspecified lower leg
7th Character Extensions
The complete code requires an additional 7th character to specify the encounter type:
- A: Initial encounter for closed fracture
- B: Initial encounter for open fracture type I or II
- C: Initial encounter for open fracture type IIIA, IIIB, or IIIC
- D: Subsequent encounter for closed fracture with routine healing
- G: Subsequent encounter for closed fracture with delayed healing
- K: Subsequent encounter for closed fracture with nonunion
- P: Subsequent encounter for closed fracture with malunion
- S: Sequela
Important Coding Considerations
The procedure codes (ORIF and syndesmosis repair) are separate from the diagnosis code. The diagnosis code reflects the injury itself, not the treatment performed. For billing purposes:
- The trimalleolar fracture diagnosis code (S82.85-X) is what you're asking about
- CPT codes 27822 or 27823 would be used for the ORIF procedure 1
- Syndesmosis repair would have its own separate CPT code
Clinical Context
Recent data shows that trimalleolar ORIF with posterior malleolus fixation increased from 17.6% to 21.4% between 2010-2021, and syndesmotic repair rates increased from 10.1% to 29.3% during the same period 1. This reflects evolving surgical practice, but does not change the underlying diagnosis code for the fracture itself.
For a typical displaced trimalleolar fracture requiring ORIF with syndesmosis repair, the most commonly used code would be S82.851A (right) or S82.852A (left) for the initial surgical encounter of a closed fracture.