What is the ICD-10 (International Classification of Diseases, 10th Revision) code for an acute fracture through the anterior cortex of S3 (third sacral vertebra)?

ICD-10 Code for Acute Fracture Through Anterior Cortex of S3

The appropriate ICD-10 code for an acute fracture through the anterior cortex of the third sacral vertebra (S3) is S32.10XA (Unspecified fracture of sacrum, initial encounter for closed fracture).

Rationale for Code Selection

The coding for sacral fractures follows these principles:

• The S32.1 code series covers sacral fractures specifically
• The fourth character "0" indicates an unspecified type of sacral fracture
• The "X" is a placeholder required by ICD-10 format
• The "A" extension indicates initial encounter for closed fracture

Detailed Code Structure

The S32.1 code family includes:

• S32.10 - Unspecified fracture of sacrum
• S32.11 - Zone I fracture of sacrum (involving S1-S2)
• S32.12 - Zone II fracture of sacrum (involving S3-S4)
• S32.13 - Zone III fracture of sacrum (involving S5)
• S32.14 - Type 1 fracture of sacrum (transverse fracture with normal appearance)
• S32.15 - Type 2 fracture of sacrum (longitudinal with anterior displacement)
• S32.16 - Type 3 fracture of sacrum (oblique with neurological involvement)
• S32.17 - Type 4 fracture of sacrum (transverse with neurological involvement)
• S32.19 - Other fracture of sacrum

Clinical Considerations

While S32.12XA (Zone II fracture of sacrum, initial encounter) might seem appropriate since it specifically mentions S3, this code is typically used for fractures involving the entire S3-S4 region rather than an isolated anterior cortical fracture of S3. Without additional information about the fracture pattern or neurological involvement, S32.10XA is the most appropriate default code.

Imaging Considerations

• Initial imaging for suspected sacral fractures should include plain radiographs, though these have limited sensitivity for sacral fractures 1
• If clinical suspicion remains high with negative radiographs, MRI without contrast is the preferred second-line imaging study 1
• CT without contrast may be useful when MRI is contraindicated or unavailable 1

Important Clinical Pearls

• Sacral fractures can be easily missed on initial evaluation, particularly when there are other distracting injuries
• Patients with sacral fractures may present with low back pain, buttock pain, or neurological symptoms including bladder/bowel dysfunction 2
• S3 fractures may have implications for nerve function as the S3 nerve roots provide innervation to the bladder and rectum 2
• Only about 15.2% of patients have an S3 osseous fixation pathway large enough to accommodate an intraosseous implant 3

Documentation Requirements

For accurate coding, medical documentation should include:

• Specific location of the fracture (anterior cortex of S3)
• Whether the fracture is open or closed
• Initial or subsequent encounter
• Any associated neurological deficits
• Mechanism of injury (trauma vs. insufficiency/fragility fracture)

If additional imaging reveals more specific information about the fracture pattern, the code may need to be updated to a more specific code within the S32.1 family.