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ICD-10 Guide
ICD-10 CodesM46.21

M46.21

Billable

Osteomyelitis of vertebra, occipito-atlanto-axial region

BILLABLE STATUSYes
IMPLEMENTATION DATEOctober 1, 2015
LAST UPDATED09/17/2025

Code Description

ICD-10 M46.21 is a billable code used to indicate a diagnosis of osteomyelitis of vertebra, occipito-atlanto-axial region.

Key Diagnostic Point:

Osteomyelitis of the vertebra in the occipito-atlanto-axial region refers to an infection of the bone in the upper cervical spine, specifically affecting the occipital bone and the first two cervical vertebrae (atlas and axis). This condition can arise from hematogenous spread, direct extension from adjacent infections, or post-surgical complications. Symptoms may include localized pain, fever, neurological deficits, and signs of systemic infection. Diagnosis typically involves imaging studies such as MRI or CT scans, which can reveal bone edema, abscess formation, or other changes indicative of osteomyelitis. Treatment often requires a combination of antibiotics and, in some cases, surgical intervention to drain abscesses or debride necrotic tissue. The condition can lead to serious complications, including spinal instability and neurological impairment, making early diagnosis and management crucial.

Code Complexity Analysis

Complexity Rating: High

High Complexity

Complexity Factors

  • Differentiating between osteomyelitis and other inflammatory conditions of the spine.
  • Need for precise documentation of the infection's origin and extent.
  • Potential for co-existing conditions such as ankylosing spondylitis complicating the clinical picture.
  • Variability in treatment approaches based on severity and patient response.

Audit Risk Factors

  • Inadequate documentation of the infection's origin.
  • Failure to document imaging studies that support the diagnosis.
  • Misclassification of the condition as a non-infectious spondylopathy.
  • Lack of clarity in treatment plans and follow-up care.

Specialty Focus

Medical Specialties

Orthopedic Surgery

Documentation Requirements

Detailed operative notes, imaging results, and post-operative care plans.

Common Clinical Scenarios

Surgical intervention for abscess drainage or debridement in cases of osteomyelitis.

Billing Considerations

Ensure clear documentation of the surgical approach and any complications encountered.

Infectious Disease

Documentation Requirements

Comprehensive history of infection, laboratory results, and treatment response.

Common Clinical Scenarios

Management of osteomyelitis with antibiotic therapy and monitoring for complications.

Billing Considerations

Document the rationale for antibiotic selection and duration of therapy.

Coding Guidelines

Inclusion Criteria

Use M46.21 When
  • Follow official ICD
  • 10 coding guidelines, ensuring accurate documentation of the site and nature of the infection
  • Include any relevant co
  • morbidities and complications

Exclusion Criteria

Do NOT use M46.21 When
  • Exclude conditions that do not meet the criteria for osteomyelitis

Related ICD-10 Codes

Related CPT Codes

20610CPT Code

Arthrocentesis, aspiration and/or injection into a major joint or bursa

Clinical Scenario

Used when joint aspiration is performed due to suspected infection.

Documentation Requirements

Document the reason for aspiration and findings.

Specialty Considerations

Orthopedic surgeons should note the joint involved and any complications.

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The transition to ICD-10 has allowed for more specific coding of osteomyelitis, improving the accuracy of data collection and reimbursement processes. M46.21 provides a clear distinction for osteomyelitis in the occipito-atlanto-axial region, which was less specific in ICD-9.

ICD-9 vs ICD-10

The transition to ICD-10 has allowed for more specific coding of osteomyelitis, improving the accuracy of data collection and reimbursement processes. M46.21 provides a clear distinction for osteomyelitis in the occipito-atlanto-axial region, which was less specific in ICD-9.

Reimbursement & Billing Impact

reimbursement processes. M46.21 provides a clear distinction for osteomyelitis in the occipito-atlanto-axial region, which was less specific in ICD-9.

Resources

Clinical References

  • •
    ICD-10-CM Official Guidelines for Coding and Reporting

Coding & Billing References

  • •
    ICD-10-CM Official Guidelines for Coding and Reporting

Frequently Asked Questions

What are the common causes of osteomyelitis in the occipito-atlanto-axial region?

Common causes include hematogenous spread from distant infections, direct extension from adjacent soft tissue infections, and post-surgical complications.