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ICD-10 Guide
ICD-10 CodesM66.18

M66.18

Billable

Rupture of synovium, other site

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

Code Description

ICD-10 M66.18 is a billable code used to indicate a diagnosis of rupture of synovium, other site.

Key Diagnostic Point:

Rupture of synovium refers to the tearing or disruption of the synovial membrane, which lines the joints and tendon sheaths. This condition can occur in various locations throughout the body, often resulting from trauma, overuse, or underlying inflammatory conditions such as rheumatoid arthritis or gout. The synovium plays a crucial role in joint health by producing synovial fluid, which lubricates joints and nourishes cartilage. When the synovium ruptures, it can lead to joint swelling, pain, and decreased mobility. In cases where the rupture is associated with tenosynovitis, inflammation of the tendon sheath may also be present, complicating the clinical picture. Surgical intervention may be required to repair the rupture, especially if it is accompanied by tendon damage or if conservative management fails. Accurate diagnosis often involves imaging studies, such as ultrasound or MRI, to assess the extent of the injury and guide treatment decisions.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

  • Variety of potential underlying causes (trauma, inflammatory diseases)
  • Need for precise documentation of the rupture site
  • Differentiation from other synovial disorders
  • Potential for associated tendon injuries

Audit Risk Factors

  • Inadequate documentation of the rupture site
  • Failure to document associated conditions (e.g., tenosynovitis)
  • Lack of imaging studies to support diagnosis
  • Inconsistent coding of related procedures

Specialty Focus

Medical Specialties

Orthopedics

Documentation Requirements

Detailed notes on the mechanism of injury, physical examination findings, and imaging results.

Common Clinical Scenarios

Patients presenting with joint pain and swelling after a fall or repetitive use injury.

Billing Considerations

Ensure clear documentation of the specific joint or tendon involved to avoid coding errors.

Rheumatology

Documentation Requirements

Comprehensive assessment of inflammatory markers and history of autoimmune conditions.

Common Clinical Scenarios

Patients with chronic inflammatory diseases presenting with acute exacerbations of joint pain.

Billing Considerations

Document any prior history of synovial disorders to support the diagnosis.

Coding Guidelines

Inclusion Criteria

Use M66.18 When
  • Follow official ICD
  • CM coding guidelines, ensuring accurate documentation of the rupture site and any associated conditions
  • Include relevant imaging studies and treatment plans in the medical record to support the diagnosis

Exclusion Criteria

Do NOT use M66.18 When
No specific exclusions found.

Related ICD-10 Codes

Related CPT Codes

29827CPT Code

Arthroscopy, knee, diagnostic, with or without synovial biopsy

Clinical Scenario

Used when a patient with knee pain undergoes arthroscopy to assess for synovial rupture.

Documentation Requirements

Document the indication for the procedure and findings during the arthroscopy.

Specialty Considerations

Orthopedic surgeons should ensure that the procedure notes clearly indicate the diagnosis.

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The transition to ICD-10 has allowed for more specific coding of synovial disorders, improving the accuracy of diagnoses and treatment tracking. M66.18 provides granularity that was not available in ICD-9, facilitating better patient management and research.

ICD-9 vs ICD-10

The transition to ICD-10 has allowed for more specific coding of synovial disorders, improving the accuracy of diagnoses and treatment tracking. M66.18 provides granularity that was not available in ICD-9, facilitating better patient management and research.

Reimbursement & Billing Impact

The transition to ICD-10 has allowed for more specific coding of synovial disorders, improving the accuracy of diagnoses and treatment tracking. M66.18 provides granularity that was not available in ICD-9, facilitating better patient management and research.

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 is the primary cause of synovial rupture?

Synovial rupture can be caused by acute trauma, repetitive strain, or underlying inflammatory conditions such as rheumatoid arthritis or gout.

How is a synovial rupture diagnosed?

Diagnosis typically involves a clinical examination, patient history, and imaging studies such as MRI or ultrasound to visualize the extent of the rupture.