ICD-10 Logo
ICDxICD-10 Medical Coding
ICD-10 Logo
ICDxICD-10 Medical Coding
ICD 10 CodesDiagnoses
ICD 10 CodesDiagnoses
ICD-10 Logo
ICDxICD-10 Medical Coding

Comprehensive ICD-10-CM code reference with AI-powered search capabilities.

© 2025 ICD Code Compass. All rights reserved.

Browse

  • All Chapters
  • All Categories
  • Diagnoses

Tools

  • AI Code Search
ICD-10-CM codes are maintained by the CDC and CMS. This tool is for reference purposes only.
v1.0.0
ICD-10 Guide
ICD-10 CodesM66.359

M66.359

Billable

Spontaneous rupture of flexor tendons, unspecified thigh

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

Code Description

ICD-10 M66.359 is a billable code used to indicate a diagnosis of spontaneous rupture of flexor tendons, unspecified thigh.

Key Diagnostic Point:

Spontaneous rupture of flexor tendons in the thigh is a condition characterized by the unexpected tearing of the flexor tendons, which are responsible for bending the knee and hip joints. This condition can occur without any apparent trauma or injury, often seen in individuals with underlying conditions such as rheumatoid arthritis, diabetes, or chronic inflammatory diseases. The rupture may lead to significant pain, swelling, and functional impairment, affecting the patient's ability to perform daily activities. Diagnosis typically involves a thorough clinical examination, imaging studies such as MRI or ultrasound, and assessment of the patient's medical history. Treatment options may include conservative management with rest and physical therapy or surgical intervention to repair the torn tendon, depending on the severity of the rupture and the patient's overall health. Accurate coding is essential for proper reimbursement and to reflect the complexity of the condition in clinical documentation.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

  • Variability in clinical presentation and severity of tendon rupture.
  • Need for precise documentation of the spontaneous nature of the rupture.
  • Differentiation from traumatic tendon injuries.
  • Potential for co-existing conditions affecting tendon health.

Audit Risk Factors

  • Inadequate documentation of the spontaneous nature of the rupture.
  • Failure to specify laterality when applicable.
  • Lack of imaging studies to support the diagnosis.
  • Inconsistent treatment documentation.

Specialty Focus

Medical Specialties

Orthopedics

Documentation Requirements

Detailed notes on the mechanism of injury, imaging results, and treatment plan.

Common Clinical Scenarios

Patients presenting with acute pain and swelling in the thigh, often with a history of chronic conditions.

Billing Considerations

Ensure to document any surgical interventions or conservative management approaches.

Rheumatology

Documentation Requirements

Comprehensive assessment of underlying rheumatologic conditions that may contribute to tendon health.

Common Clinical Scenarios

Patients with autoimmune disorders presenting with tendon ruptures.

Billing Considerations

Document the relationship between the underlying condition and the tendon rupture.

Coding Guidelines

Inclusion Criteria

Use M66.359 When
  • Follow official ICD
  • 10 coding guidelines, ensuring accurate documentation of the spontaneous nature of the rupture
  • Include any relevant co
  • existing conditions and specify the treatment approach
  • Ensure that the code reflects the clinical scenario accurately

Exclusion Criteria

Do NOT use M66.359 When
No specific exclusions found.

Related ICD-10 Codes

Related CPT Codes

27301CPT Code

Repair of tendon, flexor, thigh

Clinical Scenario

Used when surgical repair is performed for spontaneous rupture.

Documentation Requirements

Operative report detailing the procedure and findings.

Specialty Considerations

Orthopedic documentation must include pre-operative assessments and post-operative care plans.

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The transition to ICD-10 has allowed for more specific coding of spontaneous tendon ruptures, improving the accuracy of clinical data and reimbursement processes. It emphasizes the need for detailed documentation to support the diagnosis.

ICD-9 vs ICD-10

The transition to ICD-10 has allowed for more specific coding of spontaneous tendon ruptures, improving the accuracy of clinical data and reimbursement processes. It emphasizes the need for detailed documentation to support the diagnosis.

Reimbursement & Billing Impact

reimbursement processes. It emphasizes the need for detailed documentation to support the diagnosis.

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 spontaneous rupture of flexor tendons?

Spontaneous rupture of flexor tendons can occur due to degenerative changes, chronic inflammatory conditions, or systemic diseases that weaken tendon integrity.