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v1.0.0
ICD-10 Guide
ICD-10 CodesM05.061

M05.061

Billable

Felty's syndrome, right knee

BILLABLE STATUSYes
IMPLEMENTATION DATEOctober 1, 2015
LAST UPDATED09/12/2025

Code Description

ICD-10 M05.061 is a billable code used to indicate a diagnosis of felty's syndrome, right knee.

Key Diagnostic Point:

Felty's syndrome is a rare complication of rheumatoid arthritis characterized by the triad of rheumatoid arthritis, splenomegaly, and neutropenia. The right knee is often involved due to the symmetrical nature of rheumatoid arthritis, leading to synovitis, joint effusion, and pain. Anatomically, the knee joint comprises the femur, tibia, fibula, and patella, with surrounding ligaments and synovial tissue that can become inflamed. Clinically, patients may present with joint swelling, stiffness, and decreased range of motion, particularly in the right knee. The pathophysiology involves autoimmune mechanisms where the immune system mistakenly attacks joint tissues, leading to chronic inflammation and joint damage. Early diagnosis and management are crucial to prevent further complications such as joint deformity and functional impairment.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

  • Involvement of multiple body systems (rheumatologic and hematologic)
  • Need for precise documentation of laterality (right knee)
  • Potential for overlapping diagnoses (rheumatoid arthritis)
  • Variability in clinical presentation and severity

Audit Risk Factors

  • Inadequate documentation of joint involvement and laterality
  • Failure to document the severity of rheumatoid arthritis
  • Lack of evidence for neutropenia or splenomegaly in the medical record
  • Misclassification of related conditions or complications

Specialty Focus

Medical Specialties

Orthopedics

Documentation Requirements

Orthopedic documentation should include imaging studies (X-rays, MRIs) to assess joint damage, functional assessments to evaluate range of motion, and treatment plans detailing surgical or non-surgical interventions.

Common Clinical Scenarios

Common scenarios include joint injections, arthroscopy for synovitis, or total knee arthroplasty in advanced cases.

Billing Considerations

Documentation must reflect the severity of joint involvement and any deformities present.

Rheumatology

Documentation Requirements

Rheumatologic documentation should include laboratory tests for inflammatory markers (e.g., ESR, CRP), complete blood counts to monitor neutropenia, and assessments of disease activity (e.g., DAS28 score).

Common Clinical Scenarios

Management of Felty's syndrome may involve disease-modifying antirheumatic drugs (DMARDs) and biologics.

Billing Considerations

Systemic involvement must be documented, including any complications arising from neutropenia.

Physical Medicine

Documentation Requirements

Functional assessments should evaluate mobility, strength, and the need for assistive devices. Rehabilitation plans must be detailed to address specific limitations.

Common Clinical Scenarios

Rehabilitation may focus on improving joint function and managing pain through physical therapy.

Billing Considerations

Mobility limitations should be clearly documented, including the impact on daily activities.

Coding Guidelines

Inclusion Criteria

Use M05.061 When
  • 10 coding guidelines require accurate documentation of laterality (right knee), severity of the condition, and the type of encounter (initial, follow
  • up, etc
  • Ensure that all relevant clinical information is captured to support the diagnosis

Exclusion Criteria

Do NOT use M05.061 When
No specific exclusions found.

Related ICD-10 Codes

Related CPT Codes

20610CPT Code

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

Clinical Scenario

Used for managing joint effusion in the right knee due to Felty's syndrome.

Documentation Requirements

Document the indication for the procedure, including joint involvement and any prior treatments.

Specialty Considerations

Orthopedic considerations for joint health and rheumatologic implications of the procedure.

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The transition to ICD-10 has allowed for greater specificity in coding musculoskeletal conditions, enabling better tracking of complications like Felty's syndrome and its impact on joint health.

ICD-9 vs ICD-10

The transition to ICD-10 has allowed for greater specificity in coding musculoskeletal conditions, enabling better tracking of complications like Felty's syndrome and its impact on joint health.

Reimbursement & Billing Impact

The transition to ICD-10 has allowed for greater specificity in coding musculoskeletal conditions, enabling better tracking of complications like Felty's syndrome and its impact on joint health.

Resources

Clinical References

  • •
    American College of Rheumatology Guidelines

Coding & Billing References

  • •
    American College of Rheumatology Guidelines

Frequently Asked Questions

What are the key symptoms of Felty's syndrome?

Key symptoms include joint pain and swelling, particularly in the knees, fatigue, recurrent infections due to neutropenia, and splenomegaly. It is important to document these symptoms accurately for proper coding.