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v1.0.0
ICD-10 Guide
ICD-10 CodesM21.171

M21.171

Billable

Varus deformity, not elsewhere classified, right ankle

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

Code Description

ICD-10 M21.171 is a billable code used to indicate a diagnosis of varus deformity, not elsewhere classified, right ankle.

Key Diagnostic Point:

Varus deformity of the ankle is characterized by an inward angulation of the distal segment of a bone or joint, leading to a misalignment that can affect gait and overall mobility. This condition can be acquired due to various factors including trauma, degenerative diseases, or post-surgical changes. Patients may present with symptoms such as pain, swelling, and difficulty in weight-bearing activities. The right ankle specifically indicates the affected side, which is crucial for treatment planning. Varus deformities can lead to secondary complications such as arthritis or instability if left untreated. Treatment options may include physical therapy, orthotic devices, or surgical interventions such as osteotomy or arthrodesis to correct the alignment and restore function. 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

  • Differentiating between acquired and congenital deformities
  • Need for precise documentation of laterality (right ankle)
  • Potential for co-existing conditions affecting the ankle
  • Variability in treatment approaches and outcomes

Audit Risk Factors

  • Inadequate documentation of the deformity's acquired nature
  • Failure to specify laterality
  • Lack of supporting clinical evidence for the diagnosis
  • Misclassification of the deformity type

Specialty Focus

Medical Specialties

Orthopedics

Documentation Requirements

Detailed clinical notes including history, physical examination findings, imaging results, and treatment plans.

Common Clinical Scenarios

Patients presenting with ankle pain, history of trauma, or previous surgeries leading to deformity.

Billing Considerations

Ensure to document any prior interventions and their outcomes to justify the current diagnosis.

Physical Therapy

Documentation Requirements

Progress notes detailing functional assessments, treatment goals, and patient responses to therapy.

Common Clinical Scenarios

Patients undergoing rehabilitation post-surgery for varus deformity correction.

Billing Considerations

Document specific functional limitations and progress towards rehabilitation goals.

Coding Guidelines

Inclusion Criteria

Use M21.171 When
  • Follow the official ICD
  • CM coding guidelines, ensuring that the diagnosis is supported by clinical documentation
  • The code M21
  • 171 should be used when the varus deformity is not classified elsewhere and is specifically affecting the right ankle

Exclusion Criteria

Do NOT use M21.171 When
No specific exclusions found.

Related ICD-10 Codes

Related CPT Codes

28485CPT Code

Osteotomy, tibia and/or fibula

Clinical Scenario

Used when performing corrective surgery for varus deformity.

Documentation Requirements

Operative report detailing the procedure and indication for surgery.

Specialty Considerations

Orthopedic surgeons must document the rationale for surgical intervention.

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The transition to ICD-10 has allowed for more specific coding of conditions like varus deformity, improving the accuracy of clinical data and reimbursement processes.

ICD-9 vs ICD-10

The transition to ICD-10 has allowed for more specific coding of conditions like varus deformity, improving the accuracy of clinical data and reimbursement processes.

Reimbursement & Billing Impact

reimbursement processes.

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 significance of specifying laterality in coding?

Specifying laterality is crucial as it impacts treatment decisions and reflects the precise nature of the patient's condition, ensuring accurate coding and billing.