2024 ICD-10-CM Diagnosis Code M21.161

Varus deformity, not elsewhere classified, right knee

ICD-10-CM Code:
M21.161
ICD-10 Code for:
Varus deformity, not elsewhere classified, right knee
Is Billable?
Yes - Valid for Submission
Chronic Condition Indicator: [1]
Not chronic
Code Navigator:

Code Classification

  • Diseases of the musculoskeletal system and connective tissue
    (M00–M99)
    • Other joint disorders
      (M20-M25)
      • Other acquired deformities of limbs
        (M21)

M21.161 is a billable diagnosis code used to specify a medical diagnosis of varus deformity, not elsewhere classified, right knee. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2023 through September 30, 2024.

Approximate Synonyms

The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

  • Acquired deformity of left knee
  • Acquired deformity of right knee
  • Acquired deformity of right knee
  • Acquired genu valgum of bilateral knees
  • Acquired genu varum
  • Acquired genu varum
  • Acquired varus deformity of joint of lower limb
  • Acquired varus deformity of joint of lower limb
  • Acquired varus deformity of left knee
  • Acquired varus deformity of right knee
  • Acquired varus deformity of right knee
  • Bandy legged
  • Bandy legged
  • Bilateral acquired deformity of knee regions
  • Bilateral acquired varus deformity of knees

Clinical Classification

Convert M21.161 to ICD-9-CM

  • ICD-9-CM Code: 736.42 - Genu varum
    Approximate Flag - The approximate mapping means there is not an exact match between the ICD-10 and ICD-9 codes and the mapped code is not a precise representation of the original code.

Patient Education


Knee Injuries and Disorders

Your knee joint is made up of bone, cartilage, ligaments and fluid. Muscles and tendons help the knee joint move. When any of these structures is hurt or diseased, you have knee problems. Knee problems can cause pain and difficulty walking.

Knee problems are very common, and they occur in people of all ages. Knee problems can interfere with many things, from participation in sports to simply getting up from a chair and walking. This can have a big impact on your life.

The most common disease affecting the knee is osteoarthritis. The cartilage in the knee gradually wears away, causing pain and swelling.

Injuries to ligaments and tendons also cause knee problems. A common injury is to the anterior cruciate ligament (ACL). You usually injure your ACL by a sudden twisting motion. ACL and other knee injuries are common sports injuries.

Treatment of knee problems depends on the cause. In some cases your doctor may recommend knee replacement.

NIH: National Institute of Arthritis and Musculoskeletal and Skin Diseases


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Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.