2025 ICD-10-CM code M21.1

Varus deformity, not elsewhere classified.

Use additional codes to specify the location (e.g., knee, elbow, ankle) and any associated injuries or conditions.An external cause code should be appended to indicate the cause of the varus deformity, if known.

Modifiers may be applicable depending on the specific circumstances of service delivery.Consult your local coding guidelines for further clarifications.

Medical necessity is established when the varus deformity causes significant pain, functional limitations, or instability affecting the patient's ability to perform activities of daily living.Surgical intervention would require documentation demonstrating that conservative measures have failed to alleviate symptoms and that the surgical procedure is necessary to improve function and quality of life.

Diagnosis is made through physical examination, measurement of the joint angle, and imaging studies such as X-rays or MRI.Treatment may range from conservative measures like NSAIDs to surgical intervention followed by immobilization with a splint.

IMPORTANT Excludes1: metatarsus varus (Q66.22-), tibia vara (M92.51-); Excludes2: acquired deformities of fingers or toes (M20.-), coxa plana (M91.2)

In simple words: This code describes a bone deformity where a joint bends inward, like a bowleg.The doctor will specify the exact type of deformity. It can be painful and make daily tasks difficult. Treatment might include pain relievers and possibly surgery followed by a splint to keep the joint stable.

M21.1, Varus deformity, not elsewhere classified, refers to an inward angulation of the distal portion of a joint, causing one or more bones to turn toward the body's midline.This code is used when the specific type of varus deformity isn't represented by another code.The condition can cause pain, inflammation, and restrict daily activities. Diagnosis is based on physical examination, joint angle measurement, and imaging (X-rays, MRI). Treatment may involve NSAIDs for pain relief and surgical repair followed by splint immobilization.

Example 1: A patient presents with a noticeable inward bowing of the right knee (genu varum). Physical examination confirms the varus deformity, and X-rays reveal no fractures or other underlying conditions. The physician documents M21.1 to code the deformity., A child is diagnosed with a varus deformity of the ankle following a fall.The physician notes the specific malformation is not further classifiable under other ICD-10 codes. An external cause code is added to indicate the cause of the deformity., An adult patient with severe pain and limited mobility due to a longstanding varus deformity of the elbow undergoes surgical correction. The surgeon performs an osteotomy to realign the bones. The postoperative course involves immobilization with a splint until healing is complete.

Detailed physical examination documenting the presence of the varus deformity, including joint angle measurements. Imaging studies (X-rays, MRI) to rule out other causes and assess the severity of the deformity.Documentation of any treatment provided, including medications (NSAIDs) and surgical procedures.Progress notes charting the patient's response to treatment and functional outcomes.

** This code is for a general varus deformity and does not capture specific types of varus deformities.The physician should specify the affected joint and any associated conditions in additional codes.

  • Payment Status: Active
  • Modifier TC rule: Not applicable.
  • Specialties:Orthopedics, general surgery
  • Place of Service:Office, Outpatient Hospital, Inpatient Hospital, Ambulatory Surgical Center
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