Skip to content

Bilateral Ulnar Hypoplasia C4025166

Published: July 22, 2026Updated: August 20, 2026

A birth defect where the ulna bone in both forearms is underdeveloped or absent, affecting arm function. Treatment may include surgery, physical therapy, or prosthetic support.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 20, 2026Editorial policy

Key facts at a glance

ICD-10
M79.9
ICD-11
FA00.0
Body system
musculoskeletal
Severity
moderate
Chronic
true

Signs and symptoms

Common signs and symptoms that may indicate this condition.

Joint pain or stiffness

(musculoskeletal)

Noticeable symptoms that may vary in intensity over time.

Frequency: Common at all stages

Ulnar hand weakness

(musculoskeletal)

Limited elbow extension

(musculoskeletal)

Forearm shortening

(musculoskeletal)

Digit contractures

(musculoskeletal)

Diagnosis and tests

How this condition is diagnosed and what test results mean.

Initial screening tests

1

Standard diagnostic workup

Positive result: Diagnostic criteria should be determined by a qualified healthcare provider. [Content pending medical review.]

Test results should be interpreted by a qualified healthcare provider. [Content pending medical review.]

Treatment options

Evidence-based approaches to managing this condition.

First-line treatments

1

Dietary counseling and physical activity plan

Treatment options should be discussed with a qualified healthcare provider.

lifestyle
2

Upper limb reconstructive surgery

Multidisciplinary surgical approach to improve hand and forearm function through bone, tendon, and soft tissue reconstruction.

surgical
3

Hand therapy program

Specialized occupational and physical therapy focusing on grip strength, dexterity, and functional use of affected limbs.

physical_therapy

Additional treatment options

Custom orthotic devices

Individually fabricated splints and braces to support weak ulnar structures and improve hand positioning for function.

procedure

Body image and coping intervention

Psychological support addressing self-esteem, social anxiety, and adaptation to limb differences.

psychological

Assistive technology assessment

Evaluation for adaptive equipment and assistive devices to enhance independence in daily activities.

complementary

When to seek medical help

Recognize when you need immediate medical attention.

Schedule an appointment soon

Symptoms associated with this condition. Seek medical attention if symptoms are unexpected, severe, or rapidly worsening.- Contact your healthcare provider if symptoms persist or worsen. Seek emergency care for sudden severe symptoms.

Frequently asked questions

Common questions about this topic.

Q

What is Bilateral Ulnar Hypoplasia C4025166?

Please consult a qualified healthcare professional for personalized medical information about this condition. [Content pending medical review.]

general

Medication Comparisons

Compare medications used to treat Bilateral Ulnar Hypoplasia C4025166. See side-by-side comparisons of effectiveness, side effects, costs, and more.

View Medication Comparisons

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 20, 2026. · Read our editorial policy