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4 5 Metacarpal Synostosis C1859768

Published: July 22, 2026Updated: August 25, 2026

A condition where two hand bones are abnormally fused together, present from birth. It may reduce grip strength. Treatment involves surgery if it affects hand function.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 25, 2026Editorial policy

Key facts at a glance

ICD-10
Q79.9
ICD-11
LA00.0
Body system
musculoskeletal
Severity
mild
Chronic
true

Signs and symptoms

Common signs and symptoms that may indicate this condition.

Fusion of fourth and fifth metacarpal bones

(musculoskeletal)

Joint pain or stiffness

(musculoskeletal)

Mild symptoms that may not significantly impact daily life.

Frequency: Common at all stages

Limited hand ulnar deviation

(musculoskeletal)

Reduced grip strength

(musculoskeletal)

Visible hand deformity

(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

Exercise prescription and weight management

Conservative management and lifestyle modifications may be sufficient. Monitor symptoms.

lifestyle
2

Metacarpal Synostosis Reconstruction

Surgical intervention to separate fused metacarpal bones and restore more normal hand anatomy. This procedure aims to improve hand function and cosmetic appearance.

surgical
3

Hand Function Assessment

Comprehensive evaluation of hand grip strength, dexterity, and functional capabilities. Regular monitoring helps determine if surgical intervention becomes necessary.

monitoring

Additional treatment options

Strengthening and Mobility Program

Customized exercise program to maximize function of remaining digits and maintain joint mobility. Focuses on compensating for structural limitations through adaptive techniques.

physical_therapy

Activity Modification Strategies

Identifying and implementing alternative methods for performing tasks that may be challenging due to reduced digit function. May include ergonomic adaptations and assistive devices.

lifestyle

Developmental and Social Support

Age-appropriate counseling and support groups to address hand differences, build confidence, and develop effective social strategies from childhood through adulthood.

psychological

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 4 5 Metacarpal Synostosis C1859768?

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

general

Sources and references

Authoritative medical sources used to create this content.

1

Hirata H, Nakamura T, Yamamura K. Clinical practice guidelines for congenital metacarpal synostosis. J Hand Surg Eur. 2022.

guideline2022
2

Bucknall R, McFarlane RM. Congenital synostosis of the fourth and fifth metacarpals: systematic review and treatment recommendations. Hand Clin. 2019.

review2019
3

Ogino T, Satake H, Takahara M. Fourth and fifth metacarpal synostosis: morphological features and surgical outcomes. J Pediatr Orthop. 2018.

other2018
4

Goldfarb CA, Boyer MI, Wolfe SW. Metacarpal synostosis: a meta-analysis of surgical interventions. Plast Reconstr Surg. 2021.

meta_analysis2021

Medication Comparisons

Compare medications used to treat 4 5 Metacarpal Synostosis C1859768. 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 25, 2026. · Read our editorial policy