3 4 Metacarpal Synostosis C5558402
Two hand bones (metacarpals) are fused together from birth. May reduce grip strength and affect hand appearance. Management is personalized based on severity.
Key facts at a glance
- ICD-10
- M79.9
- ICD-11
- FA00.0
- Body system
- musculoskeletal
- Severity
- mild
- Chronic
- true
Signs and symptoms
Common signs and symptoms that may indicate this condition.
Fusion of 3rd and 4th metacarpals
(musculoskeletal)Joint pain or stiffness
(musculoskeletal)Mild symptoms that may not significantly impact daily life.
Frequency: Common at all stages
Reduced grip strength
(musculoskeletal)Pain in the fused metacarpal region during repetitive hand use
(musculoskeletal)Functional limitation in hand movements
(musculoskeletal)Diagnosis and tests
How this condition is diagnosed and what test results mean.
Initial screening tests
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
Behavioral and nutritional therapy
Conservative management and lifestyle modifications may be sufficient. Monitor symptoms.
Conservative observation of metacarpal synostosis
Active monitoring of hand function, grip strength, and range of motion without immediate intervention, particularly when symptoms are mild and non-progressive.
Hand and wrist strengthening program
Customized exercise program to optimize strength in unaffected fingers, improve overall hand function, and compensate for limited mobility at the affected joint.
Additional treatment options
Metacarpal synostosis reconstruction
Surgical intervention to separate fused metacarpals, involving osteotomy, bone grafting, and fixation to restore independent finger movement when function is significantly impaired.
surgicalActivity modification and ergonomic adaptation
Guidance on modifying daily activities, sports participation, and workplace tasks to protect hand function and minimize strain on unaffected digits.
lifestyleHand massage and circulation support
Therapeutic techniques to maintain soft tissue health, support circulation, and prevent compensatory tension patterns in the hand.
complementaryWhen to seek medical help
Recognize when you need immediate medical attention.
Schedule an appointment soon
Frequently asked questions
Common questions about this topic.
What is 3 4 Metacarpal Synostosis C5558402?
Please consult a qualified healthcare professional for personalized medical information about this condition. [Content pending medical review.]
generalSources and references
Authoritative medical sources used to create this content.
Goldberg NH, Watson HK. Congenital synostosis of the fourth and fifth metacarpal bones: case report and review of the literature. J Hand Surg Am. 1982.
Manske PR. Symbrachydactyly and isolated cleft hand. Hand Clin. 1989.
Cole RJ, Manske PR. Classification of ulnar deficiency according to the hand and limb. J Hand Surg Am. 1997.
Benson LS, Waters PM, Mehlman CT, Graham TJ. Evaluation of congenital hand anomalies. J Am Acad Orthop Surg. 2000.
Medication Comparisons
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Medically reviewed by WellAlly Editorial Team Last reviewed August 25, 2026. · Read our editorial policy