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)Medication Comparisons
Compare medications used to treat 3 4 Metacarpal Synostosis C5558402. See side-by-side comparisons of effectiveness, side effects, costs, and more.
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Medically reviewed by WellAlly Editorial Team Last reviewed August 25, 2026. · Read our editorial policy