Metatarsus Adductus (MTA) is a common congenital foot deformity characterized by the inward curvature of the forefoot while the hindfoot remains in a neutral position. This condition usually resolves on its own but may require intervention in some cases.
Epidemiology
- Incidence: Occurs in approximately 12% of newborns.
- Natural Resolution: 90% of cases resolve spontaneously by the age of 4.
Aetiology
Metatarsus Adductus is primarily a "packaging problem" due to limited intrauterine space, which causes the forefoot to turn inward. It is often associated with Developmental Dysplasia of the Hip (DDH), making early screening essential.
Classification
Metatarsus Adductus is commonly classified using the Bleck Classification, which considers:
Heel Bisector Line: Determines the severity based on the position of the forefoot relative to the heel.
Deformity Stiffness: Assesses the flexibility of the foot to guide treatment.
Diagnosis
- Clinical Examination:
- Observe forefoot adduction with a neutral hindfoot.
- Screen for other foot deformities and any associated conditions, such as DDH.
- Tickle Foot Test:
- Gentle stimulation of the lateral foot triggers peroneal muscle activity, indicating flexibility.
- Heel Bisector Angle:
- An abnormal heel bisector angle confirms the diagnosis.
Management
Treatment of Metatarsus Adductus varies based on the age of the child and the stiffness of the deformity.
Management Flow Chart
Management pathway
- Assess flexibility.
- Flexible deformity: passive stretching/home exercises.
- Rigid deformity: serial casting in younger children.
- Persistent deformity after 7 years: consider osteotomies, including medial column lengthening and/or lateral column shortening.
- Under 7 years: continue serial casting as appropriate.