Definition
Metatarsus varus / adduction of the forefoot at the midfoot
Epidemiology
Most common congenital forefoot deformity
- 1:1000
- bilateral 50%
Etiology
Unclear
? intrauterine positioning defect
Natural history
85% resolve by age 3 years
- 45 feet with metatarsus adductus
- 33 year followup
- flexible / untreated feet: 100% good outcome
- rigid / treated feet: 90% good outcome
Clinical features
Forefoot adducted
Curved lateral border of the foot
Differential diagnosis
Intoeing
Skewfoot
Classification
Flexible / Semi-flexible / Non-flexible
Flexible metatarus adductus
Rocca et al Musculoskeletal Surg 2023
- screened 2000 live births
- metatarsus varus 5/1000
- 98% flexible / semiflexible
- 2% nonflexible
Blecks classification
Heel Bisector line
- line through midline axis hindfoot
- should pass through second web space
X-ray
Obliquity of the medial cuneiform-metatarsal joint
Management
| Flexible | Semi-flexible | Rigid |
|---|---|---|
| No treatment | Stretching / manipulation |
Serial casting Splints / Orthotics |
Rigid metatarsus adductus
Options
Serial casting
Splinting / orthotics
- Bebax
- Universal Neonatal Foot Orthotic (UNFO)
Bebax orthotics UNFO
Results
Manipulation / stretching
Rocca et al Musculoskeletal Surg 2023
- 124 metatarsus varus 5/1000
- 122 flexible / semiflexible treated with manipulation
- 57% success
- 43% required additional bracing
Bebax versus serial casting
Herzenberg et al J Orthop Sci 2014
- RCT of 43 resistant metatarsus adductus
- serial casting versus Bebax orthotic
- both improved condition
- Bebax improved more but cost more
UNFO versus serial casting
Freedman et al J Pediatr Orthop B 2022
- 147 metatarsus adductus
- UNFO 3 months v serial casting 4 weeks + AFO 8 weeks
- no difference in outcome
Operative Management
Indications
Difficulty wearing shoes
Options
Multiple metatarsal osteotomy
Medial column lengthening / lateral column shortening
- opening wedge osteotomy medial cuneiform
- closing wedge osteotomy cuboid
