Metatarsus Adductus

Definition

 

Metatarsus varus

- adduction of the forefoot at the TMTJ

 

Intrauterine positional deformity / packaging defect

 

Epidemiology

 

1:1000

- M = F 

- bilateral in 50%

- 10% have CDH

 

Aetiology

 

Unclear

 

Theories

- intrauterine positioning defect

- prone nursing

 

NHx

 

85% resolve by age 3 years

 

Weinstein

- 31 patients 45 feet with 33 year followup

- 16 feet mild or mod deformity passively correctable, no treatment

- 29 feet partially flexible or rigid treated manipulation or casting

- good results in all the untreated feet

- 90% good results of the casted feet

 

No poor results

 

DDx

 

CTEV

ITT / PFA

Hyperactive Abductor Hallucis

Skewfoot

 

Clinical Features

 

Curved lateral border

- forefoot adducted & slightly supinated

- deformity usually fully correctable

- prominent base of 1st metatarsal

 

Heel Bisector line

- line through midline axis hindfoot

- should pass through second web space

 

Intoed gait

- exclude ITT

- exclude PFA

 

DDx CTEV

 

Metatarsus adductus

- full range of ankle dorsiflexion & mobile hindfoot

 

Classification

 

Grade 1 - actively correctable deformity

Grade 2 - passively correctable

Grade 3 - unable to passively correct

 

X-ray

 

Not routinely required

 

Management

 

Non-operative

 

Algorithm

 

< 6/12

- observation only

- sleep supine

 

> Age 6/12

- rigid deformity

- serial casting changed every 2 to 3 weeks

- 8-12 weeks treatment

- most will tend to partially recur over time

 

Operative Management

 

Indications

 

Controversial

 

Surgery if difficulty wearing shoes / severe / > age 3

 

Options

 

1.  Abductor hallucis release 

 

2.  MT osteotomy

 

3.  Supramalleolar derotation osteotomy

 

4.  Opening wedge osteotomy medial cuneiform, closing wedge osteotomy cuboid, osteotomies of 2-4