Bunionette

Definition

 

Painful prominence of lateral eminence of 5th metatarsal head 

 

Coughlin Classification 

 

Type I deformity 

- prominent lateral condyle 5th metatarsal head

- lateral condylectomy

 

Type II deformity 

- lateral bowing of 5th metatarsal

- chevron osteotomy

 

Bunionette Type 2

 

Type III deformity 

- increased 4-5 IMA > 10° (N ~5°) 

- straight but laterally deviated 5th metatarsal

- midshaft osteotomy / Scarf

 

Type IV 

- combination (especially RA)

 

Clinical Features

 

Often leads to overlying corns & calluses

- lateral keratosis / plantar keratosis / combined

 

Bunionette

 

X-ray

 

4-5th IMA is normally 5°

5th MTPJ angle is 10°

 

Management

 

Non-operative

 

Pressure relief by padding

Shoe stretching

Changing to wider softer shoes

Broad-toed shoes & insole

Callus paring

 

Operative

 

Procedure depends on the underlying deformity

- true proximal osteotomies avoided due to blood supply 

- remember problems with Jones fracture

 

1. Lateral Condylectomy

 

Indications

- Type I deformity

- enlarged lateral metatarsal head

- no increase in IMA

 

2. Coughlin Proximal Osteotomy

 

Indication

- type II deformity / lateral bowing of 5th metatarsal

 

Technique

- medial displacement

- midshaft oblique osteotomy

 

3. Chevron Osteotomy

 

Indication

- Type III lesion 

 

4. Metatarsal Head Resection

 

Issue

- can get transfer pain