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
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
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