Chevron Osteotomy

Features

Osteotomy is made through cancellous bone,
- does not shorten the metatarsal
- inherently stable
It consists of

Medial eminence removal
V-shaped intracapsular osteotomy with lateral displacement of the head
medial capsulorrhaphy

Indications

mild deformity of <30º, IM angle < 15º

Contraindications

Large deformity of the hallux, >40º or IM angle >20º

Complications

loss of position due to inadequate fixation
AVN of fragment in 1-2%

Technique

A Longitudinal medial incision from the distal proximal phalanx to end 2cm distal to the medial eminence
Make a longitudinal capsular incision, exposing the medial eminence
Do not detach it proximally, or strip to far dorsolaterally, as AVN is a risk
medial eminence is then removed at its junction with the shaft.
Using the saw, a V-shaped osteotomy is then cut

beginning 3-4mm proximal to the medial edge of the articular cartilage of the head
dorsal cut is made 30º to the longitudinal plane, & the volar cut is also made at 30º.
- (angle between them as 50-60º)
arms are usually 10-12mm long

Stabilize the metatarsal shaft with a clip, then push the head laterally with the thumb
Total displacement is about 4-5mm. (<1/3 width of metatarsal)
1mm of shift is approximately 1º of IM angle correction
inner projection of the shaft is then trimmed flush
hallux is then brought into 5º of valgus, & the osteotomy is assessed for stability
If unstable, then it is fixed with K-wires
plantar flap of the capsule is then pulled dorsally, & oversewn on the dorsal
This helps correct the sesamoid displacement.

Post operative

A plaster shoe can be applied at 48 hours