Accessory Navicular

Incidence

 

1 - 2 %

 

Anatomy

 

Medial Aspect of foot

- proximal to navicular

- part of T posterior tendon

 

Usually will fuse with navicular (50%)

 

Issues

 

1.  Probably not a cause of flat foot

- excising accessory navicular / rerouting / reattaching tibialis posterior

- will not help pes planus

 

2.  Pain

- may fracture

- may cause insertional tendonitis

 

Classification

 

Type 1

 

Small ossicle proximal to insertion

 

Type 2

 

Synchondrosis

- may fracture with injury

 

Accessory Navicular Fractured SynchondrosisAccessory Navicular

 

Management

- treat in cast 6/52

- excise if symptomatic

 

Type 3

 

Large cornuate navicular

- likely that the accessory has fused

 

Accessory Navicular Cornuate

 

Bone Scan

 

Acessory Navicular Bone Scan

 

Identifies if accessory navicular cause of symptoms

 

MRI

 

Show oedema about a symptomatic accessory navicular

 

DDx

 

T Posterior tendonitis

Navicular stress fracture

 

Management

 

Non operative

 

Rest

Moon Boot

 

Operative

 

Kidner Procedure

- medial incision dorsally over navicular

- enucleate accessory navicular from tendon

- may need to take away navicular prominence

- reattach tendon if necessary through drill holes