Midfoot / Hindfoot

Midfoot

 

A.  Lis Franc Joints OA

 

May cause flat foot

Treat with midfoot fusion

 

Rheumatoid Foot APRheumatoid Midfoot OA

 

B.  TNJ OA

 

May be affected in isolation early

- may cause passively correctable valgus foot

- UCBL insert

 

Talonavicular Arthrodesis

 

Indication

- erosion confined to this joint

- correct valgus deformity

 

Technique

- dorsomedial incision

- protect saphenous nerve and vein

 

Result

- will lose 80% STJ motion

 

Rheumatoid TNJ Fusion LateralRheumatoid TNJ Fusion AP

 

Hindfoot

 

A.  Tendo Achilles Insertional Tendonitis

 

Ankle Synovitis

 

Rheumatoid involvement of bursa at T Achilles insertion

- nodules may develop within the tendon

- can weaken attachment & precipitate rupture

 

Treatment

- excision of nodules

- may need tendon augmentation / reconstruction

 

B.  Retrocalcaneal Bursitis

 

Common

- heel lift initially

- may need debridement and excision of posterosuperior calcaneal prominence

 

C.  Tibialis Posterior Tendonitis /  Rupture

 

Synovitis of sheaths of T post & Peroneal tendons common

- treat with tenosynovectomy

 

Rupture of TP with flatfoot

- FDL transfer in Stage 2 

- triple arthrodesis in Stage 3

- pan talar arthrodesis in Stage 4

 

D.  Planovalgus

 

Causes

- STJ OA

- TNJ OA

- tibialis posterior rupture

- synovitis and rupture of the talocalcaneal interosseous ligament

- tight T Achilles

 

Pathology

- subtalar joint valgus angulation

- talar head drops into plantarflexion

- navicular subluxes laterally

- get planovalgus foot with forefoot abduction

 

Non Operative

 

Brace

- double upright with square ferrule

 

Operative

 

Triple Arthrodesis

 

Indication

- fixed painful hindfoot

- TNJ and STJ OA

- AKJ preserved

 

F.  AKJ OA

 

Total Ankle Replacement

 

Attractive concept

- reduces loading across other joints

- results similar to OA

 

Ankle Arthrodesis

 

Treatment of choice

 

Complicated by

- prolonged period to union  - 6/12

- non-union in 10%