acquired flatfoot in adults

aetiology

·      tibialis posterior tendon rupture (most common)

·      Lisfranc joint degeneration

·      arthritis of hindfoot

·      Charcot joint

Tibialis posterior tendon

·      see separate section

Lisfranc joint

aetiology

·      post injury

·      degenerative arthritis develops after fracture dislocation

·      acute injury often missed

·      adequate acute treatment may not prevent occurrence

·      idiopathic

·      not related to trauma

X-ray

·      degenerative changes invariably involve 2nd MT-2nd cuneiform jt

·      may involve 1st and 3rd jts

·      rarely involves 4th and 5th jts

treatment
Nonoperative

·      rigid support

·      try moulded arch support or UCLB initially

·      may need double upright caliper with inside T strap

Operative

·      realignment of Lisfranc joint

·      with arthrodesis

Arthritis

types
Rheumatoid arthritis

·      due to involvement of

·      ankle joint

·      subtalar joint

·      midtarsal joint

Osteoarthritis of ankle joint

·      valgus tilt of talus leads to pronation of talus and calcaneus

·      flatfoot deformity corrected when ankle joint realigned

Subtalar arthritis

·      usually follows injury to talus or calcaneus

·      typically following following calcaneal fracture

treatment
Nonoperative

·      for flexible deformity or mild symptoms

·      initially use moulded arch support or UCLB insert

·      may require rigid orthosis

·      double upright with medial T strap

Operative

·      for rigid deformity

·      arthrodesis of affected joint

Charcot joint

·      usually associated with diabetes

·      may be marked collapse

·      develop bony prominence on medial sole

·      may cause ulceration

·      treated with

·      casting and NWB during active collapse

·      bracing to minimise wt bearing on foot