Tibiotalocalcaneal fusion:(TTC fusion)

Dr.Rajiv Shah‘Foot & ankle orthopaedics’Foot & ankle surgeonPresident, Indian Foot & Ankle Society

What is TTC fusion?

Simultaneous fusion(arthrodesis) of ankle & subtalar joint

3

Indications Post trauma

Post infection

Post degenerative arthritis -OA

AVN talus

Paralytic/flail foot & ankle

Charcot neuropathy

Loss of talar body

Failed TAR

Severe instability

4

Indications Failed ankle arthrodesis

RA, Seronegative arthropathy

Skeletal defects after tumor excision

Nonunions Severe deformity

TTC fusion: Aims

Broad, congruous & bleeding articular surfaces in apposition

Well stabilized & compressed of articulating surfaces with utmost care of skin and soft tissues

Painless & stable fusion of ankle & subtalar joints in functional position

Foot at 90 degree angle to long axis of tibia with 5-7 degree of hindfoot valgus

TTC fusion: Methods

Hindfoot nail Nail + screws Blade plate External fixator Ring(Ilizarov) fixator Taylor spatial frame Combinations

TTC fusion: Lateral Approach

Valgus deformity – Supine positionVarus position – Lateral positionSevere varus – additional medial approach

Transfibular osteotomy2.5 cm above lateral malleolusFibula is cut in bevelled fashion

TTC fusion: Lateral approach

Preserve fibula in young patients for later date possibility of TAR

Preparation of ankle & subtalar joints

Fixation – nail, blade plate, ex-fix or ring fixator

Blade plate : Anterior, posterior or lateral approach

Nail: Technique

Nail: Technique

Nail case example

Nail: tips & tricks

Compression at both joints-15mm Two plane locking-40% increase in stability Lock all holes 10mm nail, 150-180 mm length Countersink nail up to 5mm Grafting if needed Use of end cap• Prevention of medullary bleeding• Preservation of threads for extraction• limiting the heterotopic ossification

Nail: Complications

Stress fracture at tip of nail(Controlled with longer nail)Non union(exchange nailing+ bone grafting)(ring fixator +bone grafts)

Newer generation nails

Pre-assembled, embedded distal locking mechanism in the nail

7 mm of in-board compression Ability to compress the subtalar and

ankle joints separately Screws can still be removed without

having to disengage compression and/or locking mechanisms

Blade plate – adoloscent/ humerus with blade length of 40mm with plate holes up to 5-8

Provisional fixation of joints with guide wires/k wires/ST pin/ Schanz screws before blade insertion

Blade plate fusion: tips & tricks

Blade plate fusion: tips & tricks

Guide wire:5-10mm of calcaneus bone shall remain plantar to the blade plate

Push flush to lateral cortex

Do contour to prevents valgus malunion

4.5 screw proximally & 6.5 screws distally

Guide wire in proximal screw hole to prevent rotation of blade plate while hammering it in

Cut a notch in lower end of tibia for sitting of blsde plate

Use AO tension device for giving compression

Blade plate fusion: tips & tricks

Blade plate: Lateral approach

Prone position Midline longitudinal

approach -14-16cms Skin+ paratenon in one

incision Z plasty of achilles FHL with NV retracted

medially

Blade plate: Posterior approach

Blade plate: Anterior approach

Ring fixator

Combinations

That’s all…Thank you all..