Arthrodesis

 

Indications

 

Salvage failed TKR / infected TKR

Tumour

Charcot joint

PFFD

 

Contraindications

 

Bilateral knee fusion

Ipsilateral hip fusion

 

Problems

 

Difficulty obtaining fusion

- often significant bone loss

 

Difficulties mobilising / sitting in small bathrooms

 

Position

 

Short leg

- fuse straight 

 

Normal leg length

- fuse in 10° flexion for swing through

 

Valgus 5 - 7^o

 

External rotation 5 - 10^o

 

Options

 

1.  Intramedullary nail

2.  Double plating

3.  External fixator

 

Results

 

Union

 

Luyet et al. KSSTA 2021

- 48 knee arthrodeses for failed TKA

- 21% reoperation rate for infection or nonunion

- eventual union rate 90%

 

Nail versus External fixation

 

Balato et al. BMC Musculoskeletal Disorder 2018

- systematic review of IMN versus external fixation for infected TKA

- 11% reinfection rate for IMN versus 5% for external fixation

- union rate 90% for IMN versus 88% for external fixation

- union 2 months faster with IMN

 

Fusion versus Above Knee Amputation (AKA)

 

Trouillez et al. Orthop Traum Surg Res 2021

- fusion versus AKA for infected TKA in 43 patients

- recurrent infection in 10% (2/20) AKA
- recurrent infection in 22% (5/23) knee fusion

- AKA group had less pain and better quality of life

 

Conversion Fusion to TKA

 

Jauregui et al. J Arthroplasty 2016

- 98 patients mean age 55

- revision rate 25%

- failure rate 11%

 

Kernkamp et al. Int Orthop 2016

- systematic review of six papers and 123 knees

- mean improvement in ROM of 80 degrees

- post-operative complication rate 65%

- 25% skin necrosis, 13% arthrofibrosis, 11% infection, 11% revision

 

Intramedullary nail

 

Options

 

A.  Bridging nail

B.  Modular nail

C.  Long fusion nail

 

Bridging nail

 

Modular nail

 

Vumedi surgical technique

 

Concept

- single knee incision

- tibial and femoral components inserted through knee & then joined together

- different sizes for femur and tibia

 

 

Long fusion nail

 

 

Design

 

Insert through proximal femur

Incorporates

- femoral curvature

- knee valgus

- different intramedullary diameter between femur and tibia

 

Technique PDFs

 

Smith & Nephew Titanium Knee Fusion Nail

Stryker T2 Arthrodesis Nailing System

 

Dual plates

 

 

 

 External Fixation

 

 

Results

 

Corona et al. Eur J Orthop Surg Traumatol 2020

- 29 cases end stage infected TKA

- biplanar external fixation eradicated infection and obtained union in 100% at 5 months

- uniplanar external fixation eradicated infection in 86% and obtained union in 81% at 10 months