total knee arthroplasty

Types of Instability

1.  AP Instability

2.  Varus Valgus Instability

3.  Global Instability

4. Frank Dislocation

Goal 

Pain relief combined with a balanced range of motion, strength & stability

Indications

Painful arthritic knee

- OA

- RA

Functional limitation

Ideal Patient

- > 65

- thin

Causes of Deformity

Metabolic Bone Disease

Paget's

Fracture Malunion

Previous Osteotomy

Options

1.  Intra-articular correction

2.  Simultaneous osteotomy and TKR

3.  Staged correction and TKR

1.  Intra-articular correction 

Indications

Femur

- draw line of mechanical axis of femur

Numbers

9 years up to 31 December 2009

- 289 000 TKR

- 80% primary

- 11% primary partial

- 8.5% revision

TKR Revision Rate 

9 year revision rate of 5.1% OA

- 4.5% in RA

Causes

- loosening  30%

- infection   20%

Principle

Correct alignment and soft tissue balancing

- two of the most important aspects of successful TKR

Technical Goals

1.  Restoration of mechanical alignment

- forces of the leg pass through the centre of the hip, knee and ankle