indications

Aim

Attempt to reduce outliers in all 3 planes of the knee

- improve alignment

- theoretically improve survival and outcomes

Types

Image based

Pre-op CT

- uncommon

- resource heavy

Philosophy

Need the least amount of constraint necessary to obtain sufficient stability

Increasing constraint

Advantages

- increase stability

Disadvantage

- increase stress at implant host interface

3 Types

1.  Unconstrained

A.  Posterior cruciate retaining

Options

1. Always resurface

2. Never resurface

3. Selectively resurface

Decision Making

Controversial

- literature divided on issue

Historically

- poor outcomes due to poor implant design

- now improved designs

- non resurfacing also improved due to better design and improved techniques in regard to tracking and rotation

Aim

UKA is intended to be load sharing

- correct to neutral or slight varus

HTO is a load-shifting / load-sparing procedure

- over correct into valgus

UKA v TKR

Advantages UKA

1.  Rapid rehabilation

Aetiology

Trauma

RA

Rickets / osteomalacia

Issues

Horizontal joint line important

- < 10° tilt acceptable

> 10^o joint line tilt / due to femoral valgus

- continues to overload lateral compartment

Aetiology Unicompartmental OA

Trauma

Meniscectomy

Osteonecrosis

Varus or valgus malalignment

Goals of Osteotomy

Relief of pain

Improve function

No loss of ROM

No or slight restriction of activity

Allow heavy functional demands 

Indications

Rheumatoid arthritis

Combined ankle and subtalar joint osteoarthritis

Indications

Revision

Multi-ligament injury

Older patient

Technique

Graft preparation

Calcaneal bone plug for femoral tunnel

Prepare bone plug

- decide on bone graft size needed

Indications

1.  RC arthropathy / > 70 / low functional demand

2.  Revision TSR

3.  Failed Hemiarthoplasty in proximal humerus fracture

Design

Biomechanics

Able to achieve relatively high level of function after STJ fusion

- previously believed that isolated STJ fusion should not be performed

- believed that triple arthrodesis was operation of choice for hindfoot

- STJ fusion has superior result with less stress on AJ

Average loss of DF 30% / PF 10%

Position of hindfoot determines flexibility of transverse tarsal (CCJ & TNJ) joints

- imperative that fusion be positioned in ~ 5^o valgus