indications

Constraint

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

Patella Resurfacing

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

 

Background

AimUKA Oxford AP

 

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

 

Background

Aetiology Unicompartmental OAKnee Medial Compartment 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 

 

Background

Rotator Cuff Arthropathy for Reverse TSR

 

Indications

 

1.  RC arthropathy / > 70 / low functional demand

 

2.  Revision TSR

 

3.  Failed Hemiarthoplasty in proximal humerus fracture

 

Design

 

Subtalar and Triple Arthodesis

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 ~ 5o valgus