xray

Definition

Burst fractures

- injury to anterior and middle columns +/- posterior column

Mechanism

Vertical compression

Epidemiology

10% cervical fractures

Most commonly C5/6

Pathology

Anterior & middle columns fail

- if severe, posterior ligament complex fails

Issues

Femur

Multiplanar deformity

- worsend by previous surgery

- may require osteotomy

Acetabulum

Dysplasia often present

- not as severe as in DDH

LLD

Can be significant

Abductors

Have been short for long time

- difficult to restore length

Definition

Minimal trauma fracture

- secondary to osteoporosis

- wedge fractures

Epidemiology

F > M

More common in elderly patients

Uncommon in men < 75

- look for alternative diagnosis

DDx

Renal failure

Malignancy - metastasis

Infection

Clinically

Can present with pain

Definition

Chronic, non metabolic bone disorder

Characterised by increased bone resorption, bone formation and remodelling

Epidemiology

Rare < 40

1 – 3 % population over 60

M > F

Aetiology

Unknown

Paramyxovirus implicated

- measles

- RSV

- canine distemper virus

Electron Microscope

Definition

A fixed equinus deformity of the forefoot in relation to the hindfoot 

- resulting in an abnormally high arch that fails to flatten with weight bearing

- deformity may be forefoot, hindfoot or combination

Aetiology

Definition

Bunion

- medial prominence of head of 1st MT

Hallux Valgus

- medial deviation 1st MT

- lateral deviation of great toe

Anatomy

Metatarsal head

- has 2 grooves separating ridge (cristae)

Incidence

1 - 2 %

Anatomy

Medial Aspect of foot

- proximal to navicular

- part of T posterior tendon

Usually will fuse with navicular (50%)

Issues

1.  Probably not a cause of flat foot

- excising accessory navicular / rerouting / reattaching tibialis posterior

- will not help pes planus

2.  Pain

- may fracture

Differential Diagnosis of the Painful TKA 

Surgical Diagnosis  

1.  Prosthetic loosening and failure 

2.  Infection 

3.  Patellofemoral tracking problems  

4.  Instability 

5.  Recurrent intra-articular soft-tissue impingement / Component overhang  

Nonsurgical Diagnoses  

1.  Referred pain - Hip / Back  

Incidence

Knee > Hip

- superficial position

- limited cover of well vascularised muscle 

- watershed area of skin blood supply anterior to the skin incision 

- much increased in fully constrained prosthesis 

Ideal < 1%

Risk Factors

Increased with

- revision

- prior infection

- RA / Psoriatic arthropathy

- DM

Types of Instability

1.  AP Instability

2.  Varus Valgus Instability

3.  Global Instability

4. Frank Dislocation