bone scan

Incidence

Definition

Insufficiency fracture

- secondary to exceeding fatigue threshold

- usually of second or third MT shaft

Epidemiology

Onset of new and very intense / strenuous physical activity

- i.e. new army recruits / dancers

Women with postmenopausal osteoporosis

Association

Cavus feet

History

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

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

Likely Origin / Hexagon / PBBLTK

                    Thyroid     Breast      

Aim 

The identification of skeletal metastasis & fixation prior to fracture

Incidence

50% of new cancer cases have metastasis

- 1% have pathological fracture

- increasing with more aggressive palliative care

Definition

Pigmented Villo-Nodular Synovitis

- benign inflammatory process that arises in synovial tissues

- contains significant amounts of hemosiderin

Epidemiology

Age: 20 - 50

Sex: M > F

Types

A.  Diffuse

- throughout joint synovium

- more difficult to treat / excise fully