xray

Meyers & McKeever classification

Type I:   Undisplaced avulsion fracture

Type II:  Anterior portion displaced & hinged

Type IIIA:   Displaced

Type IIIB:   Displaced & Rotated

Definition

Deformity characterised by 

- dorsiflexion of calcaneus 

- plantarflexion of forefoot / plantaris / forefoot equinus

Both sides of foot have elevated arch

Aetiology

Weakness of triceps surae 

- polio - most common worldwide

- spina bifida

Definition

STS composed of malignant lipoblasts

Epidemiology

Common 

- 10% of STS

- second only to MFH

Occurs almost exclusively in adults

Males age 40-60

Can be multiple origin -> examine patient

Rarely arise from lipoma

Epidemiology

Uncommon

- 4% OS

Females more common 

- similar to GCT

NHx

Less aggressive locally

- less metastasis

- size / location & duration of symptoms don't correlate with outcome

Arise from cortex of bone / periosteum

- parosteal 

- periosteal

- high grade juxtacortical

Definition

Uncontrolled proliferation of single clone of plasma cells

Epidemiology

Most common malignant tumour of bone

Age 50-60

2-3 / 100 000

Pathology

Highly differentiated B lymphocytes

- associated with abnormality of protein synthesis

Usually bone marrow of entire skeleton involved

Principles

Treatment algorithm similar to OS

Overall prognosis similar to OS

- 70% long term survival

Definition

A malignant neoplasm composed of small round cells of uncertain histogenesis

Genetics

Recent data suggests it is of neuroepithelial derivation

- ? neuroectodermal cells

Definition 

Malignant cartilage producing tumour 

Epidemiology

20% of primary bone tumours

3rd most common

- 1 in 500 000

Relatively non-aggressive / usually Grade I

Average age 40

Male > Females

Two Distinct Types

1.  Primary Chondrosarcoma

Arises de novo

Definition

Benign, bone-forming neoplasm

- characterized by a small nidus of neoplastic tissue

- surrounded by a wide zone of mature, reactive bone

Epidemiology

10% of benign bone tumours

Age 5-25

M:F 2:1

Aetiology

Unknown

- thought may be glomus tumour of bone

Pain secondary to prostaglandin production

It was described in 1983 by Dr. Nora, and is sometimes called Nora's disease or Nora's lesion

Definition

Bizarre parosteal osteochondromatous proliferation 

Epidemiology

Rare lesion 

- occurs most commonly in the hands and feet

Adults in their 20's and 30's

Males = Females

Site

AKA

Bone island

Definition

Hamartomatous lesion 

- island of mature cortical bone found in the midst of normal cancellous bone 

Epidemiology

>10

M=F

Clinical

Asymptomatic x-ray finding (usually in adolescents)