screening

AKA

Diaphyseal Aclasis / Multiple Osteochondromas

Definition

Heritable skeletal dysplasia

Epidemiology

AD with variable penetrance (96%)

Malignant Transformation

Incidence of malignant transformation much higher 

- 10% overall

- 1 % / year

Chondrosarcoma (CS) > Osteosarcoma (OS)

Pathogenesis

Virchow's Triad

1. Venous stasis

2. Hypercoagulability

3. Endothelial damage

Starts as platelet nidus at valves

- thrombogenic materials elaborated by platelets

- leads to development of fibrin thrombus

- thrombus grows

Thrombus may 

- detach as embolus

- be completely dissolved / recanalise

- organise with valve incompetence

Definition

Dysproportionate dwarfism

- short limbs and normal trunk

- rhizomelic

DDx

- physeal dysplasia (SED, MED)

Aetiology

FGF Receptor 3 

- point mutation

- decreases endochondral ossification

- normal intramembraneous ossification

- FGFR3 is found in all pre-bone cartilage & in CNS

- FGFR3 inhibits chondrocyte proliferation in the proliferative zone

Definition

Developmental dysplasia of the hip

- the femoral head does not have the normal relationship with the acetabulum

- child with subluxable, reducible or irreducible hip

- may not be present at birth (hence not called CDH)

Instability

- ability to dislocate or reduce femoral head into or out of acetabulum

Dislocated 

- complete loss of contact