MRI

Periosteal Osteosarcoma

 

Definition

 

Intermediate grade chondroblastic osteosarcoma arising from surface of long bones

 

Epidemiology

 

Extremely rare

- 1% of all osteosarcomas

- 25% of surface osteosarcomas

 

Age 15-25

 

Location

 

Typically anterior proximal tibia

- diaphysis of major long bones

- humerus

 

Pathology

 

Hoffa fracture

Definition

Hoffa Fracture Xray

 

Coronal plane fracture of distal femoral condyle

- intra-articular

- often only attachment is posterior capsule

 

Epidemiology

 

Rare

 

Mechanism

 

Usually a severe valgus trauma

 

Xray