The first 10 commandments of Orthopaedic Oncology

Dr. Michelle GhertMcMaster University

Division of Orthopaedic Surgery

Never order an MRI or CT before an xray

12 year-old female with right knee pain

Know the differential for 99% of destructive bone lesions in patients

over 40 and how to find the diagnosis

Mets, myeloma, lymphoma

Work-up

• History and physical• Bone scan• Bloodwork: CBC, lytes, BUN, Cr, LFTs, Ca,

Mg, Phos, Alk Phos, SPEP• UPEP• CT chest/abd/pelvis

65 year-old male with history of lung cancer

Diagnosis?

Metastatic lung cancer

Treatment?

Intramedullary nailing by….

…an Orthopaedic Surgeon!

NOT an Orthopaedic Oncologist

Do not refer patients with benign incidental radiographic findings to

an Orthopaedic Oncologist

Non-ossifying fibroma

Enchondroma

Fibrous Dysplasia

Know the difference between osteoid and chondroid matrix

Osteoid Chondroid

Understand the difference between a benign and malignant periosteal

reaction

Benign Malignant

General Staging Protocol

• Bone: – Local cross-sectional imaging– CT scan chest– TBBS– (Bone marrow aspiration)

•Soft-tissue:–Local cross-sectional imaging–CT scan chest–In some cases, CT scan abd/pelvis

Treatment

• Bone sarcoma: Surgery +/- chemotherapy• Soft-tissue sarcoma: Surgery +/- radiation,

(+/- chemotherapy)

Very controversial!

Understand the difference between a geographic and a non-geographic border and the significance of that

difference

Geographic-benign Non-geographicmalignant

Neocortex = benign aggressive

Do not biopsy a suspicious bone or soft-tissue lesion without speaking to

an Orthopaedic OncologistBut know the principles of biopsy!!

Principles of biopsy: Avoid contamination!

• Incision in line with resection incision• Longitudinal in extremities• Intramuscular if possible (to bury hematoma)• Avoid NV structures and joints• No skin or muscle flaps• Meticulous hemostasis• Tight closure• Approach soft tissue mass or weakened area of bone• Drain if necessary, in line and distal to incision• *never, ever biopsy a fracture!!!!!!*

Know the differential for a benign osteoblastic periosteal response

(classic location tibia)

stress fx osteoid infectionosteoma

Know the differential diagnosis for bubbly lesions in the tibial cortex

Fibrous dysplasia Osteofibrous

dysplasia

AdamantinomaNon-ossifying fibroma

Fibrous-dysplasia

Know what is always on the differential for malignant-looking

bone lesions in children

• Osteosarcoma• Ewing’s sarcoma• Hematologic

malignancy• Infection• EG

Also on the differential for all benign lesions

Questions?