Osteosarcoma is the most common primary bone cancer in children and young adults, typically occurring between ages 10 and 20 during periods of rapid growth. Modern treatment combining chemotherapy with limb salvage surgery has lifted 5-year survival from 15–20% to 65–75%, with the limb preserved in over 95% of patients.
Osteosarcoma develops from bone-forming cells (osteoblasts) and most often arises around the knee (distal femur, proximal tibia) or shoulder (proximal humerus) — sites of greatest bone growth. Pelvis and spine are less common locations.
Lasting 3–6 months, classically worse at night.
Rapidly enlarging mass around the knee or shoulder.
Pathological fracture through an unrecognised tumour.
Unexplained constitutional symptoms in an adolescent.
The exact cause is unknown, but several recognised risk factors raise vigilance — and recent genetic studies show germline predisposition is far more common than previously thought.
Peak incidence during adolescence when bones grow rapidly.
Li-Fraumeni (p53), retinoblastoma (Rb), Rothmund-Thomson, Bloom, Werner, Diamond-Blackfan.
Paget's disease, fibrous dysplasia or prior therapeutic radiation.
Taller children and those with higher birth weights have increased risk.
Most osteosarcomas are high-grade and require intensive chemotherapy plus surgery.
Most common — osteoblastic, chondroblastic and fibroblastic subtypes.
Slow-growing variant with better prognosis.
Contains blood-filled spaces; mimics aneurysmal bone cyst on imaging.
Composed of small round cells; differential with Ewing sarcoma.
Develops from pre-existing bone disease (Paget's, fibrous dysplasia, post-radiation).
Parosteal (low-grade), periosteal and high-grade surface osteosarcoma.
Diagnosis requires careful imaging followed by a planned biopsy. An improperly placed biopsy can compromise future limb salvage, so it must be performed by an experienced sarcoma team.
Site, duration, night pain, swelling and systemic symptoms.
Characteristic bone destruction with new bone formation and periosteal reaction.
Defines local extent, marrow involvement and soft tissue spread.
Screens for pulmonary metastases — the commonest site of spread.
Done by a specialist to avoid compromising future limb salvage.
Stages disease and detects distant metastases.
Standard treatment combines pre-operative chemotherapy, wide surgical resection with reconstruction and adjuvant chemotherapy — over a total of 6–9 months.
10–12 weeks of chemotherapy before surgery to shrink the tumour and treat micrometastases.
Limb salvage in >95% of patients with modern reconstruction; amputation reserved for selected cases.
Continued chemotherapy after surgery for a total treatment duration of 6–9 months.
Thoracotomy with palpation removes pulmonary metastases — 37.5% of nodules can be missed on CT alone.
Choice of reconstruction depends on patient age, tumour location, bone quality and functional demands. Children benefit from biological or expandable options that grow with them.
Metallic implant replacing resected bone and adjacent joint.
Donor bone from a tissue bank — biological reconstruction.
Combines donor bone with a metallic implant for durability and biology.
Living bone from the patient's own leg for biological healing.
For growing children — can be lengthened, sometimes non-invasively.
Growing new bone to bridge skeletal defects after resection.
A short look at how wide resection and reconstruction preserve the limb and restore function for a young patient with osteosarcoma.
Follow-up of an osteosarcoma patient showing durable function and disease-free survival after multimodal therapy and limb salvage surgery.
Modern amputation rates are under 5% — reserved for specific clinical situations:
Persistent knee pain worsening over 2 months, severe at night. X-rays revealed osteosarcoma of the distal femur. Neoadjuvant MAP chemotherapy followed by limb salvage with an expandable prosthesis allowed her to complete treatment and return to competitive swimming.
Knee pain and swelling; MRI confirmed osteosarcoma of the distal femur. After 3 months of MAP chemotherapy he underwent limb salvage with a tumor prosthesis and 6 months of adjuvant chemotherapy. He returned to sports and remains cancer-free at 5 years.
Shoulder pain led to a diagnosis of proximal humerus osteosarcoma with two small lung nodules. Intensive chemotherapy, prosthetic reconstruction of the arm and thoracotomy for metastasectomy achieved complete remission — disease-free at 3 years.
Lung metastases can occur years after initial treatment — long-term surveillance is essential.
