Osteosarcoma is the most common primary malignant bone tumour, characterised by the direct formation of osteoid by malignant mesenchymal cells. In this deep-dive, we explore everything from its bimodal epidemiology and classic sunburst periosteal reactions to the MAP chemotherapy protocol and limb salvage surgery. ⏱ Chapters 0:00 Intro 0:16 Ch1 00 0:59 Ch1 01 1:39 Ch1 02 2:17 Ch2 Card 2:54 Ch2 01 3:43 Ch2 02 4:18 Ch2 03 5:02 Ch3 Card 5:41 Ch3 01 6:12 Ch3 02 6:55 Ch3 03 7:20 Ch4 Card 8:00 Ch4 01 8:30 Ch4 02 9:04 Ch4 03 9:38 Ch5 Card 10:22 Ch5 01 10:58 Ch5 02 11:43 Ch5 03 12:21 Ch6 Card 13:05 Ch6 01 13:36 Ch6 02 14:17 Ch6 03 14:51 Ch7 Card 15:32 Ch7 01 16:05 Ch7 02 16:40 Ch7 03 17:15 Ch8 Card 17:25 Ch8 00 18:06 Ch8 01 18:54 Ch8 02 19:40 Ch8 03 20:26 Closer This comprehensive lecture builds a complete clinical picture of osteosarcoma from first principles to bedside decision-making. We cover the tumour's distinct histological subtypes, pathognomonic radiographic findingsand the critically important Enneking staging system. Viewers will understand the rationale behind neoadjuvant chemotherapy, the principles of wide surgical resectionand the vital prognostic indicators that dictate patient survival. 🦴 IN THIS VIDEO YOU'LL LEARN • Define osteosarcoma histologically by the direct production of immature osteoid by malignant cells • Identify the bimodal age distribution and the anatomical predilection for the metaphysis of long bones • Recognise pathognomonic radiographic signs including the sunburst periosteal reaction and Codman triangle • Differentiate between conventional, telangiectatic, parostealand periosteal histological subtypes • Understand the MAP chemotherapy protocol (Methotrexate, Adriamycin, cisPlatin) and its systemic role • Apply the Enneking surgical staging system to dictate treatment pathways and surgical margins • Evaluate the role of limb salvage surgery and recognise when it is contraindicated • Analyse how histological necrosis greater than 90% correlates with patient prognosis • Formulate a differential diagnosis to distinguish osteosarcoma from Ewing sarcoma and aneurysmal bone cysts ⏱️ CHAPTERS 📌 KEY TAKEAWAYS ✔️ Osteosarcoma typically presents around the knee: distal femur (50%), proximal tibia (25%), proximal humerus (10%). ✔️ Sunburst and Codman triangle periosteal reactions indicate an aggressive high-grade bone lesion. ✔️ Conventional high-grade osteosarcoma requires neoadjuvant chemotherapy, wide surgical resectionand adjuvant chemotherapy. ✔️ Parosteal osteosarcoma is a distinct low-grade variant managed with wide resection alone, without chemotherapy. ✔️ Over 90% histological necrosis following neoadjuvant chemotherapy is the strongest indicator of a good prognosis. 👩⚕️ WHO THIS IS FOR This video is designed for orthopaedic trainees, junior doctorsand medical students seeking a rigorous understanding of primary bone tumours. Curious patients and caregivers looking for a comprehensive, clinically accurate overview of osteosarcoma treatment will also find it highly valuable. 📚 RELATED TOPICS: Ewing Sarcoma Clinical Presentation and Management · Enneking Surgical Staging of Musculoskeletal Tumours · Limb Salvage Surgery Techniques in Orthopaedic Oncology · Aneurysmal Bone Cyst vs Telangiectatic Osteosarcoma · Paget's Disease of Bone and Secondary Malignancy · Neoadjuvant and Adjuvant Chemotherapy Principles 🔗 More free orthopaedic teaching at Orthovellum.com — subscribe for weekly videos. 🎨 CREDITS • Original Orthovellum production. ⚠️ DISCLAIMER: Educational only — not individual medical advice. Always consult a qualified clinician for diagnosis and treatment. #orthopaedics #osteosarcoma #orthopaedicsurgery #bonetumour #medicaleducation #oncology #limbsalvage #bonesurgery #orthovellum #medicaleducation #pathology #femurtumour #cancertreatment