Osteochondroma is the most common benign bone tumour, representing 35% of all benign osseous lesions. In this Orthovellum masterclass, we cover everything from the pathological origins of this cartilage-capped exostosis to the critical red flags for malignant transformation. ⏱ Chapters 0:00 Intro 0:18 Essentials 0:56 Pathophysiology 1:32 Classification 2:05 Caps 2:36 Imaging 3:12 Imaging Rules 3:53 Pncc 4:25 Management 5:11 Complications 5:46 Clinical reasoning — Adolescent 6:16 Clinical reasoning — Adult This comprehensive video guide breaks down the pathophysiology, geneticsand imaging of osteochondroma. We explore the crucial distinction between sporadic solitary lesions and hereditary multiple exostoses (HME), demonstrating how to use the CAPS and PNCC mnemonics to confidently identify malignant transformation and determine when surgical excision is indicated. 🦴 IN THIS VIDEO YOU'LL LEARN • The pathognomonic imaging feature of cortical and medullary continuity with the parent bone • How aberrant cartilage herniates through the perichondral ring of the growth plate • The difference between solitary osteochondromas and hereditary multiple exostoses (EXT1/EXT2) • Morphological differences between pedunculated and sessile lesions • How to apply the CAPS mnemonic to identify red flags for malignant transformation • Why the two-centimetre rule for cartilage cap thickness is vital for adult patients • The clinical indications for surgical excision using the PNCC mnemonic • How to distinguish benign enchondral ossification in children from low-grade chondrosarcoma • The appropriate use of plain radiographs versus MRI in diagnosing and monitoring lesions ⏱️ CHAPTERS 📌 KEY TAKEAWAYS ✔️ An osteochondroma must stop growing at skeletal maturity; continued growth signals potential malignant transformation. ✔️ The risk of secondary chondrosarcoma is 1% in solitary lesions but rises to 5-25% in hereditary multiple exostoses (HME). ✔️ A cartilage cap greater than 2cm on MRI in a skeletally mature adult is highly suspicious for malignancy. ✔️ Sessile lesions on flat bones like the scapula or pelvis carry a higher malignancy risk due to thicker cartilage caps. ✔️ Surgical excision is indicated for mechanical pain, neurovascular compromise, cosmesisor concern for malignancy. 👩⚕️ WHO THIS IS FOR This masterclass is designed for orthopaedic trainees, medical studentsand clinicians seeking a high-yield understanding of bone tumours. Curious patients looking to understand the pathology and management of osteochondromas will also find this comprehensive breakdown highly valuable. 📚 RELATED TOPICS: Secondary chondrosarcoma and malignant transformation · Hereditary Multiple Exostoses (HME) and EXT1/EXT2 genetics · Benign vs malignant bone tumour imaging features · Enchondral ossification and growth plate pathology · Differential diagnosis of cartilage-capped bone lesions · Surgical excision techniques for exostosis 🔗 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 #osteochondroma #bonetumour #orthopedicsurgery #chondrosarcoma #hereditarymultipleexostoses #medicaleducation #orthosurgery #pathology #bonedisease #radiology #HME #skeletalpathology #orthoteaching #cartilagecap