Multiple myeloma is the most common primary malignancy of bone and a critical topic for orthopaedic surgeons. Understand the pathognomonic purely lytic lesions of multiple myeloma, the CRAB diagnostic criteriaand how to calculate impending fracture risk using the Mirels score. ⏱ Chapters 0:00 Intro 0:24 Essentials 0:57 Crab 1:28 Crab Mnemonic 1:44 Imaging 2:14 Mirels 2:41 Staging Algorithm 3:10 Management 3:48 Medical 4:17 Clinical reasoning — Fracture 4:49 Clinical reasoning — Cord This in-depth masterclass covers everything orthopaedic trainees and clinicians need to know about multiple myeloma. We explore the pathophysiology of plasma cell neoplasia, why DKK1 and sclerostin create punched-out lesions with absolutely no sclerotic responseand how end-organ damage defines the disease. Learn exactly how to apply the Mirels scoring system for prophylactic fixation, choose the right intramedullary constructsand coordinate skeletal protection with haematology. 🦴 IN THIS VIDEO YOU'LL LEARN • Identify multiple myeloma as the most common primary malignancy of bone with purely lytic punched-out lesions • Recognise the CRAB criteria for end-organ damage including hypercalcaemia, renal failure, anaemiaand bone disease • Understand why bone scans are virtually useless and why whole-body MRI is the most sensitive imaging modality • Calculate impending pathological fracture risk using the four parameters of the Mirels scoring system • Determine the surgical threshold for prophylactic fixation versus non-operative medical management • Select appropriate orthopaedic implants like intramedullary nails augmented with PMMA cement for long bones • Manage oncological emergencies such as spinal cord compression with high-dose dexamethasone and urgent decompression • Avoid early construct failure by bypassing progressive skip lesions and avoiding isolated plates or short nails • Understand the role of mandatory bisphosphonate therapy in reducing skeletal-related events by forty percent ⏱️ CHAPTERS 📌 KEY TAKEAWAYS ✔️ Myeloma lesions are purely osteolytic with absolutely no sclerotic or blastic healing response. ✔️ Any patient presenting with elevated calcium, renal insufficiency, anaemiaor a single lytic bone lesion must be evaluated for underlying myeloma. ✔️ A Mirels score of 9 or higher mandates prophylactic fixationand over 50 percent cortical destruction in a long bone strongly prompts fixation regardless of total score. ✔️ Always use intramedullary nails to protect the entire bone and avoid isolated plates or short nails that will fail inevitably at progressive skip lesions. ✔️ Ensure dental clearance prior to starting bisphosphonates to mitigate the risk of osteonecrosis of the jaw. 👩⚕️ WHO THIS IS FOR This masterclass is designed for orthopaedic trainees, medical studentsand practising clinicians seeking a comprehensive understanding of plasma cell neoplasia and skeletal protection. Curious patients looking to understand the orthopaedic management of lytic bone lesions will also find this overview highly valuable. 📚 RELATED TOPICS: Mirels Score for Impending Pathological Fracture · Metastatic Bone Disease and Pathological Fractures · MGUS and Smoldering Myeloma Differential Diagnosis · Bisphosphonate Therapy and Osteonecrosis of the Jaw · Surgical Management of Spinal Cord Compression · Plasma Cell Dyscrasias and Paraproteinaemias 🔗 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. #MultipleMyeloma #Orthopaedics #OrthopedicSurgery #BoneTumour #LyticLesions #CRABCriteria #MirelsScore #PathologicalFracture #PlasmaCellNeoplasm #OrthoVellum #BonePathology #SkeletalProtection #Haematology #OrthopaedicOncology