MRI cartilage assessment is the cornerstone for grading the avascular articular surface that cannot heal, guiding repair planning and follow‑up. This video walks you through the optimal MRI sequences, the modified Outerbridge and MOCART grading systems, and how compositional techniques such as T2 mapping and dGEMRIC reveal biochemical changes before any morphological defect is visible. ⏱ Chapters 0:00 Intro 0:38 The Tissue And Its Limits 1:19 Normal Protocol Vs Advanced Medial Disease 2:09 The Sequences 3:27 Coronal 3D Dess — The Isotropic Measuring… 4:59 Grading What You See 5:58 Grade 4 Defect — Multiplanar, With… 7:26 Measuring Repair 8:16 T1Rho Colour Maps — Composition Before… 9:01 Mocart At Two Years — Marlovits, 26 Knees 9:48 The Cartilage Repair Clock 11:31 Recap & sources The episode covers normal articular cartilage thickness (2‑4 mm) and its zonal variation, why the tissue’s limited healing capacity makes early detection vital, and the step‑by‑step MRI protocol — from routine PD‑FS and 3D gradient‑echo sequences to direct MR arthrography. It explains how to apply the modified Outerbridge classification (Grades 0‑4) and the MOCART score for postoperative repair, and highlights what compositional MRI sees first, namely early T2‑mapping and dGEMRIC changes that precede macroscopic cartilage loss. 🦴 IN THIS VIDEO YOU'LL LEARN • Identify the normal thickness range of articular cartilage and its variation across femoral condyle, patellar surface and tibial plateau. • Recognise the layered appearance of deep radial and superficial transitional zones on high‑resolution MRI. • Explain why routine PD fat‑suppressed sequences have limited sensitivity for partial‑thickness chondral defects. • Describe the advantages of 3D gradient‑echo sequences (SPGR, FLASH, DESS) for isotropic thickness mapping and surface assessment. • Detail how direct MR arthrography with dilute gadolinium improves detection of subtle cartilage surface lesions. • Apply the modified Outerbridge classification (Grades 0‑4) to MRI findings and correlate with ICRS depth thresholds. • Interpret the six components of the MOCART score (fill, integration, surface, signal, bone interface, effusion) for postoperative cartilage repair. • Understand how compositional MRI techniques — T2 mapping and dGEMRIC — detect early biochemical cartilage degeneration before morphological changes appear. 📌 KEY TAKEAWAYS ✔️ Cartilage cannot heal spontaneously; even tiny defects progress toward osteoarthritis. ✔️ Standard knee MRI misses up to 70 % of partial‑thickness lesions — dedicated sequences are essential. ✔️ Modified Outerbridge Grades 0‑4 provide a simple, reproducible MRI grading framework. ✔️ MOCART score quantifies repair quality across fill, integration, surface, signal, bone and effusion. ✔️ T2 mapping and dGEMRIC reveal cartilage biochemical injury months before visible thinning or fissuring. ✔️ 3 Tesla field strength combined with thin isotropic 3D GRE offers the best cartilage‑fluid contrast for accurate measurement. 👩⚕️ WHO THIS IS FOR This video is designed for orthopaedic trainees, medical students, clinicians managing joint pathology, and interested patients who want to understand how MRI evaluates articular cartilage and informs treatment decisions. 📚 RELATED TOPICS: Osteochondral defect imaging · T2 mapping of cartilage · dGEMRIC for glycosaminoglycan assessment · MOCART score application post‑repair · 3D DESS thickness mapping · Direct MR arthrography technique 🔗 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 #mricartilage #outerbridge #mocart #t2mapping #dgemric #3tesla #pdfs #mrarthrography #chondraldefect #osteoarthritis #kneeimaging #cartilagerepair #quantitativemri #musculoskeletalimaging