Septic arthritis in the adult is an orthopaedic emergency that can destroy a joint within twenty-four hours. In this OrthoVellum masterclass, we explore the pathophysiology, microbiology, and surgical decision-making required to manage acute joint sepsis, native joint washout, and prosthetic joint infections. ⏱ Chapters 0:00 Intro 0:21 Essentials 0:49 Organisms 1:18 Algorithm 1:43 PJI 2:11 Numbers 2:36 Clinical Reasoning — Knee 3:01 Clinical Reasoning — Crystals This video provides a comprehensive breakdown of septic arthritis, covering everything from rapid cartilage destruction and synovial fluid analysis to tailored antibiotic regimens and definitive surgical management. We compare arthroscopic versus open washout techniques for native joints, break down the DAIR procedure and two-stage revision for prosthetic joint infection (PJI), and highlight critical clinical traps like the coexistence of crystals and infection. 🦴 IN THIS VIDEO YOU'LL LEARN: • How to interpret synovial white cell counts and polymorph percentages to diagnose a septic joint • The pathophysiological timeline of irreversible cartilage destruction caused by bacterial enzymes • Tailoring suspected organisms to specific patient populations including Neisseria, P. acnes, and IV drug user pathogens • The correct sequence of aspirating a joint before administering empiric intravenous antibiotics • Differentiating surgical approaches for native joints including arthroscopy for the knee and open arthrotomy for the hip • The decision-making algorithm for prosthetic joint infections based on symptom duration and implant stability • The indications, criteria, and success rates for performing a DAIR procedure versus a single or two-stage revision • Recognising the classic clinical trap where the presence of urate crystals does not exclude concurrent sepsis • Understanding the prognostic outcomes and the ten to fifteen percent mortality rate associated with joint sepsis 📌 KEY TAKEAWAYS: ✔️ Time is joint: you have a narrow twenty-four to forty-eight hour window before irreversible cartilage destruction occurs. ✔️ Always aspirate a hot, swollen joint and send synovial fluid before giving antibiotics to avoid culture false negatives. ✔️ A synovial white cell count greater than fifty thousand with predominant polymorphs is the diagnostic hallmark of sepsis. ✔️ Finding crystals in joint fluid never excludes septic arthritis, as gout and infection frequently coexist. ✔️ Staph aureus is the most common organism, but you must consider atypical pathogens in prosthetic, diabetic, and immunocompromised patients. 👩⚕️ WHO THIS IS FOR: This masterclass is for orthopaedic trainees, junior doctors, medical students, and anyone wanting a high-yield, structured understanding of adult joint sepsis. It also serves as a detailed educational resource for curious patients seeking to understand the urgency and surgical management of orthopaedic infections. 📚 RELATED TOPICS: Prosthetic Joint Infection and Two-Stage Revision · The DAIR Procedure for Acute PJI · Kocher Criteria for Paediatric Hip Septic Arthritis · Differential Diagnosis of the Acute Hot Swollen Joint · Gonococcal Arthritis and Dermatitis-Arthritis Syndrome · Principles of Empiric Intravenous Antibiotics in Orthopaedics 🔗 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. #septicarthritis #orthopaedics #orthopaedicemergency #jointinfection #prostheticjointinfection #dairprocedure #kneewashout #synovialfluid #staphaureus #medicaleducation #orthosurgery #jointsepsis