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Aim is to have a "triage" of the knee---sorting the common mechanical issues from the serious systemic or structural failures. Need to emphasise that imaging is not destiny and that many "tears" and "wear" patterns are normal features of an active life.

Part 1: High-Frequency Pathologies

Focus: The conditions that will make up 80% of your caseload.

1. Knee Osteoarthritis (OA): The "Joint Failure" Model

  • The Shift: Move away from "bone-on-bone" or "wear and tear" language. Use the Joint Failure model---an active (though often failing) repair process involving the whole joint (synovium, bone, and cartilage).

  • Key Indicators: Persistent pain in patients, morning stiffness minutes, and bony enlargement.

  • Treat the man not the scan: Remind students that many people have "Grade 2 OA" on X-ray with zero pain. We treat the person, not the radiograph.

Knowledge Check

What is the modern conceptual model for understanding knee osteoarthritis?
Answer: Joint Failure model involving active repair of whole joint (synovium, bone, cartilage)
The modern approach moves away from "bone-on-bone" or "wear and tear" language and uses the Joint Failure model, which recognizes OA as an active (though often failing) repair process involving the whole joint including synovium, bone, and cartilage. This is important for patient education and treatment approaches.

2. Patellofemoral Pain (PFP): The "Black Hole" of Knee Pain

  • The Consensus: Focus on the 2018/2020 consensus statements. PFP is multifactorial.

  • The Triage:

  • Proximal: Hip strength (Gluteus Medius/Maximus).

  • Local: Quadriceps capacity and patellar mobility.

  • Distal: Foot mechanics (over-pronation).

  • Clinical Pearl: "The movie-goer\'s sign" (pain with prolonged sitting) and pain on stairs are the hallmarks.

Knowledge Check

What is the "movie-goer's sign" in patellofemoral pain (PFP)?
Answer: Pain with prolonged sitting
The "movie-goer's sign" refers to pain with prolonged sitting, which along with pain on stairs are hallmark features of patellofemoral pain. This sign reflects increased patellofemoral joint compression during sustained knee flexion.

3. Meniscal Lesions: Traumatic vs. Degenerative

  • The Great Divide:

  • Traumatic: Younger patient, clear mechanism of injury (twist), mechanical locking, or "giving way."

  • Degenerative: Older patient, insidious onset. Dijkstra's philosophy applies here: Degenerative meniscal "tears" are often just "wrinkles on the inside"---normal age-related changes.

  • Clinical Testing: McMurray's and Thessaly tests have limited reliability; focus on the history of mechanical locking.

Part 2: The "Must-Not-Miss"

Focus: Red flags that require immediate diversion from physiotherapy.

1. Septic Arthritis: The True Emergency

  • Presentation: The "Hot, Red, Swollen" knee.

  • Key Signs: Fever, chills, and---most importantly---inability to weight-bear or tolerate even passive range of motion.

  • Action: Immediate referral to A&E for joint aspiration.

Knowledge Check

What is the most critical "must-not-miss" knee condition that requires immediate emergency referral?
Answer: Septic arthritis (hot, red, swollen knee with fever)
Septic arthritis is the true knee emergency. Key signs include a hot, red, swollen knee with fever, chills, and most importantly, inability to weight-bear or tolerate even passive range of motion. This requires immediate referral to A&E for joint aspiration. Delayed treatment can lead to rapid joint destruction.

2. Fractures & The Ottawa Knee Rules

  • Use the Ottawa Knee Rules to decide if an X-ray is needed for acute trauma:

  • Age≥55.

  • Isolated tenderness of the patella.

  • Tenderness at the head of the fibula.

  • Inability to flex to 90°.

  • Inability to bear weight immediately and in the ER (4 steps).

3. Slipped Capital Femoral Epiphysis (SCFE) - "The Knee Ghost"

  • Crucial Concept: In children and adolescents, hip pathology often presents as knee pain.

  • Red Flag: Any child with an antalgic gait and knee pain must have their hip range of motion (internal rotation) cleared and probably needs an X-Ray with medical follow-up.

Part 3: Soft Tissue & "Happy Knee" Adaptations

  • ACL & Ligamentous Integrity: Focus on the Copers vs. Non-Copers. Discuss the KANON trial---showing that many ACL tears can be managed successfully with high-quality rehab rather than surgery.

  • Tendon Pathology (Patellar Tendinopathy): Differentiating between "Jumper\'s Knee" and "Fat Pad Impingement."

  • Summary of Management: Transition from passive modalities (ultrasound/tape) to clinician-led progressive loading, focusing on the "functional capacity" of the kinetic chain.