2. Knee Anatomy The knee is the largest joint in the body. The knee is stabilized by the collateral ligaments. The lateral and medial menisci function as shock absorbers. The bursae decrease friction of tendons and muscles as they move over bones. CURRENT Medical Diagnosis & Treatment 2012. www.accessmedicine.com

3. Knee Anatomy

4. Knee Joint Anatomy Am Fam Physician. 1999;60(9):2599-2608.

5. Imaging the knee Plain radiograph for: Fractures Degenerative changes Osteochondral defects Effusions CT for: Fractures in patients with knee trauma MRI for: Damage to cartilage, menisci or ligaments Cleveland Clinic Journal of Medicine 2008;75:377-384

6. AP view of the knee

7. Lateral view of the knee

8. Sunrise view of the knee To assess the patellofemoral articulation Femur and tibia are superimposed Medial condyle is more rounded and prominent

9. Identify the following... femur tibia fibula patella lateral condyle medial condyle lateral epicondyle medial epicondyle intercondylar notch

10. Identify the following... medial femoral condyle lateral femoral condyle Inferior patellar tendon Quadriceps femoris tendon Tibial tuberosity femur tibia fibula patella intercondylar notch

11. Knee injuries

12. Patellar fractures The patella can be fractured through one of its poles or through its central body. Patellar fractures can be simple or comminuted. Transverse fractures are most common and are most likely to be displaced. Am Fam Physician. 1999;60(9):2599-2608.

13. Patellar fractures Displaced fracture of the lower pole of the patella

14. Patellar fractures Where is the fracture? The Color Atlas of Family Medicine: http:accessmedicine.com What type of fracture is this? Non-displaced patellar fracture

15. Fractures Femoral condyle fractures account for 4% of femur fractures. Potential complications include: DVT, fat embolus syndrome, delayed union ort malunion, and osteoarthritis. Tibial spine and tuberosity fractures usually result in cruciate ligament insufficiency. Fractures of the tibial plateau are seen more commonly in the elderly. Lateral plateau is more often fractured. Potential complications include: popliteal artery injury, DVT and osteoarthritis. Tintinalli's Emergency Medicine: A Comprehensive Study Guide, 7e. www.accessmedicine.com

16. Lateral condylar split fracture Usually the result of low impact trauma Common in kids The Color Atlas of Family Medicine : http:accessmedicine.com Where is the fracture?

17. Tibial intercondylar emminence fracture The lipohemarthrosis (composed of blood and fat from the marrow) seen above is a specific sign of an intra-articular fracture although a fracture is not visualized. Identify the lipohemarthrosis on the radiograph

18. Comminuted left tibial metaphysis and lateral plateau fracture left tibial metaphysis fracture Lateral plateau fracture

19. Fracture of the tibial eminence Koplas M et al. Cleveland Clinic Journal of Medicine 2008;75:377-384 joint effusion lateral tibial bone depressed posteriorly fracture An additional sign of a fracture includes a joint effusion

20. Epiphyseal plates Epiphyseal plates in children can be mistaken for fractures http://www.dartmouth.edu/~anatomy/Lowerextremity/leg-knee/radiology/APknee-child.htm ChildAdult

21. Knee dislocation Often associated with a fracture of the tibial plateau Usually the result of motor vehicle crashes, falls, sports, and industrial injuries Knee dislocations are associated with popliteal artery and common peroneal and tibial nerve injuries The Atlas of Emergency Medicine: http:accessmedicine.com Posterior displacement of the tibia Anterior knee displacement

22. Patellar tendon rupture The Atlas of Emergency Medicine: http:accessmedicine.com

23. Arthritis

24. Flow chart shows approach to radiographic evaluation of arthritis. Jacobson J A et al. Radiology 2008;248:737-747 ©2008 by Radiological Society of North America

25. Osteoarthritis of the knee Felson DT. N Engl J Med 2006; 354:841-848

26. Radiographic findings Osteoarthritis: initially involves medial side joint space narrowing subchondral cysts osteophytes sclerosis Basic Radiology, 2 nd edition: http:accessmedicine.com

27. Osteoarthritis Bone on bone contact Patellar osteophyte subchondral osteophyte

28. Radiographic findings Rheumatoid arthritis: Osteopenia Loss of joint space Ligamentous laxity Joint effusion Bone erosion

29. Rheumatoid arthritis Tibial erosion Joint effusion Diffuse osteopenia Symmetric joint space narrowing Bone erosion

30. Identify the type of arthritis What radiographic features do you see? joint space narrowing medial or lateral side? medial osteophyte subchondral cyst Osteoarthritis

31. References Felson DT. N Engl J Med 2006; 354:841-848. Geisel School of Medicine at Dartmouth, Department of Anatomy. Introduction to Radiology. Retreived September 6, 2012 from http://www.dartmouth.edu/~anatomy/Intro-to-radiology/index.htm. Glaspy J.N., Steele M.T. (2011). Chapter 271. Knee Injuries. In Tintinalli's Emergency Medicine: A Comprehensive Study Guide, 7e. Retrieved September 6, 2012 from http://www.accessmedicine.com. Gonzales R., Nadler P.L. (2013). Chapter 2. Common Symptoms. In M.A. Papadakis, S.J. McPhee, M.W. Rabow (Eds), CURRENT Medical Diagnosis & Treatment 2013. Retrieved September 6, 2012 from http://www.accessmedicine.com. Jacobson J, Girish G, Jiang Y, et al. Radiographic evaluation of arthritis: degenerative joint disease and variations. Radiology. 2008; 248: 737-747. Koplas M, Schils J and Sundaram M. The painful knee: choosing the right imaging test. Cleveland Clinic Journal of Medicine 2008;75:377-384. Raukar N.P., Raukar G.J., Savitt D.L. (2010). Chapter 11. Extremity Trauma. In K.J. Knoop et al. (Eds), The Atlas of Emergency Medicine, 3e. Retrieved September 7, 2012 from http://www.accessmedicine.com. Tandeter HB and P Shvartzman. Acute knee injuries: use of decision rules for selective radiograph ordering. Am Fam Physician. 1999 Dec 1;60(9):2599-2608. Wasserman P.L., Pope T.L. (2011). Chapter 7. Imaging of Joints. In M.Y. Chen, T.L. Pope, D.J. Ott (Eds), Basic Radiology, 2e. Retrieved September 7, 2012 from http://www.accessmedicine.com.