Document 15980827


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.

Knee Anatomy

Knee Joint Anatomy

Am Fam Physician. 1999;60(9):2599-2608.

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

AP view of the knee

Lateral view of the knee

Sunrise view of the knee

 To assess the patellofemoral articulation

 Femur and tibia are superimposed

 Medial condyle is more rounded and prominent

Identify the following . . .

medial epicondyle medial condyle femur patella tibia fibula intercondylar notch lateral epicondyle lateral condyle

Identify the following . . .

Quadriceps femoris tendon patella femur

Inferior patellar tendon

Tibial tuberosity tibia fibula intercondylar notch medial femoral condyle lateral femoral condyle

Knee injuries

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.

Patellar fractures

Displaced fracture of the lower pole of the patella

Patellar fractures

Where is the fracture?

What type of fracture is this?

Non-displaced patellar fracture

The Color Atlas of Family Medicine:


 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.

Lateral condylar split fracture

 Usually the result of low impact trauma

 Common in kids

Where is the fracture?

The Color Atlas of Family Medicine :

Tibial intercondylar emminence fracture

Identify the lipohemarthrosis on the radiograph

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.

Comminuted left tibial metaphysis and lateral plateau fracture

Lateral plateau fracture left tibial metaphysis fracture

Fracture of the tibial eminence joint effusion

An additional sign of a fracture includes a joint effusion fracture lateral tibial bone depressed posteriorly

Koplas M et al. Cleveland Clinic Journal of Medicine 2008;75:377-384

Epiphyseal plates

 Epiphyseal plates in children can be mistaken for fractures

Child Adult

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

Anterior knee displacement

Posterior displacement of the tibia

The Atlas of Emergency Medicine:

Patellar tendon rupture

The Atlas of Emergency Medicine:


Flow chart shows approach to radiographic evaluation of arthritis.

©2008 by Radiological Society of North America

Jacobson J A et al. Radiology 2008;248:737-747

Osteoarthritis of the knee

Felson DT. N Engl J Med 2006; 354:841-848

Radiographic findings


 initially involves medial side

 joint space narrowing

 subchondral cysts

 osteophytes

 sclerosis

Basic Radiology, 2 nd edition:

Bone on bone contact


Patellar osteophyte subchondral osteophyte

Radiographic findings

Rheumatoid arthritis:

 Osteopenia

 Loss of joint space

 Ligamentous laxity

 Joint effusion

 Bone erosion

Rheumatoid arthritis

Diffuse osteopenia

Symmetric joint space narrowing

Bone erosion

Joint effusion

Tibial erosion

Identify the type of arthritis

Osteoarthritis What radiographic features do you see? osteophyte joint space narrowing medial or lateral side? medial subchondral cyst


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

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

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

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


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

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