Osteoarthritis at patellofemoral and medial compartments. No meniscal tear.

The axial proton density image with fat saturation shows loss of patellar articular cartilage focally at the median ridge and adjacent medial and lateral facets (long arrows). There is no articular cartilage loss at the lateral trochlea (short arrow). At the medial trochlear region (arrowhead), the intermediate signal represents pre-femoral fat pad, mimicking articular cartilage. The trochlear cartilage normally extends further proximally at the lateral aspect.

The sagittal proton density image with fat saturation, obtained near trochlear midline, illustrates the moderate (partial-thickness) articular cartilage loss, with subarticular bone marrow edema (arrow). At the most proximal patella, the articular cartilage remains normal (arrowhead). At the trochlear aspect, the prefemoral fat pad (arrowhead) contacts the patella. At the medial trochlea further distally, there was a small region of partial-thickness cartilage loss (not shown).

On coronal proton density image with fat saturation, mild (partial-thickness) articular cartilage loss is shown also in the medial compartment, femoral aspect (arrow). The vague region of signal loss at the lateral tibial plateau articular cartilage (arrowhead) is artifactual. The menisci are normal.

http://www.google.com.eg/imgres?imgurl=http://www.radsource.info/_images/1110_19.jpg&imgrefurl=http://www.radsource.info/clinic/1011&usg=__-ZkHtbFwP_GuWJe6iu_TqjpQYzg=&h=325&w=350&sz=48&hl=ar&start=10&sig2=hOkf-krjqbdzj3N7zvmKJQ&zoom=1&itbs=1&tbnid=zxR6fmbnPUPvzM:&tbnh=111&tbnw=120&prev=/images%3Fq%3Dpatellar%2Bcartilage%2Bdegeneration,mri%26hl%3Dar%26gbv%3D2%26tbs%3Disch:1&ei=agblTKqKHsaT4gargenvDg

please click on image to enlarge

http://www.google.com.eg/imgres?imgurl=http://www.scielo.br/img/revistas/rb/v39n3/en_a04fig01.gif&imgrefurl=http://www.scielo.br/scielo.php%3Fpid%3DS0100-39842006000300004%26script%3Dsci_arttext%26tlng%3Den&usg=__-KbAi_xtT9HcXB556JvPTJ0XuvI=&h=437&w=565&sz=180&hl=ar&start=14&sig2=CHPN7_GsE8QRCnXOWRKGPA&zoom=1&itbs=1&tbnid=hVVzMV3yPA6WmM:&tbnh=104&tbnw=134&prev=/images%3Fq%3DCHONDROMALACIA,KNEE,MRI%26hl%3Dar%26sa%3DG%26gbv%3D2%26tbs%3Disch:1&ei=KgPlTOSELMmWhQeE0qy_DA

An axial representation of a lateral patellar dislocation illustrates the dramatic transient lateral shift of the patella that occurs as the medial patella impacts upon the anterolateral aspect of the lateral femoral condyle.

An axial proton density-weighted image with fat suppression reveals complete disruption of the medial retinaculum at its patellar attachment (arrow) in another patient who recently suffered a lateral patellar dislocation.

http://www.google.com.eg/imgres?imgurl=http://www.radsource.us/_images/0704_4.jpg&imgrefurl=http://www.radsource.us/clinic/0407&usg=__vDgkS5eCKojhgNXstZVWZk2Uy5g=&h=352&w=350&sz=40&hl=ar&start=2&sig2=rv866thH-LySpsQLUpb2Tg&zoom=1&itbs=1&tbnid=cC5YXpU0AYW9wM:&tbnh=120&tbnw=119&prev=/images%3Fq%3DTRANSIENT%2BPATELLAR%2BDISLOCATION%26hl%3Dar%26sa%3DG%26gbv%3D2%26tbs%3Disch:1&ei=CQLlTOvpN4TJhAfW4oG9DA

Sagittal MRI of the knee showing a complete ACL tear.

http://www.google.com.eg/imgres?imgurl=http://uwmsk.org/static/residentprojects/ACLtear.jpg&imgrefurl=http://uwmsk.org/residentprojects/aclreconstruction.html&usg=__TQg5xEamowIodsJ25kYPIVMtnTI=&h=336&w=288&sz=30&hl=ar&start=5&sig2=w4OLBMVln4kj4Emcz5GiWw&zoom=1&itbs=1&tbnid=j_eNvwG6SZ9LbM:&tbnh=119&tbnw=102&prev=/images%3Fq%3DACL%2BTEAR%26hl%3Dar%26sa%3DG%26gbv%3D2%26tbs%3Disch:1&ei=ZgHlTPXsDoGLhQfL6Ki7DA

This sagittal proton-density weighted, fat-saturated image of the right knee shows linear high signal (click image for arrow) in the posterior horn of the lateral meniscus. The high signal extends to the articular surface, consistent with a longitudinal tear. There is some high signal in the anterior horn which probably extends to the articular surface and may represent extension of the tear anteriorly.

http://www.google.com.eg/imgres?imgurl=http://radpod.org/wp-content/uploads/2006/12/lateral_meniscus_arrow.JPG&imgrefurl=http://www.radpod.org/2006/12/18/longitudinal-meniscal-tear/&usg=__c8EwRfOqimzUUP5XzTRKRcdydwg=&h=514&w=489&sz=34&hl=ar&start=4&sig2=WR4HT7P7nI5GkBo_N9Kp3Q&zoom=1&itbs=1&tbnid=mn_kEwKkMV9MlM:&tbnh=131&tbnw=125&prev=/images%3Fq%3Dmeniscal%2Btear%26hl%3Dar%26sa%3DG%26gbv%3D2%26tbs%3Disch:1&ei=tQDlTOz9C4OKhQeHpv3IDA

MRI showing stress fracture proximal tibia.

http://www.google.com.eg/imgres?imgurl=http://www.parksidemri.com/physician/casestudy/case-win03/images/case7-sm.jpg&imgrefurl=http://www.parksidemri.com/physician/casestudy/case-win03/&usg=__3ISquqXaxuHsRf1oTuNGp1B3-_U=&h=88&w=100&sz=4&hl=ar&start=9&sig2=tBiUiyrOSVZJ-ZOaqUzIYw&zoom=1&itbs=1&tbnid=OpK7VN7djjPQKM:&tbnh=72&tbnw=82&prev=/images%3Fq%3Dstress%2Bfracture%2B,mri%26hl%3Dar%26sa%3DG%26gbv%3D2%26tbs%3Disch:1&ei=w__kTKS1H4qLhQeM2MW-DA

Axial MRI of a knee. Popliteal cyst can be seen at the tip of the red arrow.

http://www.google.com.eg/imgres?imgurl=http://www.emedx.com/emedx/diagnosis_information/diagnosis_information_image_files/knee_images/popliteal_cyst_mri.gif&imgrefurl=http://www.emedx.com/emedx/diagnosis_information/knee_disorders/popliteal_baker%27s_cyst_mri.htm&usg=__AK8Z4G0-m05aIWSnI2XtlNyLdbM=&h=247&w=260&sz=42&hl=ar&start=1&zoom=1&itbs=1&tbnid=jWL6KxfaSw4qnM:&tbnh=106&tbnw=112&prev=/images%3Fq%3Dbaker%2Bcyst,mri%26hl%3Dar%26sa%3DG%26gbv%3D2%26tbs%3Disch:1

The axial image demonstrates increased signal (arrow) within fat interposed between the lateral aspect of the patellar tendon and the lateral trochlear ridge. Mild lateral patellar subluxation is present as indicated by the off-midline positioning of the patellar tendon (arrowhead).
The sagittal image demonstrates increased signal (arrow) within the fat below the caudal margin of the patella as well as moderate patella alta (arrowhead). Note the high riding appearance of the patella.

Three normal anterior knee fat pads are present at the knee; the quadriceps (anterior suprapatellar) (red), the prefemoral (posterior suprapatellar or supratrochelar) (blue), and Hoffa (infrapatellar) (yellow) fat pads.


The infrapatellar fat pad is bordered by the inferior pole of the patella superiorly, the joint capsule and patellar tendon anteriorly, the proximal tibia and deep infrapatellar bursa inferiorly, and the synovium-lined joint cavity posteriorly. Thus, it is intracapsular but extrasynovial. It is tethered to the intercondylar notch superiorly by the infrapatellar synovial fold or infrapatellar plica. It also is attached directly to the anterior horns of the menisci inferiorly and to the periosteum of the tibia.


On MRI, a focal area of high signal or edema on STIR or T2 weighted sequences is present at the inferolateral aspect of the patellofemoral joint, specifically the lateral portion of the infrapatellar fat pad (D,E). Specifically, this is just below the inferior margin of the patella and anterior to the lateral trochlear ridge. A focal lobulated mass with signal characteristics of fluid or cystic change can sometimes be present in the lateral soft tissues of the knee between the lateral femoral condyle and the lateral retinaculum. Associated findings of lateral patellar subluxation (F) and/or patella alta are frequently present.



http://www.radsource.us/clinic/0809

Jumper's Knee refers to a spectrum of disorders that occur in patients with degeneration and/or tearing of the patellar tendon. It is one of the most common tendon abnormalities in athletically active individuals, and as the name implies, is most common in jumping athletes such as basketball and volleyball players. In the non-athlete, rheumatoid arthritis, the seronegative arthropathies, and treatment with exogenous steroids are known to predispose to this condition.

fat-suppressed proton density-weighted sagittal images in a basketball player who sustained an acute injury reveal marked edema about the patellar tendon with a fluid filled gap (arrows) at the central tendon, compatible with a complete rupture. The retracted proximal and distal ends (arrowheads) are markedly thickened, indicating severe tendinosis. The vast majority of patellar tendon ruptures occur in patients with pre-existing patellar tendinosis.

http://www.radsource.us/clinic/0612

A proton density-weighted axial view demonstrates the normal semilunar appearance of the patellar tendon, with a convex anterior border (arrow) and well-defined posterior rim.

T1-weighted sagittal image in a patient with a normal patellar tendon reveals a homogeneously low signal intensity appearance to the tendon (arrows), which appears symmetrical in appearance throughout its course.

http://www.radsource.us/clinic/0612

The fat-suppressed proton density weighted sagittal view confirms the abnormally thickened and edematous tendon (arrow). Mild adjacent edema is seen within the surrounding subcutaneous and infrapatellar fat, and small interstitial splits (arrowheads) are present within the proximal tendon.
The T1-weighted sagittal images reveals marked thickening and increased signal intensity (arrow) within the patellar tendon.

http://www.radsource.us/clinic/0612

Quadriceps Tendon Tear,

Reference:uhrads.com

Quadriceps Tendinopathy

Extensor mechanism injuries of the knee. Sagittal fast spin-echo proton density-weighted images with fat suppression images in a 40-year-old man with anterior knee pain following trauma demonstrates diffuse thickening of the infrapatellar tendon as well as linear areas of abnormal intermediate signal intensity within the substance of the tendon. Findings are consistent with an acute partial tear of the patellar tendon. Chronic patellar tendonitis complicated by chronic tears associated with inflammation and necrosis can appear similar on MRI; however, in this patient, subcutaneous edema anterior to the tendon also is seen, suggesting a relatively acute injury.

Quadriceps Tendon Tear

Extensor mechanism injuries of the knee. FSE T2-weighted image demonstrating complete tear of the quadriceps tendon in 67-year-old man. Retraction of the quadriceps tendon consistent with complete tear is observed (arrow) with mild undulating contour of the patellar tendon. (Image courtesy of Douglas Goodwin, Dartmouth-Hitchcock Medical Center).

Patellar Retinaculum Disruption

Traumatic Lateral Patellar Dislocation Axial T2 weighted FSE fat suppressed MR image of the knee in a 16 year old female. The typical bony contusion pattern is at the medial patellar facet and the nonarticular lateral femoral condyle (arrowheads) as well as the disrupted medial retinaculum.

Patellar Tendonitis

MRI scan (side-on view) of a knee with patellar tendonitis. The tendon should be dark throughout its length. At the top of the tendon, just below the patella, there is a pale area in the tendon, caused by inflammation and swelling.

Osgood-schlatter Disease

X-ray of the left knee revealed an ossicle anterior to the tibial tuberosity.

Diagnosis is most often made clinically. When used, radiography shows fragmentation of the tibial tubercle, although this finding alone may represent a normal ossification center. Therefore, the most important diagnostic criteria are seen at MR imaging and include:- soft-tissue swelling anterior to the tibial tuberosity, - loss of the sharp inferior angle of the infrapatellar fat pad and surrounding soft tissues,- thickening and edema of the inferior patellar tendon, and- infrapatellar bursitis.

Jumpers Knee

Jumper's Knee
Jumper's knee or infrapatellar tendonitis is a chronic inflammatory disease affecting the tendon between the kneecap and the tibia resulting in pain, stiffness and weakness. The normal collagen fibres in the tendon can become disorganized and sometimes replaced by a tight cyst with gel-like substance. Physiotherapy (clic to..) is definitely the initial step to try to resume sports activities once diagnosis is confirmed with ultrasound or MRI. If this fails (in a minority) , surgery can be indicated to decompress the tendon. Rehab in these circumstances is challenging and time-consuming (up to a year).

Patellar tendon tear

Normal patellar tendon

The patellar tendon is torn. It should be a smooth black stripe, as in the normal image

Here is a magnified view of the abnormality, at the front of the knee just below the patella (kneecap)

Lateral Collateral Ligament Tear

Cor T1

Cor T2 Fat Sat

Ax PD Fat Sat

Lateral collateral ligament (LCL) tear
The lateral collateral ligament (LCL) arises from the lateral femoral condyle and inserts on the lateral aspect of the middle third of the fibular head, sometimes joining the biceps femoris tendon. This ligament has a posterior and oblique course and is seldom seen entirely on one coronal image. The LCL is 5-7 cm long, extracapsular, and free from meniscal attachments.The location of the injury relative to the lateral collateral ligament can be proximal, mid substance, or at the fibular insertion. MRI appearance of an LCL tear depends less on the degree of tearing. Most commonly an acute LCL tear is seen as a serpiginous or lax ligament with discontinuous fibers (or avulsed fibular head), often without significant thickening of the ligament.
Cor T1
Cor T2 Fat Sat
Ax PD Fat Sat
Lateral collateral ligament is a part of lateral supporting structures of the knee commonly and collectively referred to as the posterolateral corner (PLC) or posterior lateral arcuate complex. The PLC includes the LCL, popliteus tendon, lateral head of the gastrocnemius, arcuate ligament and, occasionally, popliteofibular and fabellofibular ligaments. Similar to MCL tears, isolated injuries of the LCL are uncommon and typically occur in association with ACL or posterior cruciate ligament (PCL) tears.The lateral collateral ligament (LCL) arises from the lateral femoral condyle and inserts on the lateral aspect of the middle third of the fibular head, sometimes joining the biceps femoris tendon. This ligament has a posterior and oblique course and is seldom seen entirely on one coronal image. The LCL is 5-7 cm long, extracapsular, and free from meniscal attachments.The grading system for classifying both MCL and LCL tears is the same as that used for other ligaments evaluated by MRI as follows: Grade 1 - Microscopic tears Grade 2 - Partial tears Grade 3 - Complete tearsThe location of the injury relative to the lateral collateral ligament can be proximal, mid substance, or at the fibular insertion. MRI appearance of an LCL tear depends less on the degree of tearing. Most commonly an acute LCL tear is seen as a serpiginous or lax ligament with discontinuous fibers (or avulsed fibular head), often without significant thickening of the ligament. As mentioned above, LCL tears rarely are isolated, and an LCL tear becomes more likely as associated PLC and cruciate ligament injuries increase in severity. A chronic LCL tear appears as a thickened low T1/T2-weighted signal ligament.Suggested Reading:Miller TT, Gladden P, Staron RB, Henry JH, Feldman F. Posterolateral stabilizers of the knee: anatomy and injuries assessed with MR imaging. AJR 1997;169:1641 -1647. A. H. Haims, M. J. Medvecky, R. Pavlovich Jr., and L. D. Katz. MR Imaging of the Anatomy of and Injuries to the Lateral and Posterolateral Aspects of the Knee. Am. J. Roentgenol., March 1, 2003; 180(3): 647 - 653.