0:00

Now, I had to show you, of course, a classic,

0:03

complete acute or recent injury of the ACL.

0:07

Nothing difficult about this. We see it on T one.

0:10

We see it on a fluid sensitive sequence.

0:13

We can measure the gap.

0:14

We can look for anteriorly translated torn ligament fibers.

0:19

More about that in a moment.

0:20

So this is the acute complete tear of the anterior cruciate.

0:25

Now, when we study the individual cases

0:28

where you have acute complete tears

0:30

of the anterior cruciate, we find that often

0:34

it's not the only thing that has gone wrong.

0:37

There are other abnormalities, be they of ligaments,

0:40

of cartilage, of the meniscus.

0:42

Taken from a recent article

0:44

that appeared in skeletal radiology,

0:46

these were the statistics that were noted in the study

0:50

of a large number of persons with acute complete tears

0:54

of the anterior cruciate.

0:57

You can see frequently the medial meniscus is abnormal,

1:00

the medial supporting structures shown in this example

1:04

with tearing of the ACL,

1:06

we can see lateral meniscus cartilage abnormalities

1:10

by the way, which dominate in the patella

1:12

statistically in patients who have ACL tears

1:16

lateral supporting structure shown in this case, involvement

1:20

of the fibula or lateral collateral ligament,

1:23

and then rarely associated posterior

1:26

cruciate ligament tears.

1:28

And again, when you have bi cruciate ligament tears,

1:32

you have to wonder whether

1:33

or not the knee has been dislocated.

1:38

What are the factors that will affect treatment?

1:41

Well, there are a number of these.

1:43

Finding a significant meniscal injury is important, so

1:47

that may be why the MR is ordered.

1:50

The clinician, the orthopedist knows there's an ACL tear.

1:53

He's done the stress testing.

1:55

He gets an MR to see what the meniscus looks like.

1:58

He or she may be able to pick up a men medial meniscal tear,

2:03

but the clinical tests

2:04

and the symptoms are not as reliable

2:06

for a lateral meniscal tear.

2:09

This is a case I showed you

2:10

before with a large radial tear

2:13

with a gap in the lateral meniscus in a person

2:16

who had an ACL tear.

2:18

Other factors that may affect treatment, other injuries

2:22

to ligaments and significant cartilage abnormalities.

Mechanisms of Injury

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0:00

Now, I had to show you, of course, a classic,

0:03

complete acute or recent injury of the ACL.

0:07

Nothing difficult about this. We see it on T one.

0:10

We see it on a fluid sensitive sequence.

0:13

We can measure the gap.

0:14

We can look for anteriorly translated torn ligament fibers.

0:19

More about that in a moment.

0:20

So this is the acute complete tear of the anterior cruciate.

0:25

Now, when we study the individual cases

0:28

where you have acute complete tears

0:30

of the anterior cruciate, we find that often

0:34

it's not the only thing that has gone wrong.

0:37

There are other abnormalities, be they of ligaments,

0:40

of cartilage, of the meniscus.

0:42

Taken from a recent article

0:44

that appeared in skeletal radiology,

0:46

these were the statistics that were noted in the study

0:50

of a large number of persons with acute complete tears

0:54

of the anterior cruciate.

0:57

You can see frequently the medial meniscus is abnormal,

1:00

the medial supporting structures shown in this example

1:04

with tearing of the ACL,

1:06

we can see lateral meniscus cartilage abnormalities

1:10

by the way, which dominate in the patella

1:12

statistically in patients who have ACL tears

1:16

lateral supporting structure shown in this case, involvement

1:20

of the fibula or lateral collateral ligament,

1:23

and then rarely associated posterior

1:26

cruciate ligament tears.

1:28

And again, when you have bi cruciate ligament tears,

1:32

you have to wonder whether

1:33

or not the knee has been dislocated.

1:38

What are the factors that will affect treatment?

1:41

Well, there are a number of these.

1:43

Finding a significant meniscal injury is important, so

1:47

that may be why the MR is ordered.

1:50

The clinician, the orthopedist knows there's an ACL tear.

1:53

He's done the stress testing.

1:55

He gets an MR to see what the meniscus looks like.

1:58

He or she may be able to pick up a men medial meniscal tear,

2:03

but the clinical tests

2:04

and the symptoms are not as reliable

2:06

for a lateral meniscal tear.

2:09

This is a case I showed you

2:10

before with a large radial tear

2:13

with a gap in the lateral meniscus in a person

2:16

who had an ACL tear.

2:18

Other factors that may affect treatment, other injuries

2:22

to ligaments and significant cartilage abnormalities.

Report

Faculty

Donald Resnick, MD

Professor Emeritus, Department of Radiology

University of California, San Diego

Mini N. Pathria, MD, FRCP(C)

Division Chief, Musculoskeletal Imaging

University of California San Diego

Eric Y. Chang, MD

Adjunct Professor, Radiology

University of California, San Diego

Brady K. Huang, MD

Clinical Professor of Radiology

UC San Diego Medical Center

Lesson

Meniscus (preoperative and postoperative)

Lesson

Meniscus Case Review

Lesson

Footprints and mechanisms of knee injury

Lesson

Cruciate Ligaments

Lesson

Knee Injury & Cruciate Ligament Case Review

Lesson

Medial Ligaments

Lesson

Lateral Ligaments

Lesson

Medial and Lateral Ligament Case Review

Lesson

Postoperative Ligaments

Lesson

Extensor Mechanism

Lesson

Popliteal Fossa

Lesson

Postoperative Ligaments, Extensor Mechanism & Popliteal Fossa Case Review

Mechanisms of Injury