Meniscal tears

Menisci Menisci

Dr / Hytham NafadyDr / Hytham Nafady

Anatomy of the meniscusAnatomy of the meniscus

The posterior horn medial meniscus is larger than The posterior horn medial meniscus is larger than the anterior horn.the anterior horn.

Both horns of lateral meniscus are of the same Both horns of lateral meniscus are of the same size, but the posterior horn is slightly higher in size, but the posterior horn is slightly higher in position.position.

Signs of meniscal tear

Abnormal signalMorphological

changes

Grade I

Grade II

Grade III

Abnormal size

Blunting of free edge

Displacement of meniscal fragemnt

Interrupted appearance

Abnormal mensicus Abnormal mensicus signalsignal

Normal meniscusNormal meniscus

Small meniscusSmall meniscus

Truncated free edgeTruncated free edge

Displaced meniscal Displaced meniscal fragmentfragment

Types of meniscal tears Types of meniscal tears according to plane of according to plane of

cleavagecleavageMeniscal

tears

Vertical Horizontal

Longitudinal Radial

Horizontal tearHorizontal tear

Is parallel to the Is parallel to the tibial plateautibial plateau and and divide the meniscus into upper and divide the meniscus into upper and lower segments.lower segments.

Horizontal tearHorizontal tear

Horizontal tear with Horizontal tear with parameniscal cystparameniscal cyst

Longitudinal vertical tearLongitudinal vertical tear

Is perpendicular to the Is perpendicular to the tibial tibial plateauplateau & parallel to the & parallel to the long axis long axis of the meniscusof the meniscus..

Longitudinal vertical tearLongitudinal vertical tear

Longitudinal vertical tearLongitudinal vertical tear

Peripheral longitudinal Peripheral longitudinal teartear

Peripheral longitudinal Peripheral longitudinal teartear

Radial tearRadial tear

is perpendicular to the is perpendicular to the tibial plateautibial plateau & & perpendicular to the perpendicular to the long axis of the long axis of the meniscusmeniscus..

Radial tearRadial tear

Body radial tearBody radial tear

Full thickness body Full thickness body radial tearradial tear

Posterior horn radial Posterior horn radial teartear

Meniscal extrusionMeniscal extrusion

Displaced meniscal tearsDisplaced meniscal tears

Displaced meniscal tears

Vertical Dislaced

Horizontal tear (Flap tear)

Displaced Longitudinal tear

(bucket handle tear)

Displaced Radial tear

(Parrot beak tear)

Types of displaced meniscal tears according to the original plane of cleavage

Types of displaced meniscal Types of displaced meniscal fragment according the fragment according the direction of displaced direction of displaced

fragmentfragment

Displaced mensical fragment

Displaced mensical fragment

intercondylar notch

intercondylar notch

Mensico-capsular recesses

Mensico-capsular recesses

MCMCLL

Flap tearFlap tear

Flap tearFlap tear

LCLLCLBiceps Biceps tendontendon

Flap tearFlap tear

Bucket handle tearBucket handle tear

Normal bow tie appearnace Normal bow tie appearnace of the meniscal bodyof the meniscal body

Flipped variant of bucket Flipped variant of bucket handle tearhandle tear

Double anterior horn Double anterior horn signsign

Parrot beak tear (radial Parrot beak tear (radial oblique tear) oblique tear)

Meniscal tear pitfallsMeniscal tear pitfalls

Anatomical structures.Anatomical structures. Physiological changes.Physiological changes. Arifacts.Arifacts.

Artifacts Artifacts

Magic angle phenomenon.Magic angle phenomenon. Truncation artifact.Truncation artifact.

Magic angle phenomenonMagic angle phenomenon

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Closed MRIClosed MRI Open MRIOpen MRI

In closed MRI scanner, In closed MRI scanner, magic angle artifact magic angle artifact can be found in one can be found in one location:location:

The up-sloping of the The up-sloping of the posterior horn lateral posterior horn lateral meniscus.meniscus.

in open, vertical field in open, vertical field magnets, magic angle magnets, magic angle artifact will be found in artifact will be found in two locations: two locations:

1)1) junction of anterior horn junction of anterior horn and body of meniscus and and body of meniscus and

2)2) junction of posterior horn junction of posterior horn and body of meniscus and body of meniscus

Truncation artifactTruncation artifact

How to avoid truncation artifact:How to avoid truncation artifact:

Use acquisition matrix that is larger Use acquisition matrix that is larger than 128 x 256 (i.e 192 x 256 or 256 than 128 x 256 (i.e 192 x 256 or 256 x 256).x 256).

Costs of increasing the matrix:Costs of increasing the matrix:

Increased acquisition time.Increased acquisition time.

Decreased S/N ratio.Decreased S/N ratio.

Anatomical structuresAnatomical structures

Anterior meniscal ligament.Anterior meniscal ligament. Oblique meniscal ligament.Oblique meniscal ligament. Meniscal root ligament.Meniscal root ligament. Meniscofemoral ligaments.Meniscofemoral ligaments. Popliteus tendon.Popliteus tendon. Semimembranosis tendonSemimembranosis tendon ACL insertion.ACL insertion.

Anterior intermeniscal Anterior intermeniscal ligamentligament

Meniscofemoral ligamentMeniscofemoral ligament

Popliteal tendonPopliteal tendon

Adjacent crossing fibers of Adjacent crossing fibers of the ACLthe ACL

May give the anterior horn of lateral May give the anterior horn of lateral meniscus speckled appearance.meniscus speckled appearance.

Oblique intermeniscal Oblique intermeniscal ligamentligament

Oblique intermeniscal Oblique intermeniscal ligament ligament

Vs Vs Bucket handle tearBucket handle tear

Olique intermeniscal Olique intermeniscal ligamentligament

Semimembranosis Semimembranosis tendontendon

Physilogical changesPhysilogical changes

Meniscal flounce.Meniscal flounce. Vacuum phenomenon.Vacuum phenomenon. Normal vascualrity.Normal vascualrity. Meniscal ossicleMeniscal ossicle

Meniscal flounceMeniscal flounce

Vacuum phenomenonVacuum phenomenon

Vacuum phenomenon is accumulation of Vacuum phenomenon is accumulation of nitrogen gas within the joint due to nitrogen gas within the joint due to negative pressurenegative pressure

Meniscal ossicleMeniscal ossicle

Normal vascularityNormal vascularity