Professor of Orthopaedic SurgeryBenha Faculty of Medicine

BY

T1 sequence.

Proton Density sequence.

T2 sequence.

Fat suppression sequence.

Gradient echo image.

Normal meniscus.

Sagital image. Coronal image. Axial image.

PCL

Line

Criteria of Meniscal tear:Criteria of Meniscal tear:

(1) Linear or complex intrameniscal signal extending to the superior or inferior surface of the meniscus.

(2) Gross disruption of the normal meniscal contour with obvious foreshortening.

(3) complete absence of any meniscal structure.

Criteria of Meniscal tearCriteria of Meniscal tear

Linear or complex intrameniscal signal extending to the superior or inferior surface of the meniscus

Linear or complex intrameniscal signalLinear or complex intrameniscal signal

Gross disruption

Foreshortening.

Criteria of Meniscal tearCriteria of Meniscal tear

Absence of any meniscal structure.

Ant.

Bucket-handle tearsBucket-handle tears

There are four traditional findings for bucket-handle tears:

1- Fragment in the intercondylar notch

2- Flipped meniscus sign

3- Double posterior cruciate ligament sign

4- Absent bow tie sign

Resnick, 2002

Fragment in the intercondylar notch

Flipped meniscus sign

Double posterior cruciate ligament sign

Absent bow tie sign

Bucket-handle tears.Bucket-handle tears.

Lat. M. Med.M.

Bucket-handle tear lat.M.Bucket-handle tear lat.M.

Bucket Handle TearBucket Handle Tear

Bucket Handle TearBucket Handle Tear

Bucket handle tear lat.M.

Watanabe's classification of Watanabe's classification of Discoid meniscus.Discoid meniscus.

Discoid MeniscusDiscoid Meniscus

Discoid MeniscusDiscoid Meniscus

Discoid meniscus.Discoid meniscus.

Discoid Meniscus.Discoid Meniscus.

Discoid MeniscusDiscoid Meniscus

Cleavage TearCleavage Tear

Flap TearFlap Tear

Flap TearFlap Tear

Radial TearRadial Tear

Deg. TearDeg. Tear

Meniscal cyst.Meniscal cyst.

Meniscal ossicle.

Normal vascularity.Normal vascularity.

In children there is frequently a high signal within the meniscus which reflects the normal vascularity which decreases with age.

This may confuse the diagnosis of meniscal abnormality.

(Takeda et al.1998)

Normal vascularity.Normal vascularity.

Normal vascularity.Normal vascularity.

Grade2 versus grade3.

Transverse ligament.Transverse ligament.

Transverse ligament.Transverse ligament.

PopliteusPopliteus tendon tendon

PopliteusPopliteus tendon. tendon.

Ligament of HumphreyLigament of Humphrey

An intra-articular loose body may be simulated by a branch of the

meniscofemoral ligament

Ligament of Wrisberg.Ligament of Wrisberg.

POSTOPERATIVE MRI.POSTOPERATIVE MRI.

A knee which has been operated on is always a diagnostic challenge and false-positive MRI results may occur. Surgical trimming of a meniscus may have extended almost to an area of myxoid degeneration, and MRI may erroneously suggest a persisting defect. .

Accuracy of MRIAccuracy of MRI

A multicentre review of 2000 patients assessed by both MRI and arthroscopy showed an overall accuracy for the medial meniscus of 0.89 with a sensitivity of 0.93 and a specificity of 0.84 . Overall accuracy for the lateral meniscus was similar, but the sensitivity was much lower (0.76) and the specificity was higher