Basic Knee Imaging RSSA Durban 2008
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Basic Knee Imaging RSSA Durban 2008 . Richard de Villiers Van Wageningen and Partners. Aims . Anatomy of the Meniscus Imaging protocol. Terminology. Speak the same language as your referrer Keep up to date with the relevant terminology. Anatomy. Meniscal anatomy Attachments.
Basic Knee Imaging RSSA Durban 2008
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Basic Knee ImagingRSSA Durban 2008 Richard de Villiers Van Wageningen and Partners
Aims • Anatomy of the Meniscus • Imaging protocol
Terminology • Speak the same language as your referrer • Keep up to date with the relevant terminology
Anatomy • Meniscal anatomy • Attachments
Basic anatomy Medial meniscus Lateral meniscus
Morphology • Wedge-shaped • Semilunar ( C -shaped) • Surface • Superior • concave • Inferior • flat • Fibrocartilage (collagen fibres) • Fibres • superficial • circumferential hoop • radial tie
A.Superficial layer a ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° mesh-like matrix of fine fibrils measuring 100μ
Superficial layer a 100 micrometre
° ° ° ° ° ° ° ° ° ° ° ° ° c ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° B.Circumferential hoop fibres b rope-like collagen fibre bundles c. smaller radial fibres - reeinforcement
a b
° ° ° ° ° ° ° ° ° ° ° ° ° c ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° C. Radial Tie fibres b -reinforcement
Terminology Red-white zone Free edge Menisco-capsular junction Peripheral zone (outer) Red zone Central zone Inner White zone
Vascularity • From the genicular vessels • Extent • Medial (10-30% of width) • Lateral (10-25% of width)
Arnoczky SP (1992) In: Mow VC, Arnoczky SP, Jackson DW (Eds) Knee meniscus: Basic and clinical foundations. Raven Press, New York
Relevance • If tear involves outer, vascular 1/3 (3-5 mm from capsule) • Surgical repair / or conservative • If tear involves inner,-non-vascular 1/3 • Partial / total meniscectomy
Medial Meniscus • Size (AH < PH) • AH ( 7.6 mm) • Body ( 9.6 mm) • PH ( 10.6mm)
Lateral meniscus • Size ( AH = PH) • AH (10.2 mm) • Body (11.6 mm) • PH (10.6 mm)
Attachments • Menisci maintained in optimal position • Various direct and indirect attachments to the tibia and femur. • Peripheral attachments to capsule
Medial Meniscus • Attachments • AH • Transverse ligament • Anterior root ligament • Body (capsular) • Meniscofemoral • Meniscotibial ( coronary) • Minor capsular attachments • PH • Posterior root ligament
Radiologist attending this lecture according to the attendance register
Lateral meniscus • Attachments • AH • Transverse meniscal ligament • Root ligament • Body • Capsular ligaments • Superior and inferior • To ITB • NOT attached to the LCL • PH • Meniscofemoral ligaments • Humphrey and Wrisberg • Popliteomeniscal ligaments • Meniscal struts • Root ligament
Transverse meniscal ligament • The menisci are attached to each other anteriorly by the transverseligament • 44 - 58 % incidence
Root attachments Cannabis sativa – Durban Poison • Critical attachment sites to the central tibial plateau. • Resist hoop stress • Well-defined relations to each other and to the cruciate ligament insertions • The Meniscal Roots: Gross Anatomic Correlation with 3-T MRI FindingsAm. J. Roentgenol., May 2007; 188: W446 - W450 Jeffrey M. Brody, Michael J. Hulstyn, Braden C. Fleming, and Glenn A. Tung.
Meniscofemoral ligaments • Ligaments of Humphrey and Wrisberg. • Superomedially • Posterior horn of thelateral meniscus to the lateral aspect of the medial femoral condyle. • Name based on their location • Either 70% • Both 6% • Minor role
Ligament of Wrisberg • Posterior • Larger • Inserts into the medial femoral condyle.
Ligament of Humphrey • Anterior • Smaller • 1/3 of PCL diameter
Popliteomeniscal ligaments • Superior and inferior struts • Anchor the posterior horn of the lateral meniscus to the capsule
MM capsular attachments Meniscotibial/femoral ligaments • MM attached via the deep portion of the MCL and the • meniscofemoral (f) and • meniscotibial (t) ligaments
Minor capsular attachments • Periphery of menisci usually attach to capsule via synovial attachments
Oblique menisco-meniscal ligament • Normal variant • runs obliquely from the anterior horn of one meniscus to the posterior horn of the opposite meniscus. • 1% to 4% • mimic a meniscal tear
Our institution 1.5 T Siemens Symphony Dedicated knee coil Well-trained, dedicated MR technicians Sagittal, axial and coronal PD/ PDFS PD for anatomy PDFS for pathology Occasionally MR arthrogram ( ? CT > MR) Post-surgical ? Meniscal retear Stability of osteochondral lesion Plica WE-DESS 1mm cuts : subtle meniscal & chondral abN 3D MPR GRE Subtle meniscal abN T1 Fracture/ tumour T2 Ganglion/cyst PC-T1FS Synovitis Infection Tumour MRI Protocols
Thank you • www.samsig.co.za