Meniscal Pathology Mr. Abdul Wahab
Meniscal Pathology
Mr. Abdul Wahab
Anatomy of the meniscus
Fibrocartilage C-shaped disc
Mesenchymal tissue - appear
in 8 -10 weeks of gestation
Highly cellular and vascular
initially
Type-1 collagen with 75% of
water
Fibers orientation
Posterior horn thicker & wider than the
anterior horn in medial meniscus
Lateral meniscus more mobile
Not attached with Tibia at Popliteal hiatus
Insertional Ligaments
1-Transverse Meniscal Ligament
Connects both menisci anteriorly
2- Coronary (meniscotibial) ligaments
Connect medial meniscus to Tibia anterolaterally
3-Meniscofemoral ligament of Wrisberg (70%)
Passes from posterior horn of lateral meniscus to medial femoral
condyle posterior to PCL
4-Meniscofemoral ligament of Humphrey
Passes from posterior horn of lateral meniscus to medial
femoral condyle anterior to PCL
MedialLateral
Biomechanical Functions
Load distribution
Shock absorption
Joint stability
Joint lubrication
Nutrition of articular cartilage
Helps knee locking in extension
Reduce friction between Tibia and Fibula
Chock block
Biomechanics
6/29/2013 6
• Limited contact
area
• High contact
stress
• More contact
area
• Low contact
stress
Meniscectomy Meniscus intact
Load
Distribution
BIOMECHANICS OF MENISCUS
The contact force of the menisci
on the femur helps guide the femur
anteriorly during flexion
The reaction force of the femur
on the menisci deforms the
menisci posteriorly on the tibial
plateau.
Continuity of peripheral meniscal
rim is very important for load
bearing
Partial meniscectomy still preserve
this function
A radial tear or total menisectomy
massively increase contact stress
and cause OA changes
Femoral
Condyle
Movement
Biomechanics
Blood Supply
• Periphery receives blood supply (20-40%)
• Remaining portion nourishes from synovial
fluid by diffusion
Mechanism of injury
Body rotates with foot
on ground and knee
partially flexed
Repetitive squatting
cause medial meniscal
injury
Trivial injury required
in arthritic knee
Pivoting sports i.e.
soccer, rugby, net ball,
basket ball
Normal meniscus
Small meniscus
Truncated free edge
Displaced meniscal fragment
Unhappy Triad
Also called
Terrible triad
O’Donoghue’s triad
Blown knee
Knee banged on lateral side in semi flexion with foot stable on ground
Injury to
1. Medical collateral ligament
2. ACL
3. Lateral/medial Meniscus
Signs & symptoms
Not all meniscal tears are symptomatic
Swelling
Pain and tenderness along joint line - medial or lateral
Pain worse on squatting, kneeling or pivoting
Locking of the knee
Giving way, snaps, clicks, clunks, catches in knee.
Atrophy of quadriceps
Instability of joint
Elastic block at terminal extension
Springy end feel
Knee
Examination• Look (gait, muscle atrophy, swelling, bruise)
• Feel (joint line tenderness, effusion, cyst)
• Move (pain on extreme movement,
block, check ACL, LCL, MCL)
Prone position
Knee flexed to 90 degree and
thigh fixed to the examination
table
compression and rotating
tibial plateau on femoral
condyles
Joint line pain on rotation
Thessaly Test
Hold patient’s outstretched hands for support
Ask the patient to stand on normal leg first and ask
to rotate body with knee flexed to 20 degree
Now, ask the patient to stand on affected leg
bend knee to 20 degree and rotate body 3 times
internally and externally
Test Positive if symptoms appear
Patient sits with the leg
flexed over the table about
90 degree.
Rotate tibia internally and
externally
Joint line pain confirms test
positive
Imaging
Plain Radiographs
Not helpful in meniscal injury
Rule out other bony or joint pathology
Arthrography
Invasive
Accuracy rate 60% - 90%
Largely replaced by MRI
Tibial tunnel enlargement – ACL injury
MRI
Non invasive, no ionising radiation
Differentiate between repairable and
non-repairable tears
Average sensitivity:
95% medial and 81% in lateral
Average specificity
88% medial and 95% lateral
Meniscus looks dark due low signal
(high water content).
Picks associated injuries (ACL)
Surgery can be planed ahead
Types of meniscal tears according to plane of
cleavage
Meniscal
tears
Vertical Horizontal
Longitudinal Radial
Horizontal tear
Is parallel to the tibial plateau and divide the
meniscus into upper and lower segments.
Horizontal tear
Longitudinal vertical tear
Perpendicular to the tibial plateau & parallel to
the long axis of the meniscus.
Longitudinal vertical tear
Peripheral longitudinal tear
Radial tear
is perpendicular to the tibial plateau &
perpendicular to the long axis of the meniscus.
Body radial tear
Full thickness body radial tear
Posterior horn radial tear
Displaced meniscal tears
Displaced
meniscal tears
Vertical Horizontal tear
(Flap tear)
Displaced
Longitudinal tear
(bucket handle tear)
Displaced
Radial tear
(Parrot beak tear)
Displaced Meniscal Tears
Flap tear
Flap tear
Trimmed meniscus
Bucket handle tear(Displaced Longitudinal Tear)
Bucket handle tear
Reduced bucket handle tear
Boe-ties sign (normal meniscus
Flipped variant of bucket handle tear
Meniscal extrusion
Parrot beak tear (radial oblique tear)
Management
Non Surgical
Surgical
Non surgical management
Incomplete tear
Small (5mm) peripheral stable tear
Tears associated with ligamentous injuries (where reconstruction
deferred or contraindicated)
•R-rest
I-ice
C-compression
E-elevation
•NSAIDS
•Physio
•Immobilisation
Surgical Management
1. Meniscectomy
By arthrotomy
By arthroscopy
2. Meniscal repair
By arthrotomy
By arthroscopy
3. Meniscal transplantation
Autografts
Allograft
Prosthetic scaffolds
Meniscal repair
Arnoczky and Warren -
peripheral zone is repairable
Canine model - fibrin clot
formation in red-red zone
-- scar formation in 10 weeks
Superficial zone cells –
progenitor cells
Factors affecting repair Location of tear
Location of tear
ACL reconstruction
Age of tear
Age of patient
Open technique
Inside out technique
All inside technique
Repair
All inside repair (arthroscopic)
Arrows
Darts
Cinch
• Bioabsorbable
material
• Very hard
• Can break
• Can migrate
• Device rubbing can
cause cartilage defect
Second generation delivery system
2 plastic anchors connected with sutures passed by
needle deliver system
Knots tightened outside