This document discusses meniscus injuries, detailing the anatomy, vascular supply, functions, and mechanisms of tears in the menisci of the knee. It describes the classification of tears, diagnostic tests, imaging techniques, and treatment options, including non-operative and operative methods such as meniscal repair and meniscectomy. The document emphasizes the significance of careful diagnosis and the varying approaches based on the type and location of the meniscal tear.

1. Meniscus injury
Preparedby:
Dr.AbdullahK. Ghafour 4thyearIBFMStrainee

2. The menisci are crescents, roughly triangular in cross section, that cover one
half to two thirds of the articular surface of the corresponding tibial plateau. They
are composed of dense, tightly woven collagen fibers arranged in a pattern
providing great elasticity and ability to withstand compression.
FUNCTION AND ANATOMY

3. »The medial meniscus is a C-shaped structure larger in
radius than the lateral meniscus, with the posterior horn
being wider than the anterior.
»The anterior horn is attached firmly to the tibia anterior to
the intercondylar eminence and to the anterior cruciate
ligament.
»The posterior horn is anchored immediately in front of the
attachments of the posterior cruciate ligament posterior to the
intercondylar eminence. Its entire peripheral border is firmly
attached to the medial capsule and through the coronary
ligament to the upper border of the tibia.
MEDIAL MENISCUS

4. »The lateral meniscus is more circular in form, the anterior
horn is attached to the tibia medially in front of the
intercondylar eminence, whereas the posterior horn inserts
into the posterior aspect of the intercondylar eminence and in
front of the posterior attachment of the medial meniscus.
»The posterior horn often receives anchorage also to the
femur by the ligament of Wrisberg and the ligament of
Humphrey and from fascia covering the popliteus muscle
»The lateral meniscus is smaller in diameter, thicker in
periphery, wider in body, and more mobile than the medial
meniscus. And it is attached to both cruciate ligaments
LATERAL MENISCUS

5. VASCULAR SUPPLY
»The vascular supply to the menisci originates predominantly
from the lateral and medial geniculate vessels (both inferior and
superior).
»Branches from these vessels give rise to a perimeniscal
capillary plexus within the synovial and capsular tissue. The
plexus network of vessels supply the peripheral border of the
meniscus throughout its attachment to the joint capsule.
»The depth of peripheral vascular penetration is 10% to 30% of
the width of the medial meniscus and 10% to 25% of the width
of the lateral meniscus.

6. FUNCTION
»Joint filler: compensating for gross incongruity between
femoral and tibial articulating surfaces.so prevent capsular
and synovial impingement during flexion-extension
movements.
»Joint lubrication: helping to distribute synovial fluid
throughout the joint and aiding the nutrition of the articular
cartilage.
»Stability: in all planes especially rotary stabilizers and are
probably essential for the smooth transition from a pure hinge
to a gliding or rotary motion as the knee moves from flexion
to extension.
»Shock absorbing: load-transmitting forces are carried by the
menisci, from 40% to 60% of the superimposed weight in the
standing position.

7. Traumatic lesions of the menisci are produced most commonly by
rotation as the flexed knee moves toward a extended position.
The most common location for injury is the posterior horn of the
meniscus, and longitudinal tears are the most common type of
injury.
The length, depth, and position of the tear depend on the position
of the posterior horn in relation to the femoral and tibial condyles.
MENISCAL TEAR

8. MECHANISM OF TEAR
»The menisci follow the tibial condyles during flexion and extension, but during rotation they
follow the femur and move on the tibia; consequently, the medial meniscus becomes distorted.
Its anterior and posterior attachments follow the tibia, but its intervening part follows the femur;
thus it is likely to be injured during rotation.
»However, the lateral meniscus , because it is firmly
attached to the popliteus muscle and to the ligament
of Wrisberg or of Humphry, follows the lateral femoral
condyle during rotation and therefore is less likely to
be injured.

9. CLASSIFICATION
»Numerous classifications of tears of the menisci have been proposed on the basis of
location or type of tear, etiology, and other factors.
»O’Connor classification:
I. longitudinal tears
II. horizontal tears
III. oblique tears
IV. radial tears
V. variations, which include flap tears, complex tears,
and degenerative meniscal tears.

10. CLASSIFICATION
»Zone classification of meniscus:
o bucket-handle tear : displaced longitudinal tear

11. DIAGNOSIS
»Detailed, careful, systemic history and
physical examination supplemented with
appropriate imaging studies and
arthroscopy.
»History:
●asymptomatic
●Pain
●Giving way
●Locking +/-
» Physical signs
● Effusion
● Joint line tenderness
● Quadriceps wasting
● .Limitation of movements

12. DIAGNOSIS
»DIAGNOSTIC TESTS:
■McMurrays Test
○Principle: To trap the meniscus between the tibia and femur.
Pt needs to be relaxed. One hand on knee joint line. Other hand
holds the foot & ankle.
Flex the knee as far as possible (Hyperflexion) Externally rotate
(Medial Me.) or internally rotate (Lateral Me.) the tibia and then
extend the knee.
○Positive McMurray’s : Clicking or popping felt associated with pain.

13. DIAGNOSIS
»DIAGNOSTIC TESTS:
■Apley’s Grinding test
»Principle: Patient is in prone position
• Knee flexed to 90 degrees
• The leg is rotated from side to side
• Compression force applied
• A painful response signifies a torn or degenerate meniscus.

14. DIAGNOSIS
»DIAGNOSTIC TESTS:
»Thessaly Test
• Standing at 20 degrees of knee flexion on affected limb
• Patient twists with knee external and internal rotation.
• Positive Test: Clicking, pain or discomfort on joint line.

15. DIAGNOSIS
»IMAGING:
»X-RAY
o Anteroposterior, lateral, and intercondylar notch views with
a tangential view of the inferior surface of the patella
should be routine.
○ Ordinary radiographs will not confirm the diagnosis of a
torn meniscus but are essential to exclude
osteocartilaginous loose bodies, osteochondritis
dissecans, and other pathologic processes that can mimic
a torn meniscus.

16. DIAGNOSIS
»IMAGING:
»ARTHROGRAPHY
o Previusly was used in diagnosis of pathologic conditions of
the meniscus.
o With the improvements in CT and MRI scanning, we rarely
use arthrography for knee examination.

17. DIAGNOSIS
»IMAGING:
»MRI
o Most sensitive diagnostic test
o The menisci appear as low-signal structures on all pulse
sequences. They are best studied in the sagittal and
coronal planes.
o On sagittal images, the menisci appear as dark triangles in
the central portion of the joint and assume a “bow tie”
configuration
o MRI has been shown to have 98% accuracy for medial
meniscal tears and 90% for lateral meniscal tears.

18. DIAGNOSIS
»IMAGING:
»MRI
o Meniscal Tear Grading:
I. Grade I - increase in signal, not extending to articular surface
II. Grade II - linear increased density, not extending to articular surface
III. Grade III - signal extending to articular surface

19. DIAGNOSIS
»IMAGING:
»CT-scan
o High-resolution CT has been reported to have a
sensitivity of 96%, specificity of 81%
o It also is useful for delineating synovial cysts and other
soft-tissue tumors around the knee.
Figure 5a: Sagittal SCTa image
demonstrating a small tear of the tibial
surface of the post. horn of the medial
meniscus
Figure 5b: Axial image depicting
location of sagittal slice in Figure 5a

20. ARTHROSCOPY
»Gold standard for diagnosis and treatment
»Thorough inspection of menisci, ligaments
&cartilage is possible
»Full extent ,type, site of tears & degenerative
changes can be seen.

21. NON-OPERATIVE TREATMENT
Indication:
o First line of treatment for degenerative tears
o Acute episode without locking but with acute synovitis
o Incomplete meniscal tear (5mm)
o A small stable peripheral tear (displaced < 3 mm) without any other
injuries.
MANAGEMENT

22. NON-OPERATIVE TREATMENT
»Grion-ankle cylindrical cast -4 x 6 weeks
»Toe-touch partial weight bearing
»Rehabilitative exercise program for 6 weeks
to strengthen quadriceps, hamstrings, gastro-
soleus &hip.

23. OPERATIVE TREATMENT
»Meniscal repair
»Meniscectomy
o Partial
o Subtotal
o complete
»Meniscal Transplantation

24. OPERATIVE TREATMENT
»Meniscal repair
o Depend on the location of the tear, its morphology and patients factors
 Peripheral tear--- Red on Red region
 Also on red on white region
 Size <1-2 cm
 Vertical longitudinal tears are ideal
o young patient shows better outcome
o Can be done Open or Arthroscopically

25. OPERATIVE TREATMENT
»Meniscal repair
o Contraindications:
 Tear>3 cm
 Transverse tear even in periphery
 Flap tear, radial tear, vertical tear with secondary lesions.
 Ligament instability
o SUTURE TECHNIQUES
 Inside-out : Gold standard
 Outside-in
 All inside

26. OPERATIVE TREATMENT
»Meniscal repair
o Meniscal repair associated with ACL injury
 There is 30-40% failure rate .
 Repair Anterior cruciate ligament first followed by
meniscal repair

27. OPERATIVE TREATMENT
»Meniscectomy
o Partial meniscectomy:
 Less articular cartilage degeneration
 Excision of only torn portion of meniscus .
 Treatment of choice in young adults who require vigorous activities.
 Indications:
• Tears >5mm from menisco-synovial junction.
• Flap tears
• Complex and horizontal.
 Advantage
• Short operating time.

28. OPERATIVE TREATMENT
»Meniscectomy
o Subtotal meniscectomy:
 Complex tears of posterior horn
 Anterior horn & portion of mid 1/3 of meniscus is preserved
o Total meniscectomy:
 Indication:
• Meniscus is detached from its periphery.
• Indicated in extensive meniscal tears and degenerative tears

29. OPERATIVE TREATMENT
»Meniscectomy
o FAIRBANK’S CHANGES
 Post meniscectomy change
 Narrowing of joint space
 Flattening and squaring of femoral condyle
 Antero posterior osteophyte formation

30. OPERATIVE TREATMENT
»Meniscal transplantation
o Survival rates better in patients with no degenerative changes.
o Allograft and auto graft replacement
o Quadriceps, patellar tendon & infrapatellar pad of fat are used
as allogenic substitutes for meniscus
o RECENT ADVANCES:
 Bioabsorbable meniscal fixators
 Collagen meniscus implant-from bovine achilles tendon
 Synthetic scaffolds
 Future- gene therapy & Stem cells