The document discusses meniscal injuries of the knee. It describes the anatomy and function of the menisci, types of meniscal tears, symptoms and diagnosis of tears. Treatment options include nonsurgical care, partial meniscectomy to remove torn parts, and meniscal repair surgery which is best for peripheral, vertical tears. While removal addresses pain, it increases risk for osteoarthritis long term. The goal of repair is to preserve as much viable meniscal tissue as possible for cartilage protection.

1. Meniscal injury
By
Dr.Mohammed Elbasheir Elhussein

2. Introduction
• The menisci are fibrocartilaginous structures that are semilunar in shape
and wedge-shaped in cross-section.
• Two menisci(medial and lateral) exist between the femoral and tibial
articulation.The femoral articulating meniscal surface is concave,whereas
the tibial articulating surface is convex.These surfaces conform to the
convex and concave opposing chondral surfaces, respectively.
• The conforming articulation provides perfect congruency between
the femoral condyle, meniscus,and tibial plateau, which establishes
the foundation for the biomechanical function of the menisci.

3. Introduction
Meniscal tears can be either
– Traumatic
or
– degenerative.

4. Introduction
• Degenerative tears have
been closely associated
with osteoarthritis.

5. Introduction
• Acute tears are often
related to trauma, most
frequently as a result of
a twisting motion.
• Most common in active
people aged 10–45.

6. Introduction
• Early diagnosis and
treatment of acute meniscal
tears can significantly
affect the short-term
meniscal viability and
subsequent long-term
articular chondral
protection.

7. Anatomy

8. Anatomy

9. Anatomy

10. Anatomy
• Blood supply
– medial inferior genicular artery
– lateral inferior genicular artery

11. AnatomyPopliteal artery

12. Anatomy
ILG artery

13. Anatomy
IMG artery

14. Anatomy
• Innervation
– peripheral two-thirds innervated by Type I and II nerve endings
– posterior horns have highest concentration of mechanoreceptors

15. Composition
 Made of
1. fibroelastic cartilage
2. Collagen
3. Fibers

16. Stability
• medial meniscus
– posterior horn of medial
meniscus is the
main secondary
stabilizer to anterior
translation
• lateral meniscus
– is less stabilizing and
has 2X the excursion of
the medial meniscus

17. Function
• Force transmission
1. increasing
congruency
2. shock-absorption
3. transmits 50%
weight-bearing load
in extension, 85% in
flexion

18. Meniscal Pathology
• Epidemiology
– most common indication
for knee surgery
– higher risk in ACL
deficient knees
• Location
– medial tears
– lateral tears
• more common in
acute ACL tears

19. Injury & Healing potential
• Tears in peripheral 25% red zone
– can heal via fibrocartilage scar formation
• Tears of central 75%
– have limited or no intrinsic healing ability

20. Classification
• Descriptive classification
– location
• red zone (outer third, vascularized)
• red-white zone (middle third)
• white zone (inner third, avascular)
– size
– pattern
1. vertical/longitudinal
2. bucket handle
3. oblique/flap/parrot beak
4. radial
5. horizontal
6. complex

21. • The repairability of a meniscus depends on a number of factors these
include:
1. Age/strength
2. Activity level
3. Tear pattern
4. Chronicity of the tear
5. Associated injuries (anterior cruciate ligament injury)
6. Healing potential

22. Normal meniscus on MRI (left) and during arthroscopy (right)

23. Torn meniscus on MRI (left) and during arthroscopy (right)

27. Presentation
Symptoms
1. Pain, often along the joint line of the knee .
2. Swelling (“effusion” in the joint).
3. Inability to fully extend or flex the knee without discomfort .
4. Locking or catching of the knee.
5. Weakness of the leg.

28. Presentation
 Signs
• Joint line tenderness
• Effusion
• Positive McMurray's test

29. Imaging
• X-ray:
– Images (normally during weightbearing)
to rule out other conditions .

30. Imaging
• MRI
– Indications
• MRI is most sensitive diagnostic test, but also has a high false
positive rate

31. Treatment
 Non-operative
Rest, NSAIDS, rehabilitation
• indications
– indicated as first line of treatment for degenerative tears

32. Treatment
 Operative
– The definitive treatment of meniscal tears involves either repair or
excision of the pathologic tissue.
– Surgery.

33. Treatment
The indications for arthroscopy include
(1) symptoms of meniscal injury
(2) positive physical findings
(3) failure to respond to nonsurgical
treatment
(4) ruling out other causes of knee pain

34. Treatment
– Partial meniscectomy
• indications
– tears not amenable to repair (complex, degenerative, radial tear
patterns)
• outcomes
– >80% satisfactory function at minimum follow-up
– 50% radiographic changes (osteophytes, flattening, joint space
narrowing)

35. Treatment
– Meniscal repair
• indications
– best candidate for repair is a tear with the following
characteristics
» peripheral in the red zone (vascularized region)
» rim width correlates with the ability of a meniscal repair to
heal (lower rim width has better blood supply)
» vertical and longitudinal tear
» 1-4 cm in length
» acute repair combined with ACL reconstruction

36. Treatment
• outcomes
– 70-95% successful
– highest success when done with concomitant ACL
reconstruction
– poor results with untreated ACL-deficiency (30%)

37. Treatment
– Total meniscectomy
– of historical interest only
• outcomes
– 20% have significant arthritic lesions and 70% have
radiographic changes three years after surgery
– 100% have arthrosis at 20 years
– severity of degenerative changes is proportional to % of the
meniscus that was removed

38. Treatment
• Techniques of Partial
Meniscectomy
– approach
• standard arthroscopic
approach
– technique
• minimize resection
• do not use thermal (heat
probes)
– postoperative
• early active range of motion
• prolonged immobilization
(10 weeks) is detrimental to
healing in a dog model
Typical locations of arthroscopic surgery
incisions in a knee joint following surgery for a
tear in the meniscus

39. Treatment
• Meniscal repair
– approach
1-inside-out technique
– considered gold standard
– medial approach to capsule
– lateral approach to capsule
2-all-inside technique (suture devices with plastic or
bioabsorbable anchors)
– most common
– many complications (device breakage, iatrogenic chondral
injury)
3-outside-in repair
– useful for anterior horn tears
– open repair
– uncommon except in trauma, knee dislocations

41. Treatment

42. Treatment
• Side effects of meniscectomy include:
1. The knee loses its ability to transmit and distribute load and absorb
mechanical shock.
2. Persistent and significant swelling and stiffness in the knee.
3. The knee may be not fully mobile, there may be the sensation of
knee locking or buckling in the knee.
4. The full knee may be in full motion after tear of meniscus

43. Treatment
• Meniscal Transplantation
– technique
• bone to bone healing
with plugs at each horn
or a bridge between
horns
• peripheral vertical
mattress sutures
• correct sizing of the
allograft is
essential (commonly
based on radiographs,
within 5-10% error
tolerated)

44. Prevention
 There are three major ways of
preventing a meniscus tear.
1. wearing the correct footwear.
2. Strengthening and stretching the
major leg muscles.
3. learning proper technique for the
movement.
Proper parallel squat form to improve knee
stability

45. Complications
 Saphenous neuropathy (7%)
 Arthrofibrosis (6%)
 Sterile effusion (2%)
 Peroneal neuropathy (1%)
 Superficial infection (1%)
 Deep infection (1%)