4. Superior view of tibial condyles after
removal of femur
MENISCI
MM
LM
5. • During flexion-extension movts- Prevent capsular & synovial
impingement
• Joint lubrication fn, helping to distribute synovial fluid throughout
the joint & aiding nutrition of articular cartilage
• Contribute to stability in all planes but are especially important rotary
stabilizers
11. • Miller, Warner, and Harner categorized meniscal tears according to
their location in three zones of vascularity
12. MENISCAL TEAR
• Mech - by a rotational force incurred while the joint is partially flexed.
• Medial meniscus, being far less mobile on the tibia, can become
impaled b/n the condyles & injury can result.
• M/C location for injury - posterior horn of meniscus
• M/C type of injury - longitudinal tears.
• Length, depth & position of tear depends on posterior horn position
in relation to femoral & tibial condyles at the T.O.I.
13. Classification
- based on the type of tear found at surgery.
(1) longitudinal tears (M/C)
(2) transverse and oblique tears,
(3) a combination of longitudinal and transverse tears,
(4) tears associated with cystic menisci, and
(5) tears associated with discoid menisci.
14. O’Connor classification
(1) longitudinal tears;
(2) horizontal tears;
(3) oblique tears;
(4) radial tears and
(5) variations, which include
flap tears, complex tears, and degenerative meniscal tears.
19. • Locking usually occurs with longitudinal tears and is much more
common with bucket-handle tears, usually of the medial meniscus.
• A sensation of “giving way” or snaps, clicks, catches in the knee may
be described
Or
• the history may be even more indefinite, with recurrent episodes of
pain & mild effusion in the knee and tenderness in the anterior joint
space after excessive activity.
30. NON OP -
• An incomplete meniscal tear or a small (5 mm) stable peripheral tear
with no other pathologic condition, such as a torn anterior cruciate
ligament, can be treated nonoperatively with predictably good
results.
• Many incomplete tears will not progress to complete tears if the knee
is stable.
• Small stable peripheral tears have been observed to heal after 3 to 6
weeks of protection.
33. MENISCAL AUTOGRAFTS & ALLOGRAFTS
• ALLOGRAFTS are preserved in one of four ways:
• fresh,
• fresh frozen (deepfreezing),
• freeze-dried (lyophilization), &
• cryopreserved.
• Of these four methods, only cryopreservation has been shown to
reproducibly maintain a substantially viable cell population (10% to
40%)
• Ideal candidate is a patient younger than 40 years with an absent or
nonfunctioning meniscus
35. • Partial meniscectomy is always preferable to subtotal or total
meniscectomy.
• Leaving an intact, balanced, peripheral rim of meniscus aids in the
stability of the joint and protects the articular surfaces by its load-
bearing functions.
46. All-inside repair techniques have been simplified by the development
of suture fixators, which have pre-tied knots.
These devices provide secure fixation and decrease the potential for
chondral injury present in earlier devices.
joint filler,b/n femoral & tibial articulating surfaces
.mm- c shaped, larger diameter, thinner periphery, Post horn wider than ant horn
Lm- more circular, smal dia, more mobile; more mobile than mm Post horn receive anchorage to femur by lig of wrisberg & humbrey[AMFL] & from fascia covering popliteus, arcuate complex at post.lat corner of knee
mmis firmly attached to tibial collateral ligament. In contrast, the lm is not attached
to the FCL
collagen fibers arranged in a pattern providing great elasticity and ability to withstand compression.
TENSILE STRENGTH
Cross section of meniscus showing horizontal cleavage split.
Perforating
compression of the menisci by tibia & femur generates outward forces that push the menisci out from between the bones. The circumferential tension in the menisci counteracts this outward or radial force. These hoop forces are transmitted to the tibia through the strong anterior and posterior attachments of the menisci. Hoop tension is lost when a single radial cut or tear extends to the capsular margin;
vascular supply to the medial and lateral menisci originates predominantly from lateral & medial geniculate vessels (both inferior and superior). Branches from these vessels give rise to a perimeniscal capillary plexus within the synovial and capsular tissue
Branching radial vessels from perimeniscal capillary plexus (PCP) can be seen penetrating peripheral border of medial meniscus. F, Femur; T, tibia. Three zones of meniscal vascularity are shown: 1 RR, red-red is fully within vascular area; 2 RW, red-white is at border of vascular area; and 3 WW, white-white is within avascular area.
Good healing in RR zone
tears of the medial meniscus in were approximately five to seven times more common than LM
Meniscial cyst are freq. asso. with tears & are 9 times more common on lateral than on medial side.
: incomplete radial tear part of width of meniscus (A);
complete radial tear extends to periphery (B); and
incomplete tear extending posteriorly or anteriorly is called “parrot beak” tear (C)
f posterior oblique (A) and anterior oblique (B) tears.
). Most anterior zone of medial meniscus is labeled C, whereas most anterior zone of lateral meniscus is labeled D.
0 is meniscosynovial junction; I is outer third, II is middle third, and III is inner third of each meniscus.
Classification of meniscal root tears based on tear morphology: partial stable root tear (type 1), complete radial tear within 9 mm from the bony root attachment (type 2), bucket-handle tear with complete root detachment (type 3), complex oblique or longitudinal tear with complete root detachment (type 4), and bony avulsion fracture of the root attachment (type 5)
Knee – full extension , femur slightly rotates on tibia to lock the knee jt in place
Popliteus –key to unlocking knee as it begins knee flexion by laterally rotating femur on tibia
supine MM ER + VALGUS,,LM – IR + VARUS
knee acutely & forcibly flexed
medial meniscus - palpating posteromedial margin of jt one hand while grasping the foot with other hand.
Keeping knee completely flexed, leg is ERknee is slowly extended.
As the femur passes over a tear in the meniscus, a click may be heard or felt.
A click produced by the McMurray test usually is caused by a posterior peripheral tear of the meniscus and occurs between complete flexion of the knee and 90 degrees. Popping, which occurs with greater degrees of extension when it is definitely localized to the joint line, suggests a tear of the middle and anterior portions of the meniscus. The position of the knee when the click occurs thus may help locate the lesion.
With the patient prone, the knee is flexed to 90 degrees and the anterior thigh is fixed against the examining table. The foot and leg are then pulled upward to distract the joint and rotated to place rotational strain on the ligaments (Fig. 45-40A); when ligaments have been torn, this part of the test usually is painful. Next, with the knee in the same position, the foot and leg are pressed downward and rotated as the joint is slowly flexed and extended (Fig. 45-40B); when a meniscus has been torn, popping and pain localized to the joint line may be noted
Examiner – holds pt outstretched hands while pt stands flatfooted on floor. Pt rotates knee & body, internally & externally, 3 times with knee in slight flexion (20 degrees). The same procedure is carried out with the knee flexed 20 degrees
Compared with arthroscopy, MRI has been shown to have 98% accuracy for medial meniscal tears and 90% for lateral meniscal tears. Others have reported that MRI had a positive predictive value of 75%, a negative predictive value of 90%, a sensitivity of 83%, and a specificity of 84% for pathological changes in the menisci.
knee immobilizer worn for 4 to 6 weeks- a progressive isometric exercise program- m/s around Knee & hip
At 4 to 6 weeks, the immobilization is discontinued and the rehabilitative exercise program for the muscles around the hip and knee is intensified
Systematically examine knee arthroscopically to rule out pathologic conditions KF – 60
vertical posteromedial arthrotomy incision from medial femoral epicondylar distally towards semimembranosus tendon in line with the fibers of posterior oblique ligament.
retract the posterior capsul
Debride tear edges
■ Place interrupted sutures of Mersilene or other nonabsorbable surgical suture material every 3 to 4 mm. Beginning outside the posterior capsule, pass the sutures through the capsule, then vertically from inferior to superior through the meniscus, and then back out through the capsule, but do not tie them
posterior horn of the lateral meniscus is exposed through a posterolateral capsular incision above the popliteal tendon, coursing of the popliteal tendon through a hiatus in the periphery of the lateral meniscus adds to the difficulty
. skeletally mature but too young for total knee arthroplasty and have significant knee pain and limited function. All other options for medical management of pain, including a thorough trial of conservative therapy and bracing techniques, should be exhausted. The cause of meniscal damage must be mechanical, not degenerative,
Contraindications include knee instability
depending on the amount of meniscal tissue to be removed
partial meniscectomy (A); subtotal meniscectomy (B); and total meniscectomy (C).
PM- only the loose, unstable meniscal fragments are excised
ST- excision of a portion of the peripheral rim of the meniscus. This is most commonly required in complex or degenerative tears of the posterior horn of either meniscus.
Displaced bucket-handle tear of lateral meniscus probed. B, After reduction of displaced bucket-handle tear, posterior attachment is partially released with scissors. C, Anterior attachment is released with scissors. D, Tenuous remaining posterior attachment is avulsed with grasper and extracted
Technique for longitudinal incomplete intrameniscal tears. A, Probing longitudinal intrameniscal incomplete inferior surface tear. B, Fragment is removed bit by bit with basket forceps. C, Rim is smoothed and contoured with motorized trimmer
. A, With radial tear. B, With longitudinal tear. C, With flap tear.
Radial tears can be divided into partial and complete. A partial-depth tear of the meniscus is treated with saucerization, balancing, and contouring of the edges
TREATMENT OF PARTIAL DEPTH MENISCAL TEARS
Discoid meniscus is an uncommon meniscal anomaly that occurs more frequently l
Type I • Complete Type II • Incomplete
subtotal meniscectomy or a so-called saucerization of the mobile fragment. Type III • Wrisberg (lack of posterior meniscotibial attachment to tibia lacks an adequate posterior tibial attachment, the treatment generally is total meniscectomy, either open or arthroscopic.
Anterior portion of discoid lateral meniscus is removed with rotary basket forceps. B, Further contouring of anterior rim with 90-degree rotary basket forceps. C, Posterior discoid fragment is removed with basket forceps.
T2- associated oblique tear (small white arrow) in the body of the lateral meniscus.
Cysts of LM-3 to 10 time cmon than mm
Cyst can occur following trauma or degenerative c hanges
ARTHROSCOPIC PARTIAL MENISCECTOMY AND DECOMPRESSION OF MENISCAL CYST
A and B, Excision of tears associated with meniscal cysts (see text). C, Decompression of meniscal cyst with basketpunch forceps.
Inside out - Pass the needle through the cannula to enter the meni
