Meniscal Injury

Meniscal InjuryDr Manoj DasDepartment of orthopaedicsInstitute Of Medicine,TUTH, Nepal

IntroductionMeniscal tears are the most common soft tissue injury of the knee joint and are responsible for 750,000 arthroscopies per year in the US.

Traumatic meniscal tears most commonly occur in young, active people during twisting sports such as football and basketball.

Degenerative tears commonly occur in patients with osteoarthritis, although the exact incidence and prevalence are not known.

AnatomyMenisci are two fibrocartilagenous crescents

Each menisci has:- - Two ends - Two borders - Two surfaces

MEDIAL MENISCUS C shaped structure forming 3/5 of the ring

anterior horn attached to the tibia anterior to the intercondylar eminence to the anterior cruciate ligament

posterior horn anchored immediately in front of the attachment of posterior cruciate ligament posterior to the intercondylar eminence.

MEDIAL MENISCUS...peripheral border attached to the medial capsule and through the coronary ligament to the upper border of tibia

Most of the weight borne on the posterior portion of the meniscus

LATERAL MENISCUScircular forming 4/5 the of the ring with symmetrical anterior and posterior horn

anterior horn attached to the tibia in front of the intercondylar eminence

posterior horn attached to posterior aspect of the intercondylar eminence in front of posterior attachment of the medial meniscus

Lateral MeniscusThe posterior horn receives anchorage to the femur via the ligament of Wrisberg and ligament of Humphrey and from fascia covering the popliteus muscle

The tendon of the popliteus separates the posteriolateral periphery of the lateral meniscus from the joint capsule and fibular collateral ligament

Microscopycomposed of dense, tightly woven Type-I collagen with some Type-III) and elastin to create a compressible structure

major orientation of collagen fibres in the menisci is circumferential; radial and perforating are also present.

circumferential fibres function in hoops to accept stress without gross deformation or extrusion of the joint.

Radial fibres stabilizes the meniscus, preventing circumferential splits as wells resists excessive compressive loads.

Blood SupplyThe menisci of the knee develop at eight weeks of gestation as a collection of fibroblasts.

At birth, the menisci are vascularised through their substance; with ageing through early adulthood, there is eventual peripheralization of the vascularity to the outer third of meniscus

Blood supplyVascular supply is from the lateral and medial geniculate vessels ( inferior and superior).

The branches from the vessels give rise to perimeniscal capillary plexus within the Synovial and capsular tissue and supply the peripheral border of meniscus.

The depth of the vascular penetration is 10% to 30% of the width of the medial meniscus and 0% to 25% of width of lateral meniscus

Miller, Warner and Harner classification

a. Red-Red-fully within vascular area

b. Red-White-at the border of vascular area

c. White-White within the avascular area

Functions1.Load distribution-Increase contact surfacearea and reduce contact stresses

Medial menisectomy decreases contact area by 50-70% and increase contact stress by 100%

Lateral menisectomy decrease contact by 40-50% and increase contact stress by 200- 300%

Because of convex shape of lateral 12

Functions2. Acts as joint filler compensating for the gross incongruity between tibial and femoral articulating surfaces

3. Prevent capsular and Synovial impingement during flexion-extension movements

4. Joint lubrication help to distribute Synovial fluid through the joint and aiding the nutrition of articular cartilage.

Functions5. Contribute to stability in all planes but are important rotatory stabilizers.

6. Shock absorption; the larger area provided by the meniscus reduces the average contact stress between the bones.

Mechanism of injuryTurning or twisting of the loaded joint may trap the menisci between the joint and tear the meniscus

MEDIAL MENISCUS

Internal rotation of femur over tibia with knee in flexion forces the posterior segment of medial meniscus towards the centre of the joint.

The posterior horn may be trapped in this position by sudden extension of knee

Mechanism of injuryLATERAL MENISCUS

Vigorous external rotation of femur while the knee is flexed displace the posterior half of the lateral meniscus toward the centre of the joint

During sudden extension of the knee, an anterioposterior distracting force tends to straighten the cartilage and imposes a strain on the medial concave rim, which tears transversely and obliquely.

Mechanism of injuryWhich meniscus is commonly injured???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

In addition, when the tibia is rotated internally and the knee flexed, the popliteus muscle, by way of the arcuate ligament, draws the posterior segment of the lateral meniscus backward, thereby preventing the meniscus from being caught between the condyle of the femur and the plateau of the tibia.

ClassificationOConnor classificationBased on the type of tear found at surgery

a. Longitudinal tear b. Horizontal c. Oblique d. Radial tears e. Variations which include flap tears, complex tears and degenerative tears.

Clinical FeaturesHistory

H/O twisting injury

Pain

LOCKING -common in longitudnal tear( bucket-handle tear)

Sensation of giving away: - feeling of subluxtion or the joint jumping out of place usually on rotary movement

Clinical FeaturesEffusion: - Indicates irritation of synovium

- limited specific diagnostic value

- Sudden onset after an injury denotes a hemarthrosis

- Repeated displacement of torn portion of a meniscus produce chronic synovitis with an effusion of a nonbloody nature.

Clinical FeaturesPhysical Examination Tendernessmost important physical finding

- along medial or lateral joint line or over periphery of meniscus

- most commonly located posteromedially or posterolaterally

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Clinical Features

Atrophy - recurring disability of the knee

Clicks, snaps, or catches:- If the noises localized to the joint line, the meniscus most likely contains a tear

McMurray testMcMurray first described his test in 1942 and published in paper entitled Semilunar Cartilage

APLEYS GRINDING TEST

SQUAT TESTConsists of several repetitions of full squat with the feet and leg alternately rotated as the squat is performed

Pain in the internally rotated position suggests injury to the lateral meniscus

Pain in the external rotation suggests injury to the medial meniscus

Thessaly testclinician holds the patient's outstretched hands for support, while the patient stands flat-footed

Knee flexed to 20 degrees and rotates their body and knee three times, internally and externally

The test is positive if symptoms are reproduced on rotation

STEIMANNS TESTPosition: Sitting

Patient sits with the leg bent over the table about 90 degree

To assess the M.M. tear, the foot is externally rotated which produces some discomfort.

Modified Helfet Test Position-sitting on the edge of a table with knee flexed to 90, then patient extends their knee

Normal- tibial tuberosity in line with the midline of the patella in full flexion

During extension, the tibia rotates and the tibial tubercle moves into line with the lateral border of the patella (Qangle)

Failure of the tibia to rotate during extension indicates a meniscal lesion or cruciate ligament pathology.

InvestigationsRadiological Examination: - AP, Lateral and intercondylar notch view with a tangential view of inferior surface of patella

-It is essential to exclude loose bodies, osteochondritis and other derangements of the knee

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ARTHROGRAPHYAccuracy in diagnosis Medial menisci-95% Lateral menisci-85%

With the improvement in CT scan and MRI arthrography is rarely used.

MRI - great value in the diagnostic evaluation of meniscal tears. -The accuracy of meniscal tears 98% for medial meniscus and 90% for lateral meniscus ( Campbells operative Orthopaedics 12th Edi)

ARTHROSCOPYIs the diagnostic procedure to detect the meniscal injuries.

accuracy of diagnostic arthroscopy is 97% ( campbells operative orthopaedics 12th Edi)

Non Operative Treatment Indications - Incomplete meniscal tear or small ( < 3mm) stable peripheral tear with no other pathological conditions.

- Tears associated with ligamentous instabilities can be treated non-surgically if patient defers ligament reconstruction or if reconstruction is contraindicated.

Non Operative TreatmentContraindications 1. Chronic tears with superimposed acute injury

2. In a locked knee with bucket handle tear of meniscus.

Non Operative TreatmentManagement An acute episode without locking but with an acute synovitis with effusion requires

immediate abstinence from weight bearing

rest with knee flexion

application of ice packs

compression dressing

Non Operative TreatmentManagement - cylindrical cast or knee immobilizer for 4-6 wks

-Crutch walking with touch-down weight bearing permitted when the patient gains active control of the extremity in the cast

-progressive isometric exercise in cast

- At 4 to 6 weeks, the immobilization discontinued, and the rehabilitative exercise program for the muscles around the hip and knee intensified.

Non Operative Treatment

Most important aspect of nonoperative treatment:-

- Restoration of the power of the muscles around the injured knee to a level comparable with that of the opposite knee

SURGICAL TREATMENTMeniscectomy By arthrotomy By arthroscopyMeniscal repair By arthrotomy By arthroscopyMeniscal transplantation With autografts, allograft, prosthetic scaffolds.

Repair Vs Resection

EXCISION OF MENISCIPartial meniscectomy: - Only the loose, unstable fragments excised

-stable and balanced peripheral rim preserved

; e.g. Displaceable inner fragment in bucket handle tear , the flap in flap tears or flap in oblique tears40

EXCISION OF MENISCI...ii)) Subtotal meniscectomy: - requires excision of portion of peripheral rim of meniscus

Most of the anterior horn and a portion of middle 3 rd of the meniscus are not resected.

iii) Total meniscectomy: Done when meniscus is detached from its peripheral menisco-synovial attachment and intrameniscal damage and tears are extensive.

Open menisectomyEXCISION OF MEDIAL MENISCUSUsing single anteromedial incision:

Open menisectomyEXCISION OF MEDIAL MENISCUS...Using two incision: HENDERSON -An additional posteromedial incision

-Permits easier and complete detachment of posterior horn

- Posterior incision is made 5 cm parallel and slightly posterior to the tibial collateral ligament.

Open menisectomyEXCISION OF THE LATERAL MENISCUS

Bruser lateral approach to knee. A, Skin incision (see text). B, Broken line indicates proposed incision in iliotibial band,whose fibers, when knee is fully flexed, are parallel with skin incision. C, Knee has been extended slightly, and lateral meniscus is beingexcised. D, Lateral meniscus has been excised, and synovium is being closed. (Modified from Bruser DM: A direct lateral approach to thelateral compartment of the knee joint,

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Open menisectomyAFTER TREATMENT compression bandage

Knee immobilized in extension with posterior plaster splint or with a knee immobilizer for 5-7 days

Quadriceps exercises

When the good muscular control is achieved, patient allowed to walk with crutches and with partial weight bearing

ARTHROSCOPIC SURGERY OF MENISCUSArthroscopic MeniscectomyGeneral principles

Partial meniscectomy is always prefarable to subtotal or total meniscectomy

To determine accurately the type of meniscectomy required, the meniscal lesion must be carefully probed and classified

objective is to remove the torn, mobile meniscal fragment and contour the peripheral rim, leaving a balanced, stable rim of meniscal tissue

4. Excision of the pathological tissue can be done either with en bloc resection of the mobile fragment or by morcellization of the fragments and subsequent removal

Arthroscopic Resection of Bucket handle tear

Two-portal technique for bucket-handle tears of lateral meniscus. A, 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. 48

Arthroscopic Removal of 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.

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Arthroscopic Removal of horizontal, Oblique, Radial, and complex tearIn evaluating horizontal, oblique, radial, and complex tears, it is imperative to evaluate and remove only damaged tissue, while maintaining functional, healthy meniscal tissue

Balancing meniscal resection. A, With radial tear. B, With longitudinal tear. C, With flap tear.

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COMPLICATIONS AFTER MENISCECTOMYPost operative haemarthrosis.Chronic synovitis.Synovial fistulae.Painful neuromas of the branches of the infrapatellar portion of saphanous nerve. Thrombophlebitis Postoperative infection Reflex sympathetic dystrophy. Retained meniscal fragment.

Late changes: Degenerative changes within the joint. Fairbank described three changes i) Narrowing of joint space

ii) Flattening of the peripheral half of the articular surface of condyle

iii) Development of anteroposterior ridge that projected distally from the margin of femoral condyle.

Arthroscopic Repair of torn MenisciCRITERIA Location : within 3 mm of periphery

Stability : partial thickness Full thickness- oblique and vertical tears less than 10 mm with inability to displace the central portion with a probe greater than 3mm

Arthroscopic Repair of torn MenisciCRITERIATear pattern : peripheral , vertical and longitudinal tears repaired. Bucket handle, flap, degenerative, complex, radial tears are excised

Patient age : less than 50 yrs

Chronicity : Acute tears less than 8 weeks old have better healing potential

Ligament stability : ACL deficiency must also be corrected simultaneously to prevent instability.

Arthroscopic Repair of torn Menisci

Arthroscopic Repair of torn Menisci

Recent AdvancesEnhancement of meniscal healing

Arthroscopic repair of torn meniscus using fibrin clot

Meniscal replacement with - allograft meniscus - autograft fascial material - synthetic meniscus

Biologic tissue scaffolds

Enhancement of meniscal healingVascular access channels:

creating access of peripheral vessels to avascular region, by a channel (trephination) allows avascular portion of the meniscus to heal throught the proliferation of the fibrous scar.

Synovial abrasion : encourages vascular extension to avascular regions via., formation of vascular synovial pannus.

ARTHROSCOPIC REPAIR USING FIBRIN CLOTActs as a chemotactic and mitogenic stimulus for reparative cells and provide scaffolding for reparative process

Arnocky and Warren reported the injection of exogenous fibrin clot obtained from the patients coagulated blood to improve meniscal healing.

Exogenous fibrin clot is injected with a blunt needle in the stem of the tear.

MENISCAL REPLACEMENTAIM -To prevent degenerative changes, in the post meniscectomy patient.

IndicationAge < 40 yr who had previous meniscectonySymptoms localized to tibiofemoral compartment No advanced arthrosis

ContraindicationsMalalignment and instability in the patient who does not want to wish to have correctedChondromalacia > grade III Previous joint infection

MENISCAL REPLACEMENT

A and B, Graft preparation. C, Insertion of graft, including reduction suture. D, Appearance on completion

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Conclusion.Meniscal tear management tree

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