Ian Rice MD - PowerPoint Presentation

Slide1

Ian Rice MD

Meniscus InjuriesSlide2

How far we haven’t come

“…It

is, however, a clinical fact that one of the semilunar cartilage, usually the internal one, does occasionally become loosened from its attachments; and, in consequence, this body is liable to be displaced either forwards or backwards, and so to interfere with the proper movements of the knee-

joint…”

1838 - 1907Slide3

Among most common injuries seen in orthopedic practice

61 cases per 100,000 per

year

Arthroscopic partial

menisectomy one of the most common orthopedic proceduresEpidemiologySlide4

Pathoanatomy

Overview

Crescent shaped and have triangular cross section

Fibers have circumferential orientation

Anterior and posterior root attachments prevent extrusionLateral covers 84% of the condylar surface, 12mm wide, 3-5mm thickMedial covers 64%, 10mm wide, 3-5mm thickSlide5

Vascularity

Genicular

arteries

50% vascularized at birth

10-25% in adultsMakes healing very difficult3 vascular zonesRed-redRed-white

White-white

PathoanatomySlide6

Collagen Organization

Circumferential fibers

Radial Fibers

Fine superficial layer around outside

PathoanatomySlide7

Load Sharing

Increases contact area between femur and tibia

Decreases contact stress on articular cartilage

Increases congruity

Provides stabilityAids in lubricationMeniscal functionSlide8

In extension, 50% of the load is absorbed

At 90



flexion, 90% load-sharingBeyond 90

, forces predominate through posterior hornsBiomechanicsSlide9

Meniscal excursion with knee flexion

11.2 mm excursion of lateral meniscus

5.1 mm excursion of medial meniscus

Capsule

Deep MCLCoronary ligament

Meniscal ExcursionSlide10

Complete removal of meniscus results in 2-3X increase in contact stress

Removal of inner 1/3 = 10% reduction in contact area and 65% increase in stress

Increase loss of meniscal tissue = increase contact stress

Medial meniscal root tears have pressures similar to complete

meniscectomy

BiomechanicsSlide11

History

Twisting injury with change in direction in younger patients

Squatting or falling in older patients

Acute tear usually has insidious swellingJoint line location

Mechanical complaintsEvaluationSlide12

Small effusion

Joint Line Tenderness

McMurray

Apley

ThessalyROM generally normalBucket handle blockTight due to effusion

Physical ExamSlide13

McMurraySlide14

McMurraySlide15

Apley’s

Compression TestSlide16

Thessaly TestSlide17

Plain films to assess for bony injury and OA

MRI is the gold standard of diagnosis

ImagingSlide18

Typically seen in younger patients

High association with ACL tears

90% of LVT in MM and 83% in LM are associated with ACL tears

Longitudinal Vertical TearsSlide19
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This is a LVT with central

margination

Most frequent type of displaced tear

Double PCL

Double Anterior HornAbsent Bow

Bucket Handle TearsSlide22
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Involves the free edge and propagates peripherally

Usually degenerative

Older patients

Horizontal TearsSlide24
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Also involve free edge, but path is perpendicular to long axis

Drastically affect ability to resist hoop stresses

Deeper the tear, the more drastic the biomechanical consequences

Radial TearsSlide27

Radial TearsSlide28

Radial TearSlide29

AKA vertical flap tear

Starts as a radial tear

Propagates as a longitudinal

Parrot Beak TearsSlide30

Parrot Beak TearSlide31

Root TearsSlide32

Non-surgical

Stable, longitudinal <10mm with <3-5mm displacement

Degenerative tears with concomitant OA

<3mm radial tears

Stable partial tears

TreatmentSlide33

Indications

Radial

Flap

Horizontal

ComplexWhite-white tears

MeniscectomySlide34

Goal is to debride tear and leave stable rim

Preservation is ideal

80% satisfactory function at 5 yrs

Lateral debridement = faster degeneration

MeniscectomySlide35

Predictors of Positive Result

< 40yo

Normal alignment

Minimal arthritis at initial scope

Single fragment tearMeniscectomySlide36

Relative Contraindications

Advanced OA

Complex tears

Poor tissue quality

ACL deficiency

Surgical RepairSlide37

Open Repair

Rarely used

Numerous studies have proven reduced surgical morbidity with arthroscopic repair

Reserved for peripheral tears in the posterior hornSlide38

Inside-out Repair

Suture passed on either side of tear with needle cannula

Suture is brought out of capsule

A small skin incision is made

Suture is tied down to capsulePosterior Horn RepairsSlide39

Sutures passed through the meniscus from the outside

Eliminates need for larger incision

Generally suited for anterior repair

Studies have shown similar results with both techniques

Outside-In RepairSlide40

All-inside repair devices were

developed to

reduce surgical time,

prevent complications resulting from external approaches, and allow

access to tears of the posterior hornFourth-generation repair devices allow placement of sutures in the meniscus

without the aid of an

external incision

or a suture

fixator

system

All InsideSlide41

Self-adjusting, with

the anchor

located behind

the capsule and with a sliding knot that can be tensioned appropriately by

the surgeonMechanical studies show comparable strength to outside-in sutures

All InsideSlide42
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Outcomes

Success rates for all techniques reported 70-95%

Second-look scopes show lower success rates of 45-91%

Ligamentous laxity decreases success rate to 30-70%

90% success reported in conjunction with ACL repairSlide46

Failure to heal

Stiffness

Articular surface damage

NV structure damage

ComplicationsSlide47

Transplantation

Indications:

Recurrent pain after partial or total debridement

symptomatic with ADLs

<50yoContraindications: MalalignmentLaxityInflammatory arthritisAdvanced OASlide48

Outcomes

Widely varying reports of success (Country differences)

Subjective improvement in

tibiofemoral

painNo clear long-term benefit in preventing OA has been establishedGrafts seem to do better when placed with a bone blockPreserving some peripheral rim helps to avoid extrusionVariety of meniscal scaffold options being investigated in animalsSlide49

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