knee disorders.ppt

7/27/2019 Knee disorders.ppt

1/63


2/63

Definition:-The knee joint is largest joint and mostcomplex joint of the body . Actuallyconsisting of three joints within a singlesynovial cavity.1-laterally is a tibiofemoral joint (modified hinge

joint)

2-medialy too3-an intermediate patellofemoral joint betweenpatella and patellar surface of femur (planar

joint)


3/63


4/63

1- articular capsule:- not complete, the ligamentoussheath surrounding the joint consist mostly ofmuscle, tendon and their expansions.2- medial and lateral patellar retinacula: fused

tendons of insertion of the quadriceps femorismuscle and the fascia lata (deep fascia of thigh) thatstrength the anterior surface.3- patellar ligament.

4- oblique popliteal ligament.5- medial collateral ligament.6- lateral collateral ligament.


5/63


6/63


7/63

7- intracapsular ligament :A. anterior cruciate ligament (ACL)

Extend posteriorly and laterally from a point anterior to theintercondylar area of the tibia to the posterior part of medialsurface of the lateral condyle of the femur. The ACL limitshyperextension of the knee and prevent the anterior sliding ofthe tibia on the femur. This ligament is stretched or torn inabout 70% of all serious knee injuries.

B. Posterior cruciate liagment (PCL)

Extend anteriorly and medially from a depression on the posteriorintercondylar area of the tibia, and lateral meniscus to theanterior part of the lateral surface of the medial condyle of thefemur. The PCL prevent the posterior sliding of the tibia on

the femur, especially when the knee is flexed. This is veryimportant when walking down stairs or a steep incline.


8/63


9/63


10/63

8- articular discs (menisci):two fibrocartilge discs between the tibia & femural

condyles.A. Medial meniscus. Semicircular piece of

fibrocartilage (C-shaped).B. Lateral meniscus. Nearly circular piece of

fibrocartilage (approaches an incomplete O inshape).The medial and the lateral meniscus are

connected to each other by the transversaligament and to the margins of tha head of thetibia by coronary ligaments.


11/63


12/63


13/63

The meniscus is a half moon shaped piece ofcartilage that lies between the bearing jointsurfaces of the femur and the tibia.

Roles of Menisci:

*Increasing stability of knee.

*Control rolling and gliding actions of the knee.

*


14/63


15/63

*Common among young active adults.

*Longitudinal split because of the big force grinding itbetween the femur and the tibia, because of the bearing-weight nature of the knee joint.

*Common in Football players: flexion of knee joint inaddition to twisting.

*Little force is needed in middle aged, because fibrosis

restricts mobility of meniscus.more prone to injury because of itsMedial Menisci:*

restricted anatomy due to attachment to the joint capsulemake it less mobile.


16/63

Classification according

to

Mechanism ( traumaticVs degenerative)

Pattern of tear ( bucket

handle Vs horizontal.

).


17/63

Patterns of tears:

Handle Tears:-*Bucket

The split is vertical, along the circumferenceof the meniscus

leaving anterior and posterior segments

attached loosely.

Sometimes the torn part displaces towardsthe center, causing locking (extension

block).


18/63

Horizontal tears:*Usually degenerative in origin or due to repetitive minortrauma, or with association with meniscal cysts.

*Generally speaking, most of the meniscus is avascular,except the outer third-from capsule-, due to this spontaneousrepair doesnt occur.

The loose part act as a mechanical irritant causing recurrentsynovial effusion, and in severe cases secondaryosteoarthritis.


19/63


20/63

Clinical Features:

Severe Pain preventing further activity.

Swelling appears some hours later or even the following day.

Knee is locked in partial flexion

*With rest, pain and swelling may subside, may recur aftertwisting or strains followed again by pain and swelling.

In ptn >40yrs the main complaint is recurrent giving way or

locking


21/63


22/63

ImagingX-ray Normal

MRI most useful may reveal tears missed by arthroscopy

: Diagnostic and therapeutic.Arthroscopy

You have to be certain that the lesion you can see is the onecausing the patients symptoms.

Treatment

Most meniscal tears do not heal without intervention. If conservative treatmentdoes not allow the patient to resume desired activities, occupation, or sport,surgical treatment is considered. Surgical treatment of symptomatic meniscal

because untreated tears may increase in size andtears is recommended

may abrade articular cartilage, resulting in arthritis.


23/63

Treatment

Conservative treatment of meniscal injuries

begins with RICE (Rest, Ice, Compression, and

Elevation).Arthroscopy is the preferred method

peripheral tears surgery

The displaced portion should be excised

Postoperative physiotherapy


24/63


25/63


26/63


27/63

Anatomy of patellaSoft tissue elements affectingthe patella are the stabilizingcapsular and ligamentousstructures within which thepatella lies. Some ligaments ofthe knee are continuous withthe fibrous capsule surroundingthe patella.

When injuries occur, all

structures are simultaneouslyaffected. These ligaments holdthe patella in place during staticand dynamic phases.


28/63

The knee is normally in slight valgus sothere is a natural tendency for the patellato pulled to the lateral side when thequadriceps muscle is contracted

Traumatic dislocation is due to suddensever contraction of the quadricepsmuscle while the knee is stretched invalgus and external rotation.

The patella dislocates laterally and themedial retinacular fibers may be torn

15-20. % of patient with patellardislocation will have recurrent episodes.

It may develop without initial trauma


29/63

The predisposing factors are :1- generalized ligamentous laxity .2- under development of lateral femoral

condyle and flattening of the intercondylergroove.

3- maldevelopment of the patella;too high orto small .

4- valgus deformity of the knee.5- primary muscle defect.


30/63

Females > males . Often bilateral c/o:-acute pain :tearing sensation- knee is stuck in flexion and the patient

may fall. Often the patella is repositionedspontaneouslly

- if the patella remain unreducedMedial mass because the

uncovered medial femoral condoylestand out prominently- NOT THEPATELLA-.

no active or passive movement ispossible

On exam :- Tenderness on the medial side of the joint.- Swelling .- Aspiration may reveled a blood stained

effusion .- positive Apprehension test.


31/63

X-ray (includes

anteroposterior, true lateral,and axial or sunrise views (

CT scanMRI


32/63

Apprehension sign. The knee is placed at 30

flexion, and lateral pressure is applied. Medial

instability results in apprehension by thepatient.

lateral patellar

dislocation (arrows)


33/63


34/63

Complications :-Repeated dislocation damage the contiguous surface of

patella and femoral condyle which lead to further dislocation-later Secondary OA.Rx:

If still dislocated :PUSH IT BACK ( gently) + cylinder plaster or splint is appliedfor 2-3 weeks

+ quadriceps strengthening exercise for 3 months.In children :The patellar mechanism tends to stabilize as the child grows

but 15% of these children will suffer from repeated attackswhich will be an indication for surgery .

Role of surgery in recurrent patellar dislocation :1- to repair or strengthen the medial patellofemoral ligament .2- to realign the extensor mechanism.


35/63


36/63

Osteoarthritis is a chronic joint disorder inwhich there is progressive softening anddisintegration of articular cartilage

accompanied by new growth of cartilageand bone at the joint margins (osteophytes) and capsular fibrosis.

It is defined as primary when no cause is

obvious and secondary when it follows ademonstrable abnormality.


37/63

OA is the most common joint disease of humans.Among the elderly, knee OA is the leading causeof chronic disability in developed countries.

Risk factors:1- age .2- Racial difference.3- 2ndy cause e.g hx of trauma .4- obesity.

5- family Hx.


38/63

The knee is the commenest site for OA

Predisposing factor:

1. Injury to articular surface

2. Torn meniscus3. Ligamentus instability

4. Pre-existing deformity of the knee.

In many cases no obvious cause can be found and

here the condition is usually bilateral and ass.w/ heberdens nodes


39/63

A. Trauma1. Acute2. Chronic (occupational, sports)B. Congenital or

developmental1. Localized diseases: Legg-Calve-

Perthes, congenital hip dislocation,

slipped epiphysis2. Mechanical factors: unequal lowerextremity length, valgus/varusdeformity, hypermobility syndromes

3. Bone dysplasias: epiphysealdysplasia, spondyloepiphysealdysplasia, osteonychondystrophy

C. Metabolic1. Ochronosis (alkaptonuria)2. Hemochromatosis3. Wilson's disease4. Gaucher's disease

D. Endocrine

1. Acromegaly2. Hyperparathyroidism

3. Diabetes mellitus

4. Obesity

5. Hypothyroidism

E. Calcium deposition diseases

1. Calcium pyrophosphate dihydrate deposition2. Apatite arthropathy

F. Other bone and joint diseases1. Localized: fracture, avascular necrosis, infection,

gout

2. Diffuse: rheumatoid (inflammatory) arthritis, Paget'sdisease, osteopetrosis, osteochondritis

G. Neuropathic (Charcot joints)H. Endemic1. Kashin-Beck

2. Mseleni

I. Miscellaneous

1. Frostbite

2. Caisson's disease3. Hemoglobinopathies


40/63

Osteoarthritis results from a disparity betweenthe stress applied to articular cartilage and theability of the cartilage to withstand that stress .This could be due to one or combination of twoprocesses:

1- weakening of the articular cartilage(geneticdefect in collagen type ll or inflammatory disordere.g RA).

2- increased mechanical stress in some parts ofthe articular surface.

-excessive impact-reduction of the articular contact area


41/63

Remodeling and hypertrophy of bone are major features ofOA. Appositional bone growth occurs in the subchondralregion, leading to the bony "sclerosis" seenradiographically. The abraded bone under a cartilageulcer may take on the appearance of ivory (eburnation).

Growth of cartilage and bone at the joint margins leads toosteophytes (spurs), which alter the contour of the jointand may restrict movement. A patchy chronic synovitisand thickening of the joint capsule may further restrictmovement. Periarticular muscle wasting is common and

may play a major role in symptoms and, as indicatedabove, in disability.


42/63

The cardinal features are:

1- progressive loss of cartilage thickness.

2- subarticular cyst formation and sclerosis.

3- remodling of the bone ends andosteophyte formation.

4-synovial irritation.

5- capsular fibrosis.


43/63

OA and synovitis:OA NOT primarily an inflammatory diseaseshedding of fragment from articular cartilage and

release of enzymes from damaged cells

Cause of Pain:articular cartilage and synovium VS bone and

capsule


44/63

c/o: middle age patient complain of pain startsinsidiously and increase slowly over time (months and years ) aggravated by exertion andrelieved by rest, with time relief is less and less

complete.Stiffness :mainly after restSymptoms follow an intermittent course with

periods of remission lasts for months In advance stage : deformity ,swelling, muscle

wasting and loss of mobility .No systemic manifestations in contrast to inf.

diseases.


45/63

1- narrowing of jointspace.

2- subarticular cyst

formation andsclerosis.

3- osteophyteformation.

4- evidences of 2ndrycauses e.g. oldfracture.The first two are restricted initiallyto the major load-bearing part of

the joint but later the entire joint isaffected.


46/63

Early : symptomatic1- relieve the pain .( NSAIDs) SE?.2- join mobility (physiotherapy).3- reduce load ( walking stick, soft soled shoes,wt reduction and avoid

stressful activity ).Intermediate:

If symptoms increase despite conservative treatment some form ofoperative treatment may be needed such asjoint debridement: removal of interfering osteophytes and cartilage

tags and loose bodiesrealignment osteotomy why?

Late:Surgical intervention Total Knee Arthroplasty (TKA)


47/63

The primary indication for TKA is to relievepain caused by severe arthritis. The painshould be significant and disabling. Night pain isparticularly distressing. Ifdysfunction of the

knee is causing significant reduction inthe patient's quality of life, this should betaken into account. Correction ofsignificantdeformity is an important indication but is

rarely used as the primary indication for surgery.Exhaust all conservative treatmentmeasures before considering surgery .


48/63


49/63

Valgus stresses are resisted by the fascia lata,

pes anserinus ,MCL and the posteromedial part

of the capsule.Varus:illiotibial tract and LCL

ACL & PCL provide both anteroposterior and

rotatory stability and help to resist excessive

vulgus and varus angulation


50/63

History of twisting or wrenching injury or

claim to have heard a pop as the tissue

snappedKnee is painful Immediate swellingTenderness is most acute over the torn

ligament. Stressing one or other side of thejoint may produce excruciating pain


51/63

Tests for ligamentous instability can be

preformed if pain allows

Partial tears permit no abnormal

movementComplete tears permit abnormal

movement, sometimes surprisingly

causing little pain.Doubt about the diagnosis indicates

examination under anesthesia


52/63

Sideways tilting (valgus and varus) is examined

with the knee at 30 of flexion then with the knee

straight

Movement is compared with the normal side If the knee angualtes only in slight flexion there

is probably an isolated tear of the collateral

ligaments

If it angulates in full extension there is almostcertainly a rupture of the capsule, cruciate and

collateral ligaments


53/63


54/63

Anteroposterior stability is assessed firstby placing the knees at 90 with the feetresting on the couch and looking from the

side for posterior sag of the proximal tibia,when present this is a reliable sign of PCLinstability

A positive drawer test is diagnostic of a

tear but a negative does not exclude oneThe Lachman test is more reliable; the

anteroposterior glide is tested with kneeflexed at 15-20.


55/63

drawer test Lachman test


56/63

Stress x-rays may provide evidence of

instability

Plain x-rays may show that the ligament

has avulsed a small piece of bone:--The MCL usually from the femur

-LCL from the fibula

-ACL from the tibial spine-PCL from the back of the upper tibia


57/63


58/63

Intact fibers splint the torn ones and so

spontaneous healing will occurAdhesions may result, so active exercise

is prescribedAspirating the haemarthrosis and applying

ice packs intermittently relieves painWeight-bearing is allowedKnee is protected from rotation or

angulation strains by a heavily paddedbandage or a functional brace


59/63

Isolated MCL or LCL treated as above Isolated tears of ACL may be treated by early operative

reconstruction if the individual is a professionalsportsman

Cast-brace is worn until symptoms subside, thereaftermovement and muscle-strengthening exercise. This issufficient in about half of the patients as they regain goodfunction and need no further treatment.

Remainder will have varying instability, late assessment

will identify those who will benefit from ligamentreconstruction. Isolated tears of the PCL are usually treated

conservatively


60/63

Sometimes a severe strain instead of rupturing acruciate ligament results in an avulsion fractureat the insertion of the ligament. The fragmentmay only be partially displaced and difficult to

detect on x-ray. If the fragment can be manipulated back intoposition and allow full extension of the knee,immobilization in a plaster cylinder for 6 weekswill suffice

Otherwise operative reduction and fixation(sutures or screws) and a plaster cylinder for 6weeks will also be needed

Full movement is usually regained in 3 months


61/63

In ACL and collateral ligament injury

treatment starts with joint bracing and

physiotherapy to restore a good range of

movements before ACL reconstructionCombined injuries involving the PCL the

same approach is used however all

damaged structures need to be repaired


62/63

AdhesionsIf the knee with a partial ligament tear is not actively

exercised, torn fibers will stick to intact fibers and bone.The knee gives way with catches of pain, localized

tenderness and pain on lateral or medial rotation occurConfusion with a torn meniscus can be resolved by thegrinding test or arthroscopy

Instability

The knee continues to give way and tends to get worsepredisposing to osteoarthritis. Reconstruction beforedegeneration is wise.


63/63

D1

knee disorders.ppt

Documents