Meniscus and Articular Cartilage

meniscus is made primarily of

type II collagen and proteoglycans (GAGs)

meniscus that is injured more

medial, because it is anchored down and therefore has less give

specific area of medial meniscus hurt the most

posterior horn, because it has less tensile strength

takes 70% of load on knees

meniscus

meniscus is less stiff than

articular cartilage

material properties of menisci

compression, shear, tension

blood is supplied to meniscus via

perimeniscal capillary plexus

meniscus is hurt most in a position of

FLX /c rot

Since you lose proteoglycans with age, the meniscus becomes

less shock absorbing

Someone with a flap meniscus tear would likely report

catching/knee feeling stuck

meniscus tear has a better outcome if concomitant with

ACL/PCL injury due to bleeding

gold standard for meniscus pathology dx

scope/arthroscopy (realistically MRI)

doesn’t show up well on images

posterior horn of medial meniscus

pt with meniscus pathology will have pain along

the joint line

What you should know about the meniscal surgery when treating it

where it was done and WB status

Because the HS connects to the meniscus, in the 1st 6 weeks do only (for HS)

PROM

contraindications for meniscal repair

>60, radial degenerative tear, W-W, non-compliant, frontal plane alignment issues

indication for meniscal repair

>50, concurrent ligament reconstruction, tear reducible and good tissue quality

R-R repair restrictions

limited WB, long knee immobilizer, 50% w?B for 1-2 weeks, full by 4 weeks, ROM 0-90 for 1st few weeks

R-W repair restriction

NWB 6 weeks, 1-2 weeks 0-90°, @ 4 weeks up to 120° FLX, @ 6 weeks 135°+

order for reducing AD use

2 to 1 to none

rehab for meniscectomy

normal eval, pain guides, usually no ROM precautions, AROM fine, quad sets important, rehabs a lot like ACL

don’t do a SLR with someone that has

quad lag

meniscal transplant is best for

young people that have had a ton of scopes, will likely need TKA eventually, (not a good candidate if malalignment of bones)

rehab for meniscal transplant should be handled

as or more conservatively than meniscal repair

articular cartilage lesions usually present with

delayed swelling

rehab of arthroscopic debridement of articular cartilage lesion should be treated like

menisectomy

best case for articular cartilage microfracture

<35, small tear, body habitus

micro fracture is indicated for

small lesion (<2-3cm²) in a high demand area or large lesion (≥3-4 cm²) in low demand area

restrictions after articular cartilage microfracture

NMB up to 6 weeks, long leg immobilizer, some ROM restrictions

OATS

osteochondral autograft transfer system

OATS can be used for

failed microfracture or a larger lesion

When treating OATS know

where cartilage defect was, and be cautious when engaging it

Rehab guidelines for articular cartilage reparative procedures

NMB min 6-8 weeks, lesion specific for ROM (mostly active, PROM pretty much fine, cyclic loading good (CPM may be indicated), may start /c OKC, initiating WB when you can

if OA appears to be bil

suspect RAOA

OA is usually

UL

OA risk factor

older, female, obesity, osteoporosis, occupation, sports activities, previous trauma, muscle weakness/dysfunction, proprioceptive deficits, genetic factors

conservative treatment for knee OA

PT, weight loss, viscosupplementation, corticosteroid injections, NSAIDS

knee unloaded brace creates

valgus force

knee unloader brace can be sucessful in the

short term

shoe insert into lateral knee creates

knee valgus

hi-tibial osteotomy will

de-adduct tibia

healing time of hi-tibial osteotomy

long

sacrificed in TKA

cruciates

collaterals in TKA are generally

spared

In TKA, the quad tendon may be

split

general WB for post TKA

WBAT

TKA can be

cemented or non-cemented

TKA puts a button on

the back of the patella

pre-op indicators of TKA outcome

lifestyle, pre-surg strength, comorbidities, mental/cognitive status, ROM, decreased self-efficacy scores

don’t put things under

your knee

post op predictors of outcome for TKA

the same as pre

in a hemiarthroplasty the patella is

not resurfaced

cruicaites can be spared in

hemiarthroplasty

Bakers cyst pt may complain of

trouble /c EXT, calf tightness, fullness in back of knee, common in people with OA

Ddx for bakers cyst

DVT

Distal IT band friction syndrome is also known as

Runner’s knee

distal IT band friction syndrome (runner’s knee)

overuse injury causing lateral knee pain due to friction between the distal ITB and lateral femoral epicondyle

etiology/risk factors for distal IT band friction syndrome (runner’s knee)

repetitive knee FLX/EXT (running, cycling), poor hip ABD strength, genu varum, leg length discrepancy, tight ITB or poor foot mechanics

clinical features of distal IT band friction syndrome (runner’s knee)

lateral knee pain 2-3 cm above jt line, worse with running downhill, prolonged activity, tender over lateral femoral epicondyle, positive over’s and noble’s tests

20-30° of FLX is generally more sensitive in

IT band syndrome

management of distal IT band friction syndrome (runner’s knee)

activity modification, ITB/TFL/glute stretching, hip ABD strengthening

Prepatellar bursitis is also known as

housemaids knee

pre patellar bursitis (housemaids knee)

swollen anterior aspect of the knee, hx of repetitive shearing force/kneeling