knee Flashcards
what is the purpose of the menisci
shock absorbers
which menisci is more fixed
medial (lateral more mobile)
what tendons keep the patella in place
quadriceps + patellar
what is the function of the ACL
prevent tibia rotating
function MCL
resist valgus force
function LCL
resist varus force
RF early knee OA
meniscal tears, ligament injuries, abnormal alignemt, inflammation arthritis, hobbies
indication knee replacement for OA
substantial pain!! (and disability)
signs OA knee
swelling, crepitus, limited range of motion
how do meniscal tears usually occur
twisting injury
symptoms meniscal tear
pain on joint line // effusion following day // locked knee cannot straighten (bucket handle)
what tests can be used to determine meniscal tear
steinmanns: (flex hip and knee and externally rotate foot) // thessaly (weight bear on slightly bent knee and twist)
most common site for meniscal tear
medial
symptoms of a bucket handle meniscal tear
locked knee and cannot fully extend (mechanical obstruction from meniscus)
invx for meniscal tear
MRI
criteria for meniscal repair
longitudinal (bucket handle) // acute // young
what is involved in meniscal repair
stitch to bed
if not suitable for meniscal repair what surgery can be done
arthroscopic partial menisectomy
mx degenerative meniscal tear
steroid injection
causes of ACL rupture
high rotational force eg skiing, lateral blow, rugby, football
symptoms ACL rupture
pop heard or felt // hemoarthrosis within hour // deep pain // rotatory instability
what tests can be done for ACL tears
ant draw test/ lachmanns: patient flat on bed and knee 30 flexed, pull calf forward
when is ACL reconstruction considered (repair not often done)
professional sports people // if sedentary activity // failed physio
what is ACL reconstruction sirgery
tendon graft through tibiofemoral tunnel and attach to knee
what injuries can cause PCL tears
direct blow to tibia eg dashboard injury (uncommon isolated injury)
test for PCL rupture
posterior draw test (same as ant but push back)
how do MCL tears occur
strong valgus force
symptoms MCL tear
laxity + pain when forced into valgus position
mx MCL tear
brace –> MCL tightening –> reconstruction and tendo graft
what nerve can be damaged in LCL rupture
peroneal
what is damaged in the unhappy knee triad + what causes it
high force lateral knee blow –> ACL, MCL, meniscal
what is the most common knee injury
ACL tear
what are common complications from a patella dislocation
thrombosis, popliteal artery damage, compartment syndrome
how can patella dislocations sometimes spontaneously reduce
straighten leg
invx patella dislocation
Xray
RF patella dislocation
laxity, female, genu valgum, high riding patella, femoral neck anteversion
how can extensor mechanism (quadriceps or patella tendon) ruptures occur
fast contractile force eg weightlifting, fall, degenerative
which tendon in extensor mechanism ruptures are likely in older vs younger patients
patella in young and quadriceps in old
RF extensor mechanism rupture
tendonitis (quinolones) // chronic steroid ise // diabetes / RA / renal failure
invx extensor mechanism rupture
straight leg test (gap) // Xray or USS if obese
what is chondromalacia patella/ patellofemoral dysfunction
patella and femur not alligned properly
when/ who does chondromalacia patella/ patellofemoral dysfunction occur
teenage girls esp after knee injury/ dislocation
signs and symptoms chondromalacia patella/ patellofemoral dysfunction
ant knee pain worse going downhill or at rest // pseudolocking // quads wasting
mx chondromalacia patella/ patellofemoral dysfunction
physio, taping, surgery
symptoms osteochondritis dissecans (osgood)
knee pain + swelling after exercise // knee catching and locking // painful clunk when extending knee
signs osteochondritis dissecans (osgood)
joint effusion, tenderness at medial femoral condyle
invx osteochondritis dissecans (osgood)
xray or MRI
who is usually affected by osteochondritis dissecans (osgood)
children and young adults
what causes IT band synrdome
running
symptoms IT band syndrome
tenderness 2-3cm above lateral joint line
mx IT band syndrome
stretches and physio
what are baker’s cysts
distension of knee bursa that looks like a cyst
what can cause bakers cysts
OA in adults
symptoms ruptured bakers cyst
pain, reness, swelling
where does the swelling occur in bakers cyst
behind the knee
