Knee soft tissue injuries Flashcards
what part of knee will increased weight affect the most
patella femoral joint
what causes pseudo locking
lack of synovial fluid after a prolonged sitting
who are ACL tears more common in
women
what can predispose to a extensor mechanism rupture
previous tendonitis
steroids
chronic renal failure (ciprofloxacin)
what are the signs of an extensor mechanism rupture
unable to straight leg raise,
palpable gap
what is the treatment for an extensor mechanism rupture
requires surgical repair
does the meniscus have innervation
peripheral 1/3rd does
what tears of the meniscus can be ignored
radial
how many ACL tears have meniscal tears too
50%
will radial meniscal tears heal
no
what can you consider in acute peripheral menisci tears
arthroscopic repair
when is a menisectomy done
mechanical symptoms, irreparable tears, failed meniscal repairs
what is a degenerative tear often the first stage of
OA
what does the ACL resist
anterior subluxation of the tibia and internal rotation of the tibia in extension
what does the PCL resist
posterior subluxation of the tibia and hyperextension of the knee
what might ACL rupture lead to
rotator instability
what might PCL rupture lead to
recurrent hyperextension or instability descending stairs
what rupture causes haemoarthrosis
ACL
what is bone bruising
bleeding inside the bone
what is the treatment for an MCL rupture
usually heals well, brace, early motion, physio, pain takes several months to heal, rarerly surgery
what is the main stabiliser against internal rotation of the tibia
ACL
does ACL surgical repair work
no- has to be reconstruction (autograft- hamstring or patellar tendon) (allograft- achilles)
what can stabilise ACL deficient knees
physio. if not responding to physio consider surgery
does the LCL heal
no
what artery can be affected in a knee dislocation
popliteal
what is affected in a twisting injury
ACL/ meniscal
what fall causes an extensor mechanism rupture
fall onto flexed knee with quads contraction
what injuries can cause an extensor mechanism rupture
rectus femoris tear
quadriceps tendon or patellar tendon rupture
patellar fracture
what are the roles of the menisci
distribute load,
make medial plateau more concave
which menisci is more likely to tear
medial as more fixed than lateral, also under more shear stress
what do 50% of ACL ruptures have
meniscal tear
will radial tears heal
no
how many arthroscopic repairs of acute peripheral menisci tears fail
40%
what does an acutely locked knee signify
displaced bucket handle meniscal tear
what is the treatment for a meniscal tear causing locked knee
urgent surgery, arthroscopic repair/ menisectomy
what does the MCL resist
valgus stress
what does the LCL resist
varus stress
what might a MCL rupture lead to
valgus instability
what is the rule of thirds of ACL ruptures
1/3rd compensate and can function well
1/3rd avoid instability by avoiding certain activities
1/3rd do not compensate, have frequent instabilities/ cant get back into high impact sport
how many ACL ruptures end up having reconstruction
40%
when is surgery used in ACL tears
when rotator instability not responding to physio
professional sport/ high demand job
adolescent or young adult- keen on sport
what does ACL reconstruction not help
pain and prevention of arthritis
what causes an LCL injury
varus and hyperextension
what nerve can be affected in a LCL injury
common peroneal nerve
what is the treatment for a complete LCL rupture
urgent repair (within 2-3 weeks)
what causes a PCL injury
direct blow to anterior tibia/ hyperextension
what is often involved in a knee dislocation
often high energy injuries;
- popliteal artery injury (tear, intimal tear and thrombosis)
- nerve injury (common peroneal nerve)
- compartment syndrome
what is the treatment for a knee dislocation
emergency reduction recheck neurovascular status - poss vascular surgery maybe temporary stabilisation maybe multiligament reconstruction
what causes a patella dislocation
rapid turn or direct blow
why gets patella dislocations
females more, adolescents, ligamentous laxity, valgus knee, torsional abnormalities
twisting injuries think
ACL or meniscal
getting up from squatting injury
meniscal
haemarthrosis think
ACL or fracture
effusion think
meniscal or chondral injury
pain in joint line think
meniscal/ chondral
Football injury, twist, pop, haemarthrosis, generalised pain, pain settles after a few days, rotatory instability =?
ACL rupture
Getting up from squatting, sudden sharp pain medial joint line, effusion, recurrent medial pain & catching +/- locking = ?
meniscal tear
