AP - Anterior Thigh and Knee Joint

what is the most dominant muscle in the anterior thigh?

quadraciceps femoris

what are the parts of quadriceps femoris m? (w/ a common distal tendon?)

1. rectus femoris m

2. vastus lateralis m

3. vastus medialis m

4. vastus intermedius m

what are all the muscles of the anterior thigh?

1. quadriceps femoris m*

2. sartorius m

3. iliopsoas m (iliacus + psoas major/minor m)

what nerve innervates the anterior thigh?

femoral nerve

what makes up the iliopsoas muscle?

psoas major m, psoas minor m, and iliacus m

makes up the primary hip flexor

where does the iliopsoas muscle (and its associated muscles) run?

over the superior pubic ramus and under the inguinal ligament

where does the iliopsoas muscle (and associated) attach distally?

lesser trochanter

what is the blood flow for the anterior thigh?

external iliac → common femoral → splits to profunda and superficial femoral → superficial femoral courses on top of adductor magnus and longus, dips through adductor hiatus and continues posteriorly to become the popliteal artery

what does peroneal mean?

fibula

what is the pathway of the sciatic nerve?

1. tibial nerve and 2. common fibula n

1. tibial n. and sural n

2. common fibula n → superficial and deep fibula n

where does the femoral nerve eventually turn into?

saphenous n

what are the borders of the femoral triangle?

1. inguinal ligament (superiorly)

2. adductor longus m. (medially)

3. sartorius m (laterally)

what are the contents of the femoral triangle?

NAVEL

femoral nerve/artery/vein/lymphatics

what is the inguinal ligament?

it is demarcation point where the external iliac artery becomes the common femoral

what is the landmark for the adductor canal?

tunnel within anterior thigh that helps transition vessels to the popliteal region

where does the adductor canal extend from?

femoral triangle to the adductor hiatus

why is the great saphenous VEIN not part of the adductor canal?

the great saphenous vein is SUPERFICIAL

what are the contents of the adductor canal?

1. superficial femoral artery

2. femoral vein

3. saphenous NERVE (femoral nerve eventually makes this branch)

what is the function of the adductor canal?

creates a channel to the popliteal fossa/posterior knee

what do you need in order to walk?

lower extremity flexion AND extension at the hip and knee

what muscles provide major source of hip extension → seated position?

gluteus maximus and hamstring msucles

what does the quadricep muscles provide?

anterior thigh/knee extension

what are the 4 heads of the quadriceps?

1. rectus femoris

2. vastus medialis

3. vastus intermedius

4. vastus lateralis

contributes to quadriceps tendon

what is the function of the rectus femoris?

extension of knee

what is the rectus femoris?

arises from above hip joint @ ilium and is part of the 4 part bundle of muscles that makes the quadriceps m

what does the rectus femoris attach to?

patella via the quadriceps tendon

what is the sartorius?

weak hip flexor (flexes, abducts, laterally rotates the hip)

where does the sartorius m run from?

long spiraling muscle that runs from ASIS to tibia

what muscles are in the medial compartment?

adductor L/B/M, pectineus, graciliswhat is

what is the major innervator (nerve) of medial compartment?

obturator n

what is the major innervator for posterior compartment?

sciatic n (unless you go lower, then tibial transition)

what are the muscles of the posterior compartment?

semimembranosus, semitendinosus, biceps femoris

what does the sciatic nerve split into?

tibial nerve and common fibula (peroneal) nerve

where is the popliteal fossil located?

posterior knee region between distal tendons of the hamstrings and proximal tendons of gastrocnemius m

what is the neurovasculature of the popliteal fossa?

• sciatic nerve

• popliteal a/v

popliteal artery divides into 2 main branches, which are?

• anterior tibial artery

• posterior tibial artery

tibial nerve vs. common fibular n

tibial nerve: more medial and larger

common fibular n: more lateral and smaller

if someone had surgery aggressive in the common peroneal n, you’d see?

lack of sensation on the top of the foot (since it goes to the medial/lateral cutaneous branch), but you’d also want to ask if they have decreased sensation between the webbings of the first and second toe (b/c that would also be altered)

what is acute compartment syndrome?

basically blood has no where to go to

6 P’s of compartment syndrome:

pain - out of proportion to injury (do exam on passive ROM)

paresthesias

poikilothermia - affected area cooler than unaffected (d/t compression of arteries)

pallor

pulselessness - arterial flow is limited, seen later

paralysis - seen later

what causes acute compartment syndrome?

trauma ie fracture, contusion, arterial damage

what is the tx for acute compartment syndrome?

surgery - rel fascia lata for anterior and posterior compartments

medial incision of adductor release

what is the primary and secondary function of knee joint?

p: hinge joint for flexion/extension

s: medial and lateral rotation

what are the 3 articulations of the knee joint?

1. patellofemoral

2. medial tibiofemoral joint

3. lateral tibiofemoral joint

what does stability of the knee rely heavily on?

surrounding ligaments and meniscus cushions

what is the tibial tubercle?

bony prominence on the tibia

when kid in growth spurt says they’re in pain

attachment point for patellar tendon

what is the meniscus?

crescent shaped cushion that fits between femur and tibia

what is the intercondylar notch?

space where anterior and posterior cruciate ligaments sit

what are the anterior and posterior cruciate ligaments?

2 crossing ligaments that stabilize the knee joint and prevent excessive forward/backward motion of tibia in relation to femur

what prevents the femur and tibia from rocking side to side?

fibular collateral ligament (AKA lateral collateral ligament) and tibial collateral ligament (AKA medial collateral ligament)

what are the extracapsular ligaments of the knee?

1. patellar ligament/tendon

2. lateral (fibular) collateral ligament

3. medial (tibial) collateral ligament

what is the function of lateral collateral ligament?

• protects lateral aspect of knee

• taught during extension, slack during flexion

• separate from knee capsule

what is the medial collateral ligament?

• weaker comparative to lateral

• protects medial aspect of the knee

• taught during extension, slack during flexion

• thickening of the knee capsule

what does the medial collateral ligament have an attachment to and as a result can sustain injury if MCL is injured?

medial meniscus

what are the intracapsular ligaments of the knee?

cruciate ligament (2 ligament criss cross to limit rotation movement) = anterior cruciate ligament and posterior cruciate ligament

where does the anterior cruciate ligament (ACL) extend from?

posterior aspect of medial surface of lateral femoral condyle → anterior tibia

what is the function of the anterior cruciate ligament?

prevents anterior tibial displacement and posterior femoral placement

weaker than posterior cruciate ligament

what is a test you can use to determine stability of the anterior cruciate ligament?

anterior drawer/lachman test (positive = anterior displacement of tibia)

pull on knee area

where does the posterior cruciate ligament extend from?

anterior lateral aspect of medial femoral condyle → posterior tibial plateau

what is the fx of posterior cruciate ligament?

prevents posterior tibial displacement and anterior femoral displacement

stronger and MAJOR STABILIZER especially walking down stairs (prevents femur from rolling forward) and if you push the leg INWARD to check)

you can use posterior drawer as an exam to see stability of PCL

what is knock knee (valgus) deformity?

knee inwards

what is bow legs (vargus) deformities?

knee outward

what is a peroneal injury after total knee arthroplasty risk factors

• pre-op valgus deformity

• tournique time > 120 mins

• aggressive retractor placement

• epidural

• baseline neuropathy

what is the MOA of peroneal injury after total knee arthroplasty?

correction of deformity results in acute, excessive stretch

(basically straightening valgus deformity which will piss off the nerve, so you’ll probably have issues with dorsiflexion AKA dropped foot, sensation decrease on top of the foot)

how to relieve pain for peroneal injury after total knee arthroplasty?

“unstretch” the knee, flex the joint, release the bandage

what is the largest sesamoid bone?

patella

what anchors patella superiorly?

quadriceps tendon (if damaged, have unopposed traction going downwards)

what anchors patella inferiorly?

patellar tendon/ligament (if damaged, have unopposed traction going upwards)

what is the attachment point of patella to tibial tuberosity?

patellar tendon/ligament

what is the most commonly injured ligament in the knee?

ACL tear

MOA of ACL tear?

non-contact, non-pivoting action when tibia keeps going anteriorly while the knee is slightly flexed and valgus

AKA sudden change in direction/stopping

in impact injuries, what should you consider?

ACL, medial meniscus, and MCL injury in TRIAD

what causes a quadriceps tendon rupture?

loading of knee extensor mechanism as a direct result of sudden/strong contraction of the quadriceps muscle from a jump and land mechanism/sudden change in direction while running/attempting to regain balance to avoid a fall

what are RFs of quadriceps tendon rupture?

increases with age

end-stage renal disease on hemodialsis

DM, connective tissue dz, chronic med use (steroids, FLQ)

what would you see on PE of quadriceps tendon rupture and classic diagnostic triad?

difficulty with EXTENSION

acute pain, loss of active straight leg raise (or extension), and suprapatellar defect

(maybe feel a pop and can’t bear weight)

what causes rupture of patellar tendon?

tension overload from quadriceps suddenly contracting while knee is flexed

ie running up stairs, landing from jump, sudden change in direction when running (less common than quad tendon rupture)

patellar tendon rupture risk

highest in YOUNGER ages

chronic inflammation, connective tissue dz, steroid injections

what would you see on PE of patellar tendon rupture?

acute pain and hemarthrosis/edema, inability to extend and infrapatellar defect/pain

maybe pop, inability to bear weight, longstanding pain in infrapatellar region

what is osgood schlatters dz?

common cause of anterior knee in skeletally immature athletes

what is presentation of osgood schlatters dz?

atraumatic, insidious onset, anterior knee pain, point tenderness at the patellar tendon insertion site → TIBIAL TUBERCLE

what causes osgood schlatters dz?

repeated traction from flex/ext exercises → microtears and inflammation

associated with overuse/periods of rapid growth

rest!

what is the most common cause of lateral knee pain in runners/cyclists?

iliotibial band syndrome

what are RFs of iliotibial band syndrome?

activities of prolonged extension/flexion, abrupt increase in high risk activity/intensity, hip abductor weakness, excessive foot pronation

what causes iliotibial band syndrome?

result of reptitive friction of ITB band over femoral lateral epicondyle

rest!