WEEK 11 - Knee, Patella, Intercondylar Notch

Structures Included - KNEE

• ¼ distal femur → ¼ proximal tib/fib

• ST

CR - AP KNEE

// tibial plateau

• <19 = 5 caudal

• 19-24 = perpendicular

• >24 = 5 cephalic

CP - KNEE

knee joint midline

Alignment - KNEE

LA of knee // LA of IR

• an ABD/ADD issue

BTP/CR - AP KNEE

MAIN:

• ant&post tibial margins SI prox/dist

• open knee joint

SUPPORTING:

• top of fib head midway between metaphysis and tib plateu

Rotation - AP KNEE

MAIN: femoral condyles are symmetrical

SUPPORTING:

• ½ of fib head SI by tib

• intrcndyl em centered between notch

int.rot

• lat.con wider

• less than ½ fib head SI

ext.rot

• med.con wider

• more than ½ fib head SI

F/E - AP KNEE

no flexion, full extension

• patella 1” above notch

IQ - KNEE

BTB: patella seen thru

CR - AP MED OBL KNEE

remeasure ASIS

BTP/CR - AP MED OBL KNEE

same as AP KNEE

Rotation - AP MED OBL KNEE

good med 45 OBL

• MAIN: fib head free of SI / tib-fib joint open

• SUPPORTING:

  • ½ patella free of SI

  • lat.con in profile with no SI from med.con

CR - AP LAT OBL KNEE

same angle used for AP KNEE

BTP/CR - AP LAT OBL KNEE

same as AP KNEE

Rotation - AP LAT OBL KNEE

good lat 45 OBL

• MAIN: fib aligned with ant.edge of tib

• SUPPORTING:

  • ½ patella free of SI

  • med.con in profile with no SI of lat.con

CR - LAT KNEE (med-lat)

5-7 ceph angle

Alignment - LAT KNEE (med-lat)

site dependent

• femur

• patella

• tib/fib

BTP/CR - LAT KNEE (med-lat)

same as AP KNEE

• fem.condyles SI prox.dist

• open knee joint

Rotation - LAT KNEE (med-lat)

good 90 OBL

• MAIN:

  • ant. aspects of fem condyles SI ant/post

  • open pat-fem joint

• SUPPORTING:

  • ½ fib head SI

F/E - LAT KNEE (med-lat)

good 20-30 flexion

• open pat-fem joint

IQ - LAT KNEE (med-lat)

• suprapatellar fat pads seen

• 5 main bursae seen

CR - LAT KNEE (lat-med)

5-7 caudal angle HB

Positioning - LAT KNEE (lat-med)

critique points identical to med-lat knee, EXCEPT

• flexion is not required

CR - WB AP KNEE

perpendicular

Positioning - WB AP KNEE

same as AP KNEE, EXCEPT

• knee joint may not be open due to trauma

• for bilateral projections, DVB contributes to ext.rot appearance

Structures Included - AP AXIAL NOTCH

• distal fem cons → prox tib cons

• ST borders are site dependent

CR - AP AXIAL NOTCH

perpendicular to lower leg

CP - AP AXIAL NOTCH

knee joint midline

Alignment - AP AXIAL NOTCH

fossa // LA of IR

BTP/CR - AP AXIAL NOTCH

• intercondylar notch open with no patella SI

• tib plateau SI prox/dist

Rotation - AP AXIAL NOTCH

no rotation

• MAIN:

  • med and lat surfaces of the intercondylar fossa in profile

  • femoral condyles symmetrical

• SUPPORTING: ½ fib head SI

F/E - AP AXIAL NOTCH

good 60 flexion

• apex just proximal to intercondylar fossa

Structures Included - PATELLA

• patella

• adj structures

CR - PATELLA

perpendicular

CP - AP/PA PATELLA

mid patella

Positioning - AP PATELLA

same as AP KNEE, EXCEPT

• BTB is not assessed

• only: Alignment, Rotation, IQ

CP - LAT PATELLA

mid pat-fem joint

Alignment - LAT PATELLA

patella // LA of IR

Rotation - LAT PATELLA

same as LAT KNEE, EXCEPT

• BTP is not assessed

Structures Included - TANGENTIAL PATELLA

• patella

• ant.fem cons

• intercondylar sulci

• related ST

CR - TANGENTIAL PATELLA

// patellofemoral joint (base→apex)

CP - TANGENTIAL PATELLA

mid pat-fem joint

BTP/CR - TANGENTIAL PATELLA

• apex and base SI

• open pat-fem joint

excessive

• apex more ant to base

insufficient

• apex post to base

Rotation - TANGENTIAL PATELLA

lat fem con is slightly more ant to med.fem.con

ext.rot

• lat.con is aligned with the med.con

int.rot

• med.con is ant to lat.con

F/E - TANGENTIAL PATELLA

good 60 flexion

• tib tub is post to sulcei and NOT seen in notch

insufficient flexion

• tib anterior to sulcei

how to diff fib cons in TANGENTIAL PATELLA

• lat con is more narrow

• the lateral aspect of the patella is thinner