Knee Flashcards
S3Q2
KNEE: Anatomy
ROM, PFJ insertion, TFJ purpose
growth - birth, fibula, patella, physeal plates, M vs. F
- 145, 10, 45 ROT
- PFJ: to trochlear groove
- TFJ: not part of WB
growth & development
- birth: secondary epiphyseal center of distal femur & prox tibia
- head of fibula: 3y
- patella: 4y
- physeal plates fuse post-puberty (16-18y)
- women have faster skeletal maturity
KNEE: Anatomy
MCL & LCL - other name, from to, where, against
ACL & PCL - from to, against
patellar ligament - from to, continuation of what
MCL/TCL
- medial epi of femur to medial tibia
- blends c capsule & meniscus
- against VALGUS
LCL/FCL
- lat epi of femur to fibular head
- extraarticular
- against VARUS
ACL
- tibial plateau ant to intercondylar eminence to posmed aspect of LFC
- against ANT translation
PCL
- tibial plateau to lat aspect of MFC
- against POS translation
patellar ligament
- apex of patella to tibial tuberosity
- continuation of quads tendon
KNEE: Radiograph
ideal & optional (3.2)
tunnel view - other name, see (6), ray angle
oblique view - how & see (2.1)
- optional: tunnel, oblique
TUNNEL / POSANT AXIAL
- see: intercondylar fossa, intercondylar eminence of tibia, femoral & tibial condyles, tibial plateau, osteochondral, loose bodies
- central ray: 40 caudad
OBLIQUE VIEW
- IR (45): LFC, fibular head
- ER (45): MFC
KNEE: Radiograph
AP of knee - see (4), ray angle, patella + tibial plateau + fibular head + axis
lateral of knee - see (4), how, fibular head + true lateral position + alta/baja + suprapatellar bursa describe & where + fabella what & where
AP OF KNEE
- see: femur, proximal tibia, fibular head, articulation of femur & tibia
- ray: 5-7 cephalad
- patella superimposed over distal femur, tibia over fibular head, tibial plateau only minimal, axis align
LATERAL OF KNEE
- see: PFJ, patellar tendon, quads tendon, suprapatellar bursa
- how: 20 FLEX
- true lateral position = femoral & tibial condyles over their own
- fibular head superimposed by tibia
- patella alta: superior patella, baja/infera
- suprapatellar bursa: thin radiolucent line pos to quads tendon; becomes oval & distended if injury
- fabella: sesamoid bone at pos joint capsule & gastrocs insertion; not in everyone
KNEE: Radiograph
tangential view - other name, see (2), how, beam enter (2) + directions (2), patellar facets, intercondylar sulcus, sulcus angle + normal value, congruence angle purpose + normal & abnormal values
TANGENTIAL / SUNRISE VIEW
- see: articular surface of patella & femur, PFJ space axial view
- how: 45 FLEX
- beam: enter those 2; supinf (merchant view), infsup
- medial patellar facet larger & more sloped than lat
- intercondylar sulcus: groove between femoral condyles
- sulcus angle: between highest point of femoral condyle to deepest of trochlear groove; 138 +/- 6
- congruence angle/merchant’s study: patella position in sulcus; N=6, >16=patellar sublux
KNEE: Advanced Imaging - CT
protocol - from to, scanning plan aligned with what
cartilage/joint space - (3)
soft tissue - (1.2)
- from suprapatella to prox tibia
cartilage/joint space
- PFJ space, free fragments, loose bodies
soft tissue
- continuity of quads tendon
- suprapatellar & popliteal bursa
KNEE: Advanced Imaging - CT
axial plane - patellofemoral articulation (2), tibial plateau (2) & condition = (1), tibial tuberosity (2) d/t condition
sagittal plane - high vs. low patella tears what, sinding = sx (2) where (2)
coronal plane - femoral condyle (1), intercondylar notch (2), intercondylar eminence (1), lat tibial plateau what fx + condition + sign
AXIAL PLANE
- patellofemoral articulation: osteochondral, patella position in sulcus
- tibial plateau: depression & split fx; segond = ACL tear
- tibial tuberosity: hypertrophy & fragmentation d/t osgood-shlatter
SAGITTAL PLANE
- high patella = torn patellar ligament, low = quads tendon
- sinding: ossification & fragmentation at inf patella & patellar tendon
CORONAL PLANE
- femoral condyle: split fx
- intercondylar notch: osteochondral & sclerotic patches at MFC
- intercondylar eminence: avulsion fx at ACL
- lat tibial plateau: curvilinear fx at ACL = segond/lat capsule sign
KNEE: Advanced Imaging - MRI & Trauma
protocol - from to, MRa (1)
bone signal - (2) + AVN what
cartilage - (2)
soft tissue - (4)
trauma - most what, radio if (4)
- from quads tendon to tibial tuberosity
- MRa: meniscus
- bone signal: osteochondral, tumor, cyst, AVN (serpentine separating normal bone)
- cartilage: meniscus, osteochondral
- soft tissue: bursa, fat pad, muscle, synovium
TRAUMA
- most commonly radiographed for trauma
- if: joint effusion, limping, <90 FLEX, tenderness
KNEE: Advanced Imaging - MRI
axial plane - see (6.3)
sagittal plane - see (5.2)
coronal plane - see (4.2)
axial: baker + 3 lig, sagittal: extensor, coronal: 1 & 2
AXIAL PLANE
- articular cartilage, baker’s cyst, joint effusion, patella retinaculum, pes anserine, popliteus, MCL ACL PCL
SAGITTAL PLANE
- articular cartilage, meniscus, extensor mechanism, bone marrow, hoffa’s fat pad, ACL PCL
CORONAL PLANE
- articular cartilage, meniscus, bone bruises, popliteus, ACL PCL
KNEE: Conditions - Distal Femur Fx
MOI (2.2)
view (3) + purpose of 3rd
tx - conservative (2) + duration, surgical (1) + amb when + WB when + RTF when
complication (3)
- MOI: falls & MVA, if osteoporotic then even basic fall & force
- view: AP, lat, CT (fx line)
TX
- conservative: skeletal traction -> cast (3-6w)
- surgical: internal fixation
- WB: if union signs (callus or bye fx line), amb c AD: 4w, RTF: 3-4m
COMPLICATIONS
- post-traumatic arthritis, malunion, adhesions
KNEE: Conditions - Fx of Proximal Tibia
structures (2), MOI (2)
view - (4), lipohemarthrosis what + other name (2) + in what cut
tx - conservative (for & NWB duration), surgical (1) + for (3)
classification (6)
- tibial plateaus
- MOI: pedestrian (bumper), twist if elderly osteoporotic
VIEW
- AP, lat, oblique, 3D recon CT
- lipo: fat + blood + joint synovial fluid in plateau = parfait/FBI sign in axial cut
TX
- conservative: for non or minimal displaced; NWB 4-6w
- surgical (ORIF): for depressed plateau, severe
CLASSIFICATION (SCHATZKER)
- type I: split fx of lat plateau
- type II: split = central depression
- type III: pure depression
- type IV: split fx of medial plateau
- type V: split/depression/mixed of both
- type IV: comminuted both + diaphysis & metaphysis
KNEE: Conditions - Fx of Patella
MOI (3), classification (1), view (3)
tx - conservative for (2) + (2) & durations, surgical (4)
complications (2)
- MOI: falls, dashboard (direct trauma to knee), avulsion/forceful quads
- classification: transverse linear fx as most common
- view: tangential, lat, oblique
TX
conservative
- for: non-displaced or minimal
- long leg cast (4-6w) -> hinged knee brace (til bye fx)
surgical
- tendon band wire, cancellous screws, patellectomy, excision of entire patella
complications
- post-traumatic arthritis
- bye EXT d/t bye extra moment arm from excised patella
KNEE: Conditions - PF Subluxation/Dislocation
MOI (4), view (4)
tx - conservative (1), operative (1) + (1) & d/t (2) & how
- MOI: direct trauma on flexed knee, powerful quads, rotary(varus & valgus)
- view: multiple tangential & lateral, weighted AP & oblique
TX
conservative
- patellar taping
operative
- surgical release of patellar retinaculum
- distal repositioning of ligament: move tibial tuberosity laterally = dec excessive Q angle & extensor mechanism malalignemnt
KNEE: Conditions - Meniscal Tear
MOI (3), shape (3), view (1) + signal
medial vs. lateral most common d/t (2.1)
bucket, peripheral, discoid
tx - operative for (1) + (2) which preferred/for, RTF
- MOI: compression, rotation, shear
- shape: C or O, wedge
- view: MRI hyperintense signal = tear
- medial more common d/t more peripheral attachments & dec mobility
- lat more common if developmental abnormality (discoid)
- discoid: lose wedge shape
- bucket handle tear: oh no for tx
- peripheral tear: bye junction between meniscus & capsule
TX
- operative if disrupted ROM, RTF=4-5m
- partial menisectomy: preferred
- repair of meniscus: for peripheral tears
KNEE: Conditions - Collateral Ligament
MOI (1), view (1) + signal, pelligirini lesion indicate what
medial vs. lateral - more common, d/t force, O donoghue (2)
tx - conservative (1), operative for
- MOI: direct blow to flexed knee
- view: MRI low signal
- pelligrini lesion: chronic MCL tear c calcification
- LCL d/t varus force
- MCL d/t valgus force, more common
- O donoghue: ACL, MCL, med meniscus
TX
- conservative: brace
- operative: for more severe
