Rad 2B week 7 (quiz 8)

Hip dislocations usually result of severe trauma such as...

MVA

Anterior happens ___% of the time while posterior happens ___% of the time

15%, 85%

Which fxs are common with hip dislocations

Acetabulum fxs

Posterior hip dislocation moi

Hip in flexion and adduction of the thigh followed by direct blow to knee

What associated fx happens with posterior hip dislocations

Dashboard fx (posterior Acetabular rim fx)

What % of time does posterior Acetabular rim fx happen with posterior hip dislocations

90%

Femur lies ___ and ___ to acetabulum

Cephalad and lateral

Pt will be stuck in ___ rotation with posterior hip fxs

Internal

What imaging modality is best for hip dislocations to see associated fxs

CT

Pt will be stuck in ___ rotation with anterior hip dislocations

External

Anterior hip dislocation moi

Hip in forced abduction and extension (opp of posterior dislocation)

Femoral head lies ___ and ___ to acetabulum

Caudal and medial

3 complications of hip dislocations

1. Sciatic nerve paralysis (usually from posteiror dislocation)

2. Myositis ossificans and AVN of femoral head

3. Degen arthritis

What is Myositis ossificans

formation of bone tissue within the muscle due to hematoma not healing properly —> ossifies

Akas for SCFE (3)

Adolescent coxa vara

Epiphyseal coxa vara

Epiphysiolisthesis

SCFE is a salter Harris type ___ injury

1

SCFE presents with____ displacement, ___ rotation and ____ of neck on the head

Upward, external, adduction

We see ___ deformity with SCFE

Varus

MC cause of SCFE

Being fat

If obesity isn't involved with SCFE, what do we suspect

Endocrinology:

-renal osteodystrophy (abnormal development of bone due to kidney dysfunction)

-hypothyroidism

-rickets

-radiotherapy

Bilateral SCFE is more common in males or females

Females

SCFE is not the mc disorder of adolescent hip T/F

False, it is

Exam findings for SCFE

Limp with hip pain referral to knee in a fat adolescent

What body type does SCFE usually present with

Frohlich body type (high fat in abdomen and legs)

What ortho test is positive with SCFE potentially

Trendelenburg test if severe femoral head slippage present

If bilateral SCFE present, what gait do we see pt present with

Waddling gait due to ext rotation of feet

What xray views do we use for SCFE (2)

AP and frog leg (ext rot + abduction)

We see posteiror ___ slippage of epiphysis on xray for SCFE

Medial

Apparent widening or narrowing of growth plate is seen for SCFE

Widening

___ Epiphyseal beaking is present for SCFE

Medial

Widened or narrowed teardrop space for SCFE

Widened

Do we see lateral or medial femoral neck periosteal buttressing (widening) for SCFE

Both

Buttressing def

Reinforced bone from excessive stress

What abnormal line of mensuration do we see with SCFE

Abnormal klein's line

Complications of SCFE (3)

1. Permanent coxa vara deformity —> osteoarthritis (MC)

2. AVN of femoral head (uncommon)

3. Chondrolysis (acute cartilage necrosis)

If SCFE not fixed, what deformity can occur

Pistol grip deformity

Pistol grip deformity can lead to what?

Femoral Acetabular impingement

Tibial plateau fx aka

Bumper/fender fx

Moi of tibial plateau fx

Depression impact fx of femoral condyles into weaker tibial plateau (blow to lateral knee)

Which plateau is more commonly affected with these fxs

Lateral plateau (80%)

Fx line is hard to see with tibial plateau fx, so what xray views do we do

Obliques (ext and int)

What imaging is best to see ST injury with tibial plateau fx

MRI

Ligament injury (MCL/LCL, ACL/PCL) happens ___% of the time with tibial plateau fx

10%

What views do we use to see FBI sign with tibial plateau fx

Horizontal beam/cross table lateral view

FBI sign aka

Lipohemoarthrosis

FBI sign indicates.... (Hint: not tibial plateau fx)

Intraarticular fx

-fat from bone marrow can leak into articular capsule when fx happen

Anterior tibial spine fx moi

Hyperextension of knee with internal rotation of tibia

Anterior tibial spine fx is a ___ fx at origin of what ligament

Avulsion fx of ACL

Since anterior tibial spine fx is an avulsion fx, which population do we see this injury in most commonly

Adolescence

Which xray views do we use to see anterior tibial spine fx

AP and lateral

Trampoline fx occurs in which population

Young children (2-5yrs)

Trampoline fx moi

Impaction between descending child's leg and upward moving mat of trampoline

Trampoline fx is a fracture of

Proximal tibial metaphysis

Tibial tuberosity avulsion occurs in association with a ____ or _____ fx of proximal end of tibia

Comminuted or subcondylar

Tibial tuberosity avulsion fx is mc in which population

Adolescent boys

Tibial tub avulsion fx is predisposed by presence of...

Osgood-schlatter

Tibial tuberosity avulsion fx common;y occurs in athletic activities with knee ___ and the ___ tendon contracted, and firmly resisting further ____ (jumping)

Flexed, quads, flexion

Segond's fx

Avulsion fx of bony insertion of TFL (IT band) at margin of lateral tibial condyle

What other injury is highly associated with segond's fx

ACL tear (75-100%) and meniscus tears (70%)

MOI of segond's fx

Internal rotation with Varus stress (skiing, basketball and baseball)

Proximal fibula fx moi

Hyperextended knee

90% of proximal fibular fx have ___ tear

PCL

Proximal fibula fx associated with ligamentous injuries of...

Knee, fx of lateral tibial plateau or ankle

Patella fx moi

Fall on it

What is most common orientation of patella fx

Transverse or slightly oblique

What do we ddx with patella fx

Bipartite or tripartitie patella (80% are bilateral)

Where are bipartite and tripartite patella usually seen on patella

Superolateral portion (very rare location for fx)

Stellate fx aka

Comminuted

Osteochondral patella fx orientation is highly associated with

Reoccurring dislocations

how does osteochondral fx happen

Lateral dislocations of patella (mc) would avulse medial corner of patella off medial retinaculum

Most common way patella dislocates

Lateral

Patella dislocation are at increased risk with what weak muscle

Vastus medialis obliquus

Flake fx

Sliver sign: osteochondral fx associated with lateral patellar dislocations as medial facet impacts lateral femoral condyle (hallmark sign for recurring dislocation)

What imaging do we see flake fx

CT or sunrise view

Ligamentous tears and meniscal injuries are best seen on what imaging

MRI

Osteochondral fx best seen on what imaging

Xray, MRI, CT

boot top fx

Fx through both fibula and tibia near midshaft usually from skiing