48. Knee and lower leg injuries Flashcards
1
Q
What kind of joint is the knee?
A
modified hinge
2
Q
Is the head of the fibula part of the knee joint?
A
no
3
Q
What two aspects make up the knee joint?
A
tibiofemoral
patellofemoral
4
Q
What is the trochlea of the femur?
A
anatomic structure resembling a pully, which is made by the femoral condyles on either side
allows patella to slide up and down
5
Q
What 4 ligaments attach the tibia to the femur?
A
acl
pcl
mcl
lcl
6
Q
Where does the ACL arise and attach?
A
arise: medial surface of lateral femoral condyle nad inserts on anterior surface or tibial plateau within the tibial intercondylar note
(APEX)
7
Q
Where does the PCL arise and attach?
A
meedial femoral condyle to insert on the posterior surface of the tibial plateau in the intercodylar notch
(PAIN)
8
Q
What is the role of the ACL?
A
prevent excess anterior displacement of the TIBIA on the femur
control rotation and hyperextension
9
Q
MC injured ligament in the knee?
A
ACL
10
Q
What is the role of the PCL?
A
prevent excess posterior displacement of TIBIA on femur
esp in flexion
++ stronger than ACL
11
Q
Name 4 medial stabilizers of the knee
A
joint capsule
mcl
semimembranosus
pes anserine
12
Q
What is the role of the medial stabilizers of the knee?
A
resist valgus laxity and medial rotatry instability
13
Q
Where does the MCL arise from and insert?
A
medial fem condyle
onto medial tibia
14
Q
Lateral knee stability - name 2 main structures and their role
A
LCL
lateral joint capsule
resists varus deformity
15
Q
where does the LCL arise/insert?
A
lat fem condyle
onto fibula
16
Q
what structures further stabilize the lateral aspect of the knee (other than LCL, lateral joint capsule)
A
ITB
biceps tendon
portion of posterolateral corner (particularly popliteal tnedon)
17
Q
3 knee compartments
A
patellofemoral
medial tibiofemoral
lateral tibiofemoral
18
Q
What key structure is in the patellofemoral compartment of the knee?
A
quads tendon
19
Q
What key stuctures are found within the medial tibiofemoral compartment?
A
medial femoral condyle
medial tibial condyle/plateau
medial meniscus
MCL
adductor tubercle
pes anserine
20
Q
What 3 structures make up the pes anserine?
A
gracilis
sartorius
semitendinosus
21
Q
What structures are found inside the lateral tibiofemoral compartment of the knee?
A
lat fem condyle and epicondyle
lat tibial plateau/condyle
LCL
lateral meniscus
popliteus tendon
NOT FIBULAR HEAD
22
Q
What is the fabella, found in some patients?
A
sesamoid bone in lateral head of gastrcnemius
23
Q
What are the borders of the popliteal fossa?
A
lateral: biceps fem tendon
medial: semit and semimembranosus m
inferior: two heads of gastroc m
24
Q
What 4 key structures are found within the popliteal space?
A
a
v
peroneal and tibial nerves
25
What artery are you worried about in knee dislocations?
popliteal a
26
Popliteal a is a continuation of what a beyond the adductors?
femoral
27
What three arteries are part of the trifurcation of the popliteal a?
anterior and posterior tibial a --> peroneal a then branches from posterior tibial a
28
What are the a that come from the popliteal a to the knee joint?
geniculate a
29
What two nerves are responsible for innervation of the knee?
tibial
common peroneal
30
Name 7 parts of the extensor mechanism of the knee
quads m
quad tendon
medial and latearl retinacula
patella
patellar tendon
tibial tubercle
31
What holds the patella in place?
quads tendon
patellar tendon
medial and lateral retinacula
32
How does the patellar increase effective lever of the quads in the extensor mechanism?
anteriorly displaces the quad tendon
33
What is the role of the menisci?
sit on top of tibia to functin as shock absorbers, distribute stress across joint surface
deepen the tibial plateau
34
Which menisci is more at risk of injury and why?
lateral - more mobile
35
Menisci are mostly avascular, except which part?
middle 1/3 ie best chance of healing after injury
36
ITBand connection? role?
iliac crest to lateral tibial tubercle
stabilizes knee joint in extension
37
Where is the popliteus found?
lat fem condyle to posteromedial tibia, capsule and lat meniscus
38
What does the popliteus do?
- prevents ER of tibia
- withdraws lateral meniscus during flexion to prevent femur/tibia impingment
- with PCL and quads, stabilizes knee (prevents forward displacement of FEMUR on tibia)
39
Where is the prepatellar bursae?
between patella and skin
40
Where is the superficial intrapatellar bursa?
between tibial tubercle and skin
41
Deep intrapatellar bursa. - where?
posterior margin of distal part of patellar tendon and anterior aspect of tibia
42
Where is the suprapatellar bursa? True bursa?
not true
actually ext of tibiofemoral joint capssule so it grows with knee effusion
43
Does the prepatellar bursa communicate with the tibiofemoral joint?
no
44
Where is the pes anserine bursa found?
between pes anserine and mcl/medial tibial condyle
45
Per Rosen's box 48.1, what are the 5 aspects to examination of the knee?
1. Assess neurovascular integrity of the foot.
2. Determine whether a knee effusion is present, and assess for gross defor-
mity or open wounds.
3. Identify signs of infection—redness, warmth, and effusion out of propor-
tion to mechanism of injury.
4. Localize tenderness.
5. Assess for range of motion, stability, and the integrity of the extensor
mechanism.
46
List 9 sites of palpation that may be tender in the knee
1, Quadriceps tendon injury;
2, prepatellar bursitis, patella pain; 3, retinacular pain after patella subluxation;
4, patella tendon injury;
5, fat pad tenderness;
6, tibial tubercle pain as in Osgood-Schlatter, but also consider tibial plateau frac- ture in the right setting;
7, meniscus pain or arthritis;
8, collateral ligament pain;
9, pes anserine tendinitis-bursitis
47
DDX knee dislocation
Patellar dislocation, distal femur fracture, tibial plateau fracture
48
DDx distal femur fracture
Tibial plateau fracture, knee dislocation, quadriceps tendon rupture
49
DDX tibial plateau fracture
Distal femur fracture, knee dislocation, patellar fracture, patellar dislocation, tibial spine fracture, patellar tendon rupture
50
DDX tibial spine fracture
Tibial plateau fracture, patellar tendon rupture, anterior cruciate ligament (ACL) injury
51
DDX osteochondritis dissecans
Distal femur fracture, tibial plateau fracture, meniscal injury
52
ddx OA knee
Distal femur fracture, tibial plateau fracture, meniscal injury, chronic ACL deficiency, osteochondritis dissecans
53
DDX quads/patellar tendon injury
Patellar fracture, patellar dislocation, distal femur fracture, tibial spine fracture, tibial plateau fracture
54
DDX patellar fracture
Patellar dislocation, quadriceps/patellar tendon rupture
55
DDX patellar dislocation
Patellar fracture, quadriceps/patellar tendon rupture
56
DDX cruciate ligament injury
Meniscal injury, collateral ligament injury, distal femur fracture, tibial plateau fracture, tibial spine fracture
57
DDX collateral ligament injury
Posterolateral corner injury, meniscal injury, cruciate liga- ment injury, distal femur fracture, tibial plateau fracture
58
DDX meniscal injury
Collateral ligament injury, cruciate ligament injury, osteochondritis dissecans, distal femur fracture, tibial plateau fracture
59
Overuse syndromes of the knee - 3 injuries possible
Cruciate ligament injury, collateral ligament injury, osteochondritis dissecans
60
DDX for a large knee effusion
1) TRAUMA distal femur fracture
ACL or PCL injury
dislocation
tibial plateau or spine fracture
2) NO TRAUMA
insufficeincy fracture
septic arthr
inflamm arthr like gout
hemarthrosis or lipohemarthrosis from occulr fracture
avn
ruptured baker's cyst
malignancy
61
DDX for anterior knee pain
patellofemoral knee pain
Osgood-Schlatter
fracture
Saler Harris type I foemoral or tibial aphysis fracture
tibial plateau fracture
osteochondritis dissecans
quad rupture
62
Osteochondrtis dissecans gradual pain onset picture
on femoral condyle
63
Special tests for ACL:
Anterior drawer/Lachman: how to do
supine
hip at 45
knee at 90
thumb on joint line and pull tibia forward
thumbs feel for any tibia translation relative to femur
+ if > than other knee
Lachman is similar - but knee is flexed 20-30 deg
one hand to stabilize femur
then pull tibia ant and feel if can get firm or soft end point
64
Lachman grade for endpoint
1+ (0=5mm more displacmeent than N side)
2+ (5-10mm)
3+ (>10mm)
65
Posterior drawer test: how to do
The posterior drawer test can be accomplished with the patient’s knee flexed at 90 degrees and the foot stabilized by the examiner. A smooth backward force is applied to the tibia. Posterior displacement of the tibia more than 5 mm, or a soft end point, indicates injury to the PCL.
66
Posterior sag sign for PCL - how to do
supine position, and a pillow is placed under the distal thigh for support while the heel rests on the stretcher. The knee is flexed to 45 or 90 degrees. If the tibia sags backward, the test result is considered to be positive, indicating PCL insufficiency.
laso may be appreciated during passive eleva- tion of the leg in a fully extended position, with the examiner applying the elevating force at the ankle.
67
Testing for LCL/MCL laxity - how to do?
patient lying supine, the examiner applies varus and valgus stress with the knee at 0 and 30 degrees of flexion. Joint line opening is the amount of movement produced between the tibia and femur; this can be palpated and estimated in millimeters. The normal knee should be subjected to the same amount of valgus and varus stress;
68
Grading for LCL-MCL laxity - grade i vs ii vs iii
grade I (some laxity), grade II (marked laxity), and grade III (total laxity).
69
How to perform McMurray test for meniscal tears?
supine, knee hyperflex
examiner grasps foot one hand, knee with other
flex and ext knee while IR and ER tibia on femur for valgus and varus test
+ if clicking palpable at joint line, pain or locking of knee
70
What things can be seen on xray imaging of the knee (helpful findings)
FB
sublux
dislocation
fracture
jt space narrowing
71
What findings on plain XR are suggestive of ligamentous injuries of the knee?
effusion
- lipohemarthrosis suggestive of fracture if there is a linear interface between two densities
72
Ottawa knee rule indications - how old can the injury be?
7 days
73
Standard knee trauma xray views
AP
lateral
sunrise
74
What is a tunnel view of an xray and why is it helpful?
image intercondylar notch, useful for tibial spine fracture
75
what is an oblique xray of the knee helpful for?
tibial plateau #
76
Which imaging modality for knee dislocation?
cta for popliteal a
77
Ottawa knee rules:
any + = xray
age >55
patellar tenderness
isolated fibular head tneder
flexion <90 deg
inability to wbear 4 stepps immed after injury or in ED
78
Pittsburgh knee rules - any + for xray
age <12 or >50
inability to walk 4 steps
More sn and sp than ottawa
79
What kind of joint is considered a surgical emergency?
open
80
How to assess if unclear if joint is open?
ct imaging
or sterilesaline load with 200ml into joint capsule and see if comes out of laceration *don't use meythlne blue not more sn
81
What is an arthrocentesis useful to see?
effusion
hemarthrosis
lipohemoarthrosis
rheum conditions
septic arthritis
82
Five types of knee/ tibiofemoral dislocation
what are they
how is it described (ie femur and tib relation)
ant, post, med, lat, rotary
tibia relative to femur
83
Mc knee dislocation and mechanism
ant
hyperext
84
mechanism of posterior dislocation of knee
high velocity direct trauma to a flexed knee
85
Peroneal nerve assessment post knee dislocation - how to do?
sejsation dorsum of foot
dorsiflex ankle
86
Delayed complications assoc with traumatic knee dislocation
dvt
compartment syndrome
pseudoaneurysm
arterial thrombosis
87
Longer term complication of knee dislocation found in almost half of dislocated knee
heterotopic ossifciation
88
How can the popliteal a be assessed?
abi
cta
duplex ultrasound
89
ABI >0.9 - popliteal a NPV?
approaching 100%
90
Hard signs of a vasulcar injury - list 5
lack of distal pulse
palpable thrill
pulsatile hemorrhage
expanding hematoma
classic 5 p's - pain, pallor, parethesia, poikilothermia, paralysis
91
list 4 soft signs of vascular injury
decreased pulse relative to uninjured side
sign hemorrhage at time of injury
nonexpanding hematoma
peripheral n deficit
92
Knee dislocation management in the ED
1. reduce it during secondary survey asap --> traction, counter traction
2. neurovascular status
3. immobilize in a long leg posterior splint, knee 15 to 20 deg of flexion post reduction
open joint - cefazolin 2g IV
4. any hard signs of vascular injury = OR
5.soft signs = angiogram
93
Distal femur fracture complications
thrombophlebitis
fat embolus
delayed union or malunion
94
Distal femur fracture ed management
1. Pain
2. splint
3. ortho emergent
if uncomplicated fracture dislocation, can skeleton traction adn immobilixe vs intrarticular ORIF
95
Tibial plateau fracture - mechanism?
valgus force with axial loading
96
What does a segond fracture make you think of?
likely acl disruption, can occur with tibial plateau fracture
97
What neurovascular compromise can tibial plateau fractures cause?
popliteal a
perioneal n
anterior tibial a
98
What on a plain film is suggestive of a tibial plateau fracture?
lipohemarthrosis
99
Absolute indications for tibial plateau fracture ortho consult
joint instability
open fracture
nv compromise
compartment syndrome
100
ED management tibial plateau
1. pain
2. neurovascular assessment
3. knee immobilizer
4. dvt tx consideration ind basis after talking with ortho
101
Anterior tibial spine fracture - assoc with which ligament tear?
acl
102
Tibial spine fracture mechanism
knee twist
hyperflexion
hyperext
valgus/varus forces
103
xr for tibial spine fracture
ap lat
tunnel view
104
Tibial spine fracture ed management
knee immob
nwb
ortho 3-7d
105
Osteochondritis dissecans: what is this?
rare dis
adolescent
partial or torn separation of segment of articular cartilage and subchondral bone from underlying bone
106
Osteochondritis dissecans: where is this often seen in knee?
nwb lateral aspect of medial femoral condyle
107
Osteochondritis dissecans sx
pain
swelling
giving way episodes
108
Osteochondritis dissecans XR findings
subcortical lucency
osteocondral fragment
109
Osteochondritis dissecans ed management
nwb
limit activity
ortho 3-5d
110
mechanism of quads tear
sudden contraction of quads m with knee in flexed pos, laceration or direct blow
111
RF for a quads tear
ra
gout
sle
hyperparathyroidism
iatrogenic immunosuppresion with CS
?fluoroquinolones
112
Quads tendon/extensor disruption signs on exam - 4 different clinical presentations
- acute onset of pain and ecchymoses over anterior aspect of knee and palpable defect in the patella, quads tendon or patella tendon
- loss or limitation of active leg ext with ext lag noted in last 10 deg of manuever
- high riding patella iwth patellar tendon rupture and superior retraction
- low riding patella with quad tendon rupture and inferior retraction
113
quads tendon rupture image findings
xr - patella alta with Insall salvati ratio (patellar length to patellar tendon length ratio if <0.8 = +)
obliteration of quad or patella tendon
calcific defnsities
if partial --MRI best
114
ED management of quads/patellar tendon tears
knee immob
nwb
ortho 1 wk
115
Patella fractures: xr to do
ap
lat
sunrise
116
Patellar fractures: classifcation
transverse
stellate
comminute
lorg or marginal
prox or distal pole
117
patellar dislocation mechanism
valgus stress on a flexed knee = ER of leg
118
Patellar dislocation closed reduction technique
knee passively ext while inferomedial directed pressure applied to patella
119
post patellar reduction, need xr. why?
ensure no osteochondral avulsion fragment as may need arthroscopy for removal
120
post reduction of patella dislocation: ed management
knee immob in full ext
f/u ortho 1-2 weeks
121
Unhappy triad
acl
mcl
medial meniscus tear
122
Unhappy triad actually less common than what triad seen?
acl
mcl
lat meniscus
123
PCL injury mechanism
posterior force on flexed knee
124
MCL injury mechanism
direct blow or impact to lateral knee
125
LCL injury mechanism
hyperextension with varus stress
with direct blow or rotation
++ peroneal nerve assessment
126
XR for cruciate and collateral liagment injuries
AP
lat
sunrise
intracondylar notch views
127
Manageemnt of isolated ligament knee injuries in the ED
fully unlocked
hinged knee brace with w bearing as tolerated
ortho f/u 1 week
128
Meniscus tear - which part most often injured?
posterior due to increased forces on posterior horn with knee flexion
129
Which part of meniscus has best blood supply?
lateral
but unfortunately medial most often injured
130
Meniscus diagnosis in the Ed?
Not really
MRI and arthroscopy best
131
132
Management of meniscus in the ED
Unlocked hinge knee brace
Crutches
Ortho follow up
133
Patellofemoral syndrome epidemiology
Women
20 and 30
Gradual no trauma
With pain after ongoing flexion
134
RF patellofemoral syndrome
Glute weakness or quad
Patella subluxation
Prepatellar bursitis
Arthritis
Meniscus tear
Quads and patella tendinipsthy
135
Physical exam patellofemoral syndrome
Med and lat patella tender
Recreate on single leg squat
136
Management of patellofemoral pain
NSAID
Pt
137
ITB syndrome - in who? Where?
Runners
Lat femoral epicondyle
Pain or tightenness by ober test
138
How to perform ober test?
Injured leg up on side
Flex 90, 90 hip and knee
Abduction hip, knee extend then hip aducted
If can’t do above adduction with gravity or get pain same spot indicates tight
139
Treatment ITB syndrome
Relative rest
NSAID
Pt
140
Patellar tendon path y management
Relative rest
PT
Anti inflam
141
Plicq syndrome what is this?
Ongoing embryonic tissue in the knee that may thicken tissue due to ongoing repetitive movement or minor trauma
142
Plica syndrome findings on exam and imaging
Medial femoral condyle tender
Snap or pop - worse run or sit
Arthroscopy as often won’t see mri
143
Plica syndrome management
Pt
NSAID
While awaiting ortho appt
144
Classic presentation of popliteal tendinopathy
Increasing posterior knee pain going down hill
145
Webb test for popliteal tendinopathy
Differentiate from bicep fem tendinopathy or lat meniscus or ITB
Supine, flex knees to 90. Rotate leg IR, then resist examiner ER
If + pain = + test for pop tendinopathy
146
Bursitis is a ___ dx
Clinical
147
Standard fluid studies for bursitis
Pro
Glucose
Gram stain and culture
Cell count
Crystal analysis
Plus Lyme and gonorrhea if warranted
148
Septic bursitis without joint involvement management
Abx
Staph aureus x10d
Fail = I and d
149
Aseptic bursitis management
Drainage
Then compression
Ice rest
NSAID
150
OA on X-ray
Osteocytes
Subchondral cyst
Subchondral sclerosis
Joint space narrowing
151
Management of OA
Pt
NSAID and Tylenol
Limited use of CS
152
What is a baker cyst?
Herniation of synovial membrane through posterior aspect of knee capsule
153
Signs of baker cyst
Posteromediak corner of knee mass
Pressure pain limited rom
R:o dvt
154
Tx of bakers cyst
NSAID
Rest
Compression
Output drainage
155
3 a of the lower leg
Come From popliteal a
Anterior tibial a
Posterior tibial a
Peroneal a
156
4 compartments of the lower leg
Anterior
Lateral
posterior superficial and deep
157
Lateral compartment m
Peroneus longed and Brevis with superficial peroneal n
158
Superficial posterior compartment of leg structures
Gastroc
Soles
Plantaris
Sural nerve
159
Deep posterior compartment of leg structure
Rib post
Long toe flexor m
Posterior tibial and peroneal a
Tibial n
160
Subcondylar tibial fracture: associated with which knee fracture?
Tibial plateau
161
Subcondylar tibial fracture mechanism
Rotational stress and vertical compression
162
Tibial tuberosity fracture: type I
Incomplete avulsion
163
Tibial tuberosity fracture: type ii
Complete avulsion extra articular
164
Tibial tuberosity fracture: type iii
Complete avulsion
Intraarticular
165
Which subcodnylar tibial fractures require or?
Intraarticular
Communuted
Displaced
High risk for compartment syndrome!!
166
Two classification systems for tibial tubercle fractures
Ogden
Watson - Jones
167
Name the Ogden classification types of tibial tuberosity fractures
Type 1: secondary ossification fracture
2- fracture between primary and secondary centres
3- fracture extender primary centre of ossification site
4- entire proximal tibial physis fractured
5- sleeve avulsion fracture from secondary ossification centre
A- nondisplaced
B- displaced
168
Tibial shaft fracture high risk of which n injury?
Peroneal
169
RF of tibial shaft fracture
Dvt
Fat embolus
Non union
Pseudoaneurysm
Av fistula
170
When to add gent to open fracture?
Severely contaminated
171
When to add pen G to open wounds)
Farm related
172
When to add pseudomonas coverage to open wound?
Fresh or saltwater
173
Recommended splint for tibia shaft fracture
Long leg posterior sugar tong component
174
Maissoneuve fracture components
Medial ankle disruption with a deltoid lig tear or fracture at medial mall
Complete syndesmosis tear
Proximal fib fracture
175
Isolated fibula fracture management
Ice
Analgesia
Stirrup splint
NWB
176
When to consult ortho for fib fractures (immediate)
Maissoneuve
Fracture of fib severely displaced or with peroneal n injury
177
Mc tib fib joint dislocation
Anterolateral
178
Posteromedial tibfib joint dislocation nerve injury risk?
Peroneal
179
Proximal tib fib joint dislocation - relocation technique
Knee at 90, every ankle and direct pressure on fibular head
Then to ortho!
180
Mc sites stress fracture
Tib fib femur navicular metatarsal bones
181
Stress fracture (general) management
Decrease activity 3-6 weeks to heal
182
Which stress fractures need to be made NWB given risk of progression complete fracture?
Ant TiB
Navicular
Fifth metatarsal
Patella
Seamus
Superior sided femoral neck
183
Why does medial tibia stress syndrome/shin splints occur?
Periostitits
Lack of discrete fracture line
184
