Knee Flashcards
how long will it take to lose 50% of mechanical strength following immobilization of knee
6-9 weeks
Which is faster healing at bone insertion or mid substance of ligament
bone insertion, mid substance has poor blood supply
When is the anterior medial bundle of ACL most taught
flexion
When is the posterior lateral bundle of ACL most taught
extension
Knee extension mechanics
Tibiofemoral anterior glide increases extension
Knee flexion mechanics
Tibiofemoral posterior glide increases flexion
What does joint effusion indicate?
ACL injury 0-2 hours
Traumatic meniscus injury 6-24 hours
What angle is most sensitive for valgus and varus stress testing
20-30*
When (-), we are confident it is not torn
What does the lochman’s test for
ACL laxiity for posterior lateral bundle
gold standard
Medial Meniscus traits
Shaped like MOON
Connected to SeMI-MEMBranosus
More stable
What type of effusion will happen if articular cartilage is affected
fast onset?
Hallmark signs of meniscus tears
Joint line tenderness *
Effusion
Positive entrapment tests: McMurray* Appley, Squat (max knee flexion)
Quad atrophy/inhibition
catching and locking *
pain with forced hyper ext
* meniscal pathology compotie score >3
good prognosis for meniscus tear
Under 35 years old
Peripheral damage
Longitudinal or short tear type
Acute injury with a bloody effusion (indicates good healing)
Stable joint
Bad prognosis for meniscus tear
Central damage
Complete or bucket handle tear
Chronic
Unstable joints
Older age
weight-bearing fees for meniscus repair
4 to 6 weeks then proceed with range of motion wisely or else if usual increase
indications for meniscus repair
Trauma lesion in vascular zone
Intact peripheral circumference fibers
Minimal damage to meniscus body Longer than 8 mm
KIssing defect
Occurs in traumatic Articular cartilage injuries
G2 articular lesion
<50% of cartilage is affected
G1/2 are typically asymtomatic
G3 articular damage:
> 50% articular damage to calcified layer, but not through sub subcholdral bone
Fracture surgery for articular cartilage injury. Wbing phase, population
Encourages blood flow by with fibrocartilage replacement from native hyline card which
Controlled weight-bearing for six weeks not that great for very active patients
ACI surgery for articular cartilage injury
Two-step procedure for extraction, harvesting, and planting. Good choice for big lesions
OATS surgery for articular cartilage injury
FOR Full FITNESS DEFECTS. ADDRESSED WITH PRESS AND FIT PLUGS harvested FROM NON-WEIGHT-BEARING SURFACE. CPM IS NEEDED TO AVOID COBBLESTONE AFFECTS PASSIVE RANGE OF MOTION IS VERY MUCH INDICATED
Ottawa knee rules
> 55 years
Tenderness at fibular head
Isolated patellar tenderness
Unable to flex knee beyond 90° Unable to to weight bear (4 steps immediately or not presentation)
red flags to suspect fracture of knee
trauma osteoporosis postmenopausal female
red flags to suspect AVN of knee or hip
Trauma corticosteroid therapy for over three months, EtOH, HIV, lymphoma or leukemia, blood diagnosis chemo/radiation
Pediatric red flag conditions
transient synovisits
LCPD SCFE
Wells criteria
Cancer, immobilization greater than three days, greater than 3 cm calf girth, superficial veins but not very close, swollen leg, local tenderness in Venice system, putting edema, unilateral paralysis/paresis, plaster mobilization previous DVT.
+ one for each -
2 for alternative diagnosis
>2 equals likely
Sinding Larsen Johansson syndrome
Apophysitis patellar tendon
When’s suspecting apophysitis versuvs.s avulsions, which is more common in the knee
Apophysitis is seen in growth years. Avulsions are uncommon at knee versus ASIS of hip. Treated with low reduction
Osgood-Schlatter disease
Apophysitis of tibial tubercle
Detest posterior lateral corner of the main
PLC tested with extra rotation. If Posterior drawer at 30° positive suspect isolated poster corner injury
ACL mechanism of injury
contact: Valgus with fixed foot
Non- contact: IR and valgus collapse
PCL mechanism of injury
Hyper flexion, posteriorly directed force, Deep squat landing with speed from height
Most specific PCL tests
Postier sag and quad activation test
Following PCL tear, when should you suspect posterior lateral injury
increased laxity with posterior drawer test combined with external rotation
Test results for PCL or PLC injury
Post. Latereal corner may be injured and detected with testing of 30* of Post drawer test, but (-) at 90*
Prone extension rotation test (dial test) positive when greater than 10° movement occurs.
Testing at 90° of dial test may indicated PCL involvment
What is the mechanism of a posterior lateral corner injury, what test to perform based on MOI?
hyper extension or posterior blow to proximal tibia
Post drawer at 30* > Dial test 30*
MCL mechanism of injury
Valgus force or rotation
Which ligament should be suspected next if MCL is injured
ACL or PCL involvement. If greater than 10 mm involvement is present suspect ACL involvement
Who is a ACL Cooper
No effusion
Quad index > 70%
Normal gait pattern
Timed 6 m hop test
80% ACL-KOS
GROF 60 %
Criteria must a patient present in order to go through screening process for ACL copping
Isolated ACL injury
full range of motion no pain,
no joint effusion
MVIC 70% uninvolved side
Differences between traumatic and degenerative meniscus injuries
Traumatic meniscus injuries will occur and younger patients with CKC, non-twisting MOI. Will have delayed effusion (6–24 hours). Mechanical symptoms are more likely to need surgery
Degenerative injuries are more common in older adults, most often do not require surgery and are present and 91% of OA cases
Meniscal pathology CPR
Catching/Locking, Pain with forced hyper extension pain with max knee flexion, + McMurray’s test, joint line tenderness. When ACL injury is also present positive prediction value decreases. When degenerative joint disease is present PPV increases.
What is the most specific test for a meniscus injury
Thessaly
Patellar tendinopathy
Treated with Isometrics
What is the consideration of treating quadriceps tendon apathy versus patellar tendonopathy
Avoid deep knee flexion when treating quadriceps tendinopathy
What is the most sensitive test for a meniscus injury
Joint line tenderness
Patellofemoral pain syndrome
Movie goers sign
Treated with taping
Retro-patellar or Peri-patellar pain aggravation with squats stairs and sitting. Occurs in females and related to muscle force imbalances of hips. Poor motor control, hyper mobile foot and PF floor joints in addition to poor flexibility of quads and hamstrings are attributed.
SUSPECT APOPHYSITIS IF NEW LOADS AND GROWTH YEARS ARE IN CASE
Patellar tendinopathy loading and analgesia program
- 5x45” with taping and strapping
- Slow isotonic loading
- plyos
4 sport specific
Pain under 5/10 immediately after or morning after progressed, next stage at minimum of one week before phase progression . Each phase should have 3/10 pain or less eccentric exercises are not superior to isotonics
How can you distinguish tendinopathy versus tendinitis or bursitis
Swelling or tenderness over bursa
Swelling or tenderness over bursa
What are anterior knee pain classfications
Patellofemoral pain and Tendinopathy
How do you distinguish btwn anterior knee pain tendonitis and PFPS
general anterior knee pain will fall intp classification based on impairment. PFPS is a dx of exclusion and will have retro or peripatellar pain. Will be activity related and have pain with SSS (stair, squat, sit)
Tendonitis: Agg with deep knee flexion, so avoid this initially.
What are the subcategories for anterior knee pain syndrome
Overuse/load without other impairment
PFP with movement coordination
PFP performance deficit
PFP with mobility impairment
How does TX differ between anterior knee pain classes: Overuse/load without other impairment
PFP with movement coordination
PFP performance deficit
PFP with mobility impairment
Overuse/overload without other impairment: Taping an activity modification if pain with eccentric step down
Movement coordination deficits: Poor performance of valgus step down or single leg squat, trouble controlling frontal plane movement. Address gait and movement retraining
Muscle performance deficit : MMT testing. Address hip glutes and quad strength
Mobility impairment: Look at foot mobility and patellar tilt test for deficit. Also look at range of motion and flexibility for hip and ankle. Treat with foot orthoses muscle stretching and STM as needed
how is chondromalcia differeant form PFPS
Chondromalacia will hace observable changes to cartilage
What is the most vulnerable position for patellar dislocation
20 to 30° knee flexion
Tests for anterior knee pain/ PFPS
Waldron I and II, Clarke, Grind, Compression
what is a lateral patellar retinacular release
To decompress lateral facet. Can be performed with TKA to improve congruency of of parts due to valgus deformities, or if cartilage debridement is performed and decrease the peak force over the PFJ. This can help with PFJ OA in the future
what is a lateral patellar retinacular release indicated?
recurrent dislocations, but not joint instability
not alone or wihtout objective reason, therefore impariements must be there and seen with testing
Shouldnt extned below VMO or distal to Gerdys tubercle
Plication can help with success
What attaches to Gerdys tubercle
The ITB is generally viewed as a band of dense fibrous connective tissue that passes over the lateral femoral epicondyle and attaches to Gerdy’s tubercle on the anterolateral aspect of the tibia. ITB friction syndrome is an overuse injury well recognized as a common cause of lateral knee pain.
When would suspect plica syndrome before other types of knee pain
Antero-medial knee pain
will not have effusion or swelling
Locking and catching will be present
Painful/Decreased knee flexion and kneeling if torn
Rule out with imaging and rule otu other Dx before hand
What are gait compensations following patellar subluxation
Reluctance to complete knee extension- avoidance of going into full range of motion during gait
prolonging stance phase
At which range of knee flexion is the most pressure exerted over the proximal patella
45 to 60°
Knowing which range the patella is most compresses, what ranges of knee flexion should use used for OKC and CKC exercise
OKC 0-10 and 90-50
CKC 0-50
What type of forces are converted over the patellar surface and for what functional use
The patella converts tensile forces to compressive forces which is useful to the deaccelerate walking downstairs
what are risk Facors for meniscal tears
cutting and pivoting
increased age
delay in ACL repair may lead to future tears
Female *
lower activity *
increased BMI*
* medial meniscus risk factors, others are both sides
Osteochondral fracture differnece btwn meniscus injury
Hemarthosis will be faster (within 2 hours ) and ACL will most likely be involved
Meniscus will hve delayed effusion 6-12 hours
B level recommendations for meniscus surgery
Menisectomy vs Repair not specified.
Supervised progressive ROM, strength, motor control, early Progressive ROM, supervised PT is better than HEP preferred for functional measures,NMES quad strength, functional and performance exericses should be inclided.
Knee Ottowa rules
X ray is needed if:
>55 years with acute injury
Isolated patella tenderness
FIbular head tenderness
unable to flex to 90*
Non-WBing or unable to take 4 steps imm or at eval
What are considerations for tibial eminence fractures?
Most often happen in peds due to weak subchondral bone. Hemaarthorosis may be present. Fracture occurs due to weaker subchondral. Bone failure occurs prior to ACL failure in young bones. Equvilent to ACL tear in children.
Mobilization for six weeks range of motion will start early at two weeks
what are considerations for patellar fracture
occur mostyl in closed setting, but when open fx occurs it often also has a acetabluar fracture
Majority are due to a direct blow and will result in a disruption to extensor mechanism
what surgical complications include risk patellar fracture
TKA
ACLR
what are indications to try conservative mgmt of patellar fx
extensor mechanism and no dislocation risk must be evident
what are considerations for tibia fracture
increased risk for increased compartment pressure, check for dorsalis pedis pulse and post-tib A
Knee OA criteria
age > 50 years, morning stiffness < 30 min, crepitus, bony tenderness, bony enlargement, and no palpable warmth.
What injuries accompany articulate cartilage injuries
WIll be seen with medial meniscus tears or ACL tears.
Suspect a ligament first and rule out then osteochondral defect
Will have fast onset of effusion 2 hours, Faster than meniscus injury.
Hemarthrosis will be present. Likley to occur with 2nd ACL.
The primary component of articular cartilage is:
Type 2 collagen
You are seeing a patient who is 5 weeks s/p ACL reconstruction with a bone-patellar tendon-bone autograft. Which of the following interventions is inappropriate?
Open chain leg extensions between 60 and 30 degrees’
Correct: OKC knee extension has been shown safe between the ranges of 90-70 degrees. Anything greater than 70 degrees will put increased stress through the patella, and can lead to increased anterior shear of the tibia.
What are indications for a Microfracture surgery?
2x2cm, which is well within the capacity for a microfracture technique.
Articular cartilage surgery: Good for 1st line of surgery choice-OATs procedure is too extensive of a procedure for 1st line intervention.
relationship between the native articular cartilage and new cartilage?
Type 2 collagen, the hyaline cartilage is replaced by fibrocartilage (T3), which has decreased resilience compared to native tissue
fibrocartilage has inferior stiffness and resilience, and poorer wear characteristics than does normal hyaline or hyaline-like articular cartilage
When do you suspect surgical error with ACLR?
Severe ROM deficit in 1 direction.
Anterior placement of the femoral tunnel: presentation of full knee extension, but is limited to 75 degrees knee flexion. Complaint of knee pain, especially in his posterior calf and in the popliteal fossa. He has mild-moderate joint effusion
What is the Arcuate complex and what is its role in the knee?
Supports the posterior lateral region. Consists of LCL, arcuate ligament and is reinforced by the biceps femoris and popliteus tendons
meniscus ligaments and capsule involement
-Connected to tibia via transverse ligament
.Connected to patella by patellomeniscal ligaments, which are extensions of the anterior capsule.
Lateral meniscus connects to popliteus and PCL, and to the medial femoral condyle via the meniscofemoral ligament
Posterior lateral corner of meniscus anatomy and
Lateral menisci, located outside of capsule and is separated by popliteus tendon. Avascular therefore limited in healing potential
Lateral meniscus
LOOSE (less mobile than) medial meniscus connects to populates,
posterior lateral corner is avascular. Anterior horn of the lateral meniscus shares insertion wtih ACL on tibia
Secondary MCL roles
Decrease anterior tibial translation. When MCL is injured, more demand is placed on ACL
3 primary stabilizers of the PLC
LCL, popliteofibular ligament (PFL), and popliteus tendon.
screw home mechanism
occurs in OKC
Lateral rotation of the tibia during terminal knee extension in order to lock the knee in extension.
IR of tibia must occur to allow the knee to unlock and initiate flexion from a fully extended position
which x ray view is to view the troclear groove
Sunrise view
Groove that patella sits in
Lateral ridge is higher
genu valgum and varum ranges
genu valgum >185° or knock knee Increased F over lateral knee and medial side is distracted
genu varum <175° or bow legged
progresion of tests to perform for ACL, PCL, LCL and MCL
ACL Lochman > Pivot shift. Lochman is most SP
PCL Posterior drawer > PLC if ER is also affected (Sag Quad activation test most SP)
LCL: Test in full ext
MCL: test at full ext, if >5mm movemetn than test ACL and PCL. Most SP for MCL and LCL is testing at 30*
graft is weakest at what point in rehab
12 weeks after surgery
