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*