The Knee - Lecture Flashcards
Name the two distinct joints within a single joint capsule of the knee.
Patellofemoral and Tibiofemoral
T or F
Localized swelling of the knee is usually caused by intra-articular (synovitis) problems
False
Localized swelling = bursal
Generalized swelling = intra-articular
T or F
Normally the tibia has a slight vargus angulation in comparison with the femur
False
Valgus
Are these matched correctly:
Bowleggedness = Varus
Knock Knees = Valgus
True
What is meant by the term Genu Recurvatum and in what populations do we see it occur more often?
Hyperextension of the knee
- higher amongst females and individuals with “lax” ligaments.
- taller ppl
- important to look at the elbows and if they are similar it could indicate a systemic problem = endocrine problem
T or F
The lateral supracondylar ridge of the tibia has a bigger surface area compared to the medial.
False
What do the intercondylar areas of the knee do?
Serve as attachment sites for the ACL and PCL
What type of joint is the Tibiofemoral joint?
Ginglymoid or modified hinge joint
What does it mean for a joint to be ginglymoid?
It has spin
In what direction do the femoral condyles project from the femoral shaft?
Posteriorly
T or F
The smaller lateral femoral condyle is an elliptical-shaped and faces outward, and the ball-shaped medial femoral condyle faces inward.
False
Lateral = ball-shaped Medial = elliptical
What meniscal injury is considered more serious and why?
Medial
The meniscus and the tibial collateral ligaments are all directly attached to each other and if you blow one out the other goes with it.
The medial condyle of the distal femur serves as an attachment for what structures?
Adductor Magnus
Medial Collateral Ligament
The anterior-posterior width of the medial femoral condyle is greater than the lateral by approx how much?
1.7cm
T or F
The tibial plateaus are concave in a medial-lateral direction
True
Describe the joint surfaces in the anterior-posterior direction of the tibial plateaus that help to produce more symmetry and to increase lateral mobility
The medial = concave
Lateral = convex
The posterior surface of the patella can include up to how many facets?
7
What is an aka for the edges of the patella?
Poles
Describe the relationship of the patella and the trochlear groove in flexion and extension
Patella is fixed in the groove in flexion and mobile in extension
What lines are drawn to determine the Q angle?
1 from the anterior superior iliac spine to the centre of the patella and the 2nd from the centre of the patella to the tibial tubercle.
T or F
The most common ranges of Q angle for females is 8-14 degrees and males s 15-17 degrees
False
Males = 8-14 Females = 15-17
T or F
Angles more than 15 degrees are considered abnormal
False
20 degrees
What is the Bayonet Sign?
Increased Q angle where the alignment of the quadriceps, patellar tendon, and tibial shaft resembles a French bayonet.
What is a common finding in patients with patella femoral arthralgia?
Q-angles with the knee in full extension is only slightly increased over normal however, with the knee flexed at 30 degrees there is failure of the tibia to derogate normally and failure of the patellar tendon to line up with the anterior crest of the tibia.
Patellar stability depends on what 2 factors?
Static restrains
Dynamic Restraints
How does the patella travel in flexion?
In a path inferiorly?
T or F
When the knee is extending the patella travels superiorly
True
The patella will move and cover a distance of how many cm when the knee is flexed or extended?
5-7cm
In what degree of flexion does the patellar articular surface squarely contact the anterior femur?
45 degrees
T or F
Patella baja makes the patella less efficient in exerting normal forces
True
Why are the cruciate ligaments considered to be extrasynovial yet intra-articular
The synovial membrane lines the joint capsule but excludes the cruciate ligaments from the interior portion of the knee joint.
T or F
The proximal tibiofibular joint has more motion than its distal partner.
True
Repetitive stress on the knee causing retraction of the tibial tuberosity and creates localized inflammatory changes is describing what condition?
Osgood-Schlatter’s Syndrome
What are some predisposing factors for Osgood-Schlatter’s Syndrome?
Tight hamstrings
Tight heel cord -Achilles
Tight quadriceps
T or F
Males suffer more frequently with Osgood-Schlatter’s than females
True
Name the 4 main ligaments providing joint stability of the knee
Anterior Cruciate
Posterior Cruciate
Medial Collateral - Tibial Collateral
Lateral Collateral - Fibular Collateral
Are these matched correctly:
Valgus rotation restraint = LCL
Varus rotation restraint = MCL
Anterior translation = ACL
Posterior translation = PCL
No
Valgus = MCL Varus = LCL
What ligaments restrain lateral rotation of the knee?
MCL
LCL
T or F
Medial rotation is restricted by the PCL and MCL
False
ACL and PCL
Why are the cruciate ligaments of the knee different than those of other joints?
Because they restrict NORMAL motion rather than ABNORMAL motion
T or F
The ACL and PCL are both named according to their attachment points on the Femur
False
based on their attachment sites on the Tibia
What ligament serves as the primary restraint to anterior translation of the tibia, secondary restrain to both internal and external rotation in the non-weight bearing knee?
ACL
Most common MOI for a ACL tear?
Sudden deceleration with an abrupt change of direction/speed and or velocity and fixed foot
MOI for a PCL tear?
Excess hyperflexion (forced bending)
Hyperextension - leg bent backwards
Dashboard injury - when the knee is bent to a right angle and a sudden force drives the tibia backwards
T or F
The anterior fibres of the MCL are taut in flexion and broad and fan shaped
True
The posterior fibres of the MCL are taut in flexion or extension?
Extension
When does the LCL offer the majority of the varus restraint?
At 25 degrees of knee flexion and in full extension.
T or F
The menisci are hyaline cartilage
False
Fibro
T or F
The medial meniscus is larger and thicker than the lateral
True
T or F
The medial meniscus is wider anterior than posterior
False
Which of the menisci are rounder O shaped?
Lateral
What shape is the medial meniscus?
C shaped
T or F
The medial meniscus is more mobile than the lateral
False
Name the numerous functions of the menisci
Load transmission Shock absorption Joint lubrication Joint stability Guiding movements
A meniscectomy can reduce the shock-absorbing capacity of the knee by up to what %?
20
What is the Triad of O’Donghue
Rupture of the MCL, ACL, and Medial Meniscus
Housemaid’s Knee aka ?
Prepatellar Bursitis
What is Housemaid’s Knee?
Swelling that occurs subcutaneously over the lower 1/2 of the patella and the upper 1/2 of the patellar ligament.
MOI for Prepatellar Bursitis?
Overuse
Direct blow to the area
Chronic friction such as from frequent kneeling
Clergyman’s Knee aka ?
Infrapatellar Bursitis
The superior lateral border of the popliteal fossa = ?
Biceps Femoris tendon
Superior medial border of the popliteal fossa = ?
Semitendinosus & Semimembranosus
The 2 heads of the gastrocnemius form what side of the popliteal fossa border?
Inferior border
What are the contents of the Popliteal Fossa?
Posterior Tibial Nerve
Popliteal Artery
Popliteal Nerve
An escaped synovial fluid in a enclosed membrane sac which is protruding through the joint capsule of the knee is called?
Baker’s Cyst
Baker’s Cysts are often associated with what other condition?
RA
What is a Plica?
Synovial plica represents a remnant of the 3 separate cavities in the synovial mesenchyme of the developing knee
When a patient may be unable to extend the knee through the last 10 degrees of motion or finish with great effort this is known as? Usually caused by?
Extension Lag
Weak Quadriceps
What is meant by Helfet’s Helix?
The knee cannot fully extend without some amount of external tibial rotation on the femur because of the physical configuration of the knee joint and its cruciate ligaments.
The major vascular supply to the knee includes what arteries?
Femoral, popliteal and genicular arteries
Knee pain can be referred to the knee from the lumbosacral region. What spinal segments correlate with this?
L3 - S2
How many degrees of flexion are in the knee?
135