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Flashcards in The Knee Complex Deck (69):
1

The knee joint is made up of:

three articulating surfaces, forming two distinct joints contained within a single joint capsule

2

which joints make up the knee joint

patellofemoral and tibiofemoral

3

Two types of swelling seen in the knee

localized (bursal)
generalized (intra-articular or synovitis)

4

genu recurvatum

hyperextension of the knee

5

The incidence of hyperextension is higher among?

females and individuals with longer/lax ligaments

6

Tibiofemoral joint

distal end of the femur and proximal end of the tibia

7

What type of joint is the tibiofemoral joint?

ginglymoid or modified hinge

8

knee joint stability is dependent on:

static restraints of the joint capsule, ligaments, and menisci and the dynamic restraints of the quadriceps, hamstrings, and gastrocnemius

9

Femoral condyles

project posterior from the femoral shaft

10

Medial femoral condyle

elliptical shaped
faces inward

11

lateral femoral condyle

smaller, ball shaped, faces inward

12

the medial femoral condyle is

the insertions for adductor magnus and MCL

13

the lateral femoral condyle is

the origin for the lateral head of the gastrocnemius and LCL

14

patellofemoral joint

a complex articulation, dependent on both dynamic and static restraints for its function and stability

15

The quadriceps Angle

aka the q angle
formed by the bisection of two lines
one from ASIS to center of patella and the other drawn from the center of the patella to the tibial tubercle

16

Common ranges of the Q angle

8-14 in males and 15-17 in females

17

A q angle greater than what is considered abnormal?

angles greater than 20
may be indicative of potential displacement of the patella

18

Increased Q angle leads to what sign?

bayonet sign

19

patella baja

a lower posture of the patella

20

patella alta

a higher posture of the patella
makes the patella less efficient in exerting normal forces

21

Knee joint capsule

composed of a thin, strong fibrous membrane
largest synovial capsule in the body

22

the synovial mambrane excludes

the cruciate ligaments from the interior portion of the knee joint, making them extrasynovial yet intra-articular

23

Proximal tibiofibular joint

an almost plane joint with a slight convexity on the oval tibial facet and a slight concavity of the fibular head

24

Osgood-Schlatter's syndrome

Partial disruption at the patellar ligament- tuberosity attachment creating localized inflammatory changes

25

predisposing factors to Osgood-schlatters

tight hamstrings, tight heel cord, and tight quadriceps

26

Who is osgood-schlatters commonly seen in

males more than females, ages 10-15

27

the static stability of the knee joint complex depends on

anterior cruciate ligament
posterior cruciate ligament
medial collateral ligament
lateral collateral ligament

28

What ligament restrains anterior translation

ACL

29

What ligament restrains posterior translation

PCL

30

What ligament restrains valgas rotation

MCL

31

What ligament restrains varus rotation

LCL

32

What ligament restrains lateral rotation

MCL, LCL

33

What ligament restrains medial rotation

ACL, PCL

34

Cruciate Ligaments

intra-articular, extra-synovial
different from those of other joints in that they restrict normal motion rather then restrict abnormal motion

35

Which is one of the most important ligaments in knee stability?

ACL

36

ACL

serve as a primary restraint to anterior translation of the tibia relative to the femus and secondary restraint to both internal and external rotation in the non weight bearing knee

37

Most common MOI in an ACL tear

sudden deceleration with an abrupt change of direction/speed and a fixed foot (closed kinetic chain)

38

PCL

provides 90-95% of total restraint to posterior translation of the tibia on the femur

39

After the PCL, what provides restraint to posterior translation of the tibia on the femur?

the collateral ligaments, posterior portion of the joint capsule, and popliteus tendon

40

Common MOI in a PCL tear

excessive hyperflexion
hyperextension

41

Dashboard injury

with the knee in 90 degrees of flexion can drive the tibia posterior and cause a PCL tear

42

MCL

anterior fibers are taut in flexion, broad and fan shaped
posterior fibers are taut in extension and blend with the capsule

43

LCL

main function is to resist varus forces

44

Where does the LCL provide a majority of varus restraint?

at 25 degrees knee flexion and full extension

45

Secondary collateral restraints

hamstrings and quadriceps
patellar ligament, oblique popliteal ligaments, and the fabella

46

Medial meniscus

semi-lunar
larger and thicker than lateral meniscus

47

Lateral Meniscus

o-shaped
sits atop the convex lateral tibial plateau attached by coronary ligaments
more mobile than medial meniscus
two meniscofemoral ligaments attach to the lateral meniscus

48

Functions of the Menisci

load transmission, shock absorption, joint lubrication, joint stability, and the guiding of movements

49

A meniscectomy can reduce the shock-absorbing capacity of the knee by

up to 20%

50

Triad of O'Donoghue

Rupture of ACL, MCL and medial meniscus
aka terrible triad

51

Housemaid's Knee

aka prepatellar bursitis
subcutaneous swelling over the lower half of the patella and upper half of the patellar ligament

52

MOI of housemaid's knee

overuse, as with frequent kneeling
direct blow to the area

53

Clergyman's knee

aka infrapatellar bursitis
swelling on both sides of the patellar ligament

54

MOI of clergyman's knee

repeated trauma to the region of the tibial tuberosity

55

Superior lateral border of the popliteal fossa

biceps femoris tendon

56

Superior medial border of the popliteal fossa

semitendinosus and semimembranosus tendons

57

inferior borders of the popliteal fossa

two heads of gastrocnemius

58

Contents of the popliteal fossa

posterior tibial nerve, popliteal artery and nerve

59

Baker's cyst

escaped synovial fluid in an enclosed membrane sac which is protruding through the joint capsule of the knee

60

What is baker's cyst associated with?

RA

61

Plica

represents a remnant of three separate cavities on the synovial mesenchyme of the developing knee

62

Retinacula

formed from structures in the first and second layers of the knee joint
can be subdivided into medial and lateral

63

Major muscles that act on the knee joint complex

quadriceps, hamstrings, gastrocnemius, popliteus, and the hip adductors

64

Extension lag

the arc of flexion and extension should be smooth, pt may be unable to extend the knee through the last 10 degrees and may only finish with great effort

65

extension lag occurs with

quadriceps weakness

66

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

67

the final locked knee extension allows

the patient to maintain knee extension for prolonged periods of standing without relying on muscles

68

Major blood supply to the knee comes from

femoral, popliteal, and genicular arteries

69

pain can be referred to the knee from

L3 through S2 nerve roots