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Flashcards in Knee pathologies Deck (74)
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1
Q

Meniscal tears - What are menisci?

A

C shaped discs of fibrocartilage which only have a blood supply at the periphery
Look triangular on MRI (bowtie appearance)

Acts as a cushion between the femur and tibia
Shock absorbers

2
Q

Meniscal tears - which menisci (MEDIAL/LATERAL) is more likely to be torn?

A

Medial

  • as it is fixed and less mobile than the lateral meniscus
  • as the knee pivots more on the medial meniscus
3
Q

Meniscal tears - definition

A

Rupture of the menisci

4
Q

Meniscal tears - causes

A

Sporting injury

Getting up from a squat

5
Q

Meniscal tears - mechanism of injury

A

Twisting or turning quickly often while the foot is planted with the knee bent

6
Q

Meniscal tears - clinical features

A

Very localised pain (usually at medial joint line)
Sudden pain
Sharp pain
Locking sensation (patient can’t fully extend the knee)

7
Q

Meniscal tears - examination

A

Effusion (collection of fluid) develops by the next day
Joint line tenderness
Steinmann’s test

8
Q

Meniscal tears - investigations

A

MRI (to confirm clinical suspicion)

9
Q

Meniscal tears - management

A

Limited healing ability as they only have a peripheral blood supply
RICE
Physio
Consider arthroscopic meniscectomy for mechanical symptoms for irreparable tears / failed meniscal repair

10
Q

Meniscal tears - radial tear

A

Shouldn’t be painful

Won’t heal

11
Q

Meniscal tears - bucket handle tear

A

Meniscal tear flips out of normal position and physically jams in the knee. This prevents the knee from going straight, limits extension so the patient suddenly can’t fully extend the knee. This results in true knee locking

12
Q

Meniscal tears - acute

A

Sport injury due to twisting

13
Q

Meniscal tears - chronic

A

Degenerative tear due meniscus weakening with age

14
Q

Collateral ligaments (2)

A

Medial collateral ligament (MCL)

Lateral collateral ligament (LCL)

15
Q

MCL - function

A

Connects the bottom of the femur to the top of the tibia

Resists valgus stress - ie stops the knee from getting excessively knock kneed

16
Q

MCL - causes

A

Contact sports

17
Q

MCL - mechanism of injury

A

Direct ‘hit’ to the outer aspect of the knee which stretches/tears the MCL
Rupture results in valgus instability

18
Q

MCL injury - clinical features

A

‘Popping’ sound upon injury
Pain and tenderness along the inner aspect of the knee
Swelling
Locking/catching of the knee joint

19
Q

MCL injury - examination

A

Assess for joint effusion

20
Q

MCL injury - investigations

A

MRI scan

21
Q

MCL - management

A
Has a good blood supply so heals well
RICE 
Early motion
Physio
Put leg in brace
22
Q

LCL - function

A

Runs along the outside of the knee joint between the bottom of the femur and the top of the tibia.
Resists varus stress - ie stops excessive bow-leggedness

23
Q

LCL - mechanism of injury

A

Direct force trauma to the inside of the knee. This puts pressure on the outside of the knee and results in various stress
High incidence of common fibular nerve injury

24
Q

LCL injury - clinical features

A

Swelling of the outer aspect of the knee
Stiffness (locking)
Pain

25
Q

LCL injury - examination

A

Effusion

26
Q

LCL injury - investigations

A

MRI scan

27
Q

LCL - management

A

Doesn’t heal well

A rupture needs urgent surgical repair

28
Q

Cruciate ligaments (2)

A

Anterior (ACL)

Posterior (PCL)

29
Q

ACL - function

A

Prevents abnormal internal rotation of the tibia, stops the tibia from rotating too much

30
Q

ACL rupture - cause

A

High impact sports injury

31
Q

ACL rupture - mechanism of injury

A

Twisting/turning the upper body laterally on a planted foot which causes the knee to give way.
May lead to rotatory instability

32
Q

ACL rupture - clinical features

A
'Popping' sound 
Generalised deep pain all over knee 
Unable to continue activity 
Knee gives way on turning 
Can't weight bear
33
Q

ACL rupture - examination

A

Bloody swelling accumulates in an hour (haemarthrosis)
Anterior drawer test
Lachman’s test
- excessive anterior translation of the tibia

34
Q

ACL rupture - management

A

RICE
Physio
Analgesia
Reconstruct ACL (surgery - carried out for instability, not pain)
*Reconstruction is carried out if the patient is involved in intense sports

35
Q

ACL rupture - prognosis

A

High risk of developing OA In later life
1/3 have no instability
1/3 can cope with instability
1/3 can’t cope with instability and want to het back to high impact sport

36
Q

PCL - function

A

Resists posterior subluxation of the tibia

Prevents hyperextension and anterior translation of the femur

37
Q

PCL rupture - cause

A

Direct blow to the anterior tibia whilst knee is flexed

motorbike crash, dashboard from crash

38
Q

PCL rupture - mechanism of injury

A

Direct blow to the anterior tibia on a flexed knee
Hyperextension of the knee
Posterior subluxation of the tibia

39
Q

PCL rupture - clinical features

A

Instability

Pain

40
Q

PCL rupture - examination

A

Posterior sag of the tibia (as the femur rides over the tibia) Swelling
Brusing in the popliteal fossa

41
Q

PCL rupture - management

A

If PCL is affected alone (unlikely) - no reconstruction

If other ligaments are affected - reconstruction required

42
Q

Knee dislocation - definition

A

Rupture of at least 3 of the knee ligaments

43
Q

Knee dislocation - cause

anterior, posterior, lateral

A

Anterior - severe hyperextension forces
Posterior - high energy injury (dashboard injury)
Lateral - rotational injury

44
Q

Knee dislocation - clinical features

A

Immobility
Swelling
Gross deformity
Knee pain

45
Q

Knee dislocation - examinations

A

Assess ACL, PCL, MCL, LCL

46
Q

Knee dislocation - investigations

A

X-ray

MRI

47
Q

Knee dislocation - management

A

Emergency reduction
Re-assess neuromuscular status
Confirm reduction (by doing a repeat X-ray)

Operative: ligament reconstruction

48
Q

The patella always dislocates medially/laterally?

A

Laterally

49
Q

Patella dislocation - who gets it

A

Females

Adolescence

50
Q

Patella dislocation - risk factors

A

Ligamentous laxity

Genu valgum

51
Q

Patella dislocation - clinical features

A

Obvious deformity

Patella dislocated laterally

52
Q

Patella dislocation - examinations

A

May get a lipo-haemarthrosis

53
Q

Patella dislocation - management

A

Reduction
Splint
Physio

54
Q

Knee replacement - who gets it

A

Older patients

- where conservative management is no longer effective

55
Q

Knee replacement - younger patients

A

Avoid young, active patients
Higher likelihood of failure
Likely to require revision surgery which is less effective

56
Q

Extensor mechanism rupture - constituents

A
Patella
Tibial tuberosity
Patellar tendon 
Quadraceps tendon
Quadriceps muscle
57
Q

Extensor mechanism rupture - younger patients

A

Patellar tendon rupture

58
Q

Extensor mechanism rupture - older patients

A

Quadriceps tendon rupture

59
Q

Extensor mechanism rupture - predisposing factors

A

Chronic steroid use
Quinolone antibiotics
Diabetes
Hx tendonitis

60
Q

Extensor mechanism rupture - examination

A

Unable to straight leg raise

Obvious palpable gap

61
Q

Extensor mechanism rupture - investigations

A

X-ray

62
Q

Extensor mechanism rupture - management

A

Tendon-tendon surgical repair

Reattachment of tendon to patella

63
Q

Osteochondritis dissecans - definition

A

Lack of blood supply to an area of bone causes it to break off from the main bone

64
Q

Osteichondritis dissecans - who gets it

A

Adolescents

65
Q

Osgood schlatters disease - definition

A

Inflammation in the tibial tuberosity

66
Q

Osgood schlatters disease - cause

A

Active adolescent boys

Growth spurts

67
Q

Osgood schlatters disease - clinical features

A

Pain at tibial tuberosity

68
Q

Bakers cyst - definition

A

Out pouching of the fluid that forms a lump behind the knee

69
Q

Bakers cyst - management

A

Nothing

70
Q

Septic arthritis - definition

A

Inflammation of the joint space caused by infection

71
Q

Septic arthritis - causative organism

A

Staph aureus

72
Q

Septic arthritis - clinical features

A

Similar to gout
- red hot, swollen, painful joint
Usually only one joint is affected

73
Q

Septic arthritis - investigations

A

Joint aspirate
- if frank pus is aspirated then septic arthritis is diagnosis
X-ray
- pus fills joint space

74
Q

Septic arthritis - management

A

Debridement of pus and fluid
Once causative organism is confirmed….
IV antibiotics