Soft Tissue Knee Injuries Flashcards Preview

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Flashcards in Soft Tissue Knee Injuries Deck (58)
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1
Q

How may an extensor mechanism rupture occur?

A

Fall onto flexed knee with quadriceps contracted

2
Q

What are risk factors for extensor mechanism ruptures?

A

Previous tendonitis, steroids, chronic renal failure, ciprofloxacin

3
Q

What are the signs of an extensor mechanism rupture?

A

Unable to perform straight leg raise, palpable gap

4
Q

What are the types of extensor mechanism ruptures?

A

Rectus femoris tear, quadriceps tendon rupture, patellar fracture, patellar tendon rupture = all need surgical repair

5
Q

What are the function of the knee menisci?

A

Distribute load from convex femoral condyles to relatively flat tibial articular surfaces

6
Q

What are some features of the lateral and medial menisci?

A
Medial = fixed, under greater amount of shear stress, medial plateau slightly more concave
Lateral = more mobile
7
Q

How does the knee move through flexion and extension?

A

Knee pivots on medial compartment = tibia internally rotates on flexion and externally rotates on extension

8
Q

How do meniscal tears occur in younger patients?

A

Usually sporting injury or from getting up from a squatting position

9
Q

How do meniscal tears occur in patients >40?

A

Atraumatic spontaneous degenerative tears

10
Q

What other knee pathology are meniscal tears commonly associated with?

A

ACL ruptures = 50% have meniscal tear

11
Q

On what aspect are meniscal tears more common?

A

Medial = 10 times more common than lateral meniscal tear

12
Q

Why do meniscal tears have limited healing potential?

A

Only peripheral 1/3 has blood supply = radial tears will never heal

13
Q

How is surgery used to treat meniscal tears?

A

Arthroscopic menisectomy = acute peripheral tears in younger patients, mechanical pain due to irreparable tears or failed meniscal repairs

14
Q

Can meniscal tears resolve on their own?

A

To some extent = pain from the initial injury may settle over time

15
Q

What does an acute locked knee signify?

A

Displaced bucket handle meniscal tear

16
Q

What are some features of displaced bucket handle meniscal tears?

A

15 degree springy block to extension

Urgent surgery needed = if knee remains locked patient may develop FFD

17
Q

How are displaced bucket handle meniscal tears treated?

A

Arthroscopic repair

Partial menisectomy for irreparable tear = unlocks knee and prevents further damage

18
Q

What are some features of degenerative meniscal tears?

A

Occur in >20% of patients over 50, may be asymptomatic, inflammation from initial onset may settle, may represent first stage osteoarthritis

19
Q

How are degenerative meniscal tears treated?

A

Injection may help, arthroscopic menisectomy ineffective, results form surgery less successful (especially if evidence of osteoarthritis)

20
Q

What is the function of the MCL and the LCL?

A

MCL resists valgus stress = rupture may lead to valgus instability
LCL resists varus stress

21
Q

What is the function of the ACL?

A

Resists anterior subluxation of tibia and internal rotation of tibia in extension = rupture may lead to rotational instability

22
Q

What is the function of the PCL?

A

Resists posterior subluxation of tibia (i.e anterior subluxation of femur and hyperextension of knee)

23
Q

What may occur if the PCL is ruptured?

A

Recurrent hyperextension or instability to descend stairs

24
Q

What ligaments make up the posterolateral corner of the knee?

A

PCL, LCL, popliteus and other small ligaments = resist external rotation of tibia in flexion

25
Q

What may occur in a rupture of the posterolateral corner?

A

Varus and rotary instability = multi-ligament injuries result in gross instability

26
Q

What are the different grades of knee ligament injuries?

A

Grade 1 = sprain, tear some fibres but macroscopic structure intact
Grade 2 = partial tear, some fascicles disrupted
Grade 3 = complete tear

27
Q

Do all ligaments heal at the same rate?

A

No = some heal more than others and some stabilise over time

28
Q

What are some features of a MCL injury?

A

Usually heals well even if complete tear unless combined with ACL/LCL tear, pain can take several months to settle

29
Q

How are MCL injuries treated?

A

Brace, early motion, physio, rarely requires surgery

30
Q

What is the main stabiliser against internal rotation of the tibia?

A

ACL

31
Q

What are ACL ruptures usually caused by?

A

Sports injury = football, rugby, skiing

32
Q

How are ACL ruptures treated?

A

Only treated with reconstruction = autograft (hamstring or patellar tendon), allograft (Achilles)
ACL can stick to PCL to give some stability and physio can stabilise ACL deficient knees

33
Q

How do patients cope with an ACL rupture?

A

1/3 compensate and are able to function well
1/3 can avoid instability by avoiding certain activities
1/3 don’t compensate and have frequent instability or can’t get back to high impact sport

34
Q

Which patient group are more likely to compensate with an ACL rupture?

A

Older patients = also more likely to avoid high impact sport

35
Q

When should surgery be considered for ACL ruptures?

A

Rotatory instability not responding to physio
Rapid return to professional sport/high demand job
Adolescent or young adult
Keen on high impact sport
As part of multi-ligament reconstruction

36
Q

What are some drawbacks to surgery in an ACL rupture?

A

Doesn’t treat pain or prevent arthritis

37
Q

How successful are ACL ligament reconstructions?

A

3 month to 1 year of rehab, some never get back to full sport, 10% failure rate, graft donor site morbidity, stiffness common, most have evidence of arthritis < 10 years

38
Q

What are some features of LCL injuries?

A

Relatively uncommon, don’t heal well, cause varus and rotatory instability, high incidence in common peroneal nerve palsy, often occurs with PCL/ACL injury

39
Q

How are LCL injuries treated?

A

Complete rupture needs urgent repair if early (within 2-3 weeks)
If >3 weeks then treated with reconstruction (hamstring or other tendon)

40
Q

How do PCL rupture occur?

A

Direct blow to anterior tibia or hyperextension injury = often present with popliteal knee pain and bruising

41
Q

Are isolated PCL ruptures common?

A

No, they are rare = usually occur with other injury

42
Q

What can result from a PCL rupture?

A

Instability = recurrent hyperextension or feeling unstable when going downstairs

43
Q

How are PCL ruptures treated?

A

Most isolated cases don’t require reconstruction = only gets reconstruction if part of multi-ligament injury

44
Q

What are knee dislocations?

A

Serious high energy injury with high incidence of complications (popliteal artery injury, common peroneal nerve injury, compartment syndrome)

45
Q

How are knee dislocations treated?

A

Emergency reduction
Vascular surgery may be needed
May need ex fix for temporary stabilisation
Multi-ligament

46
Q

How can patellar dislocations arise?

A

Rapid turn or direct blow

47
Q

What are some features of patellar dislocations?

A

Increased incidence in females, occurs in teens, ligamentous laxity, valgus knee, torsional abnormalities, 10% get recurrent dislocations

48
Q

What can patellar dislocations cause?

A

Chondral or osteochondral injury = may benefit from surgical stabilisation

49
Q

What are some mechanisms of injury?

A
Valgus = MCL
Twisting = ACL, meniscal injury
Varus = LCL
Dashboard/hyperextension = PCL
Getting up from squatting = meniscal tear
50
Q

What does a pop or a crack of a joint indicate?

A

Knee cap dislocation

51
Q

What are some causes of swelling?

A
Haemarthrosis = ACL, fracture
Effusion = meniscal/chondral injury
52
Q

What are some ways that pain can present?

A

Generalised haemarthrosis, joint line (meniscal/chondral injury)

53
Q

What are some recurrent symptoms that can occur with knee injuries?

A
Giving way = rotary?
Pain = joint line?
Locking
Clicking or catching
Recurrent swelling or patellar dislocation
54
Q

What are needed to diagnose osteoarthritis?

A

Biomarkers = not a uniform disease

55
Q

What are some non-pharmacological treatments for osteoarthritis?

A

Strength training, weight management, walking cane, biomechanical interventions, Balneotherapy

56
Q

What are some pharmacological treatments for osteoarthritis?

A

Capsaicin, paracetamol, topical NSAIDs, oral COX-2 inhibitors, duloxetine

57
Q

When should surgery be given for osteoarthritis?

A

Only when conservative options have been exhausted, = may get knee replacement

58
Q

What are some symptoms of osteoarthritis?

A

Pain, inflammatory flares, stiffness, loss of movement and function

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