Orthopaedic Knee Problems

Question 1

What are the possible causes of meniscal tears?

Answer 1

Acute due to twisting, especially in deep flexion

Degenerative in osteoarthritis

Question 2

Which meniscus tears most commonly and why?

Answer 2

Medial meniscus tears more common than lateral

Medial meniscus is a more fixed structure

Question 3

How do meniscal tears present?

Answer 3

• Pain
• Clicking
• Locking
• Intermittent swelling

Question 4

How is a meniscal tear examined?

Answer 4

Look
- Effusion
Feel
- Tender joint line at point of tear
Move
- Mechanical block to movement
- McMurrays test positive (flex and rotate knee, apply axial pressure and extend the knee again. Positive test involves an audible click)
- Fail deep squat (useful in younger patients, asymmetric squat)
- Thassaly’s test positive (patient holds hand on chair, bend knee to 20 degrees with one leg raised and get patient to twist, recreate injury pattern)

Question 5

How are meniscal tears investigated?

Answer 5

Investigations involve x-ray, primarily to exclude arthritis and fracture. MRI is the most sensitive test but has a high false positive rate.

Question 6

What is the treatment of a meniscal tear?

Answer 6

• Rest
• NSAIDs
• Physiotherapy (hamstring/quadriceps strengthening)
  Operative treatment is an arthroscopy, which can be either a repair or resection.

Question 7

What type of injuries most commonly causes ACL tears?

Answer 7

Non-contact pivot injuries

More common in females (5:1)

Question 8

How does an ACL tear present?

Answer 8

• Heard a pop or crack
• Immediate swelling due to bleeding
• Unable to continue playing sport
• Deep pain

Question 9

How is an ACL tear examined?

Answer 9

Look
-	Effusion
Feel
-	Not much to feel asides from if there is an associated meniscal tear
Move
-	Anterior draw
-	Lachmann’s test
-	Pivot shift (usually under anaesthetic)

Question 10

How are ACL tears investigated?

Answer 10

Investigations can include an X-ray to check for secondary fracture and an MRI (most important) to assess the ACL and the menisci

Question 11

What injury is commonly associated with an ACL tear?

Answer 11

Lateral meniscal tears occur in ~50% of ACL tears

Question 12

How is an ACL tear treated?

Answer 12

Surgery is not always required in ACL tears, if the ACL flips back and attaches to the PCL and maintains a blood supply from there then a focused quadricep programme can be sufficient. Operatively, an ACL reconstruction can have associated partial menisectomy, ligament repair or a hamstring graft.

Question 13

What injuries cause MCL tears?

Answer 13

Severe valgus stress

Usually contact related

Question 14

What are the possible related injuries to MCL tears?

Answer 14

ACL and meniscal tears

Question 15

How does a MCL tear present?

Answer 15

• Heard a ‘pop’ or ‘crack’
• Pain ++ (medial side)
• Unable to continue playing
• Bruising medial knee
• Localised swelling

Question 16

How is an MCL tear examined?

Answer 16

Look
-	Medial swelling
-	Bruising
Feel
-	Tender medial joint line
-	Tender femoral insertion of MCL
Move
-	Painful in full extension
-	Opening on valgus stress

Question 17

How is an MCL tear investigated?

Answer 17

X-ray

MRI

Question 18

How is an MCL tear treated?

Answer 18

Non-operative treatment is sufficient in the majority of MCL tears and involves:
- Rest
- NSAIDs
- Physiotherapy
- Brace for comfort
Operative treatment may be required in severe tears and in cases of failed non-operative management. Repair or reconstructions can be helpful.

Question 19

What are the two classes of osteochondrosis dissecans?

Answer 19

Juvenile

Adult

Question 20

What bone does osteochondrosis dissecans usually affect?

Answer 20

The femur

Question 21

What are the causes of osteochondrosis dissecans?

Answer 21

• Hereditary
• Traumatic
• Vascular (adult form)

Question 22

How does osteochondrosis dissecans present?

Answer 22

• Activity-related pain (poorly localised)
• Recurrent effusions
• Mechanical symptoms (locking, block to full movement)

Question 23

How is osteochondrosis dissecans examined?

Answer 23

Look
-	Effusion
Feel
-	Localised tenderness
Move 
-	Stiffness
-	Block to movement
-	Wilsons test (rarely done in practice)

Question 24

How is osteochondrosis dissecans investigated?

Answer 24

Investigations are X-ray and MRI. MRI is useful in assessing lesion size and status of cartilage. Tunnel view x-rays can be much more helpful than AP views

Question 25

How is osteochondrosis dissecans treated?

Answer 25

Non-operative treatment involves restricted weight-bearing and a range of movement brace. Operatively, arthroscopy can be done to perform subchondral drilling or fixation of loose fragment or open fixation can be done.