Common conditions of the knee

Question 1

What are the menisci?

What are their function?

Answer 1

Specialised C shaped cartilages in the knee. Formed of a medial and lateral menisci they both attach to the deep medial collateral ligament

Aid force transmission
Increase stability

Question 2

How can the menisci tear?

Which menisci is more likely to tear and why?

Answer 2

Acute-twisting in deep flexion

Degenerative- osteoarthritis

Medial menisci more common as it is a more fixed structure

Question 3

How does a meniscal tear present

Answer 3

Pain
Clicking
Locking
Intermittent swelling

Question 4

What is assessed upon examination of a suspected meniscal tear

Answer 4

Look- effusion

Feel- Tender joint line at the point of a tear (especially medial tear)

Move- mechanical block to movement, McMurrays test positive, Fail deep squat, Thassaly’s test positive

Question 5

How do you investigate a miniscal tear?

Answer 5

X-ray -arthritis, fracture

MRI- most sensitive test
High false positivity

Question 6

How do you treat a meniscal tear

Answer 6

Unlikely to heal due to there being a poor blood supply

Non-operative- rest, NSAIDS, Physio (hamstring and quadriceps strengthening)

Operative- arthroscopy, resection

Question 7

What is osteathritis?

Answer 7

Progressive loss of articular cartilage leading ti secondary bony changes. Characterised by worsening pain and stiffness of the affected joint.

Question 8

Where does the anterior cruciate ligament run between?

What is the blood supply of it

What inenrvates it?

What is its function

Answer 8

Runs from behind tibial eminences to lateral wall of intercondylar notch of femur

Blood supply: middle geniculate artery

Innervation:posterior articular nerve

Prevents anterior translation of the tibia

Question 9

How is the ACL torn

How does it present?

Answer 9

Non- contact pivot injury
Females:males 4:1

Heard a pop or cracking, immediate swelling
Immediate swelling (70%), haemarthrosis
Unable to continue playing, cant walk in a straight line
Deep pain

Question 10

How should a suspected ACL be examined?

Answer 10

Look- effusion
Feel
Move- anterior draw
           Lachmanns's test
            Pivot shift (best done under anaesthetic)

Question 11

How should an ACL tear be investigated?

Answer 11

X-ray- segond fracture, avuslion

MRI- ACL
Minsici
MCL

Question 12

How do you treat an ACL rupture?

Answer 12

Non-operative, focussed quadricep programme

Operative- ACL reconstruction
partial menisectomy, ligament repair or augmentation
Hamstring graft

Question 13

What is the MCL

What is its function?

Answer 13

two ligaments- superficial and deep MCL

Superficial- primary restraint to valgus stress
Deep- contributes in full knee extension, attaches to medial meniscus

Question 14

How is the MCL torn

What injuries are associated with it??

Answer 14

Most common ligament injury of the knee

Severe valgus stress- usually contact related

Associated injuries- ACL tear, Meniscal tear

Question 15

How does an MCL tear present

Answer 15

Hear a pop or a crack
Pain ++, medial side
Unable to continue playing
Bruising on the medial knee
Localised

Question 16

How should you examine and MCL tear

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

What imaging can be done for an MCL tear

Answer 17

X-ray-may be norma, calcification of femoral insertion

MRI- Modality of choice
Assess location and severity of injury
Identify other pathologies

Question 18

How do you treat an MCL tear

Answer 18

Majority non-operaitive, rest, NSAIDS, physio, brace for comfort

operative- severe tears, failed non operative management, repair or reconstruction, repair, avulsion. Midsubstance tear with good tissue
Reconstruction, damaged tissue

Question 19

What is osteochondritis dissecan

Answer 19

Pathological lesion affecting the articular cartilage and subchondral bone

2 forms: juvenile- 10-15 years while growth plates are still open
Adult

Question 20

What causes osteochondritis diseecans

Where does it localise?

Answer 20

Hereditary, traumatic, vascular (adult form)

Location- knee (most common) posterolasteral aspect of medial femoral condyle (70%)

Question 21

How does osteochondritis present?

Answer 21

Actively related pain (poorly localised)
Recurrent effusion
Mechanical symptoms
Locking, block to full movement

Question 22

How is osteochondritis examined?

Answer 22

LOOK- May be normal, effusion
FEEL- localised tenderness
MOVE- stiffness, block to movement, Wilson’s test

Question 23

How do you investigate Osteochondritis Dissecans

Answer 23

X-ray, add in tunnel view

MRI- lesion size, status of cartilage and subchondral bone, signal intensity (oedema suggests instability fragment)

Question 24

How do you treat osteochondritis dissecans

Answer 24

Non- operative, restrict weight bearing ROM brace

Operatic- arthroscopy, subchondral drilling
Fixation of loose fragment