Lecture 2 - The Knee

Question 1

What are the two articulations in the knee joint?

Answer 1

Patello-femoral joint - articulation between the posterior surface of the patella (sesamoid bone) and the trochlear surface of the femur

Tibiofemoral joint - articulation between the condyles of the femur and the tibial plateau forming a modified synovial hinge joint

Question 2

List the intra-articular components of the knee (excluding bones) and identify which are extra-synovial

Answer 2

PCL
ACL - extra-synovial
Menisci
Fat pads - extra-synovial
Suprapatellar bursa

Question 3

Identify 5 reasons why glutes are important to knee pathology

Answer 3

• Reduce iliotibial band loading and irritation which causes lateral knee pain
• Reduces force on knee joint
• Stabilises pelvis to maintain proper leg and knee alignment
• Stability in the hip preventing lateral tracking of kneecap
• Prevents knee from entering too much of a valgus position when squatting, running or landing from a jump

Question 4

What are the three muscles that insert into the pes anserine?

Answer 4

Gracilis
Semitendinosus
Sartorious

Question 5

Describe the general properties of a synovial effusion in the knee

Answer 5

Onsets over 3-6 hours
Slight to moderate tension
Smaller volume therefore often missed
Occurs in slight to moderate injuries

Question 6

Describe the general properties for a haemarthrosis

Answer 6

Onset is immediate
High tension
Large in volume and obvious
Occurs in significant and severe injuries

Question 7

What is the milk test and explain as you go along?

Answer 7

Milk test - finger and thumb on distal hand come up onto joint line and gently milk the suprapatella bursa

The suprapatella bursa is intra-capsular and therefore swelling in the knee joint moves into the bursa

If the finger and thumb separate on the distal hand this indicates an effusion as the swelling separates your fingers

Question 8

What is the patella tap test

Answer 8

Pressure on proximal side of the knee squeezes fluid under the patella

Tap patella down, if it drops and clicks onto the femur this is positive as it indicates that the patella is moving through the fluid to hit the femur, if it doesn’t move that’s because the patellar was already on the femur and therefore swelling isn’t indicated

Question 9

How can you treat a knee effusion

Answer 9

Medication (refer to GP)
Gentle closed chain exercises that mobilise the knee i.e. cycling
RICE
Potential aspiration if severe

Question 10

How do you clear the hip and why should you do so (name specific conditions)

Answer 10

You should clear the hip to eliminate hip conditions that refer pain to the knee. This includes conditions such as osteoarthritis, ITB syndrome, nerve compression, tight hip muscles and tendonitis

• AROM at the hip - Hip pathology indicated depends on results i.e. tight hip flexors can impact knee
• PROM at the hip - look for capsular pattern, if articular capsule of hip is indicated there will be limited internal rotation, flexion and abduction

Question 11

Why do tight hip flexors cause knee pains?

Answer 11

Tight hip flexors pull the pelvic bone into anterior tilt reducing movement of the femur

The reduced movement of the femur leads to internal rotation at the knees, this causes tendons, ligaments and muscles to tighten to protect the knee leading to pain and increase likelihood of injury