Knee Ligament Tears

Question 1

ACL tears

Answer 1

> More common than pcl
15-25 yr olds in cutting sports
Women > Men (greater Q angle)

• Commonly injured with
• Meniscal tear (medial + mcl = o’donoghues)
• Articular cartilage damage
• MCL injury
• Bone bruising

> Anatomy

• Intra-articular (extra-synovial)
• Proximal aspect - greater vascularity
• anteromedial band restrains ant. tib translation ~45 degrees flexion
• posterolateral band restrains in full extension

> Presentation

• ‘pop’
• ‘collapse’
• haemoarthrosis - large swelling
• Partial is likely to develop to full

Question 2

PCL damage

Answer 2

> Mechanism
- Posterior force to proximal tibia (fall on flexed knee, tackle, car crash)
+ rotational force - likely to injure posterolateral complex

> Symptoms

• Mild/moderate swelling
• positive posterior drawer
• often asymptomatic - vague pain in posterior knee
  - pain on kneeling

Question 3

Medial stabilisers

Answer 3

> Static 
- superficial MCL
- Deep MCL
- Posterior oblique ligament 
> Dynamic 
- Semimembranosus 
- Quadriceps 
- Pes anserinus 

> MCL = main restraint to valgus strain
Injuries are likely to fully heal
- when combined with other injuries e.g ACL - may require surgery

Question 4

Lateral Stabilisers

Answer 4

> Anterior 
- Capsule
- ITB 
> Posterior 
- Biceps Femoris tendon
- Popliteal tendon 
- Lateral Gastrocnemius head 
*aid restraint against varus/rotation/a-p translation of tibia

> LCL injuries (main restraint against varus strain)
- less common than MCL but generally more debilitating + likely to involve medial or cruciate damage