Knee

Question 1

Describe the origin and insertion of the ACL

Answer 1

• Originates in posteriomedial corner of the lateral femoral condyle
• Attaches in a fossa anteromedial to the intercondylar eminese

Question 2

How many bundles are there in the ACL

Answer 2

• Small anterior medial bundle
  
  • Tight t/o ranges of flexion
  • If anterior is torn, you may still get a positive drawer sign
• Bulky posterolateral bundle
  
  • Taut in ext, key restraint is 0-20 degrees flexion

Question 3

What where does the ACL exert the most force during flexion and extension?

Answer 3

–85% of resistance to ant translation at 30 degrees

–Slightly less at 90 degrees flexion

Question 4

How are forces in the knee disperersed between the medial and lateral compartments.

Answer 4

–compressive forces – med compartment absorbs 60%

–lat compartment absorbs 40%