Anatomy

Question 1

What is the humeral, glenoid and scapular rotational profile?

Answer 1

• Humeral version: 20-40 degrees retroverted (relative to transepicondylar axis)
• Scapula: 30-45 degrees anteverted
• Glenoid: 0-7 degrees retroverted (relative to scapular body) with a 3-5 degree superior tilt

Question 2

Name te facets of the patella and state which one is larger

Answer 2

• Lateral facet (largest)
• Medial facet
• Odd facet (Medial vertical facet, smallest and far medial, articulates with the femur in deep flexion)

Wiberg Classification:

• Type 1: Medial and lateral facets equal
• Type 2 (MOST COMMON): medial facet 1/2 size of lateral
• Type 3: medial facet so medial that central ridge not noticeble.

Question 3

What is the average thickness of the patella?

Answer 3

2.5 cm

(cartilage 5-10 mm centrally vs 2mm in periphery)

Question 4

What is the vascular supply to the ACL/PCL?

Answer 4

Middle Geniculate Artery

Question 5

What is the largest nerve providing innervation to the intra-articular knee?

Answer 5

Posterior articular branch of the tibial nerve

Question 6

Name and define anatomy of the Meniscofemoral ligaments

Answer 6

• Humphrey: Anterior meniscofemoral ligament
• Wrisberg: Posterior meniscofemoral ligament
• They originate from posterior horn of lateral meniscus and insert into substance of PCL and medial femoral condyle

Question 7

Define the insertion of the superficial MCL (relative to joint line)

Answer 7

4.6 cm distal to medial joint line of knee

Question 8

The deep MCL of the knee (medial capsular ligament) is attached to what ligament

Answer 8

Coronary ligament of medial meniscus

Question 9

What is the blood supply to the MCL of the knee

Answer 9

Superomedial and inferomedial geniculate arteries

Question 10

Name the 3 layers on the medial side of the knee

Answer 10

• Layer 1: deep crural fascia (fascia from VMO and sartorius)
• Layer 2: superficial MCL, posterior oblique ligament and MPFL
• Layer 3: dMCL, capsule, coronary ligaments

Question 11

What is the origin and insertion of the MPFL

Answer 11

• Origin: adductor tubercle (Schottl’s point)
• Insertion: supero-medial border of patella

Question 12

What are the bundles of the ACL and their function?

Answer 12

• AM bundle
  
  • Tight in flexion
• PL bundle
  
  • Tight in. Extension

Question 13

Name the bundles of ACL and their function

Answer 13

• AM bundle:
  
  • Tight in flexion
  • Stronger and stiffer
• PL bundle:
  
  • Tight in extension
  • Prevents pivot - prevents tibial internal rotation near full extension
• Function:
  
  • Primary restraint to anterior tibial translation (85%), ACL strength = 2200N
  • Secondary restraint to varus/valgus

Question 14

Name the bundles and function of the PCL

Answer 14

• AL
  
  • Tight in flexion
  • Stronger and stiffer
• PM
  
  • Tight in extension
• Function:
  
  • Primary restraint to posterior tibial translation
  • Secondary restraint to varus/valgus and PL rotatory instability.
  • 2500N strength