Chapter 47 - Radiographic Evaluation and Surgical Anatomy of the Knee

Question 1

when to get non-weightbearing XRs?

Answer 1

trauma setting - no increased risk of fracture displacement

Question 2

what does a segond fracture indicate

Answer 2

lateral capsular avulsion (meniscotibial ligament)

pathognomonic for ACL tear, but not necessary for ACL ter

Question 3

avulsion of the medial femoral epicondyle indicates what?

Answer 3

proximal MCL tear - stieda-pelligrini lesion

Question 4

what location is most common for stress fracture on knee radiographs

Answer 4

proximal medial tibia - vertical radiolucency

Question 5

increased radionuclide activity can be present for how long post operatively?

Answer 5

1 year

Question 6

indium 111

Answer 6

tagged white blood cell scan

concentrates in areas of infection

Question 7

technetium 99

Answer 7

may help identify infection, neoplasia, occult fracture, bone healing, active phases of heterotopic ossification, implant loosening, failure of osseointegration

Question 8

what does the broader anterior to posterior length of the lateral femoral condyle allow?

Answer 8

allows INTERNAL rotation of the knee when in full extension

Question 9

what type of collagen makes up the ACL?

Answer 9

type I and III

Question 10

primary blood supply to the acl

Answer 10

middle genicular a

Question 11

primary nervous supply to the acl

Answer 11

posterior articular branch of the posterior tibial nerve

Question 12

posterior cruciate ligament main blood supply

Answer 12

middle geniculate artery

Question 13

nerve supply to pcl

Answer 13

posterior articular branch of the posterior tibial nerve

Question 14

popliteus tendon insertion/origin

Answer 14

originates DISTAL to the joint (eg on the posterocentral tibia)
inserts anterior and distal to the LCL on the lateral femoral epicondyle

Question 15

superficial MCL things

Answer 15

tibial collateral ligament
deep to semitendinosis and gracillis
origin on the medial femoral condyle sulcus
broad insertion 4-6cm distal to the joint line
- anterior fibers , tight in first 90 degrees of flexion
- posterior fibers, tight in full extension

Question 16

what attaches the medial meniscus to the deep MCL?

Answer 16

coronary ligaments

Question 17

blood supply to MCL

Answer 17

superomedial and inferomedial geniculate aa

Question 18

what is the largest posterior ligamentous structure?

Answer 18

oblique popliteal ligament

Question 19

what structures make up the posteromedial knee?

Answer 19

semimembranosis tendon
capsule
oblique popliteal ligament
posterior oblique ligament

Question 20

semimembranosis tendon has how many insertions?

Answer 20

five:
posterior oblique tendon
oblique popliteal ligament
posterior capsule and posterior horn of the medial meniscus
tibia deep to mcl
popliteus aponeurosis

Question 21

what complication with knee ROM can be seen post closing wedge tibial osteotomy?

Answer 21

patella baja
loss of knee flexion

Question 22

middle geniculate artery is a branch of what?

Answer 22

popliteal artery

similar to the superior, and inferior medal and lateral geniculates which are branches of the popliteal a

descending geniculate is the only one that is a branch of the femoral a

Question 23

relationships of the peroneal nerve

Answer 23

courses deep the biceps femoris tendon, distal to the fibular collateral ligament as it crosses the joint line, and courses around the fibular head to enter the anterior compartment of the knee

Question 24

infrapatellar branch of the saphenous n

Answer 24

most commonly injured during medial parapatellar approach

courses from superomedial to inferolateral distal to the patella

can aso get trapped btwn the sartorius and the mfc

Question 25

when may a lateral parapatellar approach be useful?

Answer 25

valgus knees
lateral uni

Question 26

what vascular structure is at risk in a quad turndown

Answer 26

superior lateral geniculate a. if the connecting incision from the v is taken to distally

Question 27

when may a medial femoral epicondyle osteotomy be advantageous?

Answer 27

severe, fixed varus deformity

Question 28

MPFL dynamics

Answer 28

lax in extension
tight in flexion
related to its femoral insertion - proximal and posterior to the ME