Hip and Knee

Question 1

Hilton’s Law

Answer 1

A joint is innervated by the same nerves that innervate the muscles and skin surrounding it

Question 2

Postganglionic sympathetic adrenergic fibers

Answer 2

located around the blood vessels. Responsible for arterial flow

Question 3

Unmyelinated C fibers

Answer 3

Responsible for pain transmission
Fire only when there is trauma (nociceptive)
Prostaglandin E2 can signal nociceptive fibers

Question 4

Articular surfaces of hip joint

Answer 4

Acetabular notch is bridged by the transverse acetabular ligament
Acetabular fossa is not covered with cartilage. Synovial membrane is there. This allows positional changes of femoral head in hip joint.
Fibrocartilaginous acetabular labrum deepens the socket for femoral head.

Question 5

Hip joint type

Answer 5

Diarrhetic ball and socket synovial joint

Question 6

Hip joint movements

Answer 6

flexion-extension
abduction-adduction
circumduction
medial and lateral rotation

Question 7

Acetabular labrum tears

Answer 7

Caused by twisting on a weight bearing knee
Diffuse pain
No visible swelling
Pinching sensation bringing knee to chest if in front of joint
Repaired arthroscopically

Question 8

Iliofemoral ligament

Answer 8

y shaped band that covers anterior aspect of the hip
anterior inferior iliac spine and acetabular rim to intertrochanteric line
Prevents overextension

Question 9

Pubofemoral ligament

Answer 9

Strengthens anterior and inferior parts of fibrous capsule
Arises from obturator crest of pubic bone and passes laterally to blend with joint capsule and iliofemoral ligament
Helps prevent overabduction and overextension

Question 10

Ischiofemoral ligament

Answer 10

Strengthens posterior joint capsule
Arises from ischial part of acetabular rim
Fibers spiral antero-lateral to attach to femoral neck
Helps prevent overextension

Question 11

Round femoral head ligament (Ligamentum teres)

Answer 11

Little importance in strengthening hip
Wide end attaches to acetabular notch. Narrow to fovea
Contains an obturator vessel- assists in spreading synovial fluid
Stretched when flexed thigh is adducted or laterally rotated

Question 12

Anterior hip dislocation

Answer 12

10-15%
Neck of femur or greater trochanter impinges on rim of acetabulum. Levers head of femur out of anterior hip capsule
Happens in abducted hip

Question 13

Posterior hip dislocation

Answer 13

Thigh adducted, medially rotated and flexed
Damages sciatic nerve
-Paralyzes hamstrings and muscles distal to knee
-sensory change may occur in skin over posterolateral aspects of leg and foot

Question 14

Hip replacement

Answer 14

Metal prosthesis anchored in femoral shaft by bone cement

Plastic socket cemented to hip bone to replace acetabulum

Question 15

First class lever

Answer 15

Effort-fulcrum-load Head and neck

Question 16

Second class lever

Answer 16

fulcrum-load-effort Foot and ankle

Question 17

Third class lever

Answer 17

load-effort-fulcrum bicep

Question 18

Popliteal Artery

Answer 18

Forms genicular anastomosis
Important collateral circulation bypasses popliteal artery (knee fully flexed too long. Narrowed or occluded popliteal vessels)
Supplies articular capsule and ligaments of knee joint

Question 19

Knee joint type

Answer 19

diarthrotic, primarily hinge type of synovial joint

permits some gliding and rotation around vertical axis

Question 20

Knee articular surfaces

Answer 20

Femur slants medially at knee, where tibia is vertical
Medial and lateral articulation between femoral and tibial condyles
Intermediate articulation between patella and femur (patellofemoral joint)
Fibula is not involved

Question 21

Knee joint stability

Answer 21

Dependent on:
strength of surrounding muscles/tendons
Ligaments that bind femur to tibia

Question 22

Five external knee joint ligaments

Answer 22

1. Patellar ligament
2. Fibular collateral ligament
3. Tibial collateral ligament
4. Oblique popliteal ligament
5. Arcuate popliteal ligament

Question 23

Patellar ligament

Answer 23

anterior knee joint ligament

Continuation of the quadriceps/patellar tendon

Question 24

Patellar retinacula

Answer 24

Aponeurotic expansions of vastus medialis and lateralis

Support articular capsule laterally and medially

Question 25

Fibular collateral ligamen

Answer 25

Strong cordlike ligament that extends inferiorly from lateral femoral epicondyle to fibular head Popliteus tendon passes deep to fibular collateral ligament Biceps femoris tendon split by fibular collateral ligament

Question 26

Tibial collateral ligament

Answer 26

Flat band that extends from medial femoral epicondyle to medial tibial condyle Deep fibers attach to medial meniscus (commonly damaged) Tibial and fibular collateral ligaments -prevent disruption of the sides of the knee joint -taut when leg is extended -lax when leg is in flexion

Question 27

Oblique popliteal ligament

Answer 27

Represents and expansion of semi-membranosus tendon | Strengthens capsule posteriorly

Question 28

Arcuate popliteal ligament

Answer 28

Y-shaped band Represents edge of capsule that arches over popliteus muscle Also strengthens capsule posteriorly

Question 29

Cruciate ligaments

Answer 29

Internal ligaments- within capsule, yet separate from joint cavity Join femur to tibia Named according to attachment to tibia (Anterior and posterior)

Question 30

Anterior Cruciate Ligament (ACL)

Answer 30

``` Attachment: anterior part of intercondylar area of tibia fibers oriented superiorly, posteriorly and laterally medial side of lateral condyle of femur Taut when leg is extended: prevents posterior displacement of femur prevents anterior displacement of tibia Anterior Drawer sign ```

Question 31

Posterior Cruciate Ligament (PCL)

Answer 31

Attachment: posterior part of intercondylar area of tibia fibers directed superiorly, anteriorly and medially lateral surface of medial condyle of femur Taut when leg is flexed: prevents anterior displacement of femur prevents posterior displacement of tibia Posterior Drawer Sign

Question 32

ACL Bundles

Answer 32

``` Anteromedial Bundle (AMB)- resists anterior tibial translation especially during flexion Posterolateral Bundle (PLB)- resists anterior tibial translation and tibial rotation in extension ```

Question 33

Menisci

Answer 33

C-shaped plates of fibrocartilage on medial and lateral articular surfaces of tibia- deepens articular surface and absorb shock External margins: thick, attached to joint capsule (Coronary ligaments) Internal margins: thin, not attached to joint capsule Joined by transverse ligament of knee -Allows menisci to move together during movements of tibia and femur

Question 34

Medial Meniscus

Answer 34

Broad posteriorly Anterior horn- may attach anteriorly to ACL Posterior horn- attaches anteriorly to PCL Adherent to deep surface of tibial collateral ligament

Question 35

Lateral Meniscus

Answer 35

Nearly circular- horse shoe shaped Smaller and more mobile than medial meniscus Posterior meniscofemoral ligament- joins to PCL Popliteus tendon passes between it and fibular collateral ligament

Question 36

Unhappy triad of injuries

Answer 36

ACL Tibial Collateral ligament Medial Meniscus