THIGH & KNEE REGION

Question 1

joints of the knee

Answer 1

1. Tibiofemoraljoint
2. Patellofemoraljoint
3. Superior tibiofemoral joint (separate to the knee joint)

Question 2

Tibiofemoral joint:

Answer 2

femoral condyles + tibial plateau
bicondylar (predominantly uniaxial)
main movement in 1 plane; limited movement in orthagonal plane
- mainly F-E in the sagittal plane around a coronal axis
- limited rotation around vertical axis
- longer articular surface on medial femoral condyle = when extending will cause medial rotation of femur on tibia (during weight baring eg sit > stand)
- screw-home mechanism

Question 3

Normal frontal plane alignment:

Answer 3

5˚ anatomical genu valgus
• medial femoral condyle extends further distally
• shaft of femur inclined laterally
• femoral condyles in same transverse alignment
• brings feet closer to midline for bipedal gait

Question 4

Alignment of the femoral condyles in the transverse plane:

Answer 4

determines the orientation of the flexion/extension axis of the knee

Question 5

Distal femur

Answer 5

Distal portion of femoral condyles flat v’s anterior & posterior portions

Question 6

Medial and lateral tibial slopes in the sagittal plane:

Answer 6

medial tibial plateau has greater slope/angle
Tibial slope = angle between line P & line A-B:
P = line perpendicular to the long axis of the tibial diaphysis (L) A-B = line from anterior tibial peak to posterior tibial peak

Question 7

Tibiofemoral menisci:

Answer 7

Increase congruency / contact area between femoral condyles & tibial plateau

• decreases stress
• protects articular cartilage
• generally have fibrocartilage structure
• thickens as goes laterally
• withstrands shear forces, increases Contact area, decreases local focal points of stress
• fibrocartilage protects underlying hyline cartilage

Question 8

knee meniscus

Answer 8

After total meniscectomy:
• contact areas decreased ~75%, and PLCS increased ~ 235%
Medial meniscus - longer A-P & larger posterior horn
Lateral menisci - more variable & mobile
Meniscal coverage of plateau: medial 50-75%, lateral 75-93%

Question 9

Tibiofemoral ligaments:

Answer 9

No bony stability: ligamentous and muscular support
1. Tibial collateral
2. Fibular collateral 
3. Anterolateral
4. Anterior cruciate 
5. Posterior cruciate
(Iliotibial band)

Question 10

1. Tibial collateral ligament (TCL)

Answer 10

Resists valgus
Superficial – longer & stronger; main
restraint to valgus throughout F
Deep – shorter; lower extension to failure; also resists ant translation of tibia

Question 11

2. Fibular collateral ligament (FCL)

Answer 11

• resists varus

Question 12

3. Anterolateral ligament (ALL)

Answer 12

• resists tibial IR in 30˚ F

- anterolateral stability

Question 13

4. Anterior cruciate ligament (ACL)

Answer 13

2 functional fibre bundles:
Posterolateral band (PLB) – largest, tightest in E Anteromedial band (AMB) – tightens in F
• resists anterior translation of tibia on femur
• resists posterior translation of femur on tibia
• rotation stability*
• resists valgus
• main limit (with menisci) to end extension
*Internal & external tibial rotation @ 10˚ & 30˚ F

Question 14

4. Anterior cruciate ligament (ACL) INJURIES

Answer 14

• often non-contact
• large valgus moment
• + tibial ER
• adolescence
• pivoting sports
• females 3-5x
The slope of the tibial plateau has a direct relationship with
anterior tibial translation during the transition
from non-weightbearing to weightbearing conditions.

Question 15

5. Posterior cruciate ligament (PCL)

Answer 15

Resists posterior translation of tibia on femur

• Resists femur moving forward on tibia

Question 16

5. Posterior cruciate ligament (PCL) INJURY

Answer 16

“dashboard”

• Hyperflexion or hyperextension

Question 17

PCL tag test

Answer 17

PCL deficiency resulted in a posterior shift of the tibial resting position to 8.4 +/- 2.6 mm at 90˚ compared with the intact knee.
- need quads to be relaxed

Question 18

patellofemoral joint

Answer 18

articulates with patella surface of distal femur

- little contact in ext, increases in flx

Question 19

translations

Answer 19

Patella glides distally on the femur during knee flexion.

The patella glides medially during 0-30˚ flexion then laterally during 30-90˚ flexion.

Question 20

rotations

Answer 20

The patella flexes and

laterally tilts during knee flexion.

Question 21

Contact area location & amount change through range F/E

Answer 21

• with increasing knee F contact moves proximally and increases

Question 22

patella alters the line of action of the quadriceps group and increases in moment arm

Answer 22

patella alters the line of action of the quadriceps group and increases in moment arm

Question 23

Anterior thigh:

Answer 23

Sartorius
Quadriceps femoris
- Rectus femoris (RF) 
- Vastus intermedius (VI)
- Vastus lateralis (VL)
- Vastus medialis
* longus (VML)
*  obliquus (VMO)
• Patellofemoral
• Patella tendon
• Tibial tuberosity

Question 24

Posterior thigh:

Answer 24

Semimembranosus Semitendinosus
- Hip E + Kn F
- Tibial IR
 Proximal tendon
• Musculotendinous
junction - causes problems in sprinters
Biceps femoris
- long head: Hip E + Kn F - short head: Kn F
- tibial ER

Question 25

Posterior leg:

Answer 25

Gastrocnemius

plantaris

Question 26

popliteus

Answer 26

Medial tibia to lateral femoral condyle
- unlocking knee joint
Screw home mechanism (IR femur on tibia)
- lateral rotation of the femur on the tibia unlocks the extended knee

Question 27

Medial thigh & knee:

Answer 27

pes anserinus: insert on anteromedial tibia

1. sartorius
2. gracilis
3. semitendinosus

Question 28

“lateral thigh” & knee:

Answer 28

TFL
Biceps Femoris: Long and Short head
Iliotibial tract: inserts on girdle tubercle