Hip and Knee Ligaments Flashcards
Medial Meniscus
- C-shaped
- Attached to the MCL
- Posterior horn is attached to the semimembranosus via the capsule.
Lateral Meniscus
- O shaped
- More mobile
- Does not attach to collateral or capsular ligaments
- Attaches to the arcuate ligament and popliteus muscle
Menisci
- Menisci carry up to 70% of the load on the tibia.
- Knee joint stability during motion facilitated by menisci
Primary Knee Ligaments
- ACL
- PCL
- MCL
- LCL:
**Restrictions listed above are for the tibia. It would be the opposite for the femur
ACL Bundles
- 2 Bundles:
Anteromedial (tighter in flexion)
Posterolateral (tighter in extension)
ACL
- Checks anterior tibial shear and ER
- Handles up to 75% of anterior tibial force at full extension
- Handles up to 90% of anterior tibial force at knee flexion
PCL
- Checks posterior tibial shear
- PCL handles between 85 and 100% of posterior tibial force at both 30 and 90 degrees of flexion
LCL
- Checks tibial adduction (varus force)/IR
- Handles approx 55% of varus force at full extension and increases with flexion
MCL
- checks tibial abduction (valgus force)/ER
- Handles up to 50% of the valgus load on the knee
Knee Hyperextension
- AKA genu recurvatum
- This position stresses out the posterior structures (like the joint capsule)
Common Causes of Knee Hyperextension
- Inherent laxity of the knee ligaments
- Weakness of biceps femoris muscle
- Instability of the knee joint due to ligaments and joint capsule injuries
- Inappropriate alignment of the tibia and femur
- Congenital recurvatum
Bursa of the Knee
- Functions to decrease friction between adjacent surfaces (i.e. b/t tendon–tendon or tendon–bone)
- 4 Anterior Bursae
- 3 Posterior Bursae
- 1 Medial Bursa
Anterior Bursae
- Suprapatella
- Prepatellar
- Subcutaneous infrapatellar
- Deep infrapatellar
Posterior Bursae
- Popliteus
- Semimembranosus
- Gastrocnemius
Medial Bursa
Pes anserine (insertion of sartorius, gracilis, and semitendinosus)
Other Knee Ligaments
- Oblique popliteal
- Arcuate popliteal
- Posterior meniscofemoral: ligament of Wrisberg
- Coronary ligament: also known as meniscotibial ligament. Blends with joint capsule but holds meniscus down to periphery of tibia
- Posterior ligament
- Transverse ligament: sometimes called the anterior meniscofemoral ligament. Helps prevent anterior horns of menisci from moving forward.
- Patellar ligament
Ligaments of Hip
- Iliofemoral
- Pubofemoral
- Ischiofemoral
Iliofemoral Ligamnt
Resists extension and IR, and is one of the strongest in the body
Pubofemoral
Resists abduction and ER
Ischiofemoral
Resists extension and IR
Ligamentum Teres (or capitis) of the Hip
- Triangular in shape and somewhat flattened
- Made tense when the thigh is semiflexed, abducted or rotated outward
- Relaxed when limb is adducted
- Research suggests little influence as aligamentbut is important in transmitting arterial supply to the femoral head.
