S4) The Knee Flashcards
What is the knee joint?
The knee joint is a bicondylar type synovial join formed by articulations between the patella, femur and tibia
Describe the two articulations of the knee joint
- Tibiofemoral – medial and lateral condyles of the femur articulate with the tibia
- Patellofemoral – anterior and distal part of the femur articulate with the patella
Describe the arterial supply of the knee joint
Arterial supply via genicular anastomoses around the knee, which arise from the genicular branches of the femoral and popliteal arteries
Describe the innervation of the knee joint
Nerves which cross the knee joint – femoral, tibial and common fibular nerves
Identify and describe the three types of ligaments found in the knee joint
- Patellar ligament – a continuation of the quadriceps femoris tendon distal to the patella
- Collateral ligaments – tibial (medial) collateral ligaments and fibular (lateral) collateral ligaments
- Cruciate ligaments – anterior and posterior cruciate ligaments
Compare and contrast the structure of the medial and lateral collateral ligaments
- Medial collateral ligament is wide and flat
- Lateral collateral ligament is thinner and rounder
State the function of the collateral ligaments
The medial and lateral collateral ligaments act to stabilise the hinge motion of the knee, preventing any medial or lateral movement
State the origin and attachment of the medial collateral ligament
- Origin: medial epicondyle of the femur
- Attachment: medial surface of the tibia
State the origin and attachment of the lateral collateral ligament
- Origin: lateral epicondyle of the femur
- Attachment: depression on the lateral surface of the fibular head
State the respective functions of the ACL and PCL
- ACL: prevents anterior dislocation of the tibia onto the femur
- PCL: prevents posterior dislocation of the tibia onto the femur
State the origin and attachment of the anterior cruciate ligament
- Origin: anterior intercondylar region of the tibia
- Attachment: intercondylar fossa of femur
State the origin and attachment of the posterior cruciate ligament
- Origin: posterior intercondylar region of the tibia
- Attachment: femur in the intercondylar fossa
What are the menisci and what do they do?
The medial and lateral menisci are fibrocartilage structures in the knee that deepen the articular surface of the tibia, stabilising the joint and acting as shock absorbers
Describe the attachments of the menisci
- Both menisci are attached at both ends to the intercondylar area of the tibia
- The medial meniscus is also fixed to the tibial collateral ligament and the joint capsule (less mobile)
Identify the 4 main movements possible at the knee joint and the muscles involved
- Extension: quadriceps femoris muscles
- Flexion: hamstrings, gracilis, sartorius and popliteus
- Lateral rotation: biceps femoris
- Medial rotation: semimembranosus, semitendinosus, gracilis, sartorius and popliteus