Knee Joint

Question 1

Articulating sufaces

Answer 1

• Tibiofemoral - medial and lateral condyles of the femur with the tibia
• Patellofemoral - anterior and distal part of the femur with the patella

Question 2

Neurovasculature

Answer 2

Blood supply - genicular anastomoses around knee (supplied by genicular branches of the femoral and popliteal arteries)
Nerve supply - femoral, tibial and common fibular nerves

Question 3

Menisci

Answer 3

Fibrocartilage structures in the knee
- Deepen articular surface of tibia -> inc. stability
- Act as shock absorbers
Attached at both ends to the intercondylar area of the tibia
Medial meniscus is also fixed to tibial collateral ligament -> damage to this results in tearing of medial meniscus

Question 4

Bursae

Answer 4

• Suprapatellar bursa - extension of the synovial cavity, between quadriceps femoris and femur
• Prepatella bursa - between apex of patella and skin
• Infrapatella bursa - deep and superficial, deep - between tibia and patella ligament // superficial - between patella ligament and skin
• Semimembranosus bursa - posterior in knee joint, between semimembranosus and medial head of gastrocnemius

Question 5

Ligaments

Answer 5

• Patella ligament - continuation of quads tendon distal to patella, attaches to tibial tuberosity
• Medial (tibial) collateral ligament - proximally attaches to medial epicondyle of femur, distally attaches to medial surface of tibia
• Lateral (fibular) collateral ligament - proximally attaches to the lateral epicondyle of femur, distally attaches to a depression on lateral surface of fibular head
• Anterior cruciate ligament - attaches to the anterior intercondylar region of tibia and ascends posteriorly to attach to intercondylar fossa of femur (prevents anterior dislocation)
• Posterior cruciate ligament - attaches to the posterior intercondylar region of the tibia and ascends anteriorly to attach to the intercondylar fossa of femur (prevents posterior dislocation)

Question 6

Movements

Answer 6

Extension
Flexion
Lateral rotation
Medial rotation

Question 7

Damage to collateral ligaments

Answer 7

Force applied to the side of the knee when foot is on the ground
Ask patient to medially/laterally rotate the leg -> pain on medial rotation indicates MCL damage (+ vice versa)

Question 8

Damage to cruciate ligaments

Answer 8

ACL -> hyperextension of the knee joint or by large force to back of knee with partial flexion of joint
- Anterior draw test - pull tibia forwards -> if it moves ligament has been torn
PCL - knee flexed and large force applied to shins (often in car accidents), hyperextension of knee, damage to upper part of tibial tuberosity
- Posterior draw test - push tibia posteriorly -> movement = ligament has been torn

Question 9

Inflammation of bursa

Answer 9

Friction between skin and patella cause prepatella bursa to become inflamed, producing swelling on anterior side of knee - housemaids knee
Friction between skin and tibia can cause infrapatella bursa to become inflamed - clergyman’s knee

Question 10

Unhappy triad

Answer 10

Due to attachment of medial collateral ligament to medial meniscus, damage to the ligament can affect the meniscus
A lateral force to an extended knee (rugby tackle) can rupture the medial collateral -> damages medial meniscus -> ACL also affected -> unhappy triad