Knee Joint

Question 1

Type of joint

Answer 1

Bi-condylar synovial ,modified hinge, biaxial

2 degrees of movement

Question 2

Articular Surfaces

Answer 2

Tibial

• med and lat condyles on sup aspect of plateau covered in hyaline cartilage, concave centrally to receive convex femoral articular cartilages, flatter in periphery for attachment of menisci
• med condyle is longer/thinner than lat
• condyles separated by intercondylar eminences
• covered in articular cartilage

Femoral

• convex ant-post and med-lat, covered in thick hyaline cartilage
• lat condyle shorter and wider than med

Question 3

Collateral Ligaments

Valgus- distal aspect moving away from midline
Varus- distal aspect moving towards midline

Answer 3

MCL (tibial)- limits valgus movement of tib on femur

• from med epicondyle of femur to med prox shaft of tibia (slightly ant)
• blends with knee joint capsule and med meniscus

LCL (fibular)- limits varus movement of tib on femur

• from lat fem epicondyle to apex of fibular head, bificating biceps fem tendon
• no connection with capsule/meniscus

Question 4

Cruciate Ligaments

Answer 4

ACL- prevents ant displacement of tib on femur
-from ant intercondylar area of tibia, passes sup/post/lat to the post part of med surface of lat fem condyle

PCL- prevents post displacement of tib on femur
- from post intercondylar area of tibia, passes sup/ant/med to ant part of lat surface of med fem condyle

Question 5

Menisci

Answer 5

Medial Meniscus
-ant horn attaches into intercondylar area, ACL and intermeniscal ligts
-post horn inserts into PCL and post horn of lat men, blends with capsule and MCL
Lateral Meniscus
-ant horn attaches from ant intercondylar eminence, posteriorly to ACL and intermeniscal ligts
-post horn attaches from post intercondylar area, anteriorly to post horn of med men

• outer borders thick and vascular; capable of healing and recovery
• inner borders thin and avascular; don’t recover once damaged

Function

• improve congruence
• shock absorbers
• aid lubrication
• conforms to changing shape of fem condyles during knee movement
• (enhances tibia-femoral joint stability by deepening tib art.surf)

Question 6

Q Angle

Answer 6

• Angle between quads and patella tendon
• Measured as angle between the line from ASIS to patella centre and line from patella centre to tib tuberosity
  
  • represents angle of quad, muscle force

Normal= 13deg in men 18deg in women
Abnormal= <13 and >18
If >18 patella is predisposed to lateralisation