The KneeAnatomy

Mazyad Alotaibi

The Knee Joint Complex

Tibiofemoral Joint* Patellofemoral Joint* Tibiofibular Joint

Capsular Pattern – Greater loss of flexion than extension

Bones Femur – condyles covered with articular cartilage,

intercondylar groove, patella groove

Tibia – bifid plateau

Patella – medial and lateral articulating facets-increases the lever arm of the quadriceps-increases the distribution of compressive force on the femur in full flexion

LigamentsStrong ligaments provide the static stability system for the knee

MCL & LCL

Provide medial/ lateral stability and prevent excessive external rotation of the tibia

Frequently injured on the joint line MCL – Frequently injured by an external rotation

strain– Has deep and superficial fibres

LCL – Frequently injured by adduction blow to the knee

ACL

Ant part of intercondylar area

Up, back, lateral Med asp of lat fem

condyle

ACL & PCL

Provide ant / post stability of the knee ACL – also controls rotation

– Commonly injured by forced internal rotation of the femur on a fixed tibia and flexed knee

PCL – strongest -Commonly injured in flexion with an

anterior force

Joint capsule – attached to the medial meniscus and MCL

Coronary Ligaments – bind the menisci to the tibia

Menisci

Lateral and medial Peripherally thicker than

central Transverse lig attaches Increase stability Shock absorbing Lubrication and nutrition Injured during twisting

activities

MusculatureDynamic stability system of the knee

ITB – anterior and lateral stability and prevent excessive internal rotation of the tibia

Quadriceps – Lat vs med to maintain patella in groove

Sartorius and Gracilis – medial stability, knee and hip flex

Hamstrings

Prevent anterior displacement of the tibia

Pes anserine – sartorius, gracilis and semitendinosis.

Biceps femoris

Primarily produce knee flex and also external rotation of the tibia

Gastrocnemius – primarily ankle flexor also assists with knee flexion

Popliteus – WB external rotation and extension of the tibia– Attaches to the posterior horn of the lateral

meniscus and pulls back the posterior horn to unlock the knee

Bursa

Suprapatellar – continuation of the synovial sac

Prepatellar Deep and superficial infrapatellar Also semimembranosus and

med head of gastroc, Gastroc heads and capsule Pes anserine tendon

Surface markings

Joint line Medial collateral ligament Lateral collateral ligament Medial coronarys Gerdy’s Tubercle Pes Anseurine Bursa