biggest joint in human body

what type of joint is knee jt

Knee joint

Not purely allowing 1 degree of freedom

Primary movement of knee joint

Knee joint have a certain degree of rotation

Tibia against femur

Femur on a fixed tibia

Specialized articulation within the complex

if not normal, it can alter the normal function of the joint

PROXIMAL

DISTAL

Patellofemoral OPP

Patellofemoral CPP

Patellofemoral capsular pattern

Smaller, without broken line

When looking with the distal articulating surface at rest/standing: bigger surface contact

Bigger without broken line

Smaller contact surface in neutral standing

Arthritis contracts in this surface which degenerates first

Slightly diagonal

Posterior tibia — anterior femur

Diagonally oriented

Anterior tibia — diagonally cross upwards — posterior femur

Anteromedial crosses to the posterolateral

Coxa vara

Coxa valga

Weight bearing at rest: normal slight genu valgum degrees

If foot is very straight, BOS narrow

In walking, the GRF will matter as to where the contact is

Supporting tissues

Similar to labrum

If absent = shallow tibial plateau

how it behaves depends upon where it is attached

Distributes the load

Femur flexion

Femur extension

Moves less due to several attachments

Semicircular

10mm in width

4/5 of a ring

More mobile

Medial meniscus attachment

Lateral meniscus attachment

WB>NWB

Where femoral condyle moves, excursion follows the same direction

5-7 mm

11mm

Normal in walking, stair climbing

Increased significantly in deep squats

Most common MOI

Most commonly injured

Most common type of meniscal injury

When it tears, there will be a flap

Major supporting structures in the knee

Posterior meniscofemoral ligament is also known as

Major ligament

Longer

Shorter

Contribute to stability

Restricts side to side motion

How does ACL get torn

Has 2 bands that becomes taut during anterior translation in tibia

Stout; rarely injured

Strongest ligament

Limits posterior translation

Most common injury of PCL

Observed in vehicular accidents; head on collisions

Strong trauma to tibia anterior which translates posterior

Posterolateral ACL

Anteromedial ACL

Supporting tissue at the back of the knee

Blends with posterior capsule

Supports ACL

Supports laterally

Reinforces LCL

Thickenings of the capsule

Extends beyond knee

Becomes a supporting tissue (like the collaterals)

Has fibers going to the patella

Bulged laterally

Serves as a bony block to the patella so that it wont be pulled laterally (defense mechanism)

Cruciates are found inside the capsule

What happens when ITB becomes tensed

Angle of pull of quads is very strong towards the anterior side

Problem in the synovium

Capsule of young age

Normally does not interfere

If too thick, it tightens the capsule which then interferes with the articulating surface jt play

Very common syndrom in the knee

Passive knee flexion

Active knee flexion

Knee hyperextension

>10 deg of hyperextension

Only happens when knees are flexed 90 deg

TESTING OF TIBIAL ROT: Knee flexed 90 deg

TESTING OF TIBIAL ROT: align with thigh

TESTING OF TIBIAL ROT: align with 2nd rat of foot

TESTING ROM OF TIBIAL ROT: IR/ER leg

Lateral tibial rotation