Unit 3: The Knee is a Claustrophobia (it never ends)

Knee

• Largest joint in the body

• Does not get hurt as often as the should or ankle, but when it does get hurt, it needs surgery and rehab

• Both mobile and stable

What are the chances of losing the leg when the knee is dislocated?

• 50% chance of losing the leg

• 50% chance of walking again

• Athletes have these percentages higher unless emergency services are available right away

Bone

Below average stability

Ligaments

Average stability

Muscle/Tendon

Above average stability (with potential)

Cartilage

Assist - give bone formation more depth

1. Femur (Knee Bone)

• Largest bone in the body

• A & B are condyles

• A is the medial condyle

• B is the Lateral Condyle, which is rounded out/convex

2. Tibia (Knee Bone)

• Medial Bone

• Weight bearing bone of the lower leg

• A. = Tibial Tuberosity/Tuberocal

  • 4 quad muscles connect here

3. Fibula (Knee Bone)

• Lateral Bone

• Not weight bearing

4. Patella (Knee Bone)

• Knee Cap

• Sesmoid Bone

• Protects the condyles

• Dislocates a lot

Sesmoid Bone

• Floating bone

• Not directly connected to any bone

• Patella

1. Medial Collateral Ligament

• Also known as the Tibial Collateral Ligament

• Gets hurt the most and is easiest to hurt

• Can live with it being damaged unless cartilage is damaged

Valgus Force

Mechanism of Injury

• Shown in the diagram, valgus force comes in from the right (for the right knee) and tears the Medial Collateral Ligament

2. Lateral Collateral Ligament

• Also known as the Fibial Collateral Ligament

• Braces are super effective here

• Keep feet moving to avoid injury

Varus Force

Mechanism of Injury

• As shown in the diagram, varus force comes from the left side (of the right knee) and tears the lateral collateral lig.

• Not as common, as the left side of the right knee is on the inside.

3. Anterior Cruciate Ligament (ACL)

• Prevents the Tibia from going to far forward

• Prevent Knee from dislocation

• Once damaged, a new one is needed

• Happens in open field collisions

4. Posterior Cruciate Ligament

• Rarely needs surgery

• Only happens in skating sports

1. Medial Meniscus

• Works as a pad

• Keeps condyles in place

• Release synovial fluid

• Keeps Femur in place

• Gets injured more

2. Lateral Meniscus

• Works as a pad

• Keeps condyles in place

• Release synovial fluid

• Keeps Femur in place

Menisectomy

• Take out the tear

• Can lead to tendinitis wayyyyy faster

Meniscal Repair

• Suture the tear

• Chemicals stimulate healing

• Might not heal though

1. Vastus Medialis Oblique

• VMO

• Weakest

• Tear drop shape

• Knee Extension

2. Vastus Intermedialis

• Knee Extension

3. Vastus Laterilis

• Strongest

• Knee Extension

4. Rectus Femoris

• Hip and Knee

• Extends knee and flexes hip

The Vastus Medialis Oblique, Vastus Intermedialis, Vastus Laterilis, and Rectus Femoris categorize as…

Quadriceps

1. Semi-membrinosus

• Two Joint Muscle

• Knee and Hip

• Natural ACL brace

• Ham string

2. Bicep Femoris

• Two Joint Muscle

• Knee and Hip

• Natural ACL brace

• Ham string

3. Semitedinosus

• Two Joint Muscle

• Knee and Hip

• Natural ACL brace

• Ham string

4. Gastrocnemius

• Calf muscle

• Undertrained

• Ankle and Knee

All hamstring muscles are undertrained at…

• The hip; most injuries occur here

Patellar Dislocations

• Happen on a hard floor

• Hit straight on in a bent position

• Goes to the strongest muscle (Vastus Lateralis)

• Relocated easily by AT

• Athletes have stronger quads, so does not happen as often to them

What happens if the patella is dislocated for too long?

The tissues around it stretch out

Patella Dislocation Rehab

• Strengthen the Vastus Medialis Oblique

• Prevent it from happening again

• Brace does not address VMO

Osgood Schlatters

• Happens when the femur rapidly grows and the muscles can’t keep up

• Because the bone grows so fast, calcium is grown at Tibial Tuberosity

• Pain, tenderness, soreness, swollen

• Technically will go away itself, but ATs cheat the system with stretching, ice, and anti-inflammatory drugs

ACL Surgery

• Autograft or Allograft

• Reconstruction surgery

Autograft

• Getting the graft from somewhere else in the body

• Semi-Tendinosus (Hamstring)

• Patellar Tendon (1/3 of it - most common)

  • Lowest retear rate, but a lot of tendinitis

• Quadriceps Tendon

  • Can retear, less tendinitis

Allograft

• Getting the graft from someone else

• From cadaver: Achilles Tendon

• Don’t need to make something else weaker

• Rejection Risks: May not work with the body

• Tend to retear at a higher rate

Propioception

• Important to Rehab

• Minimize the chances of ACL Tear

McMurray’s Test

• Medial Meniscus Test

• Tends to have a lot of false positives

• FP caused by chondromalacia

Lachmens

• ACL Test

• Most Popular

Anterior Drawer

• ACL Test

• Easier for hamstrings to cheat, false negatives

Pivot Shift

• ACL Test

• Literally pop the knee out (super painful)

• Orthopedic doctors