The Knee

ACL Tear

A tear in the ligament that connects the femur to the tibia and stabilizes the knee joint
- It prevents excessive anterior tibia movement
- Limits rotational knee movements
Who tears it?
- Mostly athletes → sports with a lot of change in direction, jumps, and landing
- Female athletes are 2-8 times more likely
How does it happen/ symptoms
- The tibia rotates and translates internally
- Knee is in excessive tension
- Audible pop, sever pain, swelling, loss of range of motion, instability with weight bearing
Treatments:
- Surgery:
  - Allograft → cadaver
  - Autograft → from hamstring/tendon
- No surgery:
  - Intensive physical therapy
  - RICE

MCL Tear

A tear in the ligament that connects the femur to the tibia
- stabilizes the knee joint against valgus forces
- Found on the medial side
Who tears it?
- Young-middle aged adults that participate in contact sports
- Male to female 2:1
How does it happen/ symptoms
- Valgus forces to the lateral side
- 3 grades of severity
  - 1: mild stretch injury
    - Mild pain, swelling, tenderness
  - 2: partial tear
    - Moderate pain, swelling, tenderness
  - 3: complete tear
    - Severe pain, swelling, tenderness
Treatments
- Knee brace, PT, RICE
- Surgery
  - Allograft MCL Reconstruction

Meniscus Injury

Shock absorption, load distribution, stability, joint lubrication
Who does it?
- Athletes twisting their upper leg with planted foot
- People with discoid meniscus
- Kneeling, squating, heavy lifting
- Old age, wear and tear, arthritis
Symptoms
- Pain in knee joint (laterally and medially)
- Locking of the knee
- Pain when bending knee
Diagnostics
- Physical examination
- X-ray
- MRI
Locations of tear
- Posterior horn tears
- Central tears
- Peripheral tears
- Anterior horn tears
Types of tears
- Intrasubstance
- Radial
- Horizontal
- Complex tear
- Bucket-handle
- Flap tear
Treatments
- RICE, PT
- Surgery
  - Arthroscopy
  - Meniscus transplant
  - Knee replacement
  - Tissue engineering