Knee

Question 1

Basic Knee Anatomy

Answer 1

• Bones - femoral and tibial epicondyles and bony knee-cap (patella)
• Ligaments - ACL, PCL, lateral and medial collateral ligaments
  
  • ACL - femoral condyle –> tibia; limits rotation and forward motion
  • PCL - femoral condyle –> tibia; limits backward motion of tibia
  • Collaterals limit side to side motion
• Menisci - medial and lateral (“cushion during rotation”) and provide shock absorption
  
  • Soft cartilage

Question 2

What is the most common knee injury?

Answer 2

ACL or medial meniscus tears

Question 3

Unhappy Triad

Answer 3

torn ACL, MCL and medial meniscus from lateral blow to knee

Question 4

ACL Injury

Answer 4

• Common to have hx of hyper-extension, deceleration or internal rotation
• Hear pop followed by swelling
• PE - see effusion, restricted ROM, anterior drawer sign (feel tibia come forward more than normal when pulling forward) , Lachman test
• MRI for diagnosis

Question 5

PCL Injury

Answer 5

(very rare)

• Usually due to anterior to posterior force to lower leg
• PE - pos posterior drawer sign (lax tibia when move into posteriorly) and effusion

Question 6

Meniscal Injury

Answer 6

• Acute or chronic
• “Locking” or “clicking” when flex and extend
• May feel crepitus

Question 7

General Tx (when is surgery indicated?)

Answer 7

• Initial - ice, NSAIDs, narcotics as needed, rest
• May use immobilizers of knee BUT may also want them to maintain ROM
• Isolated/partial tears may heal on own w/ conservative therapy
• Complete tear/instable knee joint -surgery

**Delayed treatment –> inc risk for later arthritis / chronic pain / limited mobility