Knee Injuries

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Knee Injuries
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Anatomy of the knee

• Hinge joint at the articulation (point of
  contact) of 3 bones
• Stabilized by 4 major ligaments, cartilage, and
  strong musculature
• Knee also able to rotate

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Bones of the knee

• 3 bones form the knee joint
• Femur, tibia, fibula
• Primary movement occurs at the POC of the tibia
  and femur
• Patella sesamoid (floating bone)
• As the knee flexes and extends, the patella
  glides up and down on the front of the femur

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Ligaments

• 4 primary knee ligaments
• Medial collateral ligament (MCL)-provides
  stability to the inside (medial) aspect of knee
• Lateral collateral ligament (LCL)-helps stabilize
  outside (lateral) aspect

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Ligaments

• Anterior cruciate ligament (ACL)-keeps tibia from
  moving forward on the femur
• Posterior cruciate ligament (PCL)-prevents tibia
  from moving backward on femur
• PCL and ACL pass thru the middle of the knee
  joint and cross each other

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Cartilage (menisci)

• Ends of tibia and femur are covered and cushioned
  by pieces of tough cartilage tissue called
  menisci
• Without menisci, tibia and femur would rub
  against each other, causing the bones to wear
  down quickly
• Menisci also help stabilize the joint

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Muscles

• Provide movement and stability
• Primary muscles include hamstring group and
  quadricep group
• Knee extension primarily performed by the quads
  (4 muscles)
• Knee flexion performed by the hamstrings (3
  muscles)

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Preventing Knee Injuries

• Ligament sprains are the most common injuries at
  the knee
• Athletes should develop strength in the muscles
  around the knee
• If athlete has problems with knees, ATC should
  examine leg structure to determine if he/she has
  genu valgus (knock-knees) or genu varus (bowlegs)

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Treating Knee Injuries

• Knee vulnerable to injuries due to exposure to
  many forces
• Ligaments extremely vulnerable but tendon and
  bone injuries do occur

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Ligament Injuries

• ACL-athlete often disabled, complaining of knee
  giving way, collapsing, and popping
• Often the most serious and most frequently
  surgically reconstructed
• Often injured as athlete attempts to change
  directions quickly and twists lower leg
• May hear a popping sound
• Immediate treatment includes PRICE, knee
  immobilizer, and crutches
• Rehab focuses on strengthening hamstrings to help
  stabilize tibia

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PCL injuries

• Frequently injured when athlete falls and bent
  knee bears full weight, when knee is forcefully
  hyperflexed or blow is delivered to the front of
  the tibia
• Often little swelling
• Treatment includes PRICE and referral to physican
• Rehab focuses on strengthening the quads and
  regaining full function

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MCL injuries

• Injured when athlete receives a blow to the
  outside of the knee
• Treatment includes PRICE
• Moderate to severe MCL needs an immobilizer
• Rehab focuses on strengthening the muscles that
  cross the medial aspect of the knee

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Degrees of MCL sprains

• Mild MCL sprain-medial joint line pain, little if
  any swelling, no joint laxity, full flexion and
  extension
• Moderate MCL sprain-mild swelling, discomfort,
  some joint laxity
• Severe MCL sprain-moderate or severe swelling,
  loss of function, great deal of joint laxity

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LCL injuries

• Occur less frequently than MCL injuries
• Symptoms are similar except discomfort is at the
  lateral aspect
• Treatment same as MCL
• Rehab focuses on strengthening the lateral thigh
  muscles and hamstrings

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Muscle and Tendon Injuries

• Patellar tendinitis-overuse disorder
  characterized by quad weakness and tenderness
  over patellar tendon
• Treatment will attempt to control inflammation
  (apply ice, modify activity level)
• Rehab will address flexibility problems or
  weakness of the leg

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Patellar-Femoral Syndrome

• Set of symptoms that include pain and discomfort
  around the patella
• As the knee bends, instead of riding smoothly,
  the patella is grated across the femur, causing
  cartilage on the back of the patella to soften or
  wear away
• Athlete reports a grinding sensation with flexion
  and extension
• Grinding can be felt by placing hand over patella
• Treatment involves correcting patellar tracking
  problems

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Patella Dislocation

• Patella forced to the lateral aspect of the knee
• Occurs when knee is bent and forced to twist
  inward
• Athlete is often in distress
• Only physician should reduce a dislocated patella
• Treatment involves immobilizing the knee