Knee Injuries

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

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

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

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

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

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)

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)

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

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

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

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

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

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

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

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

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