The Knee Anatomy Assessment Injuries

Anatomy Hinge joint: flexion and extension Bones: tibia, fibula, femur, patella Menisci: medial and lateral Ligaments: cruciate and collateral Muscles

Menisci Cartilage btwn femur and tibia Cushions and shock absorption Help stabilize knee

Ligaments, Cruciate Anterior Cruciate Lig. (ACL): prevents knee from moving front to back Posterior Cruciate Lig. (PCL): stronger, prevents hyperextension

Collateral Ligaments Medial Collateral Lig. (MCL): prevents knee from valgus or outside forces Lateral Collateral Lig. (LCL): prevents knee from varus or inside forces

Muscles Extension: Quadriceps Flexion: Hamstrings Iliotibial Band: lateral stabilizer

Assessment History: where, how, pops, swelling, previous injury, sudden or gradual onset? Observation: walking, stairs Palpation: intra- or extracapsular Special Tests

Valgus: MCL Varus: LCL Anterior Drawer: ACL Lachman: ACL Pivot-shift: ACL Posterior Drawer: PCL Sag test: PCL

Meniscal Tests McMurray’s Apley Compression and Distraction

Patella Examinations Q Angle: Angle of thigh to knee Male: 10 degrees Female: 15 degrees Over 20 considered excessive

MCL Sprain Result from blow to lateral side or outward twist Test immediately after injury As laxity inc. so does grade

LCL Sprain Common in skiers (skis cross forcing body weight forward) Treatment similar to MCL Quad strength, ROM

ACL Sprain Most serious knee injury Caused by twisting motions (hit or making a cut) Feeling of “pop” and instability Unhappy Triad injury to MCL, ACL and medial meniscus (soccer, football)

ACL Surgery Generally required Grafts: patella tendon, hamstring, or cadaver Lots of rehab to restore atrophy

PCL Sprain Most important ligament in knee 95% of support against hyperextension Injury occurs when excessively hyperextended or fall on bent knee “pop” in back of knee

Meniscal Tears Medial  ”C” shaped Lateral  “O” shaped, more mobile Medial most common to tear Torn by twisting motions Feeling of catching and pain down stairs

Types of Tears and Treatment Bucket handle Parrot beak Arthroscopic surgery to remove torn portion or stitch together

Patella Dislocations Cutting mechanism Usually displaces laterally Treatment: reduce patella, RICE, and send for X-ray Avoid knee flexion

Osgood-Schlatter Disease Apophysitis at attachment of patella lig. to tibial tubrical Usually resolves btwn yrs. Treatment: ICE, US, patella band

Larson-Johansson Disease Similar to Osgood-Schlatter except at distal patella Pain with kneeling, jumping, and running Treatment: same as O-SD

Jumper’s Knee Patella tendonitis Treatment: reduce inflammation, NSAIDS, friction massage, US, ICE Some like patella bands

A football running back is hit on the lateral surface of his knee by an opponent making a tackle. He has significant pain and some immediate swelling on the medial surface of his knee. What is the suspected injury and what tests can be done to determine the nature and extent of the injury? List and describe the tests.

A lacrosse player carrying the ball attempts to avoid a defender by planting his right foot firmly on the ground and cutting hard to his left. His knee immediately gives way, and he hears a loud pop. He has intense pain immediately, but after a few minutes he feels as if he can get up and walk. What ligament has most likely been injured? What stability tests should be done? List and describe the tests.