KIN 188 – Prevention and Care of

Athletic Injuries

Knee Evaluation and Injuries

Anatomy

Bony Anatomy

Femur Medial/lateral femoral

condyles

Tibia Medial/lateral tibial plateaus Tibial tuberosity

Fibular head

Patella (“knee cap”)

Ligamentous Anatomy

Anterior cruciate ligament (ACL) – prevents anterior tibial translation

Posterior cruciate ligament (PCL) – prevents posterior tibial translation

Medial collateral ligament (MCL) – protects against valgus stress

Lateral collateral ligament (LCL) – protects against varus stress

Menisci

Medial meniscus Larger, C-shaped

Lateral meniscus Smaller, O-shaped

Muscular Anatomy

Anterior Quadriceps (vastus medialis/intermedius/lateralis, rectus femoris) Primary knee extensors

Posterior Hamstrings (biceps femoris/lateral, semimembranosus and

semitendinosus/medial) Primary knee flexors

Medial Pes anserine (“goose foot”) muscles (sartorius, gracilis, semitendinosus)

Lateral Iliotibial (IT) band

Evaluation

History

Mechanism of injury/etiology Direct trauma (contusion, fracture, bursitis) Hyperextension (ACL/joint capsule sprain) Hyperflexion (PCL/joint capsule sprain) Fall on flexed knee (PCL sprain) Valgus stress (MCL sprain, meniscus injury) Varus stress (LCL sprain, meniscus injury) Rotational stress (ACL sprain, meniscus injury)

History

Unusual sounds/sensationsClicking/locking – meniscus injury“Pop” – cruciate ligament injury, patellar

dislocation

History of previous injury/surgery

History

Change in activity Intensity, duration, frequency, surface change, footwear change

Acute/gradual onset of symptoms Macrotraumatic vs. microtruamatic

Characterize pain Location (point with 1 finger) Dull, sharp, burning, throbbing, etc. Rate on scale (1-10) What increases or decreases?

Treatment, medication, evaluation to date

Inspection/Observation

ALWAYS compare bilaterally Obvious deformity

Genu valgum (“knock knees”) Genu varum (“bow legged”) Genu recurvatum (“hyperextension”)

Bleeding Discoloration/ecchymosis Swelling

Immediate vs. gradual, amount Scars

Inspection/Observation

Palpation

Patella Femoral condyles Tibial plateaus Tibial tuberosity Fibular head Joint line (menisci)

MCL LCL Infrapatellar tendon Quadriceps Hamstrings Gastrocs

Special Tests

ROM Active – patient/athlete moves joint Passive – clinician moves joint, evaluates end feel Resistive – proximal stabilization and distal

application of resistance (“break” test vs. resistance through ROM)

Neurovascular

Special tests

ROM

Knee extensionPrimary movers are quadriceps

Knee flexionPrimary movers are hamstringsSecondary movers are gastrocs (cross knee

joint posteriorly)

Neurovascular

Neurological evalation Nerve root level and peripheral nerve sensory and

motor distributions

Vascular evaluation Skin temperature/color Capillary refill Popliteal pulse Dorsal pedal pulse Posterior tibial pulse

Special Tests

Anterior drawer/Lachman tests – ACL

Posterior drawer/posterior sag tests – PCL

Valgus stress tests – MCL

Varus stress tests – LCL

Apprehension test – patellar instability

McMurray’s/Apley’s tests - menisci

Injuries

Ligamentous Injuries

ACL injuries

PCL injuries

MCL injuries

LCL injuries

ACL Injuries

Most MOI are non-contact rotational forces

Tibia displaced anteriorly on femur (or vice versa), rotational stress (cutting) or hyperextension

May be isolated, but typically due to MOI, other structures (joint capsule, menisci) also injured

Positive anterior drawer and/or Lachman’s tests

PCL Injuries

Most common MOI is fall on flexed knee driving tibia posterior on femur

May also occur with rotational and/or hyperextension MOI

Often treated non-operatively as quadriceps muscles are able to minimize posterior displacement of tibia on femur

Positive posterior drawer and/or posterior sag tests

MCL Injuries

Most common MOI is blow to lateral knee with resulting valgus tension forces

May also be injured by non-contact and/or rotational stresses

Positive valgus stress test

LCL Injuries

Most common MOI is blow to medial knee with resulting varus tension forces

Internal rotation of tibia may be secondary contributor to LCL injury

Positive varus stress test

Meniscal Injuries

May be isolated from flexion/hyperflexion with rotation of the knee – “pinched” between tibia and femur

Often injured in association with cruciate ligament injury

“Classic” symptoms include joint line pain and clicking or locking – helpful but not definitive evaluative tools

Limited reliability of special tests

Patellar Injuries

Lateral displacement is most common

Positive apprehension test

Patellar Tendon Rupture

Occurs with excessive tension through tendon causing failure in mid-substance or at either insertion point

Present with gross deformity, inability to actively extend the knee and significant swelling immediately

Additional Injuries

Muscle strains to quadriceps/hamstrings Severity based upon degree of tissue damage

Tendonitis Overuse condition associated with training changes,

biomechanical insufficiencies, poor flexibility, etc. Most common to infrapatellar tendon, but can involve

IT band, pes anserine muscles and/or hamstrings as well

Additional Injuries

Osgood-Schlatter’s disease Inflammatory condition of tibial

tuberosity at patellar tendon insertion, symptoms similar to patellar tendonitis but tuberosity often enlarged and only site of pain, most prominent in adolescents

Bursitis Typically inflamed secondary

to acute trauma, but may be chronic or associated with infection

Prepatellar, presents with significant anterior swelling