The Knee

Bony AnatomyThe knee is composed

of four major bonesThe Femur

Bone of the upper leg/thigh Condyles

TibiaMedial bone in the lower

leg Tibial plateau

FibulaLateral Bone in the lower

legPatella

“Also known as kneecap”Sesamoid bone

enveloped in the quadriceps tendon

Joints of the KneeTibiofemoral

JointWeight-

bearing, hinge joint

Held together with joint capsule and several ligaments

Patellofemoral JointHelps extend

the knee

CartilageTwo types of cartilage

are found in the kneeBoth are bathed in

synovial fluid Produced by the synovial

membrane of the knee

Articular cartilageCovers the ends of the

tibia and femurCovers the retropatellar

surfaceMeniscus

Wedge shaped cartilageAid in shock absorption,

distributing forces and improving stability of the joint

Cartilage ~ MeniscusMedial Meniscus

Between the medial femoral condyle and medial tibial plateau

“C” - shaped Lateral Meniscus

Between the lateral femoral condyle and lateral tibial plateau

“U”- shaped

Ligaments of the KneeFour major ligaments

connect the tibia and femur

Two are located outside of the joint capsuleMedial Collateral

Ligament (MCL)Lateral Collateral

Ligament (LCL)Two are located on the

inside of the jointAnterior Cruciate

Ligament (ACL)Posterior Cruciate

Ligament (PCL)

Ligaments ~ CollateralLateral Collateral

Ligament (LCL)Attaches the femur

and the head of the fibula

Provides lateral stability

Only palpable ligament in the knee

Medial Collateral Ligament (MCL)Attaches the femur

to the tibiaProvides medial

stability

Ligaments ~ CruciateAnterior Cruciate Ligament

Attaches the to the femur and anterior aspect of the tibial plateau

Prevents anterior translation of the tibia on the femurPosterior Cruciate Ligament

Attaches to the femur and posterior aspect of the tibial plateau

Prevents posterior translation of the tibia on the femur

Cruciate is derived from Latin word meaning “cross”ACL running Anterior-to-Posterior-ExternallyPCL running Posterior-to-Anterior-Internally

Also help control rotation of the knee and medial/lateral stability

Muscular anatomy Muscles that

move the legs are the strongest in the bodyQuadriceps

Extend the kneeHamstrings

Flex the knee joint

Hip FlexorsAssist with knee

flexion

Muscular Anatomy ~ Quadriceps

4 muscles together join at the distal anterior thigh and attach the patella through the quadriceps tendonVatus LateralisVastus MedialisVastus

IntermediusRectus Femoris

Muscular Anatomy ~ Hamstrings

3 muscles on the posterior aspect of the thigh are divided into two groupsMedial

hamstringsSemitendonosisSemimembrano

sis Lateral

hamstringBiceps Femoris

Muscular Anatomy ~ Hip FlexorsTwo additional,

long strap-like muscles in the thigh that assist with knee flexionSartoriusGracillis

They attach to the anteriomedial tibia near the attachment of the semitendinosusArea known as the

pes ansurine

Knee Injuries A wide variety of injuries can occur to the

knee. Some of the most common arePatellarfemoral Patellar tendonitisSprains (MCL/LCL)Ligament Tears (ACL/PCL)Meniscus Tears Epiphyseal injuries Oshgood-SchlatterIliotibial Band syndromeFractures/dislocations of the patellarfemoral

joint

Patellofemoral problemsPatellofemoral

problems can be very challenging to the ATC and athleteUsually caused by

irregular tracking of the patellaIt is not easy to identify

the source of the problemClassic complaints

Anterior pain/achingCrepitusMild, or no swellingPatella may appear to

face inward, instead of forward

Patellofemoral Problems ~Recognition and TreatmentRecognition

Patellofemoral provocation test will help reproduce the symptoms for the athlete Forward lungeStep-down test

TreatmentCorrect the suspected cause

Shoe insertsLow-dye tapingStrengthening exercisesSpecialized braces/taping

Patellar TendonitisInflammation of the

patellar tendonPrimarily seen in sports

that involve jumpingAlso called “jumper’s knee”

SymptomsAnterior knee pain

inferior to the patella over the patella tendon

Minimal swelling may occurTreatment

Activity modificationNon-impact activities

cycling, swimmingStretching for tight quadsIce after activityBracing

Fat Pad SyndromeInvolves a region of fatty

tissue lying deep to the patellar tendonHoffa’s fat pad

When inflammed can become confused with patellar tendonitis

SymptomsPain inferior to the patellaMovement aggravates the

symptomsPoint tenderness and swelling

anteriorlyTreatment

Strengthening exercisesFull extension is contraindicated

Specialized tapingAnti-inflammatory medicines

Collateral Ligament SprainsResults of stretching and a valgus force to the

medial tibiofemoral joint or varus force to the lateral tibiofemoral jointSeverity of the sprain is determined by grading

scale Grade I – Grade IIISigns/Symptoms

Grade I Mild tenderness over ligament Usually no swelling Pain when ligament is stressed at 30 degrees, but no

ligamentous laxityGrade II

Significant tenderness over the ligament Some swelling Pain and some ligamentous laxitiy when stressed, but

definite end pointGrade III

Complete tear of the ligament Pain can vary When the ligament is stressed, there is significant

ligamentous laxity Knee feels wobbly or unstable

MCL/LCL SprainsTreatment of acute injuries with PRICE

After acute phase, rehab should beginSpecial Test

Valgus/Varus stress test

ACL TearsAn ACL tear is when the ligament is completely torn

and is no longer intactACL tears are more common among female athletes

than make athletes1 of 10 college athletes, 1 of 100 high school athletes Usually due to women using the quads more than men

Some athletic shoes can increase the risk of injury There seems to be no connection of ACL size to injury

ACL Tears ~ MOIACL tears can be from

contact or non-contact causes

ContactContact that causes a

blow to the lateral knee or valgus force

Non-contactSituations where the

knee is loaded and combined with flexion, valgus force and rotation of the tibia on the femur can rupture the ACL in a non-contact manner

ACL Tears ~ Signs & Symptoms Symptoms include the following

Hearing a “pop”Rapid effusionNasueaPain

Many times if the ligament is tested within 5 minutes of injury, the examiner can get a better result Lachman’s maneuver and Anterior

Drawer test the integrity of the ligamentPositive signs usually indicate rupture

Diagnosis and MRI by orthopedic will confirm the injury

ACL Tears ~ TreatmentAcute Treatment

PRICEUse an immobilizer

that prevents movement of the jointAthlete should be non-

weight bearingReferral to orthopedic

physician for diagnosisSurgical Reconstruction

Allograft vs. Autograft replacementRehabilitation from ACL

reconstruction is typically 6+ months

PCL Tears Occur when athlete’s fall on the flexed

knee with the foot in plantarflexionThe tibia hits the ground first and is pushed

backOccurs less often than ACL tearsSigns & Symptoms

A positive sag test is a good indication that the PCL has been torn

PCL tear ~ treatmentImmediate care is PRICE Referral to a physician if

suspectedSurgery can be avoided in

most casesA strong rehab program

and physical therapy are important

Specific quadriceps strength and endurance training can compensate for the torn PCL

Meniscus TearsCan be torn when the knee is suddenly

twisted and one or both menisci become trapped between the femur and tibia

Meniscus Tears ~ S & S/Treatment

Signs and SymptomsGradual swellingPainPopping LockingGiving away

TreatmentImmediate care is ice and

compressive wrapUse of crutches may be

necessaryReferral to physician if

suspected for MRISurgery is not always

required

Meniscus Tears ~ Treatment/Special Test

Non-surgical managementPhysical Therapy

Increase muscles strengthIncreases range of motionModified activityNSAISDsTime

Special TestsMcMurrays

Epiphyseal growth-plate injuriesNormally seen in skeletally immature

athletesForces that would normally cause

ligamentous injuries in adults could potentially damage the growth-plate injury in children and younger athletes.

These injuries can be quite serious so athletes may only return to play upon approval of the physician.

Osgood-Schlatter This condition is a group of

symptoms involving the tibial tubercle epiphysis A small bump of the anterior tibia

where the patella tendon attaches The tibial tubercle is a growth center

Affects males 12-16 and females 10-14

Usually caused by a inflammation of the layers of the tubercleFibrocartilage lines the layer

underneath the tibial tubercleLayers are loosely held together during

the active growth years

Osgood-SchlatterSigns & Symptoms

Pain SwellingWeakness in the

QuadsIncreased

pain/swelling with activity

A visible lumpSensitive to

palpation

Osgood-Schlatter ~ TreatmentManagement of this condition can be managed

as long as the pain, swelling and flexibility are managed.

Additional treatment include Prevention of progression

Knee padNeoprene sleeve

Icing after activityAnti-inflammatory medicinesStretching the hamstrings

Should pain continue or increase, refer to physician

Iliotibial Band SyndromeIT Band syndrome involves

inflammation of the thick band of fibrous tissue that runs down the side of the tibia, just below the kneeBursa between the mucles/bones and

IT band becomes inflamed and makes movement painful

Usually affects people who suddenly increase level of activityEx. Runners increasing mileage

Others who are prone are People who overpronateHave leg-length discrepanciesAre bowlegged

IT Band Syndrome ~ Treatment

Analyze athlete's gait and training programRule out mechanical

problemsProper footwearIcing the painful areaStretchingReduce or modify

activities until symptoms subside

IT Band ~ Stretches

FracturesUsually a result of high-

energy traumaPatella fractures

Can occur from direct impact to anterior knee

Distal femoral or proximal tibiaCan occur with violent

twisting or falls from heights