INJURIES TO THE KNEE

• Special Tests for Knee Instability

– Use endpoint feel to determine stability

– MRI may also be necessary for assessment

– Classification of Joint Instability (Laxity)• Knee laxity includes both straight and rotary

instability

• Tibial translation refers to the glide of tibial plateau relative to the femoral condyles

• As the damage to stabilization structures increases, laxity and translation also increase

– Valgus and Varus Stress Tests• Used to assess the integrity of the MCL and LCL

respectively

• Testing at 0 degrees incorporates capsular testing while testing at 30 degrees of flexion isolates the ligaments

– Anterior Cruciate Ligament Tests

• Drawer test at 90 degrees of flexion

– Tibia sliding forward from under the femur is

considered a positive sign (ACL)

– Should be performed w/ knee internally and

externally to test integrity of joint capsule

• Lachman Drawer

Test

– Will not force knee

into painful flexion

immediately after

injury

– Reduces hamstring

involvement

– At 30 degrees of

flexion an attempt

is made to

translate the tibia

anteriorly on the

femur

– A positive test

indicates damage

to the ACL

• Pivot Shift Test

– Used to determine

anterolateral rotary

instability

– Position starts w/ knee

extended and leg

internally rotated

– The thigh and knee are

then flexed w/ a valgus

stress applied to the

knee

– Reduction of the tibial

plateau (producing a

clunk) is a positive sign

• Posterior Cruciate Ligament Tests

– Posterior Drawer Test

• Knee is flexed at 90 degrees and a posterior force is

applied to determine translation posteriorly

• Positive sign indicates a PCL deficient knee

– Posterior Sag Test

• Athlete is supine w/ both knees flexed to 90 degrees

• Lateral observation is required to determine extent

of posterior sag while comparing bilaterally

• Meniscal Tests

– McMurray’s Meniscal Test

• Used to determine displaceable meniscal tear

• Leg is moved into flexion and extension while

knee is internally and externally rotated in

conjunction w/ valgus and varus stressing

• A positive test is found w/ clicking and popping

response

• Apley’s Compression Test

– Hard downward pressure is applied w/ rotation

– Pain indicates a meniscal injury

• Apley’s Distraction Test

– Traction is applied w/ rotation

– Pain will occur if there is damage to the capsule or

ligaments

– No pain will occur if it is meniscal

• Girth Measurements

– Changes in girth can occur due to atrophy,

swelling and conditioning

– Must use circumferential measures to

determine deficits and gains during the

rehabilitation process

– Measurements should be taken at the joint

line, the level of the tibial tubercle, belly of

the gastrocnemius, 2 cm above the

superior border of the patella, and 8-10 cm

above the joint line

• Subjective Rating

– Used to determine patient’s perception of

pain, stability and functional performance

• Functional Examination

– Must assess walking, running, turning and cutting

– Co-contraction test, vertical jump, single leg hop tests and the duck walk

– Resistive strength testing

• Q-Angle

– Lines which bisects the patella relative to the ASIS and the tibial tubercle

– Normal angle is 10 degrees for males and 15 degrees for females

– Elevated angles often lead to pathological conditions associated w/ improper patella tracking

ANATOMY

Mechanism of Injury

ACL TEAR

• MOST SERIOUS LIGAMENT INJURY IN

THE KNEE

• VULNERABLE TO INJURY WHEN THE

TIBIA IS EXTERNALLY ROTATED IN A

VALGUS POSITION.

• DIRECT BLOW or NON CONTACT

NON CONTACT or SINGLE

PLANE MOI

• Lower leg is externally rotated while the

foot is fixed.

• Ligament becomes taut and vulnerable to

a sprain.

• Sharp cutting motion, skiing

• Q angle (Greater in the female athlete)

– (Due to wider hips, ability to give birth)

– Causes added tension on the ACL

• Hyperextension is another MOI

Signs and Symptoms

• POP

• Immediate disability

• Knee coming apart

• Rapid Swelling at Joint Line

– (Inside the Joint Capsule)

– (Patella will “float”)

• Anterior Cruciate Ligament Sprain

– Etiology

• MOI - tibia externally rotated and valgus force

at the knee (occasionally the result of

hyperextension from direct blow)

• May be linked to inability to decelerate valgus

and rotational stresses - landing strategies

• Male versus female

• Research is quite extensive in regards to

impact of femoral notch, ACL size and laxity,

malalignments (Q-angle) faulty biomechanics

• Extrinsic factors may include, conditioning, skill

acquisition, playing style, equipment,

preparation time

• Also involves damage to other structures

including meniscus, capsule, MCL

– Signs and Symptoms• Experience pop w/ severe pain and disability

• Rapid swelling at the joint line

• Positive anterior drawer and Lachman’s

• Other ACL tests may also be positive

– Management• RICE; use of crutches

• Arthroscopy may be necessary to determine extent of injury

• Could lead to major instability in incidence of high performance

• W/out surgery joint degeneration may result

• Age and activity may factor into surgical option

• Surgery may involve joint reconstruction w/ grafts (tendon), transplantation of external structures

– Will require brief hospital stay and 3-5 weeks of a brace

Special Tests

• Lachmans -- ACL

• Anterior Drawer -- ACL

• Pivot Shift – ACL

• Float Test - Capsular Swelling

– Is the patella floating or is it sunk?

– If float – Inside capsule injury

– If sink – outside the capsule injury

Treatment

• Straight Leg Immobilizer

• Surgery

– Reconstruction

• Hamstring Tendon

• Achilles Tendon Allegraph

• Patellar Tendon

• 6 – 12 month recovery

• ?? Functional Brace not always useful

Arthroscopic Pictures

Terrible Triad

• ACL Tear

• MCL Tear

• Medial Meniscus

Prevention of Knee Injuries• Physical Conditioning and Rehabilitation

– Total body conditioning is required

• Strength, flexibility, cardiovascular and

muscular endurance, agility, speed and

balance

– Muscles around joint must be conditioned

(flexibility and strength) to maximize

stability

– Must avoid abnormal muscle action

through flexibility

– In an effort to prevent injury, extensibility of

hamstrings, erector spinae, groin,

quadriceps and gastrocnemius is important

• ACL Prevention Programs

– Focus on strength, neuromuscular control,

balance

– Series of different programs which address

balance board training, landing strategies,

plyometric training, and single leg performance

– Can be implemented in rehabilitation and

preventative training programs

• Shoe Type

– Change in football footwear has drastically

reduced the incidence of knee injuries

– Shoes w/ more shorter cleats does not allow foot

to become fixed while still allowing for control w/

running and cutting

• Functional and

Prophylactic Knee

Braces

– Used to prevent and

reduce severity of

knee injuries

– Used to protect MCL,

or prevent further

damage to grade 1 &

2 sprains of the ACL

or to protect the ACL

following surgery

– Can be custom

molded and

designed to control

rotational forces

Recognition and Management

of Specific Injuries• Medial Collateral Ligament Sprain

– Etiology

• Result of severe blow or outward twist

– Signs and Symptoms - Grade I

• Little fiber tearing or stretching

• Stable valgus test

• Little or no joint effusion

• Some joint stiffness and point tenderness on Medial

aspect over ligament and lateral aspect over contusion

from direct blow

• Relatively normal ROM

– Management

• RICE for at least 24 hours

• Crutches if necessary

• Follow-up care will include

cryokinetics w/ exercise

• Move from isometrics and

STLR exercises to bicycle

riding and isokinetics

• Return to play when all

areas have returned to

normal

• May require 3 weeks to

recover

– Signs and Symptoms (Grade II)

• Complete tear of deep capsular ligament and partial tear

of superficial layer of MCL

• No gross instability; laxity at 5-15 degrees of flexion

• Slight swelling

• Moderate to severe joint tightness w/ decreased ROM

• Pain along medial aspect of knee

– Management

• RICE for 48-72 hours; crutch use until acute phase has

resolved

• Possibly a brace or casting prior to the initiation of ROM

activities

• Modalities 2-3 times daily for pain

• Gradual progression from isometrics (quad exercises) to

functional progression activities

– Signs and Symptoms (Grade III)

• Complete tear of supporting ligaments

• Complete loss of medial stability

• Minimum to moderate swelling

• Immediate pain followed by ache

• Loss of motion due to effusion and hamstring guarding

• Positive valgus stress test

– Management

• RICE

• Conservative non-operative versus surgical approach

• Limited immobilization (w/ a brace); progressive weight

bearing for

• Rehab would be similar to Grade I & II injuries

• Lateral Collateral Ligament Sprain

– Etiology• Result of a varus force, generally w/ the tibia internally

rotated

• Direct blow is rare

• If severe enough damage can also occur to the cruciate ligaments, ITB, and meniscus, producing bony fragments as well

– Signs and Symptoms• Pain and tenderness over LCL

• Swelling and effusion around the LCL

• Joint laxity w/ varus testing

• May cause irritation of the peroneal nerve

– Management• Following management of MCL injuries depending on

severity

• Posterior Cruciate Ligament Sprain– Etiology

• Most at risk during 90 degrees of flexion

• Fall on bent knee is most common mechanism

• Can also be damaged as a result of a rotational force

– Signs and Symptoms• Feel a pop in the back of the knee

• Tenderness and relatively little swelling in the popliteal fossa

• Laxity w/ posterior sag test

– Management• RICE

• Non-operative rehab of grade I and II injuries should focus on quad strength

• Surgical versus non-operative– Surgery will require 6 weeks of immobilization in extension w/

full weight bearing on crutches

– ROM after 6 weeks and PRE at 4 months

• Meniscal Lesions– Etiology

• Medial meniscus is more commonly injured due to ligamentous attachments and decreased mobility

– Also more prone to disruption through torsional and valgus forces

• Most common MOI is rotary force w/ knee flexed or extended

• Can be longitudinal, oblique or transverse tears

– Signs and Symptoms• Effusion developing over 48-72 hour period

• Joint line pain and loss of motion

• Intermittent locking and giving way

• Pain w/ squatting

• Portions may become detached causing locking, giving way or catching w/in the joint

• If chronic, recurrent swelling or muscle atrophy may occur

– Management

• If the knee is not locked, but indications of a

tear are present further diagnostic testing may

be required

• If locking occurs, anesthesia may be necessary

to unlock the joint w/ possible arthroscopic

surgery follow-up

• W/ surgery all efforts are made to preserve the

meniscus -- will full healing being dependent on

location

• Menisectomy rehab allows partial weight

bearing and quick return to activity

• Repaired meniscus will require immobilization

and a gradual return to activity over the course

of 12 weeks

• Knee Plica

– Etiology

• Irritation of the plica (generally, mediopatellar

plica and often associated w/ chondromalacia

– Signs and Symptoms

• Possible history of knee pain/injury

• Recurrent episodes of painful pseudo-locking

• Possible snapping and popping

• Pain w/ stairs and squatting

• Little or no swelling, and no ligamentous laxity

– Management

• Treat conservatively w/ RICE and NSAID’s if

the result of trauma

• Recurrent conditions may require surgery

• Loose Bodies w/in the Knee

– Etiology

• Result of repeated trauma

• Possibly stem from osteochondritis dissecans,

meniscal fragments, synovial tissue or cruciate

ligaments

– Signs and Symptoms

• May become lodged, causing locking or

popping

• Pain and sensation of instability

– Management

• If not surgically removed it can lead to

conditions causing joint degeneration

• Joint Contusions

– Etiology

• Blow to the muscles crossing the joint (vastus medialis)

– Signs and Symptoms

• Present as knee sprain, severe pain, loss of movement and signs of acute inflammation

• Swelling, discoloration

• Possible capsular damage

– Management

• RICE initially and continue if swelling persists

• Gradual progression to normal activity following return of ROM and padding for protection

• If swelling does not resolve w/in a week a chronic condition (synovitis or bursitis) may exist requiring more rest

• Bursitis

– Etiology• Acute, chronic or recurrent swelling

• Prepatellar = continued kneeling

• Infrapatellar = overuse of patellar tendon

– Signs and Symptoms• Prepatellar bursitis may be localized swelling

above knee that is ballotable

• Swelling in popliteal fossa may indicate a Baker’s cyst

– Associated w/ semimembranosus bursa or medial head of gastrocnemius

– Commonly painless and causing little disability

– May progress and should be treated accordingly

– Management• Eliminate cause, RICE and NSAID’s

• Aspiration and steroid injection if chronic

• Patellar Fracture

– Etiology

• Direct or indirect trauma (severe pull of tendon)

• Forcible contraction, falling, jumping or running

– Signs and Symptoms

• Hemorrhaging and joint effusion w/ generalized

swelling

• Indirect fractures may cause capsular tearing,

separation of bone fragments and possible

quadriceps tendon tearing

• Little bone separation w/ direct injury

– Management

• X-ray necessary for confirmation of findings

• RICE and splinting if fracture suspected

• Refer and immobilize for 2-3 months

• Acute Patella Subluxation or Dislocation

– Etiology

• Deceleration w/ simultaneous cutting in opposite

direction (valgus force at knee)

• Quad pulls the patella out of alignment

• Some athletes may be predisposed to injury

• Repetitive subluxation will impose stress to medial

restraints

– Signs and Symptoms

• TYPICALLY DISLOCATES LATERALLY

• W/ subluxation, pain and swelling, restricted ROM,

palpable tenderness over adductor tubercle

• Dislocations result in total loss of function

– Management

• Reduction is performed by flexing hip, moving

patella medially and slowly extending the knee

• Following reduction, immobilization for at least

4 weeks w/ use of crutches and isometric

exercises during this period

• After immobilization period, horseshoe pad w/

elastic wrap should be used to support patella

• Muscle rehab focusing on muscle around the

knee, thigh and hip are key (STLR’s are optimal

for the knee)

• Possible surgery to release tight structures

• Improve postural and biomechanical factors

• Chondromalacia patella

– Etiology• Softening and deterioration of the articular cartilage

• Possible abnormal patellar tracking due to genu valgum, external tibial torsion, foot pronation, femoral anteversion, patella alta, shallow femoral groove, increased Q angle, laxity of quad tendon

– Signs and Symptoms• Pain w/ walking, running, stairs and squatting

• Possible recurrent swelling, grating sensation w/ flexion and extension

• Pain at inferior border during palpation

– Management• Conservative measures

– RICE, NSAID’s, isometrics, orthotics to correct dysfunction

• Surgical possibilities

• Osgood-Schlatter Disease and Larsen-

Johansson Disease

– Etiology

• Osgood Schlatter’s is an apophysitis occurring at

the tibial tubercle

– Begins cartilagenous and develops a bony callus,

enlarging the tubercle

– Resolves w/ aging

– Common cause = repeated avulsion of patellar tendon

• Larsen Johansson is the result of excessive

pulling on the inferior pole of the patella

– Signs and Symptoms

• Both elicit swelling, hemorrhaging and gradual

degeneration of the apophysis due to impaired

circulation

– Signs and Symptoms (continued)

• Pain w/ kneeling, jumping and running

• Point tenderness

– Management

• Conservative

– Reduce stressful activity until union occurs (6-12

months)

– Possible casting, ice before and after activity

– Isometerics

• Injury to the Infrapatellar Fat Pad

– Etiology• May become wedged between the tibia and patella

• Irritated by chronic kneeling, pressure or trauma

– Signs and Symptoms• Capillary hemorrhaging and swelling

• Chronic irritation may lead to scarring and calcification

• Pain below the patellar ligament (especially during knee extension)

• May display weakness, mild swelling and stiffness during movement

– Management• Rest from irritating activities until inflammation has

subsided and therapeutic use of cold

• Heel lift to prevent irritation during extension

• Hyperextension taping to prevent full extension

• Patellar Tendinitis (Jumper’s or Kicker’s Knee)

– Etiology• Jumping or kicking - placing tremendous stress

and strain on patellar or quadriceps tendon

• Sudden or repetitive extension

– Signs and Symptoms• Pain and tenderness at inferior pole of patella

– 3 phases - 1)pain after activity, 2)pain during and after, 3)pain during and after (possibly prolonged) and may become constant

– Management• Ice, phonophoresis, iontophoresis, ultrasound,

heat

• Exercise

• Patellar tendon bracing

• Transverse friction massage

• Patellar Tendon Rupture

– Etiology• Sudden, powerful quad contraction

• Generally does not occur unless a chronic inflammatory condition persist resulting in tissue degeneration

• Occur primarily at point of attachment

– Signs and Symptoms• Palpable defect, lack of knee extension

• Considerable swelling and pain (initially)

– Management• Surgical repair is needed

• Proper conservative care of jumper’s knee can minimize chances of occurring

• If steroids are being used, intense knee exercise should be avoided due to weakening of collagen

• Osteochondral Knee Fractures

– Etiology

• Same MOI as collateral/cruciate ligaments or

meniscal injuries

• Twisting, sudden cutting or direct blow

– Signs and Symptoms

• Hear a snap and feeling of giving way

• Immediate swelling and considerable pain

– Management

• Diagnosis confirmed through arthroscopic

exam, w/ surgery to replace fragment to avoid

joint degeneration and arthritis

• Osteochondritis Dissecans

– Etiology

• Partial or complete separation of articular

cartilage and subchondral bone

• Cause is unknown but may include blunt

trauma, possible skeletal or endocrine

abnormalities, prominent tibial spine impinging

on medial femoral condyle, or impingement due

to patellar facet

– Signs and Symptoms

• Aching pain with recurrent swelling and

possible locking

• Possible quadriceps atrophy and point

tenderness

– Management

• Rest and immobilization for children

• Surgery may be necessary in teenagers and

• Peroneal Nerve Contusion

– Etiology

• Compression of peroneal nerve due to a direct

blow

– Signs and Symptoms

• Local pain and possible shooting nerve pain

• Numbness and paresthesia in cutaneous

distribution of the nerve

• Added pressure may exacerbate condition

• Generally resolves quickly -- in the event it

does not resolve, it could result in drop foot

– Management

• RICE and return to play once symptoms

resolve and no weakness is present

• Padding for fibular head is necessary for a few

weeks

• Patellofemoral Stress Syndrome

– Etiology• Result of lateral deviation of patella while

tracking in femoral groove– Tight structures, pronation, increased Q angle,

insufficient medial musculature

– Signs and Symptoms• Tenderness of lateral facet of patella and

swelling associated w/ irritation of synovium

• Dull ache in center of knee

• Patellar compression will elicit pain and crepitus

• Apprehension when patella is forced laterally

– Management• Correct imbalances (strength and flexibility)

• McConnell taping

• Lateral retinacular release if conservative measures fail

• Runner’s Knee (Cyclist’s Knee)– Etiology

• General expression for repetitive/overuse conditions attributed to mal-alignment and structural asymmetries

– Signs and Symptoms• IT Band Friction Syndrome

– Irritation at band’s insertion - commonly seen in individual that have genu varum or pronated feet

• Pes Anserine Tendinitis or Bursitis– Result of excessive genu valgum and weak vastus

medialis

– Due to running w/ one leg higher than the other

– Management• Correction of mal-alignments

• Ice before and after activity, proper warm-up and stretching

• Avoidance of aggravating activities

• NSAID’s and orthotics

Knee Joint Rehabilitation• General Body Conditioning

– Must be maintained with non-weight

bearing activities

• Weight Bearing

– Initial crutch use, non-weight bearing

– Gradual progression to weight bearing

while wearing rehabilitative brace

• Knee Joint Mobilization

– Used to reduce arthrofibrosis

– Patellar mobilization is key following

surgery

– CPM units

• Flexibility

– Must be regained, maintained and

improved

• Muscular Strength

– Progression of isometrics, isotonic training,

isokinetics and plyometrics

– Incorporate eccentric muscle action

– Open versus closed kinetic chain exercises

• Neuromuscular Control

– Loss of control is generally the result of

pain and swelling

– Through exercise and balance equipment

proprioception can be enhanced

• Bracing

– Variety of braces for a variety of injuries

and conditions

– Typically worn for 3-6 weeks after surgery -

-used to limit ranges for a period of time

– Some are used to control for specific

injuries while others are designed for

specific forces and stability

• Functional Progression

– Gradual return to sports specific skills

– Progress w/ weight bearing, move into

walking and running, and then onto

sprinting and change of direction

• Return to Activity

– Based on healing process - sufficient time

for healing must be allowed

– Objective criteria include strength and

ROM measures as well as functional

performance tests