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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