Transcript Anatomy and Injuries of the Knee

Anatomy and Injuries of the
Knee
John Hardin
SPHS Sports Medicine
Anatomy-Bones
• Bones
– Femur
• Medial/lateral femoral condyles articulate w/ tibia
– Tibia
• Tibial plateau is flat-articulates w/ femoral condyles
– Fibula
• Articulates w/ tibia
– Patella
• Sesamoid bone protects anterior joint
• Enclosed in quadriceps/patellar tendon
Anatomy-Joints
• Joints
– Tibiofemoral
• Hinge joint with synovial lining
– diarthrodial
– Patellofemoral
– Superior Tibiofibular
Anatomy-Meniscus
• Meniscus
– Medial and lateral
– Fibrocartilaginous disks
• Thicker on outside than inside (poor blood supply)
– Lie on top of tibial plateau
– Increase stability
– Make condyles fit better
– Shock absorbers
Anatomy-Ligaments
• ACL-anterior cruciate ligament
– Runs from anterior tibia to posterior femur
– Prevents anterior displacement of tibia on
fixed femur
– Prevents femur from moving posterior during
weight bearing
– Stabilizes tibia against excessive internal
rotation
Ligaments
• PCL-posterior cruciate ligament
– Runs from posterior tibia to anterior femur
– Prevents posterior translation of tibia on fixed
femur
– Prevents femur from moving anterior during
weight bearing
• Both ACL and PCL “cross” or wrap around each
other—taut when in extension and looser when in
flexion
Ligaments
• MCL-medial collateral ligament
– Attaches on the medial femoral epicondyle &
anteromedial tibia
– Thickened portion of joint capsule
– Two parts-superficial and deep
• Deep portion attaches to medial meniscus
– Stabilizes against valgus stress applied to
lateral aspect of joint capsule
Ligaments
• LCL-lateral collateral ligament
– Attaches to lateral femoral epicondyle and
head of fibula
– Stabilizes against varus stress when force is
applied to medial aspect of joint
• Both the MCL and LCL are tightest during full
extension of knee and relaxed during flexion
Ligaments
Muscles
• Quadriceps
– Rectus femoris, vastus lateralis, vastus
medialis, vastus intermedius
• Knee extension, hip flexion
• Hamstrings
– Biceps femoris, semimembranosus,
semitendinosus
• Knee flexion, hip extension
Muscles
• Gracilis
– Knee flexion, hip adduction
• Sartorius
– Knee flexion, hip flexion, hip external rotation
• Popliteus
– Knee flexion
• Gastrocnemius
– Knee flexion
Muscles
• Plantaris
– Knee flexion
• Pes anserine
– Goose’s foot
– Knee flexion, some internal rotation
• Gracilis, sartorius, semitendinosus
• Iliotibial Band
– Thick band on lateral aspect of thigh
• Attaches at Gerdy’s tubercle on the lateral aspect of tibia
Preventing knee injuries
• Conditioning
– Strength, flexibility, cardiovascular and muscular
endurance
• Hamstring strength 60% of quad strength
• Rehabilitation
– Strengthen all muscles around knee joint
• Shoes
– proper type for surface
– Length of cleats
– Turf vs grass
Preventing knee injuries
• Knee braces
– Functional vs. prophylactic
• Functional—used to provide support to an unstable
knee
• Usually custom fitted to some degree
• Uses hinges and supports to control excessive
rotational stress and tibial translation
• Prophylactic-worn on lateral aspect knee to protect
MCL.
• Usefulness questioned—does it cause more
injuries?
ACL rupture
• Mxn:
– fixed foot and external rotation of femur
– knee in valgus position
– hyperextension
• S/S:
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“pop”,
knee gives out
instability of knee joint
swelling within knee joint—hemarthrosis
intense pain initially but still able to walk
“+” Lachman’s test
“+” anterior drawer test
MXN
MXN
• Hyperextension
ACL rupture
Inside the knee joint
• The ACL intact
The ACL torn
ACL Rupture
• Tx: RICE, knee immobilizer, crutches,
Physician referral
• Requires surgical reconstruction
– Timing of surgery decided by athlete, parents,
doctor
– Grafts used are patellar tendon, hamstring
tendon, cadaver graft, allograft
– 3-5 weeks in brace, 6-9 months return to
activity
Stress tests
• Lachman’s test
Stress tests
• Modified Lachman’s
Stress tests
• Anterior Drawer test
PCL Rupture
• Mxn:
– hyperflexion
– falling on bent knee with foot plantar flexed
– Hit on fixed anterior tibia
• S/S:
– “pop” at the back of knee
– POT and swelling in popliteal fossa
– + posterior sag test, +sunrise test, + posterior
drawer test
PCL rupture
• Tx:
– RICE
– Immobilization
– Crutches
– Physician referral
– 6-8 weeks rest/rehab
– If surgery is elected, 6 weeks immobilization
PCL rupture
Stress tests
• Posterior sag
Strest tests
• Sunrise or posterior sag
MCL Sprain
• Mxn:
– Blow to the lateral side of knee (valgus stress)
– External rotation of tibia
Mxn
MCL sprain
• 2nd degree??
MCL sprain
• S/S:
• 1st degree
– POT over MCL, stable but pain with valgus stress,
mild joint effusion, mild joint stiffness, full ROM
• 2nd degree
– Partial tearing-superficial portion, POT over MCL,
some instability with valgus stress but solid endpoint,
moderate joint effusion, joint stiffness, limited ROM,
unable to fully extend knee joint
MCL Sprain
• S/S:
• 3rd degree
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Complete tear—superficial and deep portions
POT over MCL
Moderate to severe effusion
Severe pain
Loss of motion due to pain, effusion, muscle guarding
“+” valgus stress in 0 and 30 degrees, no endpoint
Stress tests for MCL
• Valgus stress test @ 0
Valgus stress @ 30
MCL Sprain
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Tx:
RICE
Crutches
Knee immobilizer/brace
– 1st degree 1-2 weeks
– 2nd degree 2-4 weeks
– 3rd degree 4-6 weeks
• Physician referral for 2nd degree or greater
Complications
• The terrible triad or unhappy triad
– Torn ACL
– Torn MCL
– Torn Medial meniscus
LCL sprain
• Mxn:
– Varus force to medial aspect of knee
– internal rotation of tibia
• S/S:
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POT over LCL,
pain,
swelling,
loss of motion,
“+” varus stress at 30 degrees—solid endpoint with 1st degree,
less stability but solid endpoint with 2nd degree, no endpoint with
3rd degree
– if “+” varus stress at 0 degrees flexion suspect ACL or PCL injury
as well
LCL sprain
• Tx:
– RICE
– Crutches
– Knee immobilizer
– Physician referral with 2nd or 3rd degree
Meniscus tear
• Medial: more often torn than later due to
attachment to MCL
• Lateral: doesn’t attach to joint capsule
making it more mobile, less prone to injury
• Mxn:
– Weight bearing with rotational force while
extending or flexing the knee
Meniscus tear
• S/S:
– Effusion w/in 48-72 hours
– POT over joint line
– Loss of motion
– “locking”
– Giving out
– Pain with deep knee flexion--squatting
Meniscus tear
• Types of meniscus tears
Meniscus tears
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Tx:
RICE
Crutches if necessary
Physician referral
If knee is “locked” by displaced meniscus,
go to ER
• Arthroscopic surgery to fix
Injuries to the Patella
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Dislocation
Subluxation
Fracture
Chondromalacia
Patellar tendonitis
Patella Dislocation
• Mxn:
– Foot planted, deceleration, and cutting in
opposite direction from the weight bearing
foot
– Thigh rotates internally while leg rotates
externally
– Strong forceful contraction of quads (vastus
lateralis)
Dislocation
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S/S: loss of motion/function at the knee
Pain
Swelling
Deformity
POT over medial aspect of knee joint
dislocation
dislocation
Dislocation
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Tx:
immobilize in position you find it
Ice
ER visit
After reduction, immobilize in extension
about 4 weeks—use crutches
• Strengthen muscles of knee, thigh and hip
Patella Subluxation
• Mxn: same as for the dislocation
• S/S:
– same as for the dislocation except there will be no
deformity
– POT over the medial knee joint
– Pain with movement
• TX:
– RICE
– Knee Immobilizer and crutches
– Physician referral
Patella fracture
• Mxn:
– direct impact or trauma to patella
– Indirect trauma in which a severe pull of the patellar
tendon occurs against the femur when the knee if
semi-flexed
• S/S:
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hemorrhage which results in significant swelling
pain
POT over Patella
extreme pain with weight bearing/movement
Patella Fracture
Another x-ray
Patella Fracture
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Tx:
RICE
Immobilize
Crutches
ER
Possible surgery depending on type of
fracture
Chondromalacia
• Softening and deterioration of the articular
cartilage on the posterior side of the
patella
Chondro
• Mxn:
– related to abnormal movement of the patella
within the femoral groove as the knee flexes
and extends
– Lateral tracking patella as quads contract
usually associated with weak quads (VMO) or
in females a wider pelvis
Chondro
• S/S:
– Pain on the anterior aspect of the knee
(behind the patella) while walking, running,
ascending or descending stairs, sqatting or
sitting with knees flexed for a long period of
time
– Pain with compression of patella in femoral
groove
Chondro
• Tx:
– remove from activities that cause the pain
– Strenghtening exercises for the quads,
especially the VMO
– Knee sleeve with patellar support
– Ice, heat
– Surgery to smooth the posterior side of patella
Patellar tendonitis
• Also called “jumper’s knee”
• Mxn:
– excessive running, jumping or kicking causing
extreme tension of the knee extensor muscle complex
• S/S:
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Pain at the patellar tendon
POT over the distal pole of patella
Pain increases with activity
Thickening of tendon
crepitus
Patellar tendonitis
• TX:
– Rest
– Ice
– Heat
– Ultrasound
– Cross-friction massage
– NSAIDS
– Patellar tendon strap/taping
– Modify activity
Osgood-Schlatter’s Disease
• Condition common in adolescent knee
• Mxn:
– Repeated pull of patellar tendon at tibial tuberosity
apophysis due to excessive running, jumping, kicking,
etc.
• S/S:
– pain and POT at the patellar tendon attachment on
tibial tuberosity
– Excessive bony formation over tubersity as tendon
continues to pull at the apophysis
Osgood Schlatter’s
• S/S:
– usually resolves itself when the athlete reaches 18-19
years of age
– Enlarged tibial tuberosity remains
• Tx:
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Modify activity
Ice
Tape/patellar tendon strap
Padding
Strengthening of quads and hamstrings
Iliotibial Band Friction Syndrome
• Mxn:
– Overuse injury that occurs in runners or
cyclists attributed to the malalignment and
structural asymmetries of the foot and lower
leg
– Irritation develops over lateral femoral
epicondyle or at the band’s insertion at
Gerdy’s tubercle on the lateral side of the tibia
ITBS
• S/S:
– POT over the lateral femoral epicondyle
– Swelling
– Increased pain with activity especially
distance running and starts and stops and
change of direction
ITBS
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Tx:
Stretching the ITB
Ice pack/massage
Transverse friction massage ITB
Modify activity
Correct foot/lower leg malalignment
Bursitis
• Can be acute, chronic, or recurrent
• Numerous bursae involved but most
commonly injured are the prepatellar or
the deep infrapatellar
Bursitis
• Mxn:
– falling directly on knee
– Continuous kneeling
– Overuse of patellar tendon
Bursitis
• S/S:
– Localized swelling that is similar to a water
balloon and is outside the knee joint
– Pain especially with pressure
Bursitis
Bursitis
Bursitis
• Tx:
– Rest
– Ice
– Compression
– NSAIDS
– Padding for protection when returning to
activity