Anatomy and Injuries of the Knee
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Transcript of 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: – “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
– 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
• 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: – 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
• 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
• 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
• S/S: loss of motion/function at the knee
• Pain
• Swelling
• Deformity
• POT over medial aspect of knee joint
dislocation
dislocation
Dislocation
• 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: – hemorrhage which results in significant swelling – pain – POT over Patella– extreme pain with weight bearing/movement
Patella Fracture
Another x-ray
Patella Fracture
• 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: – 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: – 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
• 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