Anatomy and Injuries of the Knee

1
Anatomy and Injuries of the Knee

• Connie Rauser
• Sabino Sports Medicine

2
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

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Anatomy-Joints

• Joints
• Tibiofemoral
• Hinge joint with synovial lining
• diarthrodial
• Patellofemoral
• Superior Tibiofibular

4
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

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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

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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
  othertaut when in extension and looser when in
  flexion

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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

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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

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Ligaments
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Muscles

• Quadriceps
• Rectus femoris, vastus lateralis, vastus
  medialis, vastus intermedius
• Knee extension, hip flexion
• Hamstrings
• Biceps femoris, semimembranosus, semitendinosus
• Knee flexion, hip extension

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Muscles

• Gracilis
• Knee flexion, hip adduction
• Sartorius
• Knee flexion, hip flexion, hip external rotation
• Popliteus
• Knee flexion
• Gastrocnemius
• Knee flexion

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Muscles

• Plantaris
• Knee flexion
• Pes anserine
• Gooses foot
• Knee flexion, some internal rotation
• Gracilis, sartorius, semitendinosus
• Iliotibial Band
• Thick band on lateral aspect of thigh
• Attaches at Gerdys tubercle on the lateral
  aspect of tibia

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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

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Preventing knee injuries

• Knee braces
• Functional vs. prophylactic
• Functionalused 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 questioneddoes it cause more injuries?

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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 jointhemarthrosis
• intense pain initially but still able to walk
• Lachmans test
• anterior drawer test

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MXN
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MXN

• Hyperextension

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ACL rupture
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Inside the knee joint

• The ACL intact The ACL torn

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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

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Stress tests

• Lachmans test

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Stress tests

• Modified Lachmans

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Stress tests

• Anterior Drawer test

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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

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PCL rupture

• Tx
• RICE
• Immobilization
• Crutches
• Physician referral
• 6-8 weeks rest/rehab
• If surgery is elected, 6 weeks immobilization

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PCL rupture
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Stress tests

• Posterior sag

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Strest tests

• Sunrise or posterior sag

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MCL Sprain

• Mxn
• Blow to the lateral side of knee (valgus stress)
• External rotation of tibia

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Mxn
31
MCL sprain

• 2nd degree??

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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

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MCL Sprain

• S/S
• 3rd degree
• Complete tearsuperficial 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

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Stress tests for MCL

• Valgus stress test _at_ 0 Valgus stress _at_ 30

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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

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Complications

• The terrible triad or unhappy triad
• Torn ACL
• Torn MCL
• Torn Medial meniscus

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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 degreessolid 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

38
LCL sprain

• Tx
• RICE
• Crutches
• Knee immobilizer
• Physician referral with 2nd or 3rd degree

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Meniscus tear

• Medial more often torn than later due to
  attachment to MCL
• Lateral doesnt attach to joint capsule making
  it more mobile, less prone to injury
• Mxn
• Weight bearing with rotational force while
  extending or flexing the knee

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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

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Meniscus tear

• Types of meniscus tears

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Meniscus tears

• Tx
• RICE
• Crutches if necessary
• Physician referral
• If knee is locked by displaced meniscus, go to
  ER
• Arthroscopic surgery to fix

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Injuries to the Patella

• Dislocation
• Subluxation
• Fracture
• Chondromalacia
• Patellar tendonitis

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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)

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Dislocation

• S/S loss of motion/function at the knee
• Pain
• Swelling
• Deformity
• POT over medial aspect of knee joint

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dislocation
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dislocation
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Dislocation

• Tx
• immobilize in position you find it
• Ice
• ER visit
• After reduction, immobilize in extension about 4
  weeksuse crutches
• Strengthen muscles of knee, thigh and hip

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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

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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

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Patella Fracture
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Another x-ray
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Patella Fracture

• Tx
• RICE
• Immobilize
• Crutches
• ER
• Possible surgery depending on type of fracture

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Chondromalacia

• Softening and deterioration of the articular
  cartilage on the posterior side of the patella

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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

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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

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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

58
Patellar tendonitis

• Also called jumpers 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

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Patellar tendonitis

• TX
• Rest
• Ice
• Heat
• Ultrasound
• Cross-friction massage
• NSAIDS
• Patellar tendon strap/taping
• Modify activity

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Osgood-Schlatters 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

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Osgood Schlatters

• 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

62
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 bands insertion at Gerdys
  tubercle on the lateral side of the tibia

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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

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ITBS

• Tx
• Stretching the ITB
• Ice pack/massage
• Transverse friction massage ITB
• Modify activity
• Correct foot/lower leg malalignment

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Bursitis

• Can be acute, chronic, or recurrent
• Numerous bursae involved but most commonly
  injured are the prepatellar or the deep
  infrapatellar

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Bursitis

• Mxn
• falling directly on knee
• Continuous kneeling
• Overuse of patellar tendon

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Bursitis

• S/S
• Localized swelling that is similar to a water
  balloon and is outside the knee joint
• Pain especially with pressure

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Bursitis
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Bursitis
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Bursitis

• Tx
• Rest
• Ice
• Compression
• NSAIDS
• Padding for protection when returning to activity