Knee Flashcards
Femur
- Longest and strongest bone in body
- Distal portion forms medial and lateral condyles & epicondyles
- Features Linea Aspera
~ Posterior and serves as attachment
site
Tibia
- Proximal portion forms medial and
lateral Tibial Plateaus
Fibula
- Fibular head serves as attachment site
for numerous soft tissue structures
Patella and its purpose
- Classified as Sesamoid bone due its
shape - Improves mechanical function of quads
~ Acts as a pully - Protects anterior portion of knee
Bursae
- Act as padding and reduce friction
- Suprapatellar
- Prepatellar: On top of Patella
- Infrapatellar (2)
- Pretibial: On top of Tibia
- Popliteal
- Anserine: Medial
- Iliotibial: Lateral
Tibiofemoral Joint
- Articulation between condyles of femur
and tibial plateaus - Condyles are covered with articular
(hyaline) cartilage - Tibial plateaus are covered by medial
and lateral menisci
Menisci and purpose
- Made of fibrocartilage
- Act as shock absorbers, increase joint
congruency (bones fit better = stability),
and decrease friction - Gets most of its resources from Synovial
Fluid
~ Not supplied by blood very well; outer
1/3 has the best blood supply and
therefore better at healing
Tibiofemoral Joint Movements During Functional Loading/Pronation
- Sagittal: Flexion
- Frontal: Abduction
- Transverse: Internal Rotation
Tibiofemoral Joint Movements During Functional Unloading/Supination
- Sagittal: Extension
- Frontal: Adduction
- Transverse: External Rotation
What bone is relative to what bone at the Tibiofemoral Joint?
Tibia is relative to Femur
Patellofemoral Joint
- Articulation between the patella and the
medial and lateral condyles of femur - Both surfaces are covered by articular
cartilage
Patellofemoral Joint Movements
- Gliding along femoral condyles during functional loading and functional unloading of knee
- During extension the patella rests superior to femoral groove (out of joint)
- During flexion the patella enters the femoral groove (20-30 degrees)
When is the Patella most stable?
During flexion (loading): there’s no room for injury
Superior Tibiofibular Joint & Its Movements
- Articulation between tibia and head of fibula
- Movements:
~ Superior/Inferior Gliding
~ Anterior/Posterior Gliding
What Muscles Move the Knee?
- Vastus Lateralis
- Vastus Medialis
- Vastus Intermedius
- Rectus Femoris
- Sartorius
- Gracilis
- Semitendinosus
- Biceps Femoris
- Semimembrabosus
- Popliteus
Pes Anserine contains what Muscles?
- Common tendon formed by Sartoius, Gracilis, and Semitendinosus
- Insertion: Superior aspect of medial surface of Tibia near Tibial Tuberosity
Vastus Lateralis
- Origin: Lateral lip of Linea Aspera &
Intertrochanteric Line - Insertion: Lateral Border of Patella
- Nerve: Femoral
- Action: Knee Extension
Vastus Medialis
- Origin: Medial lip of Linea Aspera &
Intertrochanteric Line - Insertion: Medial Border of Patella
- Nerve: Femoral
- Action: Knee Extension
Vastus Intermedius
- Origin: Superior 2/3 of anterior and
lateral surfaces of femur - Insertion: Superior Border of Patella
- Nerve: Femoral
- Action: Knee Extension
Rectus Femoris
- Origin: Anterior Inferior Illiac Spine &
Superior to Acetabulum (Socket) - Insertion: Superior Border of Patella
- Nerve: Femoral
- Action: Knee Extension & Hip Flexion
Quadriceps Function: During functional loading at the Knee, the Quadriceps muscles…
Decelerate Flexion, Internal Rotation, & Abduction
Sartorius
- Origin: Anterior Superior Iliac Spine
- Insertion: Pes Anserine
- Nerve: Femoral
- Action: Knee Flexion; External Rotation &
Flexion of the Hip
Gracilis
- Origin: Inferior Ramus of Pubis & Ramus
of Ischium - Insertion: Pes Anserine
- Nerve: Obturator
- Action: Flexion & Internal Rotation of
Knee; Adduction of Hip
Semitendinosus
- Origin: Ischial Tuberosity
- Insertion: Pes Anserine
- Nerve: Tibial
- Action: Flexion & Internal Rotation of
Knee; Hip Extension
Semimembranosos
- Origin: Ischial Tuberosity
- Insertion: Medial Condyle of Tibia
- Nerve: Tibial
- Action: Flexion & Internal Rotation of
Knee; Hip Extension
Biceps Femoris
- Origin: Ischial Tuberosity (long) & Linea
Aspera (short) - Insertion: Head of Fibula
- Nerve: Tibial
- Action: Flexion & External Rotation of
Knee; Hip Extension
Biceps Femoris Function: During functional loading at the knee, the Biceps Femoris…
Decelerates Internal Rotation
Popliteus
- Origin: Lateral Condyle of Femur
- Insertion: Posterior, Proximal Tibia
- Nerve: Tibial
- Action: Internal Rotation of Knee
Tibialis Posterior Function: During functional loading at the knee, the Tibialis Posterior…
Decelerates Flexion
Soleus Function: During functional loading at the knee, the Soleus…
Decelerates Flexion
What should be noticed during Anterior Inspection?
- Knee Alignment
- Patella Position
- Quadriceps Girth and Contour
- Patellar Tendon
- Tibial Tuberosity
- Edema or Effusion?
Knee Alignment & What structures get more stress due to these alignments?
- Genu Valgum (“Knock Knee”)
~ Knees touch, ankles don’t
~ Lateral meniscus, MCL, and ACL get
more stress - Genu Varum (“Bowleg”)
~ Knees apart with ankles touching
~ Medial meniscus and LCL get more
stress
Patella Position
- Normal should be in the middle
- Grasshopper Eye: Tilt Outward
- Squinting Eye: Tilt Inward
- Patella Alta: High Position
- Patella Baja: Low Position
Edema vs. Effusion
- Edema
~ Swelling that’s all over and outside the
joint - Effusion
~ Swelling that’s localized and inside the
joint
Sweep/Brush/Stroke Test: Edema vs. Effusion Test
- Positive test indicated by observation of
fluid movement from lateral to medial
~ Indicates Effusion
Patellar Tap/Ballotable Patellar Test: Edema vs. Effusion Test
- Positive test indicated by behavior of
patella:
~ If patella sinks = Edema
~ If patella rebounds = Effusion