MS 1 knee 2

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MS 1 knee 2
2012-10-13 16:24:57
MS knee

MS 1 knee 2
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  1. semilunar cartilages is another name for __? what is the purpose of these?
    • menisci
    • increase radius of curvature of tibial condyles, distribute weightbearing, decrease friction
  2. contours of 3 surfaces of menisci
    • sup: concave w femoral condyles
    • peripheral: adherent to capsule
    • inf: almost plane, resing on edge of med and lat tibial condyles
  3. menisci are shock absorbers, taking how much force in ext and flex? if they were gone...?
    • 50% in ext
    • 85% in flex
    • w/o them - 2x force on femur, 6-7x force on tibia
  4. timing of appearance and vascularization for menisci
    • appear as early as 8 weeks
    • fully vascularized til 10 y/o, then the center 2/3rds become avascular
    • supply to outer 1/3rd comes from capsule and synovium
  5. ant horns of menisci are attached to each other by the __ lig
    transverse lig
  6. menisci attach around the periphery to the tibia by __ ligs
    coronary/neiscobibial ligaments, composed of fibers from the anterior capsule
  7. menisci are attached to patella via __ lig
    patellomeniscal/patellotibial ligaments - these are thickenings of the anterior capsule
  8. 3 things that attach to the lateral meniscus that don't attach to the medial meniscus
    • PCL
    • popliteus muscle (via coronary lig and post. capsule)
    • posterior meniscofemoral ligaments which attach to fem condyles

    (and variable attachment to ACL)

    connectionss are considered loose, tiving a fair amount of mobility on lateral tibial condyle
  9. 3 things that attach to the medial meniscus but not lat meniscus
    • MCL deep fibers
    • semimembranosus through the capsule
    • a few fibers from the ant horn of the ACL

    these attachments are more firm and less moveable than those on the lat meniscus, therefor are torn more often
  10. shapes of the 2 menisci
    • incomplete rings, crescehnt shaped, w ant and post horns
    • lat: horns close together like a circle
    • med: half moon
  11. going into flexion, which meniscus travels more?
    dir of movement for flex/ext?
    • lat recedes 2x as much as the med meniscus
    • flex - they move post
    • ext - they move ant
  12. motion of patella in flexion
    moves inf 2x its length, followed by infrapatellar fat pad
  13. ratio of patella:lenght of patellar tendon
    • 1:1 ideally, though longer for fems --> less stable
    • smaller tendon--> patella goes inf
    • longer--> sup
  14. articularis genu
    • collectoin of small fibers from vastus intermedius
    • moves suprapatellar bursa out of the way in ext
  15. 4 types of patella displacements (must be 20% of the way to be a displacement)
    • alta: superior
    • baja: inferior
    • squinting: medial
    • bull frog eyes: lateral
  16. how patella is pulled during tibal rot
    • ER - femur is medial to tib so pulls patella medially
    • IR - the opposite
  17. transverse lig of the knee does what?
    how is it attached to the patella?
    • links the two ant horns of the menisci
    • it's attached to the patella by strands of the infrapatella pad