Arthrology: Knee Flashcards
Tibiofemoral joint type
bicondylar/hinge
Menisci
Absorb shock, decrease friction, increase contact area
Hoop stress - distributes forces
Medial meniscus = “C”, larger
- attached to MCL and semimembranosus
Lateral meniscus = “O”,
Tibiofemoral morphology
Tibia = concave
Femur = convex
Tibial ER into end range extension (screw-home)
- increased stability to knee through bony congruency and ligamentous tension
Meniscal tear
Healing capacity is vascularity and age dependent
Blood flow greatest in periph 1/3
Femoral condyle imparts a sheer force to meniscus in WB beyond 115-120 deg knee flexion (deep squat)
Hamstring contraction tugs on posterior horn of meniscus
Patellofemoral joint type
plane/gliding
posterior surface covered w/ thick hyaline cartilage
slides w/in trochlear groove (depth = stability; lateral patella protrudes anterior)
compressive forces increase w/ knee flexion and quad force production
patellofemoral flexion arthrokinematics
inferior glide
patellofemoral extension arthrokinematics
superior glide
Patellar instability
MPFL or retinacular deficiency
Shallow trochlear groove
Flat patella
Patella alta
Proximal tibiofibular joint type
planar
PTFJ extension arthrokinematics
posterior glide
PTFJ flexion arthrokinematics
anterior glide
Tibiofibular dislocation
Consider structures attaching to fibular head
LCL
Popliteus m.
Fibularis longus
Biceps femoris
Innervation
femoral n.