PMC3569885_01
Finite element model of the tibiofemoral joint, showing the distal femur, proximal tibia, menisci, and femoral and tibial cartilages. The tibial cartilage on the medial side is essentially covered by the medial meniscus (right knee, medial side shown on the left of the figure). The femoral cartilage is further shown with 8 layers of elements.
CMMM2013-862903.001.jpg
PMC3569885_01_CMMM2013-862903.001.jpg
fig1
The model included the distal femur, femoral cartilage, meniscus, tibial cartilage, and proximal tibia (Figure 1).
Fluid pressure (MPa) at the normalized depth of 1/16 (superficial layer) for the normal femoral cartilage and three cases of local cartilage degeneration. Case 1: degeneration in the superficial zone; Case 2: degeneration in both superficial and middle zones; and Case 3: degeneration in all three zones. The site of degeneration is indicated with the dash lines (inferior view of the right knee, i.e., the medial condyle on the right).
CMMM2013-862903.002.jpg
PMC3569885_01_CMMM2013-862903.002.jpg
fig2
In the superficial zone, the fibers were oriented according to the split lines recorded from the surface (; adopted from Figure 2 in). As discussed earlier, local cartilage degeneration was implemented within the high load-bearing region of the medial condyle of the femoral cartilage (Figure 2, bounded by the dash line).