Indirect arthrography: IV gad followed by MR imaging after 10-20 minutes
Direct arthrography: 1:150 Gd:saline 20ml; walk on the knee to force the contrast into tear
Post repairs may show any grade changes
After partial meniscectomy, the meniscal remnant may show grade 3 signal change
T2* or T2 are sensitive in identifying extension of fluid into cleavage plane and hence more sensitive than T1 images
Meniscal changes are often seen at the apex after partial meniscectomy
Narrowing of the joint space, loss of cartiage may be seen
Regenerated meniscal tissue is smaller, low-to-int signal on T1, T2, T2*
Retear/ recurrent tear - nearly 90% accurate with MR arthrography, 66% with conventional MR
Persistent tear Healing process - healed meniscus may show grade 3 changes
Smith et al:
Group 1 - near normal length, no OA
Group 2 - significantly shortened meniscus, no OA. Contour irregularities may sumilate meniscal fragmentation in up to 40%
Group 3 - any length, but OA present
