12 terms

Orthopedic Pathology: Meniscus

fibrocartilage C-shaped cushoins in knee, relatively vascular (outer region vs. AC-completely avascular)
Structure+composition of meniscus
fibrchondrocytes(synthesize type 1 collagen fibers), key general points, macromolecules, 65-70%H2O vs. AC-up to 80%
Type I dry wt of collagen vs type ll
l - 80-95%collagen 1-2%proteoglycan vs.ll - 60% 25-30%
Framework of Meniscal matrix
superficial and deep zone
superficial zone of meniscus
very thing random oriented collagen fibers
deep zone of meniscus
circumfrential collagen fibers and radial fibers
function of meniscus
load bearing(axial loads+circumferential str), shock absorbtion(compressive stiffness, 1/2 of AC)
injury/healing of meniscus
happens when a traumatic load exceeds strength of the meniscus, meniscal degeneration beings gradually ~30 tearing is messy
3 meniscal surgical interventions
1.meniscal repair 2.menisectomy 3.meniscal replacement
Meniscal repair
arthroscopic, sutures, tear must be peripheral, slow to heal but keeps orig cartilage
most common, arthroscopic, risk of early OA, wt bearing may->pain
Meniscal replacement
sized matched allograft, @4wks lay down new matrix fibrochondrocytes repopulate @6wks revascularized periphery 3-5yrs has good results