No outgrowth of chondrocytes from non-digested particulated articular cartilage embedded in commercially available fibrin matrix: an in vitro study

BACKGROUND Commercially available fibrin is routinely being used as both a matrix in certain cartilage repair techniques and a method for scaffold fixation. Chondrocytes from non-digested particulated cartilage fragments are proposed as a possible source for new cartilage tissue formation in some operative techniques. The goal of this study was to test that chondrocytes from particulated articular cartilage embedded in fibrin have an active role in the process of cartilage repair, as well as if commercially available fibrin should be used as a suitable matrix. METHODS Articular cartilage was obtained from patients undergoing total knee replacement surgery. The biopsies were particulated in small, 1-2-mm(3) pieces and embedded in fibrin. Two groups were compared in our study, particulated articular cartilage with and without collagenase treatment. The specimens were analyzed by optical microscopy after 2-5 weeks of cultivation in a special construct embedded in a cell culture medium containing particulated cartilage embedded in fibrin in the upper phase and cancellous bone in the lower phase under the perforated nylon membrane. RESULTS None of the biopsies taken from four different patients showed the outgrowth of chondrocytes or bone marrow-originated cells into the fibrin matrix in our experimental model. CONCLUSIONS It has been shown in our experimental model in vitro little to support the theory that articular chondrocytes from particulated articular cartilage embedded in fibrin have an active role in cartilage repair in its early stage.