Viability of chondrocytes seeded onto a collagen I/III membrane for matrix‐induced autologous chondrocyte implantation

Cell viability is crucial for effective cell‐based cartilage repair. The aim of this study was to determine the effect of handling the membrane during matrix‐induced autologous chondrocyte implantation surgery on the viability of implanted chondrocytes. Images were acquired under five conditions: (i) Pre‐operative; (ii) Handled during surgery; (iii) Cut edge; (iv) Thumb pressure applied; (v) Heavily grasped with forceps. Live and dead cell stains were used. Images were obtained for cell counting and morphology. Mean cell density was 6.60 × 10 5 cells/cm 2 (5.74–7.11 × 10 5 ) in specimens that did not have significant trauma decreasing significantly in specimens that had been grasped with forceps ( p  < 0.001) or cut ( p  = 0.004). Cell viability on delivery grade membrane was 75.1%(72.4–77.8%). This dropped to 67.4%(64.1–69.7%) after handling ( p  = 0.002), 56.3%(51.5–61.6%) after being thumbed ( p  < 0.001) and 28.8%(24.7–31.2%) after crushing with forceps ( p  < 0.001). When cut with scissors there was a band of cell death approximately 275 µm in width where cell viability decreased to 13.7%(10.2–18.2%, p  < 0.001). Higher magnification revealed cells without the typical rounded appearance of chondrocytes. We found that confocal laser‐scanning microscope (CLSM) can be used to quantify and image the fine morphology of cells on a matrix‐induced autologous chondrocyte implantation (MACI) membrane. Careful handling of the membrane is essential to minimise chondrocyte death during surgery. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:1495–1502, 2014.