OBJECTIVETo investigate the effectiveness of injectable tissue engineering to repair full-thickness meniscal defects.

METHODSFrom June 2008 to February 2009 full-thickness of meniscal defects were created in the anterior corner of goats, which with no blood supply, in a diameter of 2 mm. Then bone marrow stem cells (BMSCs) was mixed with injectable calcium alginate gel to fill the defects. Other groups include the calcium alginate gel and empty group were served as control groups. At different time points, the animals were sacrificed and macroscopy, microscopy determination, electroscopy and MRI detection were performed to assess the outcomes of repairing.

RESULTSThe meniscal defects had been filled thoroughly in 16 weeks after operation with white, tough and elastic repair tissue similar to normal meniscal fibrocartilage in the tissue engineering groups. The repair tissue was mainly fibrochondrocytes in line with the calcium alginate fiber. Thick matrix secreted by the cells crammed the space between fibers. The view under electroscopy demonstrated that the microstructure of the repair tissue was normal and cells were in a fibrocartilage phenotype.

CONCLUSIONThe full-thickness meniscal defects in regions without blood supply can be reconstructed effectively with injectable tissue engineering.