Novel repair technique for articular cartilage defect using a fibrin and hyaluronic acid mixture

We evaluated the cartilage repair potential of a hyaluronic acid and fibrin mixture when transplanted into cartilage defects. Circular, articular, cartilage defects 4-mm in diameter were made in the trochlear region in 21 New Zealand white rabbits divided into three groups. The seven rabbits in the control group underwent microfracture (M group), the seven rabbits in the experimental group underwent microfracture with subsequent injection of hyaluronic acid mixed with fibrin (MH group), and seven rabbits in the other experimental group underwent microfracture followed by injection of bone marrow concentrate and hyaluronic acid mixed with fibrin (MBH group). At week 12 following surgery, the cartilage was observed and histologically compared in the three groups. The surface of the newly generated cartilage was very smooth and even, and we noticed that the entire area was completely regenerated in both experimental groups. The control group showed incomplete and irregular cartilage formation in the defect. In histologic scoring, comparison of the MBH group (M= 2.333) and the M group (M= 9.000) differed significantly (P= 0.046). Therefore, injection of a mixture of bone marrow concentrate, hyaluronic acid and fibrin to treat articular cartilage defects of the knee appears to be an effective method of cartilage regeneration.