The effect of hyaluronan combined with microfracture on the treatment of chondral defects: an experimental study in a rabbit model.

Because articular hyaline cartilage has low potential for regeneration, numerous methods and techniques have been proposed to induce the reparation process. Microfracture is a convenient procedure for this purpose. However, the quality of the new cartilage after microfracture is still not as proper as original. In this experimental study, we used microfracture in combination with intraarticular application of hyaluronan in rabbit knee articular defect. Bilateral knee arthrotomies, chondral defects, and microfracture were created on each intercondylar notch in thirty rabbits. Rabbits received intraarticular injections of hyaluronan once a week for 3 weeks in the right knee, started from 1 week after injury. The left knees, which served as controls, were injected with normal saline. Biopsy was taken from both knees at the 4th and 6th weeks. In comparison with the control group, after 6 weeks we observed a higher potential for healing in the experimental group, with thicker and more organized repair tissue filling the defect. The current study reveals that application of hyaluronan after the microfracture might be beneficial in inducing articular cartilage defect reparation.