Can chondral healing be improved following microfracture? The effect of adipocyte tissue derived stem cell therapy

Background: We aimed to investigate the effect of adipose tissue-derived mesenchymal stem cells (ADSCs) on chondral healing using the microfracture (MF) technique. Methods: Thirty male rabbits were randomly divided into three groups. Standard cylindrical osteochondral defects (OCDs) were created in the weight-bearing areas of the medial condyles of all the right knees; the defects were four millimeters in diameter and two millimeters in depth. The control group (group A) was restricted to spontaneous healing. For group B, we performed MF with a 1.5-mm drill. For group C, we applied MF using the same method and then applied 3 x 10(6) ADSCs to the defect area. At eight weeks post-operation, the subjects were sacrificed, and the distal femoral joint surfaces were evaluated histopathologically for chondral healing. The samples were scored according to the International Cartilage Repair Society (ICRS) scale. Results: The results for group C were significantly better than those for group A in terms of the surface properties (p = 0.003). The matrix evaluation was better for group A than for group C (p = 0.01). The cell distribution, cell viability and subchondral bone parameters were similar between the groups (p = 0.198, p = 0.387 and p = 0.699). The cartilage mineralization parameter was better for group C than for group A (p = 0.001). The signs of healing were better for group C than for group B, but the differences were not significant (p = 0.185). Conclusions: Improvements with additional ADSC treatments were not statistically significant in cases in which ADSC treatment was compared with isolated MF treatment.