Introduction

The purpose of this study was to observe the difference in healing of chondral and osteochondral defects treated with abrasion arthroplasty versus subchondral microfracture.

Material and methods

8 rabbits were divided in two groups (4 rabbits in group A and 4 rabbits in group B). In both groups, a 3.0 mm diameter defect was created on medial and lateral femoral condyles. In group A cartilage was shaved without penetrating the subchondral plate. In group B, defects were created into subchondral bone (3.0 mm deep). In each medial epicondyle defects, two 1.0 mm holes were performed into subchondral bone with orthopedic awl until bleeding was observed. Each lateral epicondyle defects underwent a abrasion arthroplasty until punctate bleeding was observed. Joint resurfacing and degenerative changes were evaluated grossly and histologically after 8 and 12 weeks.

Results

On gross observation a greater volume of repair tissue filled treated defects. Degenerative changes in the cartilage surface were observed in both groups with both treatments. No differences in repair score of osteochondral defects were observed. In chondral defects, defects undergoing microfracture technique had increased repair score than defects treated with abrasion arthroplasty.

Conclusion

Both techniques have potential for repair chondral and osteochondral cartilage defects. Histological evidence at 12 weeks suggests that microfracture technique may result in better repair than abrasion arthroplasty in the treatment of chondral cartilage defect.