Objective Due to the limited intrinsic healing and repair capacity of the articular cartilage, most treatment methods cannot achieve reliable regeneration of normal hyaline cartilage, resulting in early development of osteoarthritis. The purpose of this study was to determine the effects of human amniotic fluid and membrane on chondral defects. Material and Methods Sixty-four knees of 32 immature New Zealand rabbits were included in the study. Full thickness chondral defects were created in the weight-bearing surface of the medial condyles of the rabbits. The rabbits were divided randomly into four groups: no adjunct treatment was given in group 1, 0.3 ml human amniotic fluid (HAF) alone in group 2, human amniotic membrane (HAM) alone in group 3 and both of 0.3 ml HAF and HAM in group 4 was administered. The condyles were histopathologically evaluated at 4th and 12th week using the modified O’Driscoll Grading Scale. Results There were no significant differences in the quality of the regenerated tissue within and between groups (p>0.05). The mean results of groups at the 12th week were worse than results at the 4th week; however, the difference was statistically significant for only the sham group (group 1) and the combined therapy group (group 4) (p=0.007 and p=0.014, respectively). Conclusion HAF alone, HAM alone, and combined administration of both biomaterials neither affected chondral defect healing nor had any differences between each other. Nevertheless, we believe that some early regeneration due to an intrinsic repair mechanism is possible in immature rabbits as this study showed better results at 4th week than those at 12th week, although they are prone to degenerative processes in long-term follow-up. We suggest that a larger sample size in an experimental study would probably display a statistically significant difference when investigating effects of HAF, HAM, or both.
