Effects of adipose tissue-derived stromal vascular fraction on osteochondral defects treated by hyaluronic acid-based scaffold: An experimental study

Abstract

Objectives: This study aims to evaluate the effect of adipose-derived stromal vascular fraction (SVF) on osteochondral defects treated by hyaluronic acid (HA)-based scaffold in a rabbit model.

Materials and methods: Eighteen white New Zealand rabbits were randomly grouped into the experimental group (n=9) and control group (n=9). In all groups, osteochondral defects were induced on the weight-bearing surfaces of the right femoral medial condyles, and a HA-based scaffold was applied to the defect area with microfractures (MFs). In this study, 1 mL of adipose-derived SVF was injected into the knee joints of the rabbits in the experimental group. For histological and macroscopic evaluation, four rabbits were randomly selected from each group at Week 4, and the remaining rabbits were sacrificed at the end of Week 8. Macroscopic assessments of all samples were performed based on the Brittberg scoring system, and microscopic evaluations were performed based on the O'Driscoll scores.

Results: Samples were taken at Weeks 4 and 8. At Week 4, the O'Driscoll scores were significantly higher in the control group than the experimental group (p=0.038), while there was no significant difference in the Brittberg scores between the two groups (p=0.108). At Week 8, the O'Driscoll score and Brittberg scores were statistically higher in the experimental group than in the control group (p=0.008 and p=0.007, respectively). According to the microscopic evaluation, at the end of Week 8, the cartilage thickness was greater in the experimental group, and nearly all of the defect area was filled with hyaline cartilage.

Conclusion: Application of adipose-derived SVF with MF-HA-based scaffold was better than MF-HA-based scaffold treatment in improving osteochondral regeneration. Therefore, it can be used in combination with microfracture and scaffold to accelerate cartilage regeneration, particularly in the treatment of secondary osteoarthritis.

Figure 1. (a) A macroscopic view of experimental group at Week 4. (b) A macroscopic view of control group at Week 4. (c) A macroscopic view of experimental group at Week 8. (d) A macroscopic view of control group at Week 8.

Figure 2. Macroscopic scoring of the groups (Brittberg score). The box represents 50% of the sample. Single line inside the box represents median values. Cross mark inside the box represents mean values.

Figure 3. Microscopic views of the samples (H-E, X40: a, b, c, d; Masson trichrome, X4: e, f, g, h). (a, e) A microscopic view of control group at Week 4. (b, f) A microscopic view of experimental group at Week 4. (c, g) A microscopic view of control group at Week 8. (d, h) A microscopic view of experimental group at Week 8.