Hacı Ali Olçar1, Mehmet Halıcı2, İbrahim Halil Kafadar2, İbrahim Karaman2, Ayça Lekesizcan3, Zeynep Burçin Gönen4

1Department of Orthopedics and Traumatology, Yozgat City Hospital, Yozgat, Turkey
2Department of Orthopedics and Traumatology, Erciyes University Medical Faculty, Kayseri, Turkey
3Department of Histology and Embryology, Erciyes University Medical Faculty, Kayseri, Turkey
4Department of Oral and Maxillofacial Surgery, Genome and Stem Cell Center, Erciyes University, Kayseri, Turkey

Keywords: Adipose stem cell, non-union, osteoprotegerin, receptor activator of nuclear factor-kappa B, receptor activator of nuclear factor-kappa B ligand

Abstract

Objectives: This study aims to evaluate the effects of local adipose stem cell injection on non-union and diabetic non-union of rat femurs.

Materials and methods: Forty-eight female Wistar albino rats (weighing mean 200 g and aged 8 weeks) were used in this study. The rats were divided into six groups. Group 1 was chosen as a reference for receptor activator of nuclear factor-kappa (k) B (RANK), receptor activator of nuclear factor-k B ligand (RANKL) and osteoprotegerin (OPG) genes and no femur osteotomy was performed in this group. Group 2 underwent femur osteotomy, the osteotomy was fixed with a 1.5 mm K-wire as retrograde from the knee joint, and no gap was left in the osteotomy line. In order to induce non-union, femurs underwent osteotomy fixed with K-wires in groups 3, 4, 5 and 6. In addition, the osteotomy line was measured as 1.8 mm gap with electronic calipers and the gap was fixed with U staple. Before osteotomy, streptozocin was injected intraperitoneally at a dose of 60 mg/kg in 0.1 mol/L citrate buffer solution (Ph 4.4) in groups 4 and 6, in order to induce diabetes mellitus. Left femur anteroposterior and lateral X-rays were taken 10 weeks after the operation and the union in group 2 and non-union in groups 3, 4, 5, and 6 were confirmed. To see if injection of adipose stem cells into the non-union site increases bone union, 2 mL 0.9% sodium chloride (NaCl) in groups 3 and 4 and 2×106 adipose stem cell in groups 5 and 6 were locally injected into the non-union area with fluoroscopy. Femur X-rays were taken eight weeks after the injection and all rats were sacrificed. Femurs of rats were removed for histopathological and gene expression evaluation.

Results: There were significant differences between the groups injected 0.9% NaCI and adipose stem cells in terms of bone healing according to radiological and histopathological evaluations (p<0.05). No statistically significant difference was observed between the groups in terms of gene expression levels.

Conclusion: According to the results of our study, local adipose stem cell injection has positive radiological and histopathological effects in diabetic and non-diabetic femoral non-unions, independently of RANK, RANKL, or OPG gene expression pathways.

Citation: Olçar HA, Halıcı M, Kafadar İH, Karaman İ, Lekesizcan A, Gönen ZB. Can injection of adipose stem cells to non-union zone increase bone union? Experimental rat study. Jt Dis Relat Surg 2019;30(3):20-27.

Conflict of Interest

The authors declared no conflicts of interest with respect to the authorship and/or publication of this article.

Financial Disclosure

This study was funded by the Scientific Research Projects of University of Erciyes. Number of approval: TTU-2015-5780.