Tehran University Medical Journal

An increase in the average age of the population and physical activities where the musculoskeletal system is involved as well as large number of people suffering from skeletal injuries which impose high costs on the society. Bone grafting is currently a standard clinical approach to treat or replace lost tissues. Autografts are the most common grafts, but they can lead to complications such as pain, infection, scarring and donor site morbidity. The alternative is allografts, but they also carry the risk of carrying infectious agents or immune rejection. Therefore, surgeons and researchers are looking for new therapeutic methods to improve bone tissue repair. The field of tissue engineering and the use of stem cells as an ideal cell source have emerged as a promising approach in recent years. Three main components in the field of tissue engineering include proper scaffolds, cells and growth factors that their combination leads to formation of tissue-engineered constructs, resulting in tissue repair and regeneration. The use of scaffolds with suitable properties could effectively improve the tissue function or even regenerate the damaged tissue. The main idea of tissue engineering is to design and fabricate an appropriate scaffold which can support cell attachment, proliferation, migration and differentiation to relevant tissue. Scaffold gives the tissue its structural and mechanical properties, for instance flexibility and stiffness that is related with the tissue functions. Biomaterials used to fabricate scaffolds can be categorized into natural or synthetic biodegradable or non-biodegradable materials. Polymers are the most widely used materials in tissue engineering. Growth factors are a group of proteins that cause cell proliferation and differentiation. Two main cell sources are specialized cells of desired tissue and stem cells. However, according to the low proliferation and limited accessibility to the cells of desired tissue, stem cells are better suggestion. Combination of mesenchymal stem cells harvested from bone marrow, adipose tissue and cord blood with proper scaffolds and growth factors could be a useful method in treatment of skeletal injuries. In this review paper, we focus on the application of mesenchymal stem cells in the repair of damaged bone, cartilage, meniscus, ligaments, tendons and spine tissue.

Results: Radiofrequency ablation with drilling was used in 22(81.5%) patients, and for the rest 5(18.5%), radiofrequency ablation with curettage and drilling was performed as a treatment procedure. The overall clinical success rate was 92.6%(25/27), with a low complication rate (7.4%). The mean diameter of nidus in pre/pos treatment was 3.46±2.02 and 2.22±1.75 mm, respectively. Femur 12(44.4%) was the most common bone in the patients. Significant differences between pre/post treatment follow up examinations in nidus size (P=0.03), nidus diameter (P=0.02), bone and calcification size (P=0.005) were detected. Additionally, it depicts that the mean values of tumor size and cortical thickening decreased after treatment. Conclusion: It is noteworthy that the present study had some limitations, including the small sample size and the relatively short follow-up period. There is no significant difference between radiofrequency ablation after drilling and curettage in treating Osteoid Osteoma. It is concluded that although there was a significant difference in pre/post-treatment imaging, there is no need for continuous imaging follow-up in treated patients without clinical complications such as pain to mitigate radiation dose risks and healthcare expenses.