Background: Growth plate injury in children could produce limb length discrepancy and angular deformity. Removal of damaged physis or bony bar and insertion of spacers produced variable results and for large defects in young children the treatment is challenging. In this study, we used mesenchymal stem cells (MSC) on chitin scaffold for restoration of damaged physis. The useage chitin as a spacer was also investigated.
Material and methods: An experimental model of growth arrest was created by removing lateral 50% of distal femoral physis of 34 weeks of age, albino rabbits. The left side growth plate defects were filled with MSC on chitin scaffold in nine, and scaffold alone in four rabbits. For all rabbits right side defects were left alone as control limb. After 3 months, femoral bones were harvested and gross in spection and radiology for measurement of angulations was done, histological study for evaluation of regeneration of physis were also done.
Results: The hemi-physeal resection procedures were successful and all of the operated limbs showed angular deformities. There was a trend toward less angular deformity in cases in which more concentration of MSCs with chitin scaffold were used. In cases of transfer of MSCs with concentration of less than 1.5 millions, mixed results were observed and angular deformities were not reduced. Transfer of chitin alone yielded poor results.
Conclusion: In this study, we have developed an in vitro construction of transplantable tissue-engineered disks, using the natural chitin scaffold and MSCs. We investigated the efficacy of these disks for repairing defect of growth plate cartilage at distal femoral physis. Our results showed that the beneficial effect of these cells on scaffold was appeared in more concentration of cells.
Key Words: Growth plate injury, Tissue-engineering, Mesenchymal stem cells, Chitin scaffold
Growth plate injury in growing children could produce major problems, causing limb growth arrest leading to limb length discrepancy, angular or rotational mal-alignments.1 The bony bars produced in the physes may be removed and replaced by different materials to reconstitute the continuity of the growth plate.2 The outcome of such procedures is variable depending on the patient’s age, and also size and location of the bony bar.3 The interposition materials used for such a purpose are quite variable and are usually acting only as passive spacers.
The idea of having active cells to re-build the damaged and destroyed growth plate cells is an intriguing concept. Polypotential stem cell regeneration and its transformation into various cell-lines, is gaining popularity in different branches of medicine.4-6 The use of mesenchymal stem cells for growth plate regeneration has been studied by Ahn J.I. et al. in 2004. The implantation of autologous MSC, stimulated by transforming growth factor-beta (TGF-ß), into the physeal defect at proximal end of tibia in rabbits...