The effect of repeated metaphyso-diaphyseal perforations on the growth plate and articular cartilage of the growing rat femur
Metin Manouchehr Eskandari1, Ebru Ballı2, İrfan Ayan1, Savaş Aktaş2, Cengiz Yılmaz1
1Mersin Üniversitesi Tıp Fakültesi, Ortopedi ve Travmatoloji Anabilim Dalı, Mersin
2Mersin Üniversitesi Tıp Fakültesi, Histoloji ve Embriyoloji Anabilim Dalı, Mersin
Keywords: Cartilage, articular; femur/injuries; growth plate/cytology/metabolism; models, biological; rats; tibia/injuries; wound healing/physiology.
Abstract
Objectives: The stimulus applied to the diaphysis or metaphysis of the growing bone may lead to increased activity of the growth plate. We described a model of repeated percutaneous metaphyso-diaphyseal perforations of rat femora and evaluated the ensuing effects. Materials and methods: The study included 10 immature male Sprague-Dawley rats. Distal metaphyso-diaphyseal perforations were performed in the right femora of the rats under short time inhalation anesthesia every three days for a total of 10 times. Four rats were excluded due to death or fracture occurrence. The rats were sacrificed, all femora and tibias were dissected and removed from soft tissue, and their lengths were measured. In histological evaluation, the thickness of the growth plate and articular cartilage of the distal femora and proximal tibias were measured micrometrically. The chondrocyte contents of the proliferative zone of the distal femoral growth plate and articular cartilage were also counted. The findings were compared with corresponding values of the left side as controls using paired t-test.
Results: There were no significant differences between the lengths of the left and right femoral and tibial bones. Significant increases were found in the thickness of the growth plate and articular cartilage of the right femora as well as an increased number of chondrocytes and a hypertrophied appearance. The increase in the cell count of the articular cartilage was statistically significant.
Conclusion: Our data provide evidence that repeated and limited metaphyso-diaphyseal injury is associated with increased chondrogenesis in the growth plate and articular cartilage, which is confined to the injured bone.