The anatomical basis of the medial sural artery perforator flaps.

OBJECTIVES: To study the perforators of the medial sural artery and the possible size of their flap. METHODS: The external iliac arteries often adult preserved cadavers (males and females) were injected with a mixture of red latex and lead oxide. The skin was reflected and the medial sural artery and its perforators were identified. The diameters and origins of perforators were measured from the central popliteal crease. RESULTS: The medial sural artery originated from the popliteal artery in 70% and had its external diameter at a mean of 3 +/- 0.02 mm and was accompanied by two venae comitantes. The number of its perforators was at a mean of two perforators. Length of the pedicle of the medial sural artery perforator flap was at a mean of 18 +/- 0.03 cm. The largest of the perforator had an average external diameter of 0.9 mm. The perforators ramified the skin with branches of the artery accompanying the posterior cutaneous nerve and the perforating branches of the peroneal and the posterior tibial arteries. The possible size of the medial sural perforators flap was at an average 8.2 cm x 13.3 cm. CONCLUSION: The medial sural artery perforator flap has at least one or two perforators with an average size of 8.2 cm x 13.3 cm. Elevation of the flap will not affect the vascularity of the gastrocnemius muscle.

Ascorbate-enhanced chondrogenesis of ATDC5 cells.

The ATDC5 cell line exhibits the multistep chondrogenic differentiation observed during endochondral bone formation. However, it takes up to two months to complete the process of cell expansion, insulin addition to promote differentiation and further changes in culture conditions effectively to induce hypertrophy. We sought to produce consistent chondrogenesis with significant hypertrophic differentiation with simpler conditions in a more practical time period. By adding ascorbate, the prechondrogenic proliferation phase was shortened from 21 to 7 days, with production of cartilaginous nodules during the chondrogenic phase, after insulin addition, that were greater in number and larger in size. Immunohistochemistry indicated much greater matrix elaboration and the mRNA expression of sox9, aggrecan and collagen type II were all significantly increased earlier and to a much higher degree when compared with controls. Moreover, there was a robust induction of hypertrophy: Col10a1, Runx2 and Mmp13 were all induced within 7-10 days. In conclusion, addition of ascorbate to ATDC5 cultures shortened the prechondrogenic proliferation phase, produced earlier chondrogenic differentiation, heightened gene expression and robust hypertrophic differentiation, abrogating the need for extended culture times and the changes in culture conditions. This simple modification considerably enhances the practicality of this cell line for studies of chondrogenesis.