Cell yield, proliferation, and postexpansion differentiation capacity of human ear, nasal, and rib chondrocytes.

Human ear, nasal, and rib chondrocytes were compared with respect to their suitability to generate autologous cartilage grafts for nonarticular reconstructive surgery. Cells were expanded for two passages in medium containing 10% fetal bovine serum without (control) or with transforming growth factor beta(1) (TGF-beta(1)), fibroblast growth factor 2 (FGF-2), and platelet-derived growth factor bb (PDGF-bb) (TFP). Expanded cells were cultured as three-dimensional pellets in chondrogenic serum-free medium containing insulin, dexamethasone, and TGF-beta(1). Chondrocytes from all three sources were successfully isolated, increased their proliferation rate in response to TFP, and dedifferentiated during passaging. Redifferentiation by ear and nasal, but not rib, chondrocytes was enhanced after TFP expansion, as assessed by the significant increase in glycosaminoglycan (GAG)/DNA content and collagen type II mRNA expression in the resulting pellets. TFP-expanded ear and nasal chondrocytes generated pellets of better quality than rib chondrocytes, as assessed by the significantly higher GAG/DNA content and collagen type II mRNA expression, and by the relative stain intensities for GAG and collagen types I and II. In conclusion, postexpansion cell yields suggest that all three sources investigated could be used to generate autologous grafts of clinically relevant size. However, ear and nasal chondrocytes, if expanded with TFP, display superior postexpansion chondrogenic potential and may be a preferred cell source for cartilage tissue engineering.

The gluteus maximus muscle flap for reconstruction of sacral chordoma defects.

Four patients diagnosed with sacral chordoma underwent reconstruction with the gluteus maximus flap using an approach based on available muscle remnants and their residual blood supply. The entire unilateral gluteus maximus muscle was turned over to fill the defect in 2 patients. The flap was based on 1 or 2 gluteal vessels, depending on vessel availability following tumor resection. When all 4 major pedicles had been ligated, bilateral advancement gluteal muscle flaps based on their distal blood supply were used (patient 3). A longitudinally split flap was used for secondary reconstruction of a partially obliterated defect (patient 4). Over a mean follow-up period of 8 months, there was no wound breakdown and all patients were ambulant.