Histological, Physical Studies after Xenograft of Porcine Ear Cartilage

Glycosaminoglycan-Mediated Interactions in Articular, Auricular, Meniscal, and Nasal Cartilage

Glycosaminoglycans (GAGs) are ubiquitous components in the cartilage extracellular matrix (ECM). Ultrastructural arrangement of ECM and GAG-mediated interactions with collagen are known to govern the mechanics in articular cartilage, but these interactions are less clear in other cartilage types. Therefore, this article reviews the current literature on ultrastructure of articular, auricular, meniscal, and nasal septal cartilage, seeking insight into GAG-mediated interactions influencing mechanics. Ultrastructural features of these cartilages are discussed to highlight differences between them. GAG-mediated interactions are reviewed under two categories: interactions with chondrocytes and interactions with other fibrillar macromolecules of the ECM. Moreover, efforts to replicate GAG-mediated interactions to improve mechanical integrity of tissue-engineered cartilage constructs are discussed. In conclusion, studies exploring cartilage specific GAGs are poorly represented in the literature, and the ultrastructure of nasal septal and auricular cartilage is less studied compared with articular and meniscal cartilages. Understanding the contribution of GAGs in cartilage mechanics at the ultrastructural level and translating that knowledge to engineered cartilage will facilitate improvement of cartilage tissue engineering approaches.

Does periosteum promote chondrogenesis? A comparison of free periosteal and perichondrial grafts in the regeneration of ear cartilage

Background

Elastic ear cartilage is a good source of tissue for support or augmentation in plastic and reconstructive surgery. However, the amount of ear cartilage is limited and excessive use of cartilage can cause deformation of the auricular framework. This animal study investigated the potential of periosteal chondrogenesis in an ear cartilage defect model.

Methods

Twelve New Zealand white rabbits were used in the present study. Four ear cartilage defects were created in both ears of each rabbit, between the central artery and marginal veins. The defects were covered with perichondrium (group 1), periosteum taken from the calvarium (group 2), or periosteum taken from the tibia (group 3). No coverage was performed in a control group (group 4). All animals were sacrificed 6 weeks later, and the ratio of neo-cartilage to defect size was measured.

Results

Significant chondrogenesis occurred only in group 1 (cartilage regeneration ratio: mean± standard deviation, 0.97± 0.60), whereas the cartilage regeneration ratio was substantially lower in group 2 (0.10± 0.11), group 3 (0.08± 0.09), and group 4 (0.08± 0.14) (p=0.004). Instead of chondrogenesis, osteogenesis was observed in the periosteal graft groups. No statistically significant differences were found in the amount of osteogenesis or chondrogenesis between groups 2 and 3. Group 4 showed fibrous tissue accumulation in the defect area.

Conclusion

Periosteal grafts showed weak chondrogenic potential in an ear cartilage defect model of rabbits; instead, they exhibited osteogenesis, irrespective of their embryological origin.

[Application of thin-ribbed cartilage with the perichondrium in correction of secondary cleft lip nasal deformity as lateral crural onlay graft]

Objective

To explore the application and effectiveness of thin-ribbed cartilage with the perichondrium in the correction of secondary cleft lip nasal deformity as the lateral crural onlay graft.

Methods

A retrospective study was performed based on the data of 28 patients with secondary nasal deformity of cleft lip between October 2015 and April 2017. There were 16 males and 12 females with an average age of 24 years (range, 18-31 years). There were 11 cases with secondary nasal deformities on the left side, 13 cases on the right side, and 4 cases on both sides. Three-dimensional stereotaxy of the nasolabial muscles was used to correct the deformity. The costal cartilage as the support was used to perform nasal columella and nasal dorsum while the thin-ribbed cartilage with the perichondrium was used as wing cartilage support. The photography of nasal position was taken before operation and at 6-8 months after operation. The midpoint of the junction between the nasal columella and the upper lip was marked point O; the lateral horizontal line passing through the point O was marked as X-line, and the longitudinal line (the midline) as Y-line. The distance of the highest point of the affected nostril to the X-line, the distance of the nostril's outermost point to the Y-line, the symmetries of both the most lateral and the highest point of the bilateral nostrils, and the distance of the highest point of the nasal tip to the X-line were measured.

Results

All incisions healed by first intention. All patients were followed up 6 to 24 months with an average of 12 months. The size and shape of the noses were stable, and no compli cation, such as cartilage exposure, hematoma, or infection occurred during the postoperative follow-up. There were 4 cases with obvious incision scars, 3 cases with nostril and alar asymmetry, and 1 case of lateral side of the nose without well positioned. The symmetry of the highest points of bilateral nostrils was 57.643%±27.491% before operation and 90.246%±18.769% after operation. The symmetry of the most lateral points of the bilateral nostrils was 77.391%±30.628% before operation and 92.373%±21.662% after operation. And there were significant differences between pre- and post-operation ( P<0.05). There were also significant differences in the distance of highest point of the affected nostril to the X-line, the distance of the nostril's outermost point to the Y-line, and the distance of the highest point of the nasal tip to the X-line ( P<0.05). No thoracic contour change occurred at the costal cartilage donor site.

Conclusion

The thin-ribbed cartilage with the perichondrium has good support and long-term stability, and it can be used as one of the ideal materials for nasal alar cartilage transplantation for nasal deformity secondary to cleft lip.