Costal Cartilage

Intraflagellar transport proteins (IFT) play important roles in cilia formation and organ development. Partial loss of IFT80 function leads Jeune asphyxiating thoracic dystrophy (JATD) or short-rib polydactyly (SRP) syndrome type III, displaying narrow thoracic cavity and multiple cartilage anomalies. However, it is unknown how IFT80 regulates cartilage formation. To define the role and mechanism of IFT80 in chondrocyte function and cartilage formation, we generated a Col2α1; IFT80f/f mouse model by crossing IFT80f/f mice with inducible Col2α1-CreER mice, and deleted IFT80 in chondrocyte lineage by injection of tamoxifen into the mice in embryonic or postnatal stage. Loss of IFT80 in the embryonic stage resulted in short limbs at birth. Histological studies showed that IFT80-deficient mice have shortened cartilage with marked changes in cellular morphology and organization in the resting, proliferative, pre-hypertrophic, and hypertrophic zones. Moreover, deletion of IFT80 in the postnatal stage led to mouse stunted growth with shortened growth plate but thickened articular cartilage. Defects of ciliogenesis were found in the cartilage of IFT80-deficient mice and primary IFT80-deficient chondrocytes. Further study showed that chondrogenic differentiation was significantly inhibited in IFT80-deficient mice due to reduced hedgehog (Hh) signaling and increased Wnt signaling activities. These findings demonstrate that loss of IFT80 blocks chondrocyte differentiation by disruption of ciliogenesis and alteration of Hh and Wnt signaling transduction, which in turn alters epiphyseal and articular cartilage formation.

To assess characteristics of Chinese costal cartilage and costa calcification using Dual-Energy computed tomography(DECT). 154 patients who underwent chest DECT scanning were included in our study. They were divided into following groups: less than 30 years old, 31-40 years old, 41-50 years old, 51-60 years old and over 60 years old. The sixth, seventh and eighth costal cartilages and costas were evaluated. Calcification patterns of cartilage were classified as central(C), peripheral(P), mixed(M) and no calcification(N) types. Calcification degree of cartilage was distinguished as 1(0-25%), 2(26-50%) and 3(>50%). CT value, calcium and water concentrations were measured in costal cartilage, cortical or cancellous bone respectively. An increasing C pattern of cartilage was displayed in females, while P type preferred in males as age increased. Calcification degree generally changed from 1 to 2 or 3 in females. CT value and calcium concentration of cartilage went through a gradual rising course and peaked in their 40-50 years, while those two indices of cancellous bone decreased gradually since their 50 years in females. The findings suggest a gradual calcification of the costal cartilage took place before 40-50 years old and a sharp bone loss of the costa happened after 40-50 years old in females.

IntroductionAugmentation rhinoplasty depends mainly on intact stable bony and cartilaginous parts. Many trials have used different materials as a graft to perform the operation and support the nose. Debate exists whether alloplastic or autogenic grafts are more appropriate. Common available alloplastic grafts include silicone, medpor, and gore-tex. Autogenic grafts are usually derived from costal cartilages. Warping, infection, and hypertrophic scars are the main complications of the procedure. Yet no subgroup analysis has been performed to investigate the effect of different risk factors.ObjectiveTo investigate the effect of different types of grafts and the association of the income level of the country on surgery complications.MethodsA comprehensive literature search of articles was conducted in PubMed, Cochrane Library, Web of Science, and SCOPUS databases through October 2019. We included articles that used autologous or alloplastic grafts in nasal dorsum reconstruction surgery. We performed subgroup analysis according to the type of graft used, region, and income level of the country. A meta-regression analysis model was carried out from the period of 1999-2018, to study the incidence of these complications over time.ResultsThe overall complication rate was 7.1%, which was higher in the alloplastic group (7.8%) than the autogenic group (6.9%). The most common complications were secondary surgery for re-correction (4.1%), infection (2.1%), warping (1.6%), and hypertrophic scars (1.6%). All outcomes were homogeneous (I2 ConclusionPatients with autogenic grafts are less liable to develop complications than their peers reconstructed with alloplastic grafts. Moreover, Asian patients are less susceptible to overall rhinoplasty complications. Attention should be noted for low-income countries in which surgical complications are more prone to occur.

Toward the development of biologic products intended to repair articular cartilage, this study evaluated native structure-function relationships of rib and knee cartilage and compared the capacity of articular chondrocytes (ACs) and costochondral cells (CCs) to generate tissue-engineered analogous cellular products (ACPs) for preclinical cartilage repair studies. Utilizing the relevant preclinical model of the Yucatan minipig, both knee and rib cartilages were characterized by topography and age. Key findings include that: 1) knee cartilage had higher tensile properties than rib cartilage (e.g., ultimate tensile strength of adult knee cartilage being 218 % of adult rib cartilage), 2) rib cartilage had higher compressive properties than knee cartilage (e.g., aggregate modulus of adult rib cartilage being 177 % of adult knee cartilage), 3) functional (i.e., biomechanical and biochemical) properties were dependent on age (e.g., adult coefficient of friction being 186 % of that of the juvenile in the medial-lateral axis of the knee), 4) functional properties were dependent on topography, 5) compressive properties were significantly correlated to glycosaminoglycan content and hydration, and 6) tensile properties were significantly correlated to collagen content. Additionally, juvenile ACs and CCs were compared for their capacity to generate self-assembled neocartilage with constructs achieving functionality index values (i.e., a weighted average of neocartilage functional properties compared to native tissue) of 0.54 and 0.44, respectively, when compared to native adult minipig knee cartilage. Overall, this study provides gold-standard characterization values for minipigs of different ages for preclinical cartilage repair studies and demonstrates that both ACs and CCs can be used to generate functional self-assembled neocartilage ACPs. STATEMENT OF SIGNIFICANCE: Toward the clinical translation of tissue-engineered cartilage implants, this study characterizes the functional properties of knee and rib cartilage in the clinically relevant Yucatan minipig model. Additionally, it evaluates the ability of knee- and rib-derived chondrocytes to generate neocartilage that recapitulates the functional properties of native cartilage tissues. Age-related changes in rib and knee cartilage are also described, along with structure-function relationships involving correlating biochemical composition and mechanical properties of cartilage tissues. Overall, this study provides data essential to the translation of cartilage implants for the knee and describes how these data are relevant to the FDA regulatory process.