Age and sexually dimorphic changes in costal cartilages. A preliminary microscopic study

Autologous Costal Chondral/Osteochondral Transplantation and Costa-Derived Chondrocyte Implantation for Articular Cartilage Repair: Basic Science and Clinical Applications

There has been increasing application of autologous costal chondral/osteochondral transplantation (ACCT/ACOT) and costa-derived chondrocyte implantation (ACCI) for articular cartilage repair over the past three decades. This review presents the major evidence on the properties of costal cartilage and bone and their qualifications as grafts for articular cartilage repair, the major clinical applications, and the risks and strategies for costal chondral/osteochondral graft(s) harvest. First, costal cartilage has many specific properties that help restore the articular surface. Costa, which can provide abundant cartilage and cylindrical corticocancellous bone, preserves permanent chondrocyte and is the largest source of hyaline cartilage. Second, in the past three decades, autologous costal cartilage-derived grafts, including cartilage, osteochondral graft(s), and chondrocyte, have expanded their indications in trauma and orthopaedic therapy from small to large joints, from the upper to lower limbs, and from non-weight-bearing to weight-bearing joints. Third, the rate of donor-site complications of ACCT or ACOT is low, acceptable, and controllable, and some skills and accumulated experience can help reduce the risks of ACCT and ACOT. Costal cartilage-derived autografting is a promising technique and could be an ideal option for articular chondral lesions with or without subchondral cysts. More high-quality clinical studies are urgently needed to help us further understand the clinical value of such technologies.

Modified Technique for Auricular Helical Rim Reconstruction in Adult Patients with Subtotal Helical Rim Defects

BACKGROUND

In adults, the volume of costal cartilage is enough for reconstruction, but floating cartilage is hard, brittle, and easily broken due to calcification, in addition to being short, making it unsuitable for helical rim reconstruction in such age groups.

AIM OF STUDY

This study describes a novel technique in which adult patients underwent 2-stage helical rim reconstruction using the syncytium of sixth and seventh costal cartilage.

MATERIAL AND METHODS

A single-arm clinical trial involves 35 adults with total and subtotal helical rim defects, either congenital, post-traumatic, postburn, or postvascular malformation excision. Twenty-nine unilateral and 6 bilateral cases. The age of patients ranged between 19 and 40 years. In the period between April 2021 and April 2023. Follow-up was 6 months.

RESULTS

There were no technique-related complications, such as broken helix. In most cases, scars were invisible, with the normal contour of helical rim. Among the 35 patients, 19 were graded as excellent, 13 as good, and 3 as fair. In objective photographic evaluation, all patients were evaluated with high (3 or 4) ratings; the score was 3 in 19 patients and 4 in 16 patients. All patients were satisfied with the size, contour, position and details of the new helix.

CONCLUSION

Using the syncytium of the sixth and seventh costal cartilage to fabricate the helical rim in adult patients gives a suitable volume of cartilage graft as regards the length and width, which suits the reconstruction of the helical rim, and shows a good configuration with satisfactory surgical results.

Costal Cartilage Graft Repair Osteochondral Defect in a Mouse Model

OBJECTIVE

Osteochondral defects develop into osteoarthritis without intervention. Costal cartilage can be utilized as an alternative source for repairing osteochondral defect. Our previous clinical study has shown the successful osteochondral repair by costal cartilage graft with integration into host bone bed. In this study, we investigate how cartilaginous graft adapt to osteochondral environment and the mechanism of bone-cartilage interface formation.

DESIGN

Costal cartilage grafting was performed in C57BL/6J mice and full-thickness osteochondral defect was made as control. 3D optical profiles and micro-CT were applied to evaluate the reconstruction of articular cartilage surface and subchondral bone as well as gait analysis to evaluate articular function. Histological staining was performed at 2, 4, and 8 weeks after surgery. Moreover, costal cartilage from transgenic mice with fluorescent markers were transplanted into wild-type mice to observe the in vivo changes of costal chondrocytes.

RESULTS

At 8 weeks after surgery, 3D optical profiles and micro-CT showed that in the graft group, the articular surface and subchondral bone were well preserved. Gait analysis and International Cartilage Repair Society (ICRS) score evaluation showed a good recovery of joint function and histological repair in the graft group. Safranin O staining showed the gradual integration of graft and host tissue. Costal cartilage from transgenic mice with fluorescent markers showed that donor-derived costal chondrocytes turned into osteocytes in the subchondral area of host femur.

CONCLUSION

Costal cartilage grafting shows both functional and histological repair of osteochondral defect in mice. Graft-derived costal chondrocytes differentiate into osteocytes and contribute to endochondral ossification.

Characterization of costal cartilage allografts

Background

Human costal cartilage remains widely used in the reconstruction of soft tissues, particularly within the field of plastic and orthopaedic surgery. The biologic expense of using autologous human costal cartilage has become superseded by the increasingly common use of irradiated costal cartilage allografts. To date, there has been no histologic investigation of such costal cartilage allografts. This study aims to characterize the histologic variations that exist between different costal cartilage specimens, and to quantify this between specimens in spite of their common anatomical derivation.

Methods

Twenty‐five specimens of cadaveric human costal cartilage were obtained from Australian Biotechnologies. Each specimen was irradiated, sectioned and stained with Haematoxylin and Eosin, Masson's trichrome and tetrachrome stains. After being analysed under light microscopy, specimen dimensions, chondrocyte counts and mineral content was quantified and measured.

Results

The median specimen diameter was 8.20 mm, with an interquartile range (IQR) of 1.59 mm. The median measurement from the superficial to basal chondrocyte layer was 1409.91 μm (IQR = 885.59 μm), and the median measurement from superficial to calcified zone was 4146.26 μm (IQR 1441.83 μm). The median chondrocyte area was 442.74 μm² (IQR = 2622.72 μm²) with their total chondrocyte count ranging from 289 to 591 chondrocytes per square millimetre. The median percentages of collagen and mineral content were 45.17% and 71.82%, respectively (IQR = 20.48%, 14.75%).

Conclusion

These findings emphasize the histologic and biochemical degree of variation that exists between specimens of human cadaveric costal cartilage on a microscopic level. This has the potential to influence the selection of costal cartilage allografts for reconstructive purposes.

Frequency of biological non-skeletal materials in dry bone scenarios

In forensic anthropology, many small biological non-osseous materials may be found associated to skeletonized remains and can provide crucial information to the biological profile. Indeed, their careful recovery and correct identification can add information related to age-at-death, sex, ancestry, health, diet, migration and habits, and may be used in specific analysis such as DNA typing. However, and despite their potential, little is known about these non-osteological materials. Indeed, how frequent are they in dry bone cases? To answer this question, 100 skeletal remains with postmortem intervals ranging from 23 to 76 years from the CAL Milano Cemetery Skeletal Collection were meticulously examined for the presence of non-skeletal materials and in particular ossified cartilage, vascular calcifications, hair and nails. As a result, non-skeletal materials were found in 81 skeletal remains and showed high frequencies of recovery, despite the less-than-optimal conditions of exhumation of the skeletons. The high frequencies of non-skeletal materials obtained demonstrate the need for additional training and research given their informative power in forensic cases.

Amianthoid transformation of costal cartilage matrix in children with pectus excavatum and pectus carinatum

Background

It is unclear if amianthoid transformation (AT) of costal cartilage extracellular matrix (ECM) has an impact on the development of pectus excavatum (PE) and pectus carinatum (PC).

Methods

AT foci were examined in intrasurgical biopsy specimens of costal cartilages of children (8–17 years old) with PE (n = 12) and PC (n = 12) and in age-matching autopsy control samples (n = 10) using histological and immunohistochemical staining, atomic force and nonlinear optical microscopy, transmission and scanning electron microscopy, morphometry and statistics.

Results

AT areas were identified in the costal cartilage ECM in children with normal chest, PE and PC. Each type of the AT areas (“canonical”, “intertwined”, “fine-fibred” and “intralacunary”) had a unique morphological pattern of thickness and alignment of amianthoid fibers (AFs). AFs were formed via lateral aggregation of collagen type II fibrils in the intact ECM. Foci of the AT were observed significantly more frequently in the PE and PC groups. The AT areas had unique quantitative features in each study group.

Conclusion

AT is a structurally diverse form of ECM alteration present in healthy and pathological costal cartilage. PE and PC are associated with specific AT disorders.

Anti‑chondrocyte apoptosis effect of genistein in treating inflammation‑induced osteoarthritis

Osteoarthritis (OA) is a chronic disease that is mainly characterized by chondrocyte degeneration. Inflammatory mediators participate in the development of OA, leading to chondrocyte apoptosis and destruction of the cartilage. Genistein is the major active component of isoflavone, with a chemical composition and a biological effect that is similar to that of estrogens, which prevents the degradation of cartilage; however, its underlying mechanisms of action remain unknown. The aim of the present study was to investigate the anti-apoptotic effects of genistein on chondrocytes for the treatment of inflammation-induced OA. Interleukin (IL)-1β was used to establish a chondrocyte OA model. After treatment with different concentrations of genistein, western blotting identified that expression levels of collagen II and aggrecan were increased in a concentration-dependent manner, while caspase 3 expression gradually decreased after genistein application. Moreover, flow cytometry and ELISA results demonstrated that genistein could decrease chondrocyte apoptosis and reduce the levels of tumor necrosis factor (TNF)-α in a dose-dependent manner. Furthermore, the in vitro data were evaluated in an OA rat model. Genistein increased the collagen and acid glycosaminoglycan content, as well as decreased the levels of TNF-α and IL-1β. Genistein also promoted the expression levels of collagen II and aggrecan in the articular cartilage, and decreased the expression of caspase 3, thus alleviating cartilage degradation. In conclusion, the results indicated that genistein mediated inflammation and had an anti-apoptotic role in treating OA. Therefore, genistein may serve as an alternative treatment for OA.

Forensic age estimation based on the pigmentation in the costal cartilage from human mortal remains

Age estimation is considered a crucial and challenging issue in forensic casework. Costal cartilage appears a potential mortal remain in age-at-death estimation attributable to its correlative alteration in color based on pigment accumulation with the advancing age. In this study, samples from the second costal cartilage were collected in a Chinese Han population, and the cross sections were subsequently scanned and digitalized in a standard way. Color change was quantified using mean gray value (MGV), which was measured by Photoshop CS5. After the exclusion of samples with factors which could impair the quality of images and the accuracy of values, a high correlation was demonstrated between age and MGV in samples. A linear regression model (AGE = 173.425-0.755*aveMGV) was established for age prediction, with its performance evaluated using both samples from the training set and the blind test set, in which a mean absolute deviation of 4.42 years and 3.57 years was obtained, respectively. Altogether, MGV could be reckoned as a precise quantification of pigmentation in costal cartilage and an excellent indicator of age prediction in the age interval from 20 to 60 years. Moreover, our strategy appears more user-friendly and accurate, thus exceedingly practical for age estimation in forensic anthropology.

[Costal cartilage changes in children with pectus excavatum and pectus carinatum]

Pectus excavatum (PE) and pectus carinatum (PC) in children are the most common congenital deformities that cause complications in the thoracic organs; however, the role of chondrocytes and cartilage canals in the pathogenesis of these conditions remains unexplored.

OBJECTIVE

To investigate qualitative and quantitative changes of cartilage lacunae and canals in the costal cartilages in children with PE and PC compared to those with normal chests.

SUBJECT AND METHODS

Costal cartilages were investigated in 10 children with normal chests (a control group), in 12 children with PE, and in 12 children with PC. Tissue fragments were fixed in 10% neutral formalin and embedded in compacted paraffin. Sections were stained with hematoxylin and eosin. Slides were examined by light microscopy. Cartilage lacunae, hyper- and hypolacunar zones, and cartilage canals were morphometrically examined, followed by statistical data analysis.

RESULTS

There was a significant decrease in the number of cartilage lacunae and in the frequency of hyperlacunar zones and an increase in that of hypolacunar zones in the PE and PC groups. There were no significant differences in these parameters between the PE and PC groups; however, there was a tendency to the smallest number of cartilage lacunae and canals in the PC group and that to the preponderance of empty lacunae in the PE group. Only the PC group showed also negative correlations between the proportions of empty lacunae and the age of children.

CONCLUSION

The pathogenesis of PE and PC in children is related to the impaired trophism of costal cartilages due to the smaller number of cartilage channels containing vessels and lacunae with chondrocytes. The development of PE and PC is associated with specific costal cartilage morphological changes that suggest that PE and PC are different manifestations of the same disease, namely connective tissue dysplasia.

[Costal cartilage structural and functional changes in children with a funnel or keeled chest]

Congenital chest wall deformities (CCWDs) in children are severe diseases leading to cosmetic defects and diseases of the respiratory and cardiovascular systems. The most common of these deformities are funnel-shaped (pectus excavatum, FD) and keeled (pectus carinatum, KD) ones. The pathogenesis of CCWDs and the role of costal cartilage structural and functional changes in their pathogenesis have now been not well studied, which makes it difficult to elaborate pathogenetic approaches to correcting these diseases. Analysis of the literature has shown that structural and functional changes occur in the matrix and chondrocytes from the costal cartilage in FD. Similar costal cartilage changes are observed in KD. It is still unknown exactly which pathological processes are present in the costal cartilage and how they result in the development of one or other type of CCWDs. The role of amianthoid transformation (AT) of costal cartilages in these processes is also unknown. It is not improbable that it is AT drastically changing the native cartilage matrix, which is one of the key mechanisms leading to changes in its properties and to the subsequent development of FD or KD.

A pilot study comparing mechanical properties of tissue-engineered cartilages and various endogenous cartilages

BACKGROUND

Mechanical properties of tissue-engineered cartilage and a variety of endogenous cartilage were measured. The main goal was to evaluate if the tissue-engineered cartilage have similar mechanical characteristics to be replaced with rib cartilage in microtia reconstruction. Such study lays the foundation for future human clinical trials for microtia reconstruction.

METHOD

Atomic force microscopy and compression testing were used to measure the viscoelasticity of tissue-engineered cartilage (stem cell seeded on Poly lactic co-glycolytic acid nanofibers and Pellet) and endogenous cartilage: conchal bowl, microtic ears, preauricular remnants, and rib. Atomic force microscopy, calculates biomaterial elasticity through force-deformation measurement and Hertz model. Compression testing determines the stress relaxation by measuring slope of stress reduction at 10% strain.

FINDING

Tissue-engineered cartilage demonstrated elasticity (4.6kPa for pellet and 6.6kPa for PLGA) and stress relaxation properties (7.6 (SD 1.1) kPa/s for pellet) most similar to those of native conchal bowl cartilage (31.8 (SD 18) kPa for the elasticity and 15.1 (SD 2.1) kPa/s for stress relaxation factor). Rib cartilage was most dissimilar from the mechanical characteristics of conchal cartilage and demonstrated the highest elastic modulus (361 (SD 372) kPa). Moreover, except preauricular cartilage samples, the level of elastic modulus increased with age.

INTERPRETATION

The use of tissue-engineered cartilage developed via PLGA and Pellet methods, may be an appropriate substitute for rib cartilage in the reconstruction of microtic ears, however their mechanical characteristics still need to be improved and require further validation in animal studies.

[The morphological and morphometric study of amianthoid transformation of the costal cartilage in health and in keeled chest deformity in children]

Amianthoid transformation (AT) is the accumulations of abnormal collagen structures (amianthoid fibers) in the hyaline cartilages, tumors, and tendons. Neither functional value of costal cartilage matrix AT, nor its role in the pathogenesis of congenital chest deformities is known now.

AIM

to examine the morphological features of AT in the costal cartilage of children with the normal and keeled chest.

SUBJECTS AND METHODS

Costal cartilages were studied in 6 children with the normal chest (autopsy material) and in 5 ones with keeled chest (surgical material). Tissue fragments were fixed in 10% neutral formalin and embedded in compacted paraffin. The sections were stained with hematoxylin and eosin, picrofuchsin by van Gieson, with picrosirius, toluidine blue and by the Malaurie method modified by Gallego. The specimens were examined by light, phase-contrast, dark-field, fluorescence, and polarization microscopy. The frequency of AT sites and their area were morphometrically studied and the findings were then statistically processed.

RESULTS

Various types of AT in the costal cartilages were described as both the normal and keeled chest. According to their morphological features, classic, fine-fiber, twisted, and intralacunar types were identified. There were statistically significant increases in the incidence of all types (except the intralacunar one) and in the area of the fine-fiber AT type in keeled chest deformity as compared to health. There were positive correlations between the area of classic, intralacunar, and twisted types in both groups and between the area of a classic type and age in the controls.

CONCLUSION

A classification of AT areas varying in structures in health and disease has been given for the first time; their relation to each other and to the presence of keeled deformity shown, which, in our opinion, suggests that AT is implicated in the pathogenesis of the disease.

Aesthetic auricular reconstruction with autologous rib cartilage grafts in adult microtia patients

BACKGROUND

Cartilage calcification is an important factor in aesthetic auricular reconstruction using autologous rib cartilage grafts in adults, a technique that involves difficult manipulation and unexpected absorption. As a result, artificial implants or prosthetics are considered for auricular reconstruction in adult patients despite the limitations of artificial material. In this article, we present our experience with auricular reconstruction using autologous rib cartilage grafts in adult microtia patients with reliable aesthetic results and minimal complications.

METHODS

A retrospective chart review was performed for 84 microtia patients ranging in age from 21 to 56 (average: 29.9) years who underwent auricular reconstruction using autologous rib cartilage grafts from March 2001 to March 2013. To validate our acceptable reconstructive results, two independent observers performed postoperative photographic evaluation of two groups (adults and children) using non-inferiority tests in addition to patient questionnaires.

RESULTS

The mean operation time for rib cartilage grafts was 3 h and 53 min, and the follow-up time for all patients ranged from 6 months to 8 years. Surgery-related complications occurred in only three cases. On objective photographic evaluation, the adult group was not inferior to the child group in auricular shape, location, or symmetry. The subjective patient satisfaction evaluation reported a high satisfaction rate.

CONCLUSIONS

As this study shows, aesthetic auricular reconstruction using rib cartilage grafts in adult microtia patients is possible even in cases with advanced cartilage calcification. Modification of the fabricating framework, well-preserved flap vascularity, and complete understanding of physiological aspects of rib cartilage are essential for aesthetic auricular reconstruction.

Morphology, distribution, mineral density and volume fraction of human calcified costal cartilage

This study examines the properties of calcifying human costal cartilage and adjacent rib bone using qualitative and quantitative micro-computed tomography analysis. Calcifications are categorized with respect to location, microstructure, shape, and contiguity using a novel classification scheme and quantified in terms of mineral density, volume fraction, and length of infiltration from the costo-chondral junction (CCJ). Calcifications were present throughout the cartilage by location and ranged from small diffuse calcifications to nodes, rods, plates, and even large complex structures that exhibited a microstructural morphology similar to a cross-section of diaphysial bone, with a dense shell surrounding a trabecular core. Solid microstructure was most common for calcifications (44.5%), and the morphologies were found to vary with location, with rods and plates being most prevalent at the periphery (91.7% of all rods, 98.4% of all plates). The average mineral density of the calcifications over all locations and morphologies was 658.8±86.36, compared with 662.7±50.37 mgHA cm(-3) for the adjacent rib bone. The calcification volume fraction (6.54±4.71%) was less than the volume fraction of rib bone (21.62±6.44%). The length of contiguous calcification infiltrating from the CCJ into the costal cartilage, when present, was 19.21±11.65 mm. These changes in the costal cartilage should be considered in biomechanical models of the thorax since the presence, location, and morphology of the calcifications alter the material behavior of the costal cartilage, as well as the structural behavior of the entire rib.