Spatial periodicity in growth plate shear mechanical properties is disrupted by vitamin D deficiency

Role of Physiotherapy in Osgood-Schlatter's Disease in Adolescent Volleyball Smasher: A Case Report

A 14-year-old female presented to the sports physiotherapy with a diagnosis of Osgood-Schlatter's disease (OSD), a condition particularly prevalent in adolescents engaged in sports with repetitive knee motions, such as volleyball. This ailment commonly manifests at the tibia, directly beneath the patella, eliciting discomfort and inflammation. The chronic overuse injuries involve repetitive activities inducing fatigue in specific anatomical structures. Adequate recovery mechanisms allow for tissue adaptation, mitigating the risk of injury. In the absence of proper recovery, microtrauma ensues, instigating inflammation mediated by substances like histamines. The release of inflammatory cells and enzymes inflicts damage on local tissue, and prolonged stress contributes to degenerative changes, resulting in weakness, diminished flexibility, and chronic pain. These manifestations are intimately associated with OSD in chronic or recurrent instances. The primary symptom of OSD is knee pain, often of sufficient severity to induce limping. Patients report discomfort during activities such as kneeling, descending stairs, prolonged stationary positions, prolonged episodes of sitting with the knee rendered immobile, and engagement in sporting activities. This case study specifically underscores the efficacy of tailored physiotherapy in the management of OSD among adolescent volleyball players. The study's findings indicate that the patient successfully alleviated symptoms, facilitating recovery with improved outcomes. Furthermore, the physiotherapy regimen appears instrumental in enhancing the patient's functional mobility, as evidenced by the study's outcomes.

Vitamin D deficiency and anatomical region alters porcine growth plate properties

Ossification of growth plate cartilage mediates longitudinal extension of long bones. Biomechanical and biochemical disruptions of growth plate function may lead to abnormal bone growth. In humans and animals, severe dietary vitamin D deficiency can lead to rickets which features growth plate widening, resulting in abnormalities in growth. However, effects of marginal vitamin D deficiencies on growth plates are not well understood. The purpose of this study was to examine the effects of a vitamin D deficient diet in the 26-day nursery phase on mechanical properties (ultimate normal stress, ultimate shear stress, ultimate strain, and tangent modulus) of porcine growth plate. Standard uniaxial tensile tests were applied on bone-growth plate-bone sections and the total stress was decomposed into normal stress and shear stress. Ultimate shear stress and ultimate strain traits were lower in the vitamin D deficient group than in the control. Regional differences were observed in all four variables. Ultimate normal stress was higher in the anterior region, which was consistent with a previous study. Sex differences were detected in ultimate normal stress, which was higher in females than in males. Interestingly, the classical finding of growth plate widening seen in severe vitamin D deficiency was not observed in the pigs with marginal vitamin D deficiency utilized in this study.

Osgood-Schlatter Disease: Appearance, Diagnosis and Treatment: A Narrative Review

Osgood-Schlatter disease is the most common osteochondritis of the lower limb in sport-practicing children and adolescents. Its manifestation usually coincides with the appearance of the secondary ossification center of the tibia and is linked to the practice of sports with an explosive component. In the present study, a review of the factors related to its appearance, diagnosis and treatment was carried out. Its appearance seems to be multifactorial and related to multiple morphological, functional, mechanical and environmental factors. Given all the above, risk factor reduction and prevention seem the most logical strategies to effectively prevent the appearance of the condition. In addition, it is essential to create prevention programs that can be objectively assessed and would allow to stop the progress of the pathology, particularly in those sports where high forces are generated on the insertion zone of the patellar tendon at sensitive ages. More studies are needed to clarify which type of treatment is the most appropriate—specific exercises or the usual care treatment.

Understanding the Stiff-to-Compliant Transition of the Meniscal Attachments by Spatial Correlation of Composition, Structure, and Mechanics

Recently, the scientific community has shown considerable interest in engineering tissues with organized compositional and structural gradients to mimic hard-to-soft tissue interfaces. This effort is hindered by an incomplete understanding of the construction of native tissue interfaces. In this work, we combined Raman microscopy and confocal elastography to map compositional, structural, and mechanical features across the stiff-to-compliant interface of the attachments of the meniscus in the knee. This study provides new insight into the methods by which biology mediates multiple orders of magnitude changes in stiffness over tens of microns. We identified how the nano- to mesoscale architecture mediates complex microscale transitional regions across the interface: two regions defined by chemical composition, five distinguished by structural features, and three mechanically distinct regions. We identified three major components that lead to a robust interface between a soft tissue and bone: mobile collagen fiber units, a continuous interfacial region, and a local stiffness gradient. This tissue architecture allows for large displacements of collagen fibers in the attachments, enabling meniscal movement without localizing strains to the soft tissue-to-bone interface. The interplay of these regions reveals a method relying on hierarchical structuring across multiple length scales to minimize stress concentrators between highly dissimilar materials. These insights inspire new design strategies for synthetic soft tissue-to-bone attachments and biomimetic material interfaces.

Seasonal Variation in Slipped Capital Femoral Epiphysis: New Findings Using a National Children's Hospital Database

BACKGROUND

Slipped capital femoral epiphysis (SCFE) demonstrates seasonal variation in certain latitudes but not others. Is such variation influenced by temperature differences, sunlight exposure and subsequent vitamin D production, or other climate variables? It was the purpose of this study to further investigate the seasonal variation in month of presentation for SCFE.

METHODS

Data for this study originated from the Pediatric Hospital Information System for all children with a diagnosis of SCFE from January 1, 2004 through December 31, 2014. From this database the patient's sex, ethnicity, hospital location, and month of presentation was determined. Only those patients treated primarily for SCFE were included. Geographic and climate data [latitude, average annual temperature, precipitation, climate type (Köppen-Geiger and Liss), horticultural plant zone hardiness, and sunlight exposure] for each of the 49 Pediatric Hospital Information System hospitals was determined. Seasonal variation was analyzed using cosinor analysis. A P<0.05 was considered statistically significant.

RESULTS

There were 10,350 cases of SCFE with an overall peak presentation in mid August. For those living at a latitude of >35-degree N there was single peak, a less prominent double peak for those 31- to 35-degree N, and no variation for those <31-degree N. As the average annual temperature increased there was less seasonal variability. Humid, temperate and cold winter climates demonstrated seasonal variation, whereas other climate types did not. Those living in areas having <2500 hours of sunlight per year demonstrated seasonal variation. Further, areas having a photovoltaic solar production potential <5.0 kWh/m/d also demonstrated seasonal variation.

CONCLUSIONS

We discovered new seasonal variation findings regarding SCFE. These are a double peak pattern for those between 31- and 35-degree N latitude; less variability as the average annual temperature increases; and sunlight exposure correlates with seasonal variability. Potential explanations are a rachitic state due to seasonal variation in vitamin D production, and seasonal variation in physeal growth and strength. These new findings will require further investigation.

LEVEL OF EVIDENCE

Level III.

Chondron curvature mapping in growth plate cartilage under compressive loading

The physis, or growth plate, is a layer of cartilage responsible for long bone growth. It is organized into reserve, proliferative and hypertrophic zones. Unlike the reserve zone where chondrocytes are randomly arranged, either singly or in pairs, the proliferative and hypertrophic chondrocytes are arranged within tubular structures called chondrons. In previous studies, the strain patterns within the compressed growth plate have been reported to be nonuniform and inhomogeneous, with an apparent random pattern in compressive strains and a localized appearance of tensile strains. In this study we measured structural deformations along the entire lengths of chondrons when the physis was subjected to physiological (20%) and hyper-physiological (30% and 40%) levels of compression. This provided a means to interpret the apparent random strain patterns seen in texture correlation maps in terms of bending deformations of chondron structures and provided a physical explanation for the inhomogeneous and nonuniform strain patterns reported in previous studies. We observed relatively large bending deformations (kinking) of the chondron structures at the interface of the reserve and proliferative zones during compression. Bending in this region may induce dividing cells to align longitudinally to maintain column formation and drive longitudinal growth.

Depth-Dependent Out-of-Plane Young's Modulus of the Human Cornea

Purpose/Aim: Despite their importance in accurate mechanical modeling of the cornea, the depth-dependent material properties of the cornea have only been partially elucidated. In this work, we characterized the depth-dependent out-of-plane Young's modulus of the central and peripheral human cornea with high spatial resolution.

MATERIALS AND METHODS

Central and peripheral corneal buttons from human donors were subjected to unconfined axial compression followed by stress relaxation for 30 min. Sequences of fluorescent micrographs of full-thickness corneal buttons were acquired throughout the experiment to enable tracking of fluorescently labeled stromal keratocyte nuclei and measurements of depth-dependent infinitesimal strains. The nominal (gross) out-of-plane Young's modulus and drained Poisson's ratio for each whole specimen was computed from the equilibrium stress and overall tissue deformation. The depth-dependent (local) out-of-plane Young's modulus was computed from the equilibrium stress and local tissue strain based on an anisotropic model (transverse isotropy).

RESULTS

The out-of-plane Young's modulus of the cornea exhibited a strong dependence on in-plane location (peripheral versus central cornea), but not depth. The depth-dependent out-of-plane Young's modulus of central and peripheral specimens ranged between 72.4-102.4 kPa and 38.3-58.9 kPa. The nominal out-of-plane Young's modulus was 87 ± 41.51 kPa and 39.9 ± 15.28 kPa in the central and peripheral cornea, while the drained Poisson's ratio was 0.05 ± 0.02 and 0.07 ± 0.04.

CONCLUSIONS

The out-of-plane Young's modulus of the cornea is mostly independent of depth, but not in-plane location (i.e. central vs. peripheral). These results may help inform more accurate finite element computer models of the cornea.

Bulbous epiphysis and popcorn calcification as related to growth plate differentiation in osteogenesis imperfecta

BACKGROUND

Osteogenesis Imperfecta (OI) is an heritable systemic disorder of connective tissue due to different sequence variants in genes affecting both the synthesis of type I collagen and osteoblast function. Dominant and recessive inheritance is recognized. Approximately 90% of the OI cases are due to mutations in COL1A1/A2 genes. We clinically and radiologically describes an adult male with type III osteogenesis imperfecta who presents a rare bone dysplasia termed bulbous epiphyseal deformity in association with popcorn calcifications. Popcorn calcifications may occur with bulbous epiphyseal deformity or independently.

METHODS

Molecular analysis was performed for COL1A1, COL1A2, LEPRE1 and WNT1 genes.

RESULTS

An uncommon COL1A1 mutation was identified. Clinical and radiological exams confirmed a distinctive bulbous epiphyseal deformity with popcorn calcifications in distal femurs. We have identified four additional OI patients reported in current literature, whose X-rays show bulbous epiphyseal deformity related to mutations in CR-TAP, LEPRE1 and WNT1 genes.

CONCLUSION

The mutation identified here had been previously described twice in OI patients and no previous correlation with bulbous epiphyseal deformity was described. The occurrence of this bone dysplasia focuses attention on alterations in normal growth plate differentiation and the subsequent effect on endochondral bone formation in OI.