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

Abstract

The growth plate is a highly organized section of cartilage in the long bones of growing children that is susceptible to mechanical failure as well as structural and functional disruption caused by a dietary deficiency of vitamin D. The shear mechanical properties of the proximal tibial growth plate of rats raised either on normal or vitamin D and calcium deficient diets were measured. A sinusoidal oscillating shear load was applied to small excised growth plate specimens perpendicular to the direction of growth while imaging the deformation in real time with a fast confocal microscope. Local deformations and shear strains were quantified using image correlation. The proliferative zone of the growth plate bores the majority of the shear strain and the resting, hypertrophic and calcification zones deformed less. Surprisingly, we regularly observed discontinuous deformations in the proliferative zone in both groups that resembled cell columns sliding past one another in the direction of growth. These discontinuities manifested as regions of concentrated longitudinal shear strain. Furthermore, these shear strain concentrations were spaced evenly in the proliferative zone and the spacing between them was similar across growth plate regions and across control specimens. In contrast to the healthy controls, the vitamin D deficient growth plate exhibited larger variations in the size and orientation of cellular columns in the proliferative and hypertrophic zones. High strains were observed between columns, much as they were in the controls. However, the regular spacing of shear strain concentrations was not preserved, echoing the observation of decreased structural organization.

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

“…The appearance of OSD may be induced by factors related to the management of training loads, such as the intensity level during physical exercise, volume [ 54 ] and its modification [ 57 , 58 ], early specialization [ 56 ] and even with certain dietary deficiencies, such as vitamin D deficiency, particularly in countries with few hours of sun [ 59 , 60 ]. It also seems that the incidence is greater during the winter, especially in cold countries.…”

“…For these reasons, some authors have theorized about the possibility that fragility in the tibial tuberosity could appear in adolescents with vitamin D deficiency, which would compromise the enthesis’ mechanical response. Although this theory has yet to be confirmed, when children with OSD and vitamin D deficiency took a supplement, symptoms disappeared [ 60 ].…”

The Location- and Depth-Dependent Mechanical Response of the Human Cornea Under Shear Loading

“…This device has been used extensively to characterize the location-dependent mechanical properties of several other collagenous connective tissues including articular cartilage and intervertebral disk. [24][25][26][27][28][29][30] The orientation of the cylindrical sections in the grips was critical to determining direction-dependent shear properties, so careful attention was paid to ensure shear would occur in either the NT or SI axial direction. Two cylindrical sections (one central and one superior) from six donor corneas (total of 12 cylindrical sections) were shear tested in the NT direction, while two cylindrical sections (one central and one superior) from four donor corneas (total of eight cylindrical sections) were tested in the SI direction.…”

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

“…These findings nicely fit the known demographics of SCFE which is more common in obese (19) and Black (15,19) children. Vitamin D deficient rats demonstrate extensive disorganization in the growth plate (20). In such rats the chondrocyte columns in the hypertrophic and proliferative zones are aligned in varying directions and not parallel to the axis of growth, impacting its mechanical properties to shear stress.…”