Normal variation in cortical osteocyte lacunar parameters in healthy young males

Abstract

The most abundant cell in bone, osteocytes form an interconnected system upon which the regulation of healthy bone relies. Although the complete nature of the role of osteocytes has yet to be defined, they are generally accepted to play a part in the sensing of load and the initiation of damage repair. A previous study conducted by our group identified variation of up to 30% in osteocyte lacunar density and morphological parameters between regions of a single cross-section of human femoral shaft; that study, however, was limited to a single individual. The aim of the current study was to determine whether this pattern consistently occurs in healthy young male femora. Anterior, posterior, medial and lateral blocks were prepared from the proximal femoral shaft of seven males and synchrotron radiation micro-CT imaged. Average lacunar densities (AE SD) from the anterior, posterior, medial and lateral regions were 23 394 AE 1705, 30 180 AE 4860, 35 946 AE 5990 and 29 678 AE 6081 lacunae per mm 3 of bone tissue, respectively. These values were significantly different between the anterior and both the medial and posterior regions (P < 0.05). The density of the combined anterior and posterior regions was also significantly lower (P = 0.006) than the density of the combined medial and lateral regions. Although no difference was found in predominant orientation, shape differences were found; with the combined anterior-posterior regions having lacunae that were significantly more elongated and less flat than the combined medial-lateral values (P < 0.001). As expected, in this larger study, there was a dramatic difference in lacunar density between the medial and anterior region (up to~54%). The study clearly demonstrates that the high variation seen in osteocyte lacunar density as well as other lacunar parameters, noted in a number of biomechanical, age and pathology studies, are well within the range of normal variation; however, the reasons for and consequences of this variation remain unclear. Lacunar parameters including abundance and shape are being increasingly incorporated into computational modeling of bone biology and this paper represents a more comprehensive description of normal healthy lacunae.

Osteocyte lacunar properties in rat cortical bone: Differences between lamellar and central bone

“…We found no significant difference in osteocyte lacunar volumes between the circumferential lamellar bone and central bone, confirming recent findings (Shipov et al, 2013). The rat model is widely used in bone research, and since large variations are reported in osteocyte lacunar volumes in humans (Carter et al, 2014), it is essential to map potential variations of Lc.V under normal conditions in rat bone in order to verify its extensive use as a model.…”

“…Indeed, it is well established that bone is a complex three-dimensional material, and probing such structures is best achieved using 3D methods such as synchrotron radiation µCT. Despite using 3D methods, large variations in osteocyte lacunar properties are reported, indicating a natural morphological heterogeneity in osteocyte populations (Buenzli and Sims, 2015;Carter et al, 2014;Hesse et al, 2014b). Furthermore, the lacunocanalicular network organization in lamellar bone has been reported to be closely coupled to that of the extracellular matrix (Kerschnitzki et al, 2011;Reznikov et al, 2014a;Reznikov et al, 2013).…”

Three‐dimensional reconstruction of Haversian systems in human cortical bone using synchrotron radiation‐based micro‐CT: morphology and quantification of branching and transverse connections across age

“…; Carter et al. , ). Accordingly, the 3D reality of Haversian systems is quite complex; they are both branched and connected through transversely oriented canals, building complex, dynamic networks (Koltze, ; Cohen & Harris, ; Stout et al.…”

“…Studies of resorption cavities in human cortical bone show a potential for variable morphologies of Haversian systems from interconnected or clustered to branched. Resorption cavities have been shown to run unidirectional or simultaneously in two or more directions through several branches (Schumacher, 1935;Cohen & Harris, 1958;Vasci-aveo & Bartoli, 1961;Johnson, 1964;Tappen, 1977;Cooper et al 2003Cooper et al , 2004Cooper et al , 2006Basillais et al 2004;Matsumoto et al 2005;Schneider et al 2007;Britz et al 2012;Carter et al 2013Carter et al , 2014. Accordingly, the 3D reality of Haversian systems is quite complex; they are both branched and connected through transversely oriented canals, building complex, dynamic networks (Koltze, 1951;Cohen & Harris, 1958;Stout et al 1999;Cooper et al 2011).…”

Histomorphometric and osteocytic characteristics of cortical bone in male subtrochanteric femoral shaft

“…; Carter et al. ). In addition, the understanding of cortical bone changes across adulthood and studies of the underlying morphometric changes that might predispose to subtrochanteric fractures are limited.…”