The bone matrix adjacent to lacunae and canaliculi

Abstract

Three techniques, phase contrast microscopy, microradiography, and electron microscopy, have been used to study the variation in mineralization and presence of collagen fibers in the bone matrix adjacent to lacunae and canaliculi. Undecalcified, partially decalcified and fully decalcified sections of normal bone from old individuals have been studied. No stains were used. A fairly good correlation of the results obtained with these techniques could be demonstrated as far as the degree of mineralization is concerned. A zone of modified matrix is found adjacent to lacunae and canaliculi and this zone is prone to hypermineralization. In certain areas, especially in interstitial bone, lacunae may become completely obliterated with a hypermineralized material. Collagen fibers are found at the surface of the lumen of lacunae and canaliculi. The arrangement of these fibers is in most cases different from that in the adjoining bone matrix producing a well delimited zone which separates the lacunae and canaliculi from the rest of the matrix. Microradiography of bone sections partially decalcified in EDTA indicates that decalcification in vitro may result in an initial preferential decalcification of areas previously hypercalcified.

Changes in bone mineral in experimentally induced rickets in the rat: Electron microprobe and chemical studies

“…Conversely, in rickets the "'perilacunar matrix" [31] appears to be hypomineralized with respect to the adjacent bone matrix [30,32]. In the present study, no evidence has been obtained to suggest that the perilacunar matrix in normal rat bone is hypermineralized, nor that it is hypomineralized in rachitic rat bone.…”

Apparently hypermineralized perilacunar bone an artefact in microradiographs

“…Although the appearance of the radiopaque perilacunar bone matrix in our microradiographs is clearly an artefact of development, a similar zone has been described in electron micrographs by MJ6R (1962MJ6R ( , 1963. Furthermore, it is quite possible that more sensitive microradiographic techniques could demonstrate the presence of such a layer.…”

“…Since such a hypermineralized layer would correspond in position to the hypermineralized peritubular dentin, it would complete an analogy which began with the electron microscope demonstration of a layer of distinct perilacunar bone matrix (WAsseRMANN and YAEaER, 1965). MJ6R (1962MJ6R ( , 1963 has also described a hypermineralized perilaeunar and pericanalicular zone in electron micrographs of bone. On the other hand, cracks which resulted from section grinding frequently showed * This investigation was supported by U. apparently radiopaque edges which could be interpreted as artefacts of development (fringe effects, Mackie lines).…”

The material properties of acellular bone in a teleost fish

“…The presence of osteocytes creates a morphologically distinctive skeletal material with an extensive interconnected network of microscopic canals (canaliculi) associated with cell lacunae (Gray, 1941;Moss, 1961;Mjor, 1962;Wassermann and Yaeger, 1965;Cowin, 2007). Dendritic processes radiate from the osteocytes and project into these canals allowing for direct communication between the adjacent osteocytes and the external environment via gap junctions (Aarden et al, 1994;Donahue, 2000;Kusuzaki et al, 2000).…”