Mapping trabecular disconnection “hotspots” in aged human spine and hip

Abstract

Trabecular bone disconnection is an independent factor in age-related skeletal failure where real termini (ReTm; rare in youth) may cause weakness disproportionate to tissue loss, yet their structural contribution at vulnerable locations remains uncertain. ReTm (previously recorded at the iliac crest) were mapped in "normal" aged vertebral bodies (T11-L5 autopsy; 20 females, 10 males) and corresponding proximal femora (autopsy; 10 females). Results were compared with biomechanically failed femora from orthopaedic subjects aged >58 yr (osteoporosis OP, 10 females; osteoarthritis OA, 10 females). A novel direct 2D/3D histological method was applied to large, thick (300 μm) slices superficially silver-stained to separate ReTm (unstained) from apparent termini (planar artefacts, brown). Light microscope field co-ordinates enabled ReTm mapping and statistical testing relative to i) sex, ii) tissue sector and iii) slicing plane. In men ReTm populations were small and random while in women they were large and sector-specific. In vertebrae they clustered anterior/superior being rare posterior/inferior; in the femoral head they concentrated distal/superior and also near the fovea, being fewer distal/inferior. A distribution polarity was evident with 100% more ReTm observed transversely (i.e., on tensile-related cross struts) than longitudinally (i.e., on compression-related vertical struts). Their numbers rose in OP (BV/TV<14%, microCT) and in OA (BV/TV>14%), remaining polarised and sector-specific in OP only. Comparative experimentation by marrow elution of an OP animal model demonstrated "floating segments" as a possible outcome. Conclusions were supported statistically that trabecular disconnection "hotspots" at vulnerable locations are sex- and sector-specific, mainly transaxial, and subject to disease modulation.

Total Flavonoids of Drynariae Rhizoma Prevent Bone Loss Induced by Hindlimb Unloading in Rats

“…In addition, trabecular disconnection is an independent factor in age-related skeletal failure where real termini (ReTm) may cause weakness disproportionate to tissue loss. This parameter should be pay more attention to in further research [ 39 ]. Although we observed some positive effects from DRTF treatments on trabecular bone micro-architectural properties, it is difficult to restore the deteriorated trabecular bone [ 40 ].…”

Iliac crest histomorphometry and skeletal heterogeneity in men

“…iliac crest, spine and proximal femur. Previous skeletal heterogeneity related studies have predominantly focused on the differences in structural and remodelling parameters of cancellous bone (Hildebrand et al, 1999, Lochmüller et al, 2008, Aaron et al, 2015), or the physical measurements of cortical composition (Boskey et al, 2016, Scerpella et al, 2016). Except for the cortical width (Dempster et al, 1993, Castillo et al, 2012), structural characteristics of the cortical bone have rarely been compared between different skeletal sites.…”

Bone Mineral “Quality”: Differing Characteristics of Calcified Microsphere Populations at the Osteoporotic and Osteoarthritic Femoral Articulation Front

“…The calcified skeletal matrix has evolved to optimise biomechanical performance in the young adult and with skeletal ageing there is a well-established physical decline. In particular, the functioning of the bipedal hip deteriorates to a level that compromises mobility and this deficiency may pertain as much to the intrinsic properties of the extracellular matrix [30] as to its general mass. In addition, the property of the subchondral bone is regarded by some authors as proactive rather than a reactive response to cartilage change in the development of OA (for example, [1] [31]- [33]).…”