Comparison of eight histomorphometric methods for measuring trabecular bone architecture by image analysis on histological sections

Osteoporosis is defined as a disease characterized by low bone mass and mic roarchitectural deterioration of trabecular bone leading to enhanced bone f ragility. Various histomorphometric methods have been described to measure bone architecture on histological sections. However, not all of the methods are strictly equivalent and some of them appear able to detect differences earlier in the course of the disease. We have compared 8 histomorphometric methods known to characterize the architecture of trabecular bone in 154 m ale osteoporotic patients. Measurements were done on transiliac bone biopsi es: Trabecular number, thickness, and separation (Tb.N, Tb.Th, Tb.Sp); Trab ecular Bone Pattern Factor (TBPf); Euler-Poincare's number (E); Interconnec tivity Index (ICI); strut analysis of the trabecular network with the ratio of nodes/free-end (N/F); star volume of the bone marrow (V-m.space*) and t rabeculae (V-Tb*) and the Kolmogorov fractal dimension of the trabecular bo undaries (D). Relationships between the various architectural parameters we re studied by hierarchical cluster analysis. Linear, hyperbolic, and expone ntial correlations were found between trabecular bone volume (BV/TV) and ar chitectural parameters, Cluster analysis demonstrates the link between thes e architectural parameters. ICI, E, and TBPf, which reflect the amount of o pen/closed marrow cavities clustered together and appeared related to Tb.Sp , V-m.space* which are indicators of the mean size of marrow cavities. Tb.T h, V-Tb* and N/F flocked together as they reflect the trabecular size. Tb.N and D segregated together and seemed to best describe the trabecular netwo rk complexity. These histomorphometric techniques are correlated but correl ations may be linear or nonlinear. Several histomorphometric techniques nee d to be used in parallel to appreciate the pathophysiological mechanisms of osteoporotic states. Microsc. Res. Tech. 45:303-312, 1999. (C) 1999 Wiley- Liss, Inc.