Human tibia Bone Marrow: Defining a Model for the Study of Haemodynamics as a Function of Age by Near Infrared Spectroscopy

Abstract

A human model allowing the non-invasive study of bone marrow haemodynamics has been developed. A decrease in postischaemic tissue reperfusion capability (postischaemic hyperaemia) as a function of age (range 25-72 years) was observed both in the human tibia and tibialis anterior muscle. In the tibia bone marrow the reperfusion capability started to decrease after 50 years and was lower than for muscle for all the age range. Mean basal muscle O(2) saturation (80.8% at 25 years) decreases as a function of age (-0.35%+/-0.13% per year) whereas it remains constant for bone marrow (84.8+/-2.8%). A Monte Carlo simulation has been performed to evaluate the accuracy of the derived O(2) saturation measurements and has shown that this parameter is robust even in the presence of substantial noise. It has also been demonstrated that it is necessary to use a multi wavelength NIR spectrometer and a second derivative based fitting algorithm to obtain reliable measurements from the bone marrow, and that the tissue scattering changes occurring during the protocol do not allow the use of the standard near infrared spectroscopy algorithms. The human tibia bone marrow model presented here and the related measurement technique should enable access to new areas of physiological research.

Blood Volume and Haemoglobin Oxygen Content Changes in Human Bone Marrow during Orthostatic Stress

“…The use of the second derivative allows one to eliminate some of the other optical artifacts produced by the water itself and tissue scattering properties. These artifacts manifest themselves in the NIR spectra as an arbitrary DC baseline shift (scattering losses plus unknown absolute photometry) and a quasi-linear background due to the wavelength-dependent scattering losses (Matcher et al, 1993;Matcher and Cooper, 1994) and thus introduce errors in the estimated DHb and DHbO 2 values (Binzoni et al, 2003b). In these studies, using this analysis we observed no statistically significant changes in DH 2 O during the protocol.…”

“…This may be explained by the fact that the metabolism of tibia bone marrow (mainly composed of fat, for a subject mean age of ϳ34 yr) is lower than muscle basal metabolism. In fact, it has been observed that average tissue blood oxygen saturation is also higher in bone marrow than in skeletal muscle (Binzoni et al, 2003b) and thus the DHbO 2 percentage changes must be by definition higher in bone marrow.…”

Non-invasive continuous estimation of blood flow changes in human patellar bone

“…The last two techniques require surgical manipulation of the bone and therefore may introduce artifacts attributable to local manipulation of the vessels. Near-infrared spectroscopy has been used to assess the perfusion index in the tibia bone marrow [3]. To our knowledge no method for measuring local blood flow in human bone tissue continuously and non-invasively has been previously published.…”

A near infrared instrument to monitor relative hemoglobin concentrations of human bone tissue in vitro and in vivo

“…2 The principle that changes in the relative concentrations of Hb and HbO 2 can be used to evaluate tissue oxygenation in vivo has been established in a number of tissue types. [3][4][5][6][7][8] What is less clear is how this technology can be applied in hospital or community health settings to interrogate the homeostatic "health" of living bone and also, vasculopathies of bone.…”