Blood flow rates in compact and cancellous bone, and bone marrow.

Several attempts are now on record at measuring rates of blood flow in skeletal tissue. All methods employed to elucidate this problem, particularly relevant to an understanding of the local control of osteogenesis, have to reckon with the complex mode of vascularization of tubular bones. Numerous arteries, epiphyseo-metaphyseal as well as the nutrient artery, form the afferent limb of the osseous circulation: the efferent pathway is even more diffuse and includes the entire surface of the shaft (Brookes, 1964, 1965; Oliveros & Palacios, 1964). To date, the methods that have be.n devised in individual laboratories do not evaluate rates of flow in the various anatomically distinct tissues comprising a whole bone organ, nor have they readily been taken up by other workers, possibly because of the complexity of instrumentation involved. Only one method (Edholm, Howarth & McMichael, 1945) claims applicability to man and this has not been repeated since its publication twenty years ago. The following method of measuring flow rates in various parts of the osseous circulation is therefore offered as a practical approach to the acquisition of a wider range of skeletal haemodynamic data than attempted heretofore, and in the hope that its relative simplicity (nothing more sophisticated than a scintillation counter being required) will lead to its testing by other investigators.