Cortical bone cross-sectional osteon size in chronic pulmonary insufficiency and regional ischemic states

Cross sectional osteon diameter (D) and Haversian canal diameter (d) were measured in undecalcified, unstained sections from the mid-diaphysis of femoral bones from 13 patients with long lasting chronic pulmonary insufficiency, 10 patients with unilateral thrombosis of the femoral artery and from sex- and age-matched normal controls. The cross sectional osteon radius (R = the distance travelled by osteoclats), the mean wall thickness (MWT = (D-d)/2 = distance travelled by osteoblasts) and the structural unit balance (B = R/MWT) were calculated. No significant differences were found in R, MWT og B between chronic pulmonary insufficiency patients and normal controls. Furthermore, no significant differences were found between thrombotic or non-thrombotic legs or between thrombotic legs and their normal controls. This part of the study does not support the concept that the distance travelled by the osteoclasts (R) depends on local supply of nutrients and/or removal of waste products. However, in all patients and controls R was larger in the inner zone than in the outer zone (p less than 0.01). This could be explained by the anatomy of the arterial supply to cortical bone supporting the above hypothesis.