Laser doppler flowmetry for estimation of bone blood flow: Studies of reproducibility and correlation with microsphere technique

Abstract

The blood flow in the femoral condyles of six pigs was measured by the microsphere technique and by laser Doppler flowmetry (LDF) before and after clamping of the external iliac artery. A significant decrease in the bone blood flow was found with both microsphere and LDF measurements, and a high correlation was found between the two methods. After release of the arterial clamp, the LDF values rapidly returned to approximately the same values as before clamping. In a second part of the study, the LDF output signal was studied in the intertrochanteric area of eight patients. The reproducibility of two LDF measurements at the same location was within 15%. The temporal variability of the LDF signal during 10 min of recording showed only slight variations. It is concluded that LDF is relative in nature and that the mean LDF output signal is suitable for monitoring dynamic responses of the bone blood flow to various stimuli. Several consecutive measurements have to be performed if the blood flow at different locations of a specific bone are to be compared with each other.

Patellar blood flow during knee arthroplasty surgical exposure: Intraoperative monitoring by laser doppler flowmetry

“…The measured amplitude height was dependent on the specific position of the probe, but the relative changes would identify any maneuvers altering perfusion. 17 Mean values and standard deviation of the waves were calculated during a period of at least 10 s after the signal had stabilized (the duration of the measurement in each knee position was less than 20 s).…”

Measurement of bone blood flow using the hydrogen washout Technique—Part I: Quantitative evaluation of tissue perfusion in the laboratory rat

“…The results of laser Doppler flowmetry cannot be necessarily pooled when different test animals are studied. 7 Hydrogen washout seems to provide a reliable method for measuring blood flow in bone. Although this method is not suitable for measuring average blood flow in the nonhomogenously perfused marrow, it is suitable for cortical and cancellous bone.…”

“…The results cannot necessarily be pooled when different test animals are studied. 7 The method requires bone to be measured in situ, an advantage in some situations.…”

Measurement of bone blood flow using the hydrogen washout technique—part II: Validation by comparison to microsphere entrapment

“…48 Despite these limitations, it has been used under many different experimental circumstances to measure regional bone blood flow 2,33,37,39,40,43,45, and has been used to validate new blood flow methods in bone such as noble gas washout 34 and laser Doppler flowmetry. 70 The hydrogen washout method of regional blood flow measurement was developed by the Norwegian physiologist Aukland and colleagues 38 and first applied to bone tissue by Whiteside et al 6 in the rabbit; he assumed that his measurements were accurate because they were similar to those reported by other methods. Other authors have made the same assumption when using hydrogen washout for bone blood flow measurements, 1,19 or have referred to other articles using the method in bone.…”