Introduction: Duplex ultrasound has recently been used to demonstrate inflammatory hyperaemia in arteries supplying inflamed joints in RA, bursitis, and tendonitis. The technique has yet to be applied to examine blood flow in lumbar arteries in LBP patients, though we have previously shown its feasibility in healthy subjects. Our aim was to determine if there are differences in the flow characteristics of lumbar arteries in patients with LBP that may be reflective of pathology.

Materials and Methods: Sixty four patients with LBP (21–82 years) and 30 volunteers with no history of LBP (19–82 years) were studied. Sacral and lumbar arteries at L5 to L1 were identified and hemodynamic data was obtained using Duplex ultrasound. Angle corrected measurements of blood flow peak systolic velocity (PSV) were obtained at all lumbar levels and the aorta.

Results: Mean lumbar artery PSV was normalized with mean aorta PSV for patient and control groups. Reference range (mean ± 1.96SD) for normal lumbar artery PSV was defined from the control data and the proportion of patients with abnormally high PSV determined.

Discussion: Blood flow velocity in lumbar arteries of LBP patients is significantly higher compared with asymptomatic controls (p< 0.01). Approximately 40% of the LBP group have abnormally high lumbar artery flow velocity and the proportion of abnormal values increases at lower levels. Abnormally high velocity flow suggests the presence of an inflammatory component in the lumbar spinal structures. This technique has important applications in improving diagnostic specificity and assessing outcome of treatment in patients with LBP.

Introduction and Aims: We have developed a novel murine open tibial fracture model to compare the vascularity of muscle and fasciocutaneous flaps during fracture healing and investigate their role in angiogenesis.

Method: Flaps were emulated by insertion of a piece of sterile, inert material (Polytetrafluoroethylene, PTFE), at the fracture site to exclude either muscle posteriorly (fasciocutaneous flap) or skin and fascia anteriorly (muscle flap). Animals were harvested at days three, five, seven, nine and 14 post-fracture. Immunohistochemistry was performed on specimens, to estimate vascularity using an antibody to factor VIII, which selectively demonstrates vascular endothelium. Vascular densities were determined within the muscle and fasciocutaneous tissues adjacent to the fracture sites. Vascular Endothelial Growth Factor (VEGF) was measured by ELISA in tissue specimens. Immunohistochemistry was performed to qualitatively assess distribution of VEGF.

Results: Significantly greater vascular densities per unit area were observed in fasciocutaneous flaps at all time points compared to muscle flaps (p< 0.0001). VEGF levels peaked at day seven post-fracture, fell at day nine, and increased again at day 14. This time-dependent variation was statistically significant (p< 0.02). However, there was no significant difference between muscle and fasciocutaneous flaps. Maximal staining for VEGF occurred on the deep surface of the flaps adjacent to the fracture site. We found that fasciocutaneous flaps have significantly higher vascular densities compared to muscle flaps during early fracture healing.

Conclusion: Our results contradict the widely held view that muscle flaps are superior. However, there was no significant difference between levels of the pro-angiogenic factor VEGF within the flaps. This would suggest that both flaps are equally effective in supplying the factors necessary for new vessel formation. Our data supports the continuing use of muscle and fasciocutaneous flaps in the clinical setting.