Blood Vessels: Their Role in Tendon Pain and Pathology
Doppler US gives clear indication of vessels in abnormal tendons, in normal tendons no vascularity is evident. Increased vascularity can be seen in the patellar, Achilles and elbow tendons. Deeper and smaller tendons, or those with large amounts of fibrocartilage are more difficult to image. Increased vascularity can be accurately estimated and measured clinically.
In abnormal tendon there is clear evidence of neural ingrowth associated with blood vessels. Clinically, those tendons with increased vascularity have more pain, however the association is not absolute. Longitudinal studies on outcomes have shown that the presence of vascularity at baseline has not been shown to be associated with poorer outcome.
Ohberg and colleagues in Sweden have been directly treating the neovascularisation in painful tendons with sclerosing injections.The effectiveness of this treatment has been demonstrated in a randomized double-blind study. The treatment appears to be less successful in those with bony changes at the Achilles insertion and in jumping athletes with patellar tendinopathy. The effect of the treatment may not be only on the vessels, as the sclerosing substance used also is mildly neurotoxic. Further research is needed to further clarify the role of vascularity in tendon pain and to elucidate the most effective treatment options.