Abstract

Tendinopathy is of distinct interest in rheumatology as it describes a painful tendon disease with local tenderness, swelling and pain associated with sonographic features such as hypoechogenic texture and diameter enlargement. Recent research elucidated microcirculatory changes in tendinopathy using laser Doppler flowmetry. Tendon capillary blood flow is increased at the point of pain correlating to neovascularisation. Tendon oxygen saturation as well as tendon postcapillary venous filling pressures, determined non-invasively using combined Laser Doppler flowmetry and spectrophotometry, can quantify, in real-time, how tendon microcirculation changes over with pathology or in response to therapy. Tendon oxygen saturation can be increased by repetitive, intermittent short-term ice applications; this corresponds to ‘ischemic preconditioning’, a method used to train tissue to sustain ischemic damage. Decreasing tendon oxygenation reflects local acidosis and deteriorating tendon metabolism. Eccentric training, a common therapy for tendinopathy decreases abnormal capillary tendon flow without compromising local tendon oxygenation. Combining an Achilles pneumatic wrap with eccentric training changes tendon microcirculation in a different way than does eccentric training alone; both approaches reduce pain in Achilles tendinopathy. Future research should focus on how novel therapies, such as non-invasive nitroglycerin application, non-invasive laser therapy, and invasive sclerosing therapy, influence vascularisation in tendinopathy.

Keywords: Angiogenesis, Power Doppler technology, tendinopathic tendons, vascular endothelial growth factor, microcirculation assessment, capillary flow